Skip to content

M
mariadb
Commit 21586dfb authored by Ingo Struewing's avatar Ingo Struewing
Browse files
Options

WL#4259 - Debug Sync Facility 

Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.

  The Debug Sync Facility allows to place synchronization points
  in the code:
  
  open_tables(...)
  
  DEBUG_SYNC(thd, "after_open_tables");
  
  lock_tables(...)
  
  When activated, a sync point can
  
  - Send a signal and/or
  - Wait for a signal
  
  Nomenclature:
  
  - signal:            A value of a global variable that persists
                       until overwritten by a new signal. The global
                       variable can also be seen as a "signal post"
                       or "flag mast". Then the signal is what is
                       attached to the "signal post" or "flag mast".
  
  - send a signal:     Assign the value (the signal) to the global
                       variable ("set a flag") and broadcast a
                       global condition to wake those waiting for
                       a signal.
  
  - wait for a signal: Loop over waiting for the global condition until
                       the global value matches the wait-for signal.
  
  Please find more information in the top comment in debug_sync.cc
  or in the worklog entry.
parent 8b984340
Show whitespace changes
Inline Side-by-side
Showing with 2846 additions and 2 deletions
.bzrignore
View file @ 21586dfb
......@@ -3064,3 +3064,4 @@ sql/share/spanish
sql/share/swedish
sql/share/ukrainian
libmysqld/examples/mysqltest.cc
libmysqld/debug_sync.cc
CMakeLists.txt
View file @ 21586dfb
......@@ -66,6 +66,12 @@ IF(EXTRA_DEBUG)
ADD_DEFINITIONS(-D EXTRA_DEBUG)
ENDIF(EXTRA_DEBUG)
IF(ENABLED_DEBUG_SYNC)
ADD_DEFINITIONS(-D ENABLED_DEBUG_SYNC)
ENDIF(ENABLED_DEBUG_SYNC)
SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DENABLED_DEBUG_SYNC")
SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -DENABLED_DEBUG_SYNC")
# in some places we use DBUG_OFF
SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DDBUG_OFF")
SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -DDBUG_OFF")
......
configure.in
View file @ 21586dfb
......@@ -1708,6 +1708,23 @@ else
CXXFLAGS="$OPTIMIZE_CXXFLAGS $CXXFLAGS"
fi
# Debug Sync Facility. NOTE: depends on 'with_debug'. Must be behind it.
AC_MSG_CHECKING(if Debug Sync Facility should be enabled.)
AC_ARG_ENABLE(debug_sync,
AS_HELP_STRING([--enable-debug-sync],
[Build a version with Debug Sync Facility]),
[ enable_debug_sync=$enableval ],
[ enable_debug_sync=$with_debug ])
if test "$enable_debug_sync" != "no"
then
AC_DEFINE([ENABLED_DEBUG_SYNC], [1],
[If Debug Sync Facility should be enabled])
AC_MSG_RESULT([yes])
else
AC_MSG_RESULT([no])
fi
# If we should allow error injection tests
AC_ARG_WITH(error-inject,
AC_HELP_STRING([--with-error-inject],[Enable error injection in MySQL Server]),
......
include/my_sys.h
View file @ 21586dfb
......@@ -172,6 +172,16 @@ extern char *my_strndup(const char *from, size_t length,
#define TRASH(A,B) /* nothing */
#endif
#if defined(ENABLED_DEBUG_SYNC)
extern void (*debug_sync_C_callback_ptr)(const char *, size_t);
#define DEBUG_SYNC_C(_sync_point_name_) do { \
if (debug_sync_C_callback_ptr != NULL) \
(*debug_sync_C_callback_ptr)(STRING_WITH_LEN(_sync_point_name_)); } \
while(0)
#else
#define DEBUG_SYNC_C(_sync_point_name_)
#endif /* defined(ENABLED_DEBUG_SYNC) */
#ifdef HAVE_LARGE_PAGES
extern uint my_get_large_page_size(void);
extern uchar * my_large_malloc(size_t size, myf my_flags);
......
libmysqld/CMakeLists.txt
View file @ 21586dfb
......@@ -129,6 +129,7 @@ SET(LIBMYSQLD_SOURCES emb_qcache.cc libmysqld.c lib_sql.cc
../sql/sql_list.cc ../sql/sql_load.cc ../sql/sql_locale.cc
../sql/sql_binlog.cc ../sql/sql_manager.cc ../sql/sql_map.cc
../sql/sql_parse.cc ../sql/sql_partition.cc ../sql/sql_plugin.cc
../sql/debug_sync.cc
../sql/sql_prepare.cc ../sql/sql_rename.cc ../sql/sql_repl.cc
../sql/sql_select.cc ../sql/sql_servers.cc
../sql/sql_show.cc ../sql/sql_state.c ../sql/sql_string.cc
......
libmysqld/Makefile.am
View file @ 21586dfb
......@@ -74,6 +74,7 @@ sqlsources = derror.cc field.cc field_conv.cc strfunc.cc filesort.cc \
sp_head.cc sp_pcontext.cc sp.cc sp_cache.cc sp_rcontext.cc \
parse_file.cc sql_view.cc sql_trigger.cc my_decimal.cc \
rpl_filter.cc sql_partition.cc sql_builtin.cc sql_plugin.cc \
debug_sync.cc \
sql_tablespace.cc \
rpl_injector.cc my_user.c partition_info.cc \
sql_servers.cc event_parse_data.cc
......
mysql-test/include/have_debug_sync.inc 0 → 100644
View file @ 21586dfb
--require r/have_debug_sync.require
disable_query_log;
let $value= query_get_value(SHOW VARIABLES LIKE 'debug_sync', Value, 1);
eval SELECT ('$value' LIKE 'ON %') AS debug_sync;
enable_query_log;
mysql-test/mysql-test-run.pl
View file @ 21586dfb
......@@ -226,6 +226,7 @@ my @default_valgrind_args= ("--show-reachable=yes");
my @valgrind_args;
my $opt_valgrind_path;
my $opt_callgrind;
my $opt_debug_sync_timeout= 300; # Default timeout for WAIT_FOR actions.
our $opt_warnings= 1;
......@@ -867,6 +868,7 @@ sub command_line_setup {
'valgrind-option=s' => \@valgrind_args,
'valgrind-path=s' => \$opt_valgrind_path,
'callgrind' => \$opt_callgrind,
'debug-sync-timeout=i' => \$opt_debug_sync_timeout,
# Directories
'tmpdir=s' => \$opt_tmpdir,
......@@ -4170,6 +4172,11 @@ sub mysqld_arguments ($$$) {
mtr_add_arg($args, "%s", "--core-file");
}
# Enable the debug sync facility, set default wait timeout.
# Facility stays disabled if timeout value is zero.
mtr_add_arg($args, "--loose-debug-sync-timeout=%s",
$opt_debug_sync_timeout);
return $args;
}
......@@ -5280,6 +5287,8 @@ Misc options
to turn off.
sleep=SECONDS Passed to mysqltest, will be used as fixed sleep time
debug-sync-timeout=NUM Set default timeout for WAIT_FOR debug sync
actions. Disable facility with NUM=0.
gcov Collect coverage information after the test.
The result is a gcov file per source and header file.
experimental=<file> Refer to list of tests considered experimental;
......
mysql-test/r/debug_sync.result 0 → 100644
View file @ 21586dfb
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: ''
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6';
SET DEBUG_SYNC='p0 WAIT_FOR s2 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 EXECUTE 2';
SET DEBUG_SYNC='p0 WAIT_FOR s2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2';
SET DEBUG_SYNC='p0 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 CLEAR';
SET DEBUG_SYNC='p0 TEST';
SET DEBUG_SYNC='RESET';
set debug_sync='p0 signal s1 wait_for s2 timeout 6 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 timeout 6 execute 2';
set debug_sync='p0 signal s1 wait_for s2 timeout 6 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 timeout 6';
set debug_sync='p0 signal s1 wait_for s2 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 execute 2';
set debug_sync='p0 signal s1 wait_for s2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2';
set debug_sync='p0 signal s1 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 execute 2';
set debug_sync='p0 signal s1 hit_limit 3';
set debug_sync='p0 signal s1';
set debug_sync='p0 wait_for s2 timeout 6 execute 2 hit_limit 3';
set debug_sync='p0 wait_for s2 timeout 6 execute 2';
set debug_sync='p0 wait_for s2 timeout 6 hit_limit 3';
set debug_sync='p0 wait_for s2 timeout 6';
set debug_sync='p0 wait_for s2 execute 2 hit_limit 3';
set debug_sync='p0 wait_for s2 execute 2';
set debug_sync='p0 wait_for s2 hit_limit 3';
set debug_sync='p0 wait_for s2';
set debug_sync='p0 hit_limit 3';
set debug_sync='p0 clear';
set debug_sync='p0 test';
set debug_sync='reset';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6
EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 ';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2 ';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2 ';
SET DEBUG_SYNC='';
ERROR 42000: Missing synchronization point name
SET DEBUG_SYNC=' ';
ERROR 42000: Missing synchronization point name
SET DEBUG_SYNC='p0';
ERROR 42000: Missing action after synchronization point name 'p0'
SET DEBUG_SYNC='p0 EXECUTE 2';
ERROR 42000: Missing action before EXECUTE
SET DEBUG_SYNC='p0 TIMEOUT 6 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 TIMEOUT 6';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 TIMEOUT 6 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 TIMEOUT 6';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 SIGNAL s1 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 SIGNAL s1';
ERROR 42000: Illegal or out of order stuff: 'SIGNAL'
SET DEBUG_SYNC='p0 TIMEOUT 6 WAIT_FOR s2 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 TIMEOUT 6 WAIT_FOR s2';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 SIGNAL s1 TIMEOUT 6 EXECUTE 2';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 SIGNAL s1 TIMEOUT 6';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 EXECUTE 2 SIGNAL s1 TIMEOUT 6';
ERROR 42000: Missing action before EXECUTE
SET DEBUG_SYNC='p0 TIMEOUT 6 SIGNAL s1';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUT'
SET DEBUG_SYNC='p0 EXECUTE 2 TIMEOUT 6 SIGNAL s1';
ERROR 42000: Missing action before EXECUTE
SET DEBUG_SYNC='p0 CLEAR HIT_LIMIT 3';
ERROR 42000: Nothing must follow action CLEAR
SET DEBUG_SYNC='CLEAR';
ERROR 42000: Missing action after synchronization point name 'CLEAR'
SET DEBUG_SYNC='p0 CLEAR p0';
ERROR 42000: Nothing must follow action CLEAR
SET DEBUG_SYNC='TEST';
ERROR 42000: Missing action after synchronization point name 'TEST'
SET DEBUG_SYNC='p0 TEST p0';
ERROR 42000: Nothing must follow action TEST
SET DEBUG_SYNC='p0 RESET';
ERROR 42000: Illegal or out of order stuff: 'RESET'
SET DEBUG_SYNC='RESET p0';
ERROR 42000: Illegal or out of order stuff: 'p0'
SET DEBUG_SYNC='p0 RESET p0';
ERROR 42000: Illegal or out of order stuff: 'RESET'
SET DEBUG_SYNC='p0 SIGNAL ';
ERROR 42000: Missing signal name after action SIGNAL
SET DEBUG_SYNC='p0 WAIT_FOR ';
ERROR 42000: Missing signal name after action WAIT_FOR
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE ';
ERROR 42000: Missing valid number after EXECUTE
SET DEBUG_SYNCx='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
ERROR HY000: Unknown system variable 'DEBUG_SYNCx'
SET DEBUG_SYNC='p0 SIGNAx s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
ERROR 42000: Illegal or out of order stuff: 'SIGNAx'
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOx s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
ERROR 42000: Illegal or out of order stuff: 'WAIT_FOx'
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUx 0 EXECUTE 2 HIT_LIMIT 3';
ERROR 42000: Illegal or out of order stuff: 'TIMEOUx'
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTx 2 HIT_LIMIT 3';
ERROR 42000: Illegal or out of order stuff: 'EXECUTx'
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIx 3';
ERROR 42000: Illegal or out of order stuff: 'HIT_LIMIx'
SET DEBUG_SYNC='p0 CLEARx';
ERROR 42000: Illegal or out of order stuff: 'CLEARx'
SET DEBUG_SYNC='p0 TESTx';
ERROR 42000: Illegal or out of order stuff: 'TESTx'
SET DEBUG_SYNC='RESETx';
ERROR 42000: Missing action after synchronization point name 'RESETx'
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 0x6 EXECUTE 2 HIT_LIMIT 3';
ERROR 42000: Missing valid number after TIMEOUT
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 0x2 HIT_LIMIT 3';
ERROR 42000: Missing valid number after EXECUTE
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 7 EXECUTE 2 HIT_LIMIT 0x3';
ERROR 42000: Missing valid number after HIT_LIMIT
SET DEBUG_SYNC= 7;
ERROR 42000: Incorrect argument type to variable 'debug_sync'
SET GLOBAL DEBUG_SYNC= 'p0 CLEAR';
ERROR HY000: Variable 'debug_sync' is a SESSION variable and can't be used with SET GLOBAL
SET @myvar= 'now SIGNAL from_myvar';
SET DEBUG_SYNC= @myvar;
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 'from_myvar'
SET DEBUG_SYNC= LEFT('now SIGNAL from_function_cut_here', 24);
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 'from_function'
SET DEBUG_SYNC= 'now SIGNAL something';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 'something'
SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
Warnings:
Warning #### debug sync point wait timed out
SET DEBUG_SYNC= 'now SIGNAL nothing';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 'nothing'
SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
SET DEBUG_SYNC= 'now SIGNAL something EXECUTE 0';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 'nothing'
SET DEBUG_SYNC= 'now WAIT_FOR anotherthing TIMEOUT 0 EXECUTE 0';
SET DEBUG_SYNC= 'now HIT_LIMIT 1';
ERROR HY000: debug sync point hit limit reached
SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: ''
SET DEBUG_SYNC= 'p1abcd SIGNAL s1 EXECUTE 2';
SET DEBUG_SYNC= 'p2abc SIGNAL s2 EXECUTE 2';
SET DEBUG_SYNC= 'p9abcdef SIGNAL s9 EXECUTE 2';
SET DEBUG_SYNC= 'p4a SIGNAL s4 EXECUTE 2';
SET DEBUG_SYNC= 'p5abcde SIGNAL s5 EXECUTE 2';
SET DEBUG_SYNC= 'p6ab SIGNAL s6 EXECUTE 2';
SET DEBUG_SYNC= 'p7 SIGNAL s7 EXECUTE 2';
SET DEBUG_SYNC= 'p8abcdef SIGNAL s8 EXECUTE 2';
SET DEBUG_SYNC= 'p3abcdef SIGNAL s3 EXECUTE 2';
SET DEBUG_SYNC= 'p4a TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's4'
SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's1'
SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's7'
SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's9'
SET DEBUG_SYNC= 'p3abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's3'
SET DEBUG_SYNC= 'p1abcd CLEAR';
SET DEBUG_SYNC= 'p2abc CLEAR';
SET DEBUG_SYNC= 'p5abcde CLEAR';
SET DEBUG_SYNC= 'p6ab CLEAR';
SET DEBUG_SYNC= 'p8abcdef CLEAR';
SET DEBUG_SYNC= 'p9abcdef CLEAR';
SET DEBUG_SYNC= 'p3abcdef CLEAR';
SET DEBUG_SYNC= 'p4a CLEAR';
SET DEBUG_SYNC= 'p7 CLEAR';
SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's3'
SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's3'
SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: 's3'
SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value
debug_sync ON - current signal: ''
CREATE USER mysqltest_1@localhost;
GRANT SUPER ON *.* TO mysqltest_1@localhost;
connection con1, mysqltest_1
SET DEBUG_SYNC= 'RESET';
connection default
DROP USER mysqltest_1@localhost;
CREATE USER mysqltest_2@localhost;
GRANT ALL ON *.* TO mysqltest_2@localhost;
REVOKE SUPER ON *.* FROM mysqltest_2@localhost;
connection con1, mysqltest_2
SET DEBUG_SYNC= 'RESET';
ERROR 42000: Access denied; you need the SUPER privilege for this operation
connection default
DROP USER mysqltest_2@localhost;
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (c1 INT);
connection con1
SET DEBUG_SYNC= 'before_lock_tables_takes_lock
SIGNAL opened WAIT_FOR flushed';
INSERT INTO t1 VALUES(1);
connection default
SET DEBUG_SYNC= 'now WAIT_FOR opened';
SET DEBUG_SYNC= 'after_flush_unlock SIGNAL flushed';
FLUSH TABLE t1;
connection con1
connection default
DROP TABLE t1;
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (c1 INT);
LOCK TABLE t1 WRITE;
connection con1
SET DEBUG_SYNC= 'wait_for_lock SIGNAL locked EXECUTE 2';
INSERT INTO t1 VALUES (1);
connection default
SET DEBUG_SYNC= 'now WAIT_FOR locked';
UNLOCK TABLES;
connection con1
retrieve INSERT result.
connection default
DROP TABLE t1;
SET DEBUG_SYNC= 'RESET';
mysql-test/t/debug_sync.test 0 → 100644
View file @ 21586dfb
###################### t/debug_sync.test ###############################
# #
# Testing of the Debug Sync Facility. #
# #
# There is important documentation within sql/debug_sync.cc #
# #
# Used objects in this test case: #
# p0 - synchronization point 0. Non-existent dummy sync point. #
# s1 - signal 1. #
# s2 - signal 2. #
# #
# Creation: #
# 2008-02-18 istruewing #
# #
########################################################################
#
# We need the Debug Sync Facility.
#
--source include/have_debug_sync.inc
#
# We are checking privileges, which the embedded server cannot do.
#
--source include/not_embedded.inc
#
# Preparative cleanup.
#
--disable_warnings
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
--enable_warnings
#
# Show the special system variable.
# It shows ON or OFF depending on the command line option --debug-sync.
# The test case assumes it is ON (command line option present).
#
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
# Syntax. Valid forms.
#
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 SIGNAL s1';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6';
SET DEBUG_SYNC='p0 WAIT_FOR s2 EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2 EXECUTE 2';
SET DEBUG_SYNC='p0 WAIT_FOR s2 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 WAIT_FOR s2';
SET DEBUG_SYNC='p0 HIT_LIMIT 3';
SET DEBUG_SYNC='p0 CLEAR';
SET DEBUG_SYNC='p0 TEST';
SET DEBUG_SYNC='RESET';
#
# Syntax. Valid forms. Lower case.
#
set debug_sync='p0 signal s1 wait_for s2 timeout 6 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 timeout 6 execute 2';
set debug_sync='p0 signal s1 wait_for s2 timeout 6 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 timeout 6';
set debug_sync='p0 signal s1 wait_for s2 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2 execute 2';
set debug_sync='p0 signal s1 wait_for s2 hit_limit 3';
set debug_sync='p0 signal s1 wait_for s2';
set debug_sync='p0 signal s1 execute 2 hit_limit 3';
set debug_sync='p0 signal s1 execute 2';
set debug_sync='p0 signal s1 hit_limit 3';
set debug_sync='p0 signal s1';
set debug_sync='p0 wait_for s2 timeout 6 execute 2 hit_limit 3';
set debug_sync='p0 wait_for s2 timeout 6 execute 2';
set debug_sync='p0 wait_for s2 timeout 6 hit_limit 3';
set debug_sync='p0 wait_for s2 timeout 6';
set debug_sync='p0 wait_for s2 execute 2 hit_limit 3';
set debug_sync='p0 wait_for s2 execute 2';
set debug_sync='p0 wait_for s2 hit_limit 3';
set debug_sync='p0 wait_for s2';
set debug_sync='p0 hit_limit 3';
set debug_sync='p0 clear';
set debug_sync='p0 test';
set debug_sync='reset';
#
# Syntax. Valid forms. Line wrap, leading, mid, trailing space.
#
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6
EXECUTE 2 HIT_LIMIT 3';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 ';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2 ';
SET DEBUG_SYNC=' p0 SIGNAL s1 WAIT_FOR s2 ';
#
# Syntax. Invalid forms.
#
--error ER_PARSE_ERROR
SET DEBUG_SYNC='';
--error ER_PARSE_ERROR
SET DEBUG_SYNC=' ';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TIMEOUT 6 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TIMEOUT 6';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 TIMEOUT 6 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 SIGNAL s1 TIMEOUT 6';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 SIGNAL s1 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 SIGNAL s1';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TIMEOUT 6 WAIT_FOR s2 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TIMEOUT 6 WAIT_FOR s2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 TIMEOUT 6 EXECUTE 2';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 TIMEOUT 6';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 EXECUTE 2 SIGNAL s1 TIMEOUT 6';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TIMEOUT 6 SIGNAL s1';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 EXECUTE 2 TIMEOUT 6 SIGNAL s1';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 CLEAR HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='CLEAR';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 CLEAR p0';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='TEST';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TEST p0';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 RESET';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='RESET p0';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 RESET p0';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL ';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR ';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 EXECUTE ';
#
# Syntax. Invalid keywords used.
#
--error ER_UNKNOWN_SYSTEM_VARIABLE
SET DEBUG_SYNCx='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAx s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOx s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUx 0 EXECUTE 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTx 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIx 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 CLEARx';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 TESTx';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='RESETx';
#
# Syntax. Invalid numbers. Decimal only.
#
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 0x6 EXECUTE 2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 6 EXECUTE 0x2 HIT_LIMIT 3';
--error ER_PARSE_ERROR
SET DEBUG_SYNC='p0 WAIT_FOR s2 TIMEOUT 7 EXECUTE 2 HIT_LIMIT 0x3';
#
# Syntax. Invalid value type.
#
--error ER_WRONG_TYPE_FOR_VAR
SET DEBUG_SYNC= 7;
#
# Syntax. DEBUG_SYNC is a SESSION-only variable.
#
--error ER_LOCAL_VARIABLE
SET GLOBAL DEBUG_SYNC= 'p0 CLEAR';
#
# Syntax. The variable value does not need to be a string literal.
#
SET @myvar= 'now SIGNAL from_myvar';
SET DEBUG_SYNC= @myvar;
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
SET DEBUG_SYNC= LEFT('now SIGNAL from_function_cut_here', 24);
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
# Functional tests.
#
# NOTE: There is the special synchronization point 'now'. It is placed
# immediately after setting of the DEBUG_SYNC variable.
# So it is executed before the SET statement ends.
#
# NOTE: There is only one global signal (say "signal post" or "flag mast").
# A SIGNAL action writes its signal into it ("sets a flag").
# The signal persists until explicitly overwritten.
# To avoid confusion for later tests, it is recommended to clear
# the signal by signalling "empty" ("setting the 'empty' flag"):
# SET DEBUG_SYNC= 'now SIGNAL empty';
# Preferably you can reset the whole facility with:
# SET DEBUG_SYNC= 'RESET';
# The signal is then '' (really empty) which connot be done otherwise.
#
#
# Time out immediately. This gives just a warning.
#
SET DEBUG_SYNC= 'now SIGNAL something';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
# Suppress warning number
--replace_column 2 ####
SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
#
# If signal is present already, TIMEOUT 0 does not give a warning.
#
SET DEBUG_SYNC= 'now SIGNAL nothing';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
#
# EXECUTE 0 is effectively a no-op.
#
SET DEBUG_SYNC= 'now SIGNAL something EXECUTE 0';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'now WAIT_FOR anotherthing TIMEOUT 0 EXECUTE 0';
#
# Run into HIT_LIMIT. This gives an error.
#
--error ER_DEBUG_SYNC_HIT_LIMIT
SET DEBUG_SYNC= 'now HIT_LIMIT 1';
#
# Many actions. Watch the array growing and shrinking in the debug trace:
# egrep 'query:|debug_sync_action:' mysql-test/var/log/master.trace
#
SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p1abcd SIGNAL s1 EXECUTE 2';
SET DEBUG_SYNC= 'p2abc SIGNAL s2 EXECUTE 2';
SET DEBUG_SYNC= 'p9abcdef SIGNAL s9 EXECUTE 2';
SET DEBUG_SYNC= 'p4a SIGNAL s4 EXECUTE 2';
SET DEBUG_SYNC= 'p5abcde SIGNAL s5 EXECUTE 2';
SET DEBUG_SYNC= 'p6ab SIGNAL s6 EXECUTE 2';
SET DEBUG_SYNC= 'p7 SIGNAL s7 EXECUTE 2';
SET DEBUG_SYNC= 'p8abcdef SIGNAL s8 EXECUTE 2';
SET DEBUG_SYNC= 'p3abcdef SIGNAL s3 EXECUTE 2';
#
# Execute some actions to show they exist. Each sets a distinct signal.
#
SET DEBUG_SYNC= 'p4a TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p3abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
# Clear the actions.
#
SET DEBUG_SYNC= 'p1abcd CLEAR';
SET DEBUG_SYNC= 'p2abc CLEAR';
SET DEBUG_SYNC= 'p5abcde CLEAR';
SET DEBUG_SYNC= 'p6ab CLEAR';
SET DEBUG_SYNC= 'p8abcdef CLEAR';
SET DEBUG_SYNC= 'p9abcdef CLEAR';
SET DEBUG_SYNC= 'p3abcdef CLEAR';
SET DEBUG_SYNC= 'p4a CLEAR';
SET DEBUG_SYNC= 'p7 CLEAR';
#
# Execute some actions to show they have gone.
#
SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
# Now cleanup. Actions are clear already, but signal needs to be cleared.
#
SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC';
#
# Facility requires SUPER privilege.
#
CREATE USER mysqltest_1@localhost;
GRANT SUPER ON *.* TO mysqltest_1@localhost;
--echo connection con1, mysqltest_1
connect (con1,localhost,mysqltest_1,,);
SET DEBUG_SYNC= 'RESET';
disconnect con1;
--echo connection default
connection default;
DROP USER mysqltest_1@localhost;
#
CREATE USER mysqltest_2@localhost;
GRANT ALL ON *.* TO mysqltest_2@localhost;
REVOKE SUPER ON *.* FROM mysqltest_2@localhost;
--echo connection con1, mysqltest_2
connect (con1,localhost,mysqltest_2,,);
--error ER_SPECIFIC_ACCESS_DENIED_ERROR
SET DEBUG_SYNC= 'RESET';
disconnect con1;
--echo connection default
connection default;
DROP USER mysqltest_2@localhost;
#
# Example 1.
#
# Preparative cleanup.
--disable_warnings
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
--enable_warnings
#
# Test.
CREATE TABLE t1 (c1 INT);
--echo connection con1
connect (con1,localhost,root,,);
SET DEBUG_SYNC= 'before_lock_tables_takes_lock
SIGNAL opened WAIT_FOR flushed';
send INSERT INTO t1 VALUES(1);
--echo connection default
connection default;
SET DEBUG_SYNC= 'now WAIT_FOR opened';
SET DEBUG_SYNC= 'after_flush_unlock SIGNAL flushed';
FLUSH TABLE t1;
--echo connection con1
connection con1;
reap;
disconnect con1;
--echo connection default
connection default;
DROP TABLE t1;
#
# Example 2.
#
# Preparative cleanup.
--disable_warnings
SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1;
--enable_warnings
#
# Test.
CREATE TABLE t1 (c1 INT);
LOCK TABLE t1 WRITE;
--echo connection con1
connect (con1,localhost,root,,);
# Retain action after use. First used by general_log.
SET DEBUG_SYNC= 'wait_for_lock SIGNAL locked EXECUTE 2';
send INSERT INTO t1 VALUES (1);
--echo connection default
connection default;
# Wait until INSERT waits for lock.
SET DEBUG_SYNC= 'now WAIT_FOR locked';
# let INSERT continue.
UNLOCK TABLES;
--echo connection con1
connection con1;
--echo retrieve INSERT result.
reap;
disconnect con1;
--echo connection default
connection default;
DROP TABLE t1;
#
# Cleanup after test case.
# Otherwise signal would contain 'flushed' here,
# which could confuse the next test.
#
SET DEBUG_SYNC= 'RESET';
mysys/my_static.c
View file @ 21586dfb
......@@ -92,6 +92,14 @@ int (*error_handler_hook)(uint error,const char *str,myf MyFlags)=
int (*fatal_error_handler_hook)(uint error,const char *str,myf MyFlags)=
my_message_no_curses;
#if defined(ENABLED_DEBUG_SYNC)
/**
Global pointer to be set if callback function is defined
(e.g. in mysqld). See sql/debug_sync.cc.
*/
void (*debug_sync_C_callback_ptr)(const char *, size_t);
#endif /* defined(ENABLED_DEBUG_SYNC) */
#ifdef __WIN__
/* from my_getsystime.c */
ulonglong query_performance_frequency, query_performance_offset;
......
mysys/thr_lock.c
View file @ 21586dfb
......@@ -398,6 +398,28 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
my_bool can_deadlock= test(data->owner->info->n_cursors);
DBUG_ENTER("wait_for_lock");
/*
One can use this to signal when a thread is going to wait for a lock.
See debug_sync.cc.
Beware of waiting for a signal here. The lock has aquired its mutex.
While waiting on a signal here, the locking thread could not aquire
the mutex to release the lock. One could lock up the table
completely.
In detail it works so: When thr_lock() tries to acquire a table
lock, it locks the lock->mutex, checks if it can have the lock, and
if not, it calls wait_for_lock(). Here it unlocks the table lock
while waiting on a condition. The sync point is located before this
wait for condition. If we have a waiting action here, we hold the
the table locks mutex all the time. Any attempt to look at the table
lock by another thread blocks it immediately on lock->mutex. This
can easily become an unexpected and unobvious blockage. So be
warned: Do not request a WAIT_FOR action for the 'wait_for_lock'
sync point unless you really know what you do.
*/
DEBUG_SYNC_C("wait_for_lock");
if (!in_wait_list)
{
(*wait->last)=data; /* Wait for lock */
......
sql/CMakeLists.txt
View file @ 21586dfb
......@@ -64,6 +64,7 @@ SET (SQL_SOURCE
sql_error.cc sql_handler.cc sql_help.cc sql_insert.cc sql_lex.cc
sql_list.cc sql_load.cc sql_manager.cc sql_map.cc sql_parse.cc
sql_partition.cc sql_plugin.cc sql_prepare.cc sql_rename.cc
debug_sync.cc debug_sync.h
sql_repl.cc sql_select.cc sql_show.cc sql_state.c sql_string.cc
sql_table.cc sql_test.cc sql_trigger.cc sql_udf.cc sql_union.cc
sql_update.cc sql_view.cc strfunc.cc table.cc thr_malloc.cc
......
sql/Makefile.am
View file @ 21586dfb
......@@ -58,6 +58,7 @@ noinst_HEADERS = item.h item_func.h item_sum.h item_cmpfunc.h \
ha_ndbcluster.h ha_ndbcluster_cond.h \
ha_ndbcluster_binlog.h ha_ndbcluster_tables.h \
ha_partition.h rpl_constants.h \
debug_sync.h \
opt_range.h protocol.h rpl_tblmap.h rpl_utility.h \
rpl_reporting.h \
log.h sql_show.h rpl_rli.h rpl_mi.h \
......@@ -102,6 +103,7 @@ mysqld_SOURCES = sql_lex.cc sql_handler.cc sql_partition.cc \
discover.cc time.cc opt_range.cc opt_sum.cc \
records.cc filesort.cc handler.cc \
ha_partition.cc \
debug_sync.cc \
sql_db.cc sql_table.cc sql_rename.cc sql_crypt.cc \
sql_load.cc mf_iocache.cc field_conv.cc sql_show.cc \
sql_udf.cc sql_analyse.cc sql_analyse.h sql_cache.cc \
......
sql/debug_sync.cc 0 → 100644
View file @ 21586dfb
/* Copyright (C) 2008 MySQL AB, 2008 - 2009 Sun Microsystems, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
== Debug Sync Facility ==
The Debug Sync Facility allows placement of synchronization points in
the server code by using the DEBUG_SYNC macro:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Emit a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- emit a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
By default, all sync points are inactive. They do nothing (except to
burn a couple of CPU cycles for checking if they are active).
A sync point becomes active when an action is requested for it.
To do so, put a line like this in the test case file:
SET DEBUG_SYNC= 'after_open_tables SIGNAL opened WAIT_FOR flushed';
This activates the sync point 'after_open_tables'. It requests it to
emit the signal 'opened' and wait for another thread to emit the signal
'flushed' when the thread's execution runs through the sync point.
For every sync point there can be one action per thread only. Every
thread can request multiple actions, but only one per sync point. In
other words, a thread can activate multiple sync points.
Here is an example how to activate and use the sync points:
--connection conn1
SET DEBUG_SYNC= 'after_open_tables SIGNAL opened WAIT_FOR flushed';
send INSERT INTO t1 VALUES(1);
--connection conn2
SET DEBUG_SYNC= 'now WAIT_FOR opened';
SET DEBUG_SYNC= 'after_abort_locks SIGNAL flushed';
FLUSH TABLE t1;
When conn1 runs through the INSERT statement, it hits the sync point
'after_open_tables'. It notices that it is active and executes its
action. It emits the signal 'opened' and waits for another thread to
emit the signal 'flushed'.
conn2 waits immediately at the special sync point 'now' for another
thread to emit the 'opened' signal.
A signal remains in effect until it is overwritten. If conn1 signals
'opened' before conn2 reaches 'now', conn2 will still find the 'opened'
signal. It does not wait in this case.
When conn2 reaches 'after_abort_locks', it signals 'flushed', which lets
conn1 awake.
Normally the activation of a sync point is cleared when it has been
executed. Sometimes it is necessary to keep the sync point active for
another execution. You can add an execute count to the action:
SET DEBUG_SYNC= 'name SIGNAL sig EXECUTE 3';
This sets the signal point's activation counter to 3. Each execution
decrements the counter. After the third execution the sync point
becomes inactive.
One of the primary goals of this facility is to eliminate sleeps from
the test suite. In most cases it should be possible to rewrite test
cases so that they do not need to sleep. (But this facility cannot
synchronize multiple processes.) However, to support test development,
and as a last resort, sync point waiting times out. There is a default
timeout, but it can be overridden:
SET DEBUG_SYNC= 'name WAIT_FOR sig TIMEOUT 10 EXECUTE 2';
TIMEOUT 0 is special: If the signal is not present, the wait times out
immediately.
When a wait timed out (even on TIMEOUT 0), a warning is generated so
that it shows up in the test result.
You can throw an error message and kill the query when a synchronization
point is hit a certain number of times:
SET DEBUG_SYNC= 'name HIT_LIMIT 3';
Or combine it with signal and/or wait:
SET DEBUG_SYNC= 'name SIGNAL sig EXECUTE 2 HIT_LIMIT 3';
Here the first two hits emit the signal, the third hit returns the error
message and kills the query.
For cases where you are not sure that an action is taken and thus
cleared in any case, you can force to clear (deactivate) a sync point:
SET DEBUG_SYNC= 'name CLEAR';
If you want to clear all actions and clear the global signal, use:
SET DEBUG_SYNC= 'RESET';
This is the only way to reset the global signal to an empty string.
For testing of the facility itself you can execute a sync point just
as if it had been hit:
SET DEBUG_SYNC= 'name TEST';
=== Formal Syntax ===
The string to "assign" to the DEBUG_SYNC variable can contain:
{RESET |
<sync point name> TEST |
<sync point name> CLEAR |
<sync point name> {{SIGNAL <signal name> |
WAIT_FOR <signal name> [TIMEOUT <seconds>]}
[EXECUTE <count>] &| HIT_LIMIT <count>}
Here '&|' means 'and/or'. This means that one of the sections
separated by '&|' must be present or both of them.
=== Activation/Deactivation ===
The facility is an optional part of the MySQL server.
It is enabled in a debug server by default.
./configure --enable-debug-sync
The Debug Sync Facility, when compiled in, is disabled by default. It
can be enabled by a mysqld command line option:
--debug-sync-timeout[=default_wait_timeout_value_in_seconds]
'default_wait_timeout_value_in_seconds' is the default timeout for the
WAIT_FOR action. If set to zero, the facility stays disabled.
The facility is enabled by default in the test suite, but can be
disabled with:
mysql-test-run.pl ... --debug-sync-timeout=0 ...
Likewise the default wait timeout can be set:
mysql-test-run.pl ... --debug-sync-timeout=10 ...
The command line option influences the readable value of the system
variable 'debug_sync'.
* If the facility is not compiled in, the system variable does not exist.
* If --debug-sync-timeout=0 the value of the variable reads as "OFF".
* Otherwise the value reads as "ON - current signal: " followed by the
current signal string, which can be empty.
The readable variable value is the same, regardless if read as global
or session value.
Setting the 'debug-sync' system variable requires 'SUPER' privilege.
You can never read back the string that you assigned to the variable,
unless you assign the value that the variable does already have. But
that would give a parse error. A syntactically correct string is
parsed into a debug sync action and stored apart from the variable value.
=== Implementation ===
Pseudo code for a sync point:
#define DEBUG_SYNC(thd, sync_point_name)
if (unlikely(opt_debug_sync_timeout))
debug_sync(thd, STRING_WITH_LEN(sync_point_name))
The sync point performs a binary search in a sorted array of actions
for this thread.
The SET DEBUG_SYNC statement adds a requested action to the array or
overwrites an existing action for the same sync point. When it adds a
new action, the array is sorted again.
=== A typical synchronization pattern ===
There are quite a few places in MySQL, where we use a synchronization
pattern like this:
pthread_mutex_lock(&mutex);
thd->enter_cond(&condition_variable, &mutex, new_message);
#if defined(ENABLE_DEBUG_SYNC)
if (!thd->killed && !end_of_wait_condition)
DEBUG_SYNC(thd, "sync_point_name");
#endif
while (!thd->killed && !end_of_wait_condition)
pthread_cond_wait(&condition_variable, &mutex);
thd->exit_cond(old_message);
Here some explanations:
thd->enter_cond() is used to register the condition variable and the
mutex in thd->mysys_var. This is done to allow the thread to be
interrupted (killed) from its sleep. Another thread can find the
condition variable to signal and mutex to use for synchronization in
this thread's THD::mysys_var.
thd->enter_cond() requires the mutex to be acquired in advance.
thd->exit_cond() unregisters the condition variable and mutex and
releases the mutex.
If you want to have a Debug Sync point with the wait, please place it
behind enter_cond(). Only then you can safely decide, if the wait will
be taken. Also you will have THD::proc_info correct when the sync
point emits a signal. DEBUG_SYNC sets its own proc_info, but restores
the previous one before releasing its internal mutex. As soon as
another thread sees the signal, it does also see the proc_info from
before entering the sync point. In this case it will be "new_message",
which is associated with the wait that is to be synchronized.
In the example above, the wait condition is repeated before the sync
point. This is done to skip the sync point, if no wait takes place.
The sync point is before the loop (not inside the loop) to have it hit
once only. It is possible that the condition variable is signaled
multiple times without the wait condition to be true.
A bit off-topic: At some places, the loop is taken around the whole
synchronization pattern:
while (!thd->killed && !end_of_wait_condition)
{
pthread_mutex_lock(&mutex);
thd->enter_cond(&condition_variable, &mutex, new_message);
if (!thd->killed [&& !end_of_wait_condition])
{
[DEBUG_SYNC(thd, "sync_point_name");]
pthread_cond_wait(&condition_variable, &mutex);
}
thd->exit_cond(old_message);
}
Note that it is important to repeat the test for thd->killed after
enter_cond(). Otherwise the killing thread may kill this thread after
it tested thd->killed in the loop condition and before it registered
the condition variable and mutex in enter_cond(). In this case, the
killing thread does not know that this thread is going to wait on a
condition variable. It would just set THD::killed. But if we would not
test it again, we would go asleep though we are killed. If the killing
thread would kill us when we are after the second test, but still
before sleeping, we hold the mutex, which is registered in mysys_var.
The killing thread would try to acquire the mutex before signaling
the condition variable. Since the mutex is only released implicitly in
pthread_cond_wait(), the signaling happens at the right place. We
have a safe synchronization.
=== Co-work with the DBUG facility ===
When running the MySQL test suite with the --debug command line
option, the Debug Sync Facility writes trace messages to the DBUG
trace. The following shell commands proved very useful in extracting
relevant information:
egrep 'query:|debug_sync_exec:' mysql-test/var/log/mysqld.1.trace
It shows all executed SQL statements and all actions executed by
synchronization points.
Sometimes it is also useful to see, which synchronization points have
been run through (hit) with or without executing actions. Then add
"|debug_sync_point:" to the egrep pattern.
=== Further reading ===
For a discussion of other methods to synchronize threads see
http://forge.mysql.com/wiki/MySQL_Internals_Test_Synchronization
For complete syntax tests, functional tests, and examples see the test
case debug_sync.test.
See also worklog entry WL#4259 - Test Synchronization Facility
*/
#include "debug_sync.h"
#if defined(ENABLED_DEBUG_SYNC)
/*
Due to weaknesses in our include files, we need to include
mysql_priv.h here. To have THD declared, we need to include
sql_class.h. This includes log_event.h, which in turn requires
declarations from mysql_priv.h (e.g. OPTION_AUTO_IS_NULL).
mysql_priv.h includes almost everything, so is sufficient here.
*/
#include "mysql_priv.h"
/*
Action to perform at a synchronization point.
NOTE: This structure is moved around in memory by realloc(), qsort(),
and memmove(). Do not add objects with non-trivial constuctors
or destructors, which might prevent moving of this structure
with these functions.
*/
struct st_debug_sync_action
{
ulong activation_count; /* max(hit_limit, execute) */
ulong hit_limit; /* hits before kill query */
ulong execute; /* executes before self-clear */
ulong timeout; /* wait_for timeout */
String signal; /* signal to emit */
String wait_for; /* signal to wait for */
String sync_point; /* sync point name */
bool need_sort; /* if new action, array needs sort */
};
/* Debug sync control. Referenced by THD. */
struct st_debug_sync_control
{
st_debug_sync_action *ds_action; /* array of actions */
uint ds_active; /* # active actions */
uint ds_allocated; /* # allocated actions */
ulonglong dsp_hits; /* statistics */
ulonglong dsp_executed; /* statistics */
ulonglong dsp_max_active; /* statistics */
/*
thd->proc_info points at unsynchronized memory.
It must not go away as long as the thread exists.
*/
char ds_proc_info[80]; /* proc_info string */
};
/**
Definitions for the debug sync facility.
1. Global string variable to hold a "signal" ("signal post", "flag mast").
2. Global condition variable for signaling and waiting.
3. Global mutex to synchronize access to the above.
*/
struct st_debug_sync_globals
{
String ds_signal; /* signal variable */
pthread_cond_t ds_cond; /* condition variable */
pthread_mutex_t ds_mutex; /* mutex variable */
ulonglong dsp_hits; /* statistics */
ulonglong dsp_executed; /* statistics */
ulonglong dsp_max_active; /* statistics */
};
static st_debug_sync_globals debug_sync_global; /* All globals in one object */
/**
Callback pointer for C files.
*/
extern "C" void (*debug_sync_C_callback_ptr)(const char *, size_t);
/**
Callback for debug sync, to be used by C files. See thr_lock.c for example.
@description
We cannot place a sync point directly in C files (like those in mysys or
certain storage engines written mostly in C like MyISAM or Maria). Because
they are C code and do not include mysql_priv.h. So they do not know the
macro DEBUG_SYNC(thd, sync_point_name). The macro needs a 'thd' argument.
Hence it cannot be used in files outside of the sql/ directory.
The workaround is to call back simple functions like this one from
non-sql/ files.
We want to allow modules like thr_lock to be used without sql/ and
especially without Debug Sync. So we cannot just do a simple call
of the callback function. Instead we provide a global pointer in
the other file, which is to be set to the callback by Debug Sync.
If the pointer is not set, no call back will be done. If Debug
Sync sets the pointer to a callback function like this one, it will
be called. That way thr_lock.c does not have an undefined reference
to Debug Sync and can be used without it. Debug Sync, in contrast,
has an undefined reference to that pointer and thus requires
thr_lock to be linked too. But this is not a problem as it is part
of the MySQL server anyway.
@note
The callback pointer in C files is set only if debug sync is
initialized. And this is done only if opt_debug_sync_timeout is set.
*/
static void debug_sync_C_callback(const char *sync_point_name,
size_t name_len)
{
if (unlikely(opt_debug_sync_timeout))
debug_sync(current_thd, sync_point_name, name_len);
}
/**
Initialize the debug sync facility at server start.
@return status
@retval 0 ok
@retval != 0 error
*/
int debug_sync_init(void)
{
DBUG_ENTER("debug_sync_init");
if (opt_debug_sync_timeout)
{
int rc;
/* Initialize the global variables. */
debug_sync_global.ds_signal.length(0);
if ((rc= pthread_cond_init(&debug_sync_global.ds_cond, NULL)) ||
(rc= pthread_mutex_init(&debug_sync_global.ds_mutex,
MY_MUTEX_INIT_FAST)))
DBUG_RETURN(rc); /* purecov: inspected */
/* Set the call back pointer in C files. */
debug_sync_C_callback_ptr= debug_sync_C_callback;
}
DBUG_RETURN(0);
}
/**
End the debug sync facility.
@description
This is called at server shutdown or after a thread initialization error.
*/
void debug_sync_end(void)
{
DBUG_ENTER("debug_sync_end");
/* End the facility only if it had been initialized. */
if (debug_sync_C_callback_ptr)
{
/* Clear the call back pointer in C files. */
debug_sync_C_callback_ptr= NULL;
/* Destroy the global variables. */
debug_sync_global.ds_signal.free();
(void) pthread_cond_destroy(&debug_sync_global.ds_cond);
(void) pthread_mutex_destroy(&debug_sync_global.ds_mutex);
/* Print statistics. */
{
char llbuff[22];
sql_print_information("Debug sync points hit: %22s",
llstr(debug_sync_global.dsp_hits, llbuff));
sql_print_information("Debug sync points executed: %22s",
llstr(debug_sync_global.dsp_executed, llbuff));
sql_print_information("Debug sync points max active per thread: %22s",
llstr(debug_sync_global.dsp_max_active, llbuff));
}
}
DBUG_VOID_RETURN;
}
/* purecov: begin tested */
/**
Disable the facility after lack of memory if no error can be returned.
@note
Do not end the facility here because the global variables can
be in use by other threads.
*/
static void debug_sync_emergency_disable(void)
{
DBUG_ENTER("debug_sync_emergency_disable");
opt_debug_sync_timeout= 0;
DBUG_PRINT("debug_sync",
("Debug Sync Facility disabled due to lack of memory."));
sql_print_error("Debug Sync Facility disabled due to lack of memory.");
DBUG_VOID_RETURN;
}
/* purecov: end */
/**
Initialize the debug sync facility at thread start.
@param[in] thd thread handle
*/
void debug_sync_init_thread(THD *thd)
{
DBUG_ENTER("debug_sync_init_thread");
DBUG_ASSERT(thd);
if (opt_debug_sync_timeout)
{
thd->debug_sync_control= (st_debug_sync_control*)
my_malloc(sizeof(st_debug_sync_control), MYF(MY_WME | MY_ZEROFILL));
if (!thd->debug_sync_control)
{
/*
Error is reported by my_malloc().
We must disable the facility. We have no way to return an error.
*/
debug_sync_emergency_disable(); /* purecov: tested */
}
}
DBUG_VOID_RETURN;
}
/**
End the debug sync facility at thread end.
@param[in] thd thread handle
*/
void debug_sync_end_thread(THD *thd)
{
DBUG_ENTER("debug_sync_end_thread");
DBUG_ASSERT(thd);
if (thd->debug_sync_control)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
/*
This synchronization point can be used to synchronize on thread end.
This is the latest point in a THD's life, where this can be done.
*/
DEBUG_SYNC(thd, "thread_end");
if (ds_control->ds_action)
{
st_debug_sync_action *action= ds_control->ds_action;
st_debug_sync_action *action_end= action + ds_control->ds_allocated;
for (; action < action_end; action++)
{
action->signal.free();
action->wait_for.free();
action->sync_point.free();
}
my_free(ds_control->ds_action, MYF(0));
}
/* Statistics. */
pthread_mutex_lock(&debug_sync_global.ds_mutex);
debug_sync_global.dsp_hits+= ds_control->dsp_hits;
debug_sync_global.dsp_executed+= ds_control->dsp_executed;
if (debug_sync_global.dsp_max_active < ds_control->dsp_max_active)
debug_sync_global.dsp_max_active= ds_control->dsp_max_active;
pthread_mutex_unlock(&debug_sync_global.ds_mutex);
my_free(ds_control, MYF(0));
thd->debug_sync_control= NULL;
}
DBUG_VOID_RETURN;
}
/**
Move a string by length.
@param[out] to buffer for the resulting string
@param[in] to_end end of buffer
@param[in] from source string
@param[in] length number of bytes to copy
@return pointer to end of copied string
*/
static char *debug_sync_bmove_len(char *to, char *to_end,
const char *from, size_t length)
{
DBUG_ASSERT(to);
DBUG_ASSERT(to_end);
DBUG_ASSERT(!length || from);
set_if_smaller(length, (size_t) (to_end - to));
memcpy(to, from, length);
return (to + length);
}
#if !defined(DBUG_OFF)
/**
Create a string that describes an action.
@param[out] result buffer for the resulting string
@param[in] size size of result buffer
@param[in] action action to describe
*/
static void debug_sync_action_string(char *result, uint size,
st_debug_sync_action *action)
{
char *wtxt= result;
char *wend= wtxt + size - 1; /* Allow emergency '\0'. */
DBUG_ASSERT(result);
DBUG_ASSERT(action);
/* If an execute count is present, signal or wait_for are needed too. */
DBUG_ASSERT(!action->execute ||
action->signal.length() || action->wait_for.length());
if (action->execute)
{
if (action->signal.length())
{
wtxt= debug_sync_bmove_len(wtxt, wend, STRING_WITH_LEN("SIGNAL "));
wtxt= debug_sync_bmove_len(wtxt, wend, action->signal.ptr(),
action->signal.length());
}
if (action->wait_for.length())
{
if ((wtxt == result) && (wtxt < wend))
*(wtxt++)= ' ';
wtxt= debug_sync_bmove_len(wtxt, wend, STRING_WITH_LEN(" WAIT_FOR "));
wtxt= debug_sync_bmove_len(wtxt, wend, action->wait_for.ptr(),
action->wait_for.length());
if (action->timeout != opt_debug_sync_timeout)
{
wtxt+= my_snprintf(wtxt, wend - wtxt, " TIMEOUT %lu", action->timeout);
}
}
if (action->execute != 1)
{
wtxt+= my_snprintf(wtxt, wend - wtxt, " EXECUTE %lu", action->execute);
}
}
if (action->hit_limit)
{
wtxt+= my_snprintf(wtxt, wend - wtxt, "%sHIT_LIMIT %lu",
(wtxt == result) ? "" : " ", action->hit_limit);
}
/*
If (wtxt == wend) string may not be terminated.
There is one byte left for an emergency termination.
*/
*wtxt= '\0';
}
/**
Print actions.
@param[in] thd thread handle
*/
static void debug_sync_print_actions(THD *thd)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
uint idx;
DBUG_ENTER("debug_sync_print_actions");
DBUG_ASSERT(thd);
if (!ds_control)
return;
for (idx= 0; idx < ds_control->ds_active; idx++)
{
const char *dsp_name= ds_control->ds_action[idx].sync_point.c_ptr();
char action_string[256];
debug_sync_action_string(action_string, sizeof(action_string),
ds_control->ds_action + idx);
DBUG_PRINT("debug_sync_list", ("%s %s", dsp_name, action_string));
}
DBUG_VOID_RETURN;
}
#endif /* !defined(DBUG_OFF) */
/**
Compare two actions by sync point name length, string.
@param[in] arg1 reference to action1
@param[in] arg2 reference to action2
@return difference
@retval == 0 length1/string1 is same as length2/string2
@retval < 0 length1/string1 is smaller
@retval > 0 length1/string1 is bigger
*/
static int debug_sync_qsort_cmp(const void* arg1, const void* arg2)
{
st_debug_sync_action *action1= (st_debug_sync_action*) arg1;
st_debug_sync_action *action2= (st_debug_sync_action*) arg2;
int diff;
DBUG_ASSERT(action1);
DBUG_ASSERT(action2);
if (!(diff= action1->sync_point.length() - action2->sync_point.length()))
diff= memcmp(action1->sync_point.ptr(), action2->sync_point.ptr(),
action1->sync_point.length());
return diff;
}
/**
Find a debug sync action.
@param[in] actionarr array of debug sync actions
@param[in] quantity number of actions in array
@param[in] dsp_name name of debug sync point to find
@param[in] name_len length of name of debug sync point
@return action
@retval != NULL found sync point in array
@retval NULL not found
@description
Binary search. Array needs to be sorted by length, sync point name.
*/
static st_debug_sync_action *debug_sync_find(st_debug_sync_action *actionarr,
int quantity,
const char *dsp_name,
uint name_len)
{
st_debug_sync_action *action;
int low ;
int high ;
int mid ;
int diff ;
DBUG_ASSERT(actionarr);
DBUG_ASSERT(dsp_name);
DBUG_ASSERT(name_len);
low= 0;
high= quantity;
while (low < high)
{
mid= (low + high) / 2;
action= actionarr + mid;
if (!(diff= name_len - action->sync_point.length()) &&
!(diff= memcmp(dsp_name, action->sync_point.ptr(), name_len)))
return action;
if (diff > 0)
low= mid + 1;
else
high= mid - 1;
}
if (low < quantity)
{
action= actionarr + low;
if ((name_len == action->sync_point.length()) &&
!memcmp(dsp_name, action->sync_point.ptr(), name_len))
return action;
}
return NULL;
}
/**
Reset the debug sync facility.
@param[in] thd thread handle
@description
Remove all actions of this thread.
Clear the global signal.
*/
static void debug_sync_reset(THD *thd)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
DBUG_ENTER("debug_sync_reset");
DBUG_ASSERT(thd);
DBUG_ASSERT(ds_control);
/* Remove all actions of this thread. */
ds_control->ds_active= 0;
/* Clear the global signal. */
pthread_mutex_lock(&debug_sync_global.ds_mutex);
debug_sync_global.ds_signal.length(0);
pthread_mutex_unlock(&debug_sync_global.ds_mutex);
DBUG_VOID_RETURN;
}
/**
Remove a debug sync action.
@param[in] ds_control control object
@param[in] action action to be removed
@description
Removing an action mainly means to decrement the ds_active counter.
But if the action is between other active action in the array, then
the array needs to be shrinked. The active actions above the one to
be removed have to be moved down by one slot.
*/
static void debug_sync_remove_action(st_debug_sync_control *ds_control,
st_debug_sync_action *action)
{
uint dsp_idx= action - ds_control->ds_action;
DBUG_ENTER("debug_sync_remove_action");
DBUG_ASSERT(ds_control);
DBUG_ASSERT(ds_control == current_thd->debug_sync_control);
DBUG_ASSERT(action);
DBUG_ASSERT(dsp_idx < ds_control->ds_active);
/* Decrement the number of currently active actions. */
ds_control->ds_active--;
/*
If this was not the last active action in the array, we need to
shift remaining active actions down to keep the array gap-free.
Otherwise binary search might fail or take longer than necessary at
least. Also new actions are always put to the end of the array.
*/
if (ds_control->ds_active > dsp_idx)
{
/*
Do not make save_action an object of class st_debug_sync_action.
Its destructor would tamper with the String pointers.
*/
uchar save_action[sizeof(st_debug_sync_action)];
/*
Copy the to-be-removed action object to temporary storage before
the shift copies the string pointers over. Do not use assignment
because it would use assignment operator methods for the Strings.
This would copy the strings. The shift below overwrite the string
pointers without freeing them first. By using memmove() we save
the pointers, which are overwritten by the shift.
*/
memmove(save_action, action, sizeof(st_debug_sync_action));
/* Move actions down. */
memmove(ds_control->ds_action + dsp_idx,
ds_control->ds_action + dsp_idx + 1,
(ds_control->ds_active - dsp_idx) *
sizeof(st_debug_sync_action));
/*
Copy back the saved action object to the now free array slot. This
replaces the double references of String pointers that have been
produced by the shift. Again do not use an assignment operator to
avoid string allocation/copy.
*/
memmove(ds_control->ds_action + ds_control->ds_active, save_action,
sizeof(st_debug_sync_action));
}
DBUG_VOID_RETURN;
}
/**
Get a debug sync action.
@param[in] thd thread handle
@param[in] dsp_name debug sync point name
@param[in] name_len length of sync point name
@return action
@retval != NULL ok
@retval NULL error
@description
Find the debug sync action for a debug sync point or make a new one.
*/
static st_debug_sync_action *debug_sync_get_action(THD *thd,
const char *dsp_name,
uint name_len)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
st_debug_sync_action *action;
DBUG_ENTER("debug_sync_get_action");
DBUG_ASSERT(thd);
DBUG_ASSERT(dsp_name);
DBUG_ASSERT(name_len);
DBUG_ASSERT(ds_control);
DBUG_PRINT("debug_sync", ("sync_point: '%.*s'", (int) name_len, dsp_name));
DBUG_PRINT("debug_sync", ("active: %u allocated: %u",
ds_control->ds_active, ds_control->ds_allocated));
/* There cannot be more active actions than allocated. */
DBUG_ASSERT(ds_control->ds_active <= ds_control->ds_allocated);
/* If there are active actions, the action array must be present. */
DBUG_ASSERT(!ds_control->ds_active || ds_control->ds_action);
/* Try to reuse existing action if there is one for this sync point. */
if (ds_control->ds_active &&
(action= debug_sync_find(ds_control->ds_action, ds_control->ds_active,
dsp_name, name_len)))
{
/* Reuse an already active sync point action. */
DBUG_ASSERT((uint)(action - ds_control->ds_action) < ds_control->ds_active);
DBUG_PRINT("debug_sync", ("reuse action idx: %ld",
(long) (action - ds_control->ds_action)));
}
else
{
/* Create a new action. */
int dsp_idx= ds_control->ds_active++;
set_if_bigger(ds_control->dsp_max_active, ds_control->ds_active);
if (ds_control->ds_active > ds_control->ds_allocated)
{
uint new_alloc= ds_control->ds_active + 3;
void *new_action= my_realloc(ds_control->ds_action,
new_alloc * sizeof(st_debug_sync_action),
MYF(MY_WME | MY_ALLOW_ZERO_PTR));
if (!new_action)
{
/* Error is reported by my_malloc(). */
goto err; /* purecov: tested */
}
ds_control->ds_action= (st_debug_sync_action*) new_action;
ds_control->ds_allocated= new_alloc;
/* Clear memory as we do not run string constructors here. */
bzero((uchar*) (ds_control->ds_action + dsp_idx),
(new_alloc - dsp_idx) * sizeof(st_debug_sync_action));
}
DBUG_PRINT("debug_sync", ("added action idx: %u", dsp_idx));
action= ds_control->ds_action + dsp_idx;
if (action->sync_point.copy(dsp_name, name_len, system_charset_info))
{
/* Error is reported by my_malloc(). */
goto err; /* purecov: tested */
}
action->need_sort= TRUE;
}
DBUG_ASSERT(action >= ds_control->ds_action);
DBUG_ASSERT(action < ds_control->ds_action + ds_control->ds_active);
DBUG_PRINT("debug_sync", ("action: 0x%lx array: 0x%lx count: %u",
(long) action, (long) ds_control->ds_action,
ds_control->ds_active));
DBUG_RETURN(action);
/* purecov: begin tested */
err:
DBUG_RETURN(NULL);
/* purecov: end */
}
/**
Set a debug sync action.
@param[in] thd thread handle
@param[in] action synchronization action
@return status
@retval FALSE ok
@retval TRUE error
@description
This is called from the debug sync parser. It arms the action for
the requested sync point. If the action parsed into an empty action,
it is removed instead.
Setting an action for a sync point means to make the sync point
active. When it is hit it will execute this action.
Before parsing, we "get" an action object. This is placed at the
end of the thread's action array unless the requested sync point
has an action already.
Then the parser fills the action object from the request string.
Finally the action is "set" for the sync point. If it was parsed
to be empty, it is removed from the array. If it did belong to a
sync point before, the sync point becomes inactive. If the action
became non-empty and it did not belong to a sync point before (it
was added at the end of the action array), the action array needs
to be sorted by sync point.
If the sync point name is "now", it is executed immediately.
*/
static bool debug_sync_set_action(THD *thd, st_debug_sync_action *action)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
bool is_dsp_now= FALSE;
DBUG_ENTER("debug_sync_set_action");
DBUG_ASSERT(thd);
DBUG_ASSERT(action);
DBUG_ASSERT(ds_control);
action->activation_count= max(action->hit_limit, action->execute);
if (!action->activation_count)
{
debug_sync_remove_action(ds_control, action);
DBUG_PRINT("debug_sync", ("action cleared"));
}
else
{
const char *dsp_name= action->sync_point.c_ptr();
DBUG_EXECUTE("debug_sync", {
/* Functions as DBUG_PRINT args can change keyword and line nr. */
const char *sig_emit= action->signal.c_ptr();
const char *sig_wait= action->wait_for.c_ptr();
DBUG_PRINT("debug_sync",
("sync_point: '%s' activation_count: %lu hit_limit: %lu "
"execute: %lu timeout: %lu signal: '%s' wait_for: '%s'",
dsp_name, action->activation_count,
action->hit_limit, action->execute, action->timeout,
sig_emit, sig_wait));});
/* Check this before sorting the array. action may move. */
is_dsp_now= !my_strcasecmp(system_charset_info, dsp_name, "now");
if (action->need_sort)
{
action->need_sort= FALSE;
/* Sort actions by (name_len, name). */
my_qsort(ds_control->ds_action, ds_control->ds_active,
sizeof(st_debug_sync_action), debug_sync_qsort_cmp);
}
}
DBUG_EXECUTE("debug_sync_list", debug_sync_print_actions(thd););
/* Execute the special sync point 'now' if activated above. */
if (is_dsp_now)
{
DEBUG_SYNC(thd, "now");
/*
If HIT_LIMIT for sync point "now" was 1, the execution of the sync
point decremented it to 0. In this case the following happened:
- an error message was reported with my_error() and
- the statement was killed with thd->killed= THD::KILL_QUERY.
If a statement reports an error, it must not call send_ok().
The calling functions will not call send_ok(), if we return TRUE
from this function.
thd->killed is also set if the wait is interrupted from a
KILL or KILL QUERY statement. In this case, no error is reported
and shall not be reported as a result of SET DEBUG_SYNC.
Hence, we check for the first condition above.
*/
if (thd->is_error())
DBUG_RETURN(TRUE);
}
DBUG_RETURN(FALSE);
}
/**
Extract a token from a string.
@param[out] token_p returns start of token
@param[out] token_length_p returns length of token
@param[in,out] ptr current string pointer, adds '\0' terminators
@return string pointer or NULL
@retval != NULL ptr behind token terminator or at string end
@retval NULL no token found in remainder of string
@note
This function assumes that the string is in system_charset_info,
that this charset is single byte for ASCII NUL ('\0'), that no
character except of ASCII NUL ('\0') contains a byte with value 0,
and that ASCII NUL ('\0') is used as the string terminator.
This function needs to return tokens that are terminated with ASCII
NUL ('\0'). The tokens are used in my_strcasecmp(). Unfortunately
there is no my_strncasecmp().
To return the last token without copying it, we require the input
string to be nul terminated.
@description
This function skips space characters at string begin.
It returns a pointer to the first non-space character in *token_p.
If no non-space character is found before the string terminator
ASCII NUL ('\0'), the function returns NULL. *token_p and
*token_length_p remain unchanged in this case (they are not set).
The function takes a space character or an ASCII NUL ('\0') as a
terminator of the token. The space character could be multi-byte.
It returns the length of the token in bytes, excluding the
terminator, in *token_length_p.
If the terminator of the token is ASCII NUL ('\0'), it returns a
pointer to the terminator (string end).
If the terminator is a space character, it replaces the the first
byte of the terminator character by ASCII NUL ('\0'), skips the (now
corrupted) terminator character, and skips all following space
characters. It returns a pointer to the next non-space character or
to the string terminator ASCII NUL ('\0').
*/
static char *debug_sync_token(char **token_p, uint *token_length_p, char *ptr)
{
DBUG_ASSERT(token_p);
DBUG_ASSERT(token_length_p);
DBUG_ASSERT(ptr);
/* Skip leading space */
while (my_isspace(system_charset_info, *ptr))
ptr+= my_mbcharlen(system_charset_info, (uchar) *ptr);
if (!*ptr)
{
ptr= NULL;
goto end;
}
/* Get token start. */
*token_p= ptr;
/* Find token end. */
while (*ptr && !my_isspace(system_charset_info, *ptr))
ptr+= my_mbcharlen(system_charset_info, (uchar) *ptr);
/* Get token length. */
*token_length_p= ptr - *token_p;
/* If necessary, terminate token. */
if (*ptr)
{
/* Get terminator character length. */
uint mbspacelen= my_mbcharlen(system_charset_info, (uchar) *ptr);
/* Terminate token. */
*ptr= '\0';
/* Skip the terminator. */
ptr+= mbspacelen;
/* Skip trailing space */
while (my_isspace(system_charset_info, *ptr))
ptr+= my_mbcharlen(system_charset_info, (uchar) *ptr);
}
end:
return ptr;
}
/**
Extract a number from a string.
@param[out] number_p returns number
@param[in] actstrptr current pointer in action string
@return string pointer or NULL
@retval != NULL ptr behind token terminator or at string end
@retval NULL no token found or token is not valid number
@note
The same assumptions about charset apply as for debug_sync_token().
@description
This function fetches a token from the string and converts it
into a number.
If there is no token left in the string, or the token is not a valid
decimal number, NULL is returned. The result in *number_p is
undefined in this case.
*/
static char *debug_sync_number(ulong *number_p, char *actstrptr)
{
char *ptr;
char *ept;
char *token;
uint token_length;
DBUG_ASSERT(number_p);
DBUG_ASSERT(actstrptr);
/* Get token from string. */
if (!(ptr= debug_sync_token(&token, &token_length, actstrptr)))
goto end;
*number_p= strtoul(token, &ept, 10);
if (*ept)
ptr= NULL;
end:
return ptr;
}
/**
Evaluate a debug sync action string.
@param[in] thd thread handle
@param[in,out] action_str action string to receive '\0' terminators
@return status
@retval FALSE ok
@retval TRUE error
@description
This is called when the DEBUG_SYNC system variable is set.
Parse action string, build a debug sync action, activate it.
Before parsing, we "get" an action object. This is placed at the
end of the thread's action array unless the requested sync point
has an action already.
Then the parser fills the action object from the request string.
Finally the action is "set" for the sync point. This means that the
sync point becomes active or inactive, depending on the action
values.
@note
The input string needs to be ASCII NUL ('\0') terminated. We split
nul-terminated tokens in it without copy.
@see the function comment of debug_sync_token() for more constraints
for the string.
*/
static bool debug_sync_eval_action(THD *thd, char *action_str)
{
st_debug_sync_action *action= NULL;
const char *errmsg;
char *ptr;
char *token;
uint token_length;
DBUG_ENTER("debug_sync_eval_action");
DBUG_ASSERT(thd);
DBUG_ASSERT(action_str);
/*
Get debug sync point name. Or a special command.
*/
if (!(ptr= debug_sync_token(&token, &token_length, action_str)))
{
errmsg= "Missing synchronization point name";
goto err;
}
/*
If there is a second token, the first one is the sync point name.
*/
if (*ptr)
{
/* Get an action object to collect the requested action parameters. */
action= debug_sync_get_action(thd, token, token_length);
if (!action)
{
/* Error message is sent. */
DBUG_RETURN(TRUE); /* purecov: tested */
}
}
/*
Get kind of action to be taken at sync point.
*/
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
{
/* No action present. Try special commands. Token unchanged. */
/*
Try RESET.
*/
if (!my_strcasecmp(system_charset_info, token, "RESET"))
{
/* It is RESET. Reset all actions and global signal. */
debug_sync_reset(thd);
goto end;
}
/* Token unchanged. It still contains sync point name. */
errmsg= "Missing action after synchronization point name '%.*s'";
goto err;
}
/*
Check for pseudo actions first. Start with actions that work on
an existing action.
*/
DBUG_ASSERT(action);
/*
Try TEST.
*/
if (!my_strcasecmp(system_charset_info, token, "TEST"))
{
/* It is TEST. Nothing must follow it. */
if (*ptr)
{
errmsg= "Nothing must follow action TEST";
goto err;
}
/* Execute sync point. */
debug_sync(thd, action->sync_point.ptr(), action->sync_point.length());
/* Fix statistics. This was not a real hit of the sync point. */
thd->debug_sync_control->dsp_hits--;
goto end;
}
/*
Now check for actions that define a new action.
Initialize action. Do not use bzero(). Strings may have malloced.
*/
action->activation_count= 0;
action->hit_limit= 0;
action->execute= 0;
action->timeout= 0;
action->signal.length(0);
action->wait_for.length(0);
/*
Try CLEAR.
*/
if (!my_strcasecmp(system_charset_info, token, "CLEAR"))
{
/* It is CLEAR. Nothing must follow it. */
if (*ptr)
{
errmsg= "Nothing must follow action CLEAR";
goto err;
}
/* Set (clear/remove) action. */
goto set_action;
}
/*
Now check for real sync point actions.
*/
/*
Try SIGNAL.
*/
if (!my_strcasecmp(system_charset_info, token, "SIGNAL"))
{
/* It is SIGNAL. Signal name must follow. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
{
errmsg= "Missing signal name after action SIGNAL";
goto err;
}
if (action->signal.copy(token, token_length, system_charset_info))
{
/* Error is reported by my_malloc(). */
/* purecov: begin tested */
errmsg= NULL;
goto err;
/* purecov: end */
}
/* Set default for EXECUTE option. */
action->execute= 1;
/* Get next token. If none follows, set action. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
goto set_action;
}
/*
Try WAIT_FOR.
*/
if (!my_strcasecmp(system_charset_info, token, "WAIT_FOR"))
{
/* It is WAIT_FOR. Wait_for signal name must follow. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
{
errmsg= "Missing signal name after action WAIT_FOR";
goto err;
}
if (action->wait_for.copy(token, token_length, system_charset_info))
{
/* Error is reported by my_malloc(). */
/* purecov: begin tested */
errmsg= NULL;
goto err;
/* purecov: end */
}
/* Set default for EXECUTE and TIMEOUT options. */
action->execute= 1;
action->timeout= opt_debug_sync_timeout;
/* Get next token. If none follows, set action. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
goto set_action;
/*
Try TIMEOUT.
*/
if (!my_strcasecmp(system_charset_info, token, "TIMEOUT"))
{
/* It is TIMEOUT. Number must follow. */
if (!(ptr= debug_sync_number(&action->timeout, ptr)))
{
errmsg= "Missing valid number after TIMEOUT";
goto err;
}
/* Get next token. If none follows, set action. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
goto set_action;
}
}
/*
Try EXECUTE.
*/
if (!my_strcasecmp(system_charset_info, token, "EXECUTE"))
{
/*
EXECUTE requires either SIGNAL and/or WAIT_FOR to be present.
In this case action->execute has been preset to 1.
*/
if (!action->execute)
{
errmsg= "Missing action before EXECUTE";
goto err;
}
/* Number must follow. */
if (!(ptr= debug_sync_number(&action->execute, ptr)))
{
errmsg= "Missing valid number after EXECUTE";
goto err;
}
/* Get next token. If none follows, set action. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
goto set_action;
}
/*
Try HIT_LIMIT.
*/
if (!my_strcasecmp(system_charset_info, token, "HIT_LIMIT"))
{
/* Number must follow. */
if (!(ptr= debug_sync_number(&action->hit_limit, ptr)))
{
errmsg= "Missing valid number after HIT_LIMIT";
goto err;
}
/* Get next token. If none follows, set action. */
if (!(ptr= debug_sync_token(&token, &token_length, ptr)))
goto set_action;
}
errmsg= "Illegal or out of order stuff: '%.*s'";
err:
if (errmsg)
{
/*
NOTE: errmsg must either have %.*s or none % at all.
It can be NULL if an error message is already reported
(e.g. by my_malloc()).
*/
set_if_smaller(token_length, 64); /* Limit error message length. */
my_printf_error(ER_PARSE_ERROR, errmsg, MYF(0), token_length, token);
}
if (action)
debug_sync_remove_action(thd->debug_sync_control, action);
DBUG_RETURN(TRUE);
set_action:
DBUG_RETURN(debug_sync_set_action(thd, action));
end:
DBUG_RETURN(FALSE);
}
/**
Check if the system variable 'debug_sync' can be set.
@param[in] thd thread handle
@param[in] var set variable request
@return status
@retval FALSE ok, variable can be set
@retval TRUE error, variable cannot be set
*/
bool sys_var_debug_sync::check(THD *thd, set_var *var)
{
DBUG_ENTER("sys_var_debug_sync::check");
DBUG_ASSERT(thd);
DBUG_ASSERT(var);
/*
Variable can be set for the session only.
This could be changed later. Then we need to have a global array of
actions in addition to the thread local ones. SET GLOBAL would
manage the global array, SET [SESSION] the local array. A sync point
would need to look for a local and a global action. Setting and
executing of global actions need to be protected by a mutex.
The purpose of global actions could be to allow synchronizing with
connectionless threads that cannot execute SET statements.
*/
if (var->type == OPT_GLOBAL)
{
my_error(ER_LOCAL_VARIABLE, MYF(0), name);
DBUG_RETURN(TRUE);
}
/*
Do not check for disabled facility. Test result should not
unnecessarily differ from enabled facility.
*/
/*
Facility requires SUPER privilege. Sync points could be inside
global mutexes (e.g. LOCK_open). Waiting there forever would
stall the whole server.
*/
DBUG_RETURN(check_global_access(thd, SUPER_ACL));
}
/**
Set the system variable 'debug_sync'.
@param[in] thd thread handle
@param[in] var set variable request
@return status
@retval FALSE ok, variable is set
@retval TRUE error, variable could not be set
@note
"Setting" of the system variable 'debug_sync' does not mean to
assign a value to it as usual. Instead a debug sync action is parsed
from the input string and stored apart from the variable value.
@note
For efficiency reasons, the action string parser places '\0'
terminators in the string. So we need to take a copy here.
*/
bool sys_var_debug_sync::update(THD *thd, set_var *var)
{
char *val_str;
String *val_ptr;
String val_buf;
DBUG_ENTER("sys_var_debug_sync::update");
DBUG_ASSERT(thd);
/*
Depending on the value type (string literal, user variable, ...)
val_buf receives a copy of the value or not. But we always need
a copy. So we take a copy, if it is not done by val_str().
If val_str() puts a copy into val_buf, then it returns &val_buf,
otherwise it returns a pointer to the string object that we need
to copy.
*/
val_ptr= var ? var->value->val_str(&val_buf) : &val_buf;
if (val_ptr != &val_buf)
{
val_buf.copy(*val_ptr);
}
val_str= val_buf.c_ptr();
DBUG_PRINT("debug_sync", ("set action: '%s'", val_str));
/*
debug_sync_eval_action() places '\0' in the string, which itself
must be '\0' terminated.
*/
DBUG_RETURN(opt_debug_sync_timeout ?
debug_sync_eval_action(thd, val_str) :
FALSE);
}
/**
Retrieve the value of the system variable 'debug_sync'.
@param[in] thd thread handle
@param[in] type variable type, unused
@param[in] base variable base, unused
@return string
@retval != NULL ok, string pointer
@retval NULL memory allocation error
@note
The value of the system variable 'debug_sync' reflects if
the facility is enabled ("ON") or disabled (default, "OFF").
When "ON", the current signal is added.
*/
uchar *sys_var_debug_sync::value_ptr(THD *thd,
enum_var_type type __attribute__((unused)),
LEX_STRING *base __attribute__((unused)))
{
char *value;
DBUG_ENTER("sys_var_debug_sync::value_ptr");
DBUG_ASSERT(thd);
if (opt_debug_sync_timeout)
{
static char on[]= "ON - current signal: '";
// Ensure exclusive access to debug_sync_global.ds_signal
pthread_mutex_lock(&debug_sync_global.ds_mutex);
size_t lgt= (sizeof(on) /* includes '\0' */ +
debug_sync_global.ds_signal.length() + 1 /* for '\'' */);
char *vend;
char *vptr;
if ((value= (char*) alloc_root(thd->mem_root, lgt)))
{
vend= value + lgt - 1; /* reserve space for '\0'. */
vptr= debug_sync_bmove_len(value, vend, STRING_WITH_LEN(on));
vptr= debug_sync_bmove_len(vptr, vend, debug_sync_global.ds_signal.ptr(),
debug_sync_global.ds_signal.length());
if (vptr < vend)
*(vptr++)= '\'';
*vptr= '\0'; /* We have one byte reserved for the worst case. */
}
pthread_mutex_unlock(&debug_sync_global.ds_mutex);
}
else
{
/* purecov: begin tested */
value= strmake_root(thd->mem_root, STRING_WITH_LEN("OFF"));
/* purecov: end */
}
DBUG_RETURN((uchar*) value);
}
/**
Execute requested action at a synchronization point.
@param[in] thd thread handle
@param[in] action action to be executed
@note
This is to be called only if activation count > 0.
*/
static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
{
IF_DBUG(const char *dsp_name= action->sync_point.c_ptr());
IF_DBUG(const char *sig_emit= action->signal.c_ptr());
IF_DBUG(const char *sig_wait= action->wait_for.c_ptr());
DBUG_ENTER("debug_sync_execute");
DBUG_ASSERT(thd);
DBUG_ASSERT(action);
DBUG_PRINT("debug_sync",
("sync_point: '%s' activation_count: %lu hit_limit: %lu "
"execute: %lu timeout: %lu signal: '%s' wait_for: '%s'",
dsp_name, action->activation_count, action->hit_limit,
action->execute, action->timeout, sig_emit, sig_wait));
DBUG_ASSERT(action->activation_count);
action->activation_count--;
if (action->execute)
{
const char *old_proc_info;
action->execute--;
/*
If we will be going to wait, set proc_info for the PROCESSLIST table.
Do this before emitting the signal, so other threads can see it
if they awake before we enter_cond() below.
*/
if (action->wait_for.length())
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
strxnmov(ds_control->ds_proc_info, sizeof(ds_control->ds_proc_info)-1,
"debug sync point: ", action->sync_point.c_ptr(), NullS);
old_proc_info= thd->proc_info;
thd_proc_info(thd, ds_control->ds_proc_info);
}
/*
Take mutex to ensure that only one thread access
debug_sync_global.ds_signal at a time. Need to take mutex for
read access too, to create a memory barrier in order to avoid that
threads just reads an old cached version of the signal.
*/
pthread_mutex_lock(&debug_sync_global.ds_mutex);
if (action->signal.length())
{
/* Copy the signal to the global variable. */
if (debug_sync_global.ds_signal.copy(action->signal))
{
/*
Error is reported by my_malloc().
We must disable the facility. We have no way to return an error.
*/
debug_sync_emergency_disable(); /* purecov: tested */
}
/* Wake threads waiting in a sync point. */
pthread_cond_broadcast(&debug_sync_global.ds_cond);
DBUG_PRINT("debug_sync_exec", ("signal '%s' at: '%s'",
sig_emit, dsp_name));
} /* end if (action->signal.length()) */
if (action->wait_for.length())
{
pthread_mutex_t *old_mutex;
pthread_cond_t *old_cond;
int error= 0;
struct timespec abstime;
/*
We don't use enter_cond()/exit_cond(). They do not save old
mutex and cond. This would prohibit the use of DEBUG_SYNC
between other places of enter_cond() and exit_cond().
*/
old_mutex= thd->mysys_var->current_mutex;
old_cond= thd->mysys_var->current_cond;
thd->mysys_var->current_mutex= &debug_sync_global.ds_mutex;
thd->mysys_var->current_cond= &debug_sync_global.ds_cond;
set_timespec(abstime, action->timeout);
DBUG_EXECUTE("debug_sync_exec", {
/* Functions as DBUG_PRINT args can change keyword and line nr. */
const char *sig_glob= debug_sync_global.ds_signal.c_ptr();
DBUG_PRINT("debug_sync_exec",
("wait for '%s' at: '%s' curr: '%s'",
sig_wait, dsp_name, sig_glob));});
/*
Wait until global signal string matches the wait_for string.
Interrupt when thread or query is killed or facility disabled.
The facility can become disabled when some thread cannot get
the required dynamic memory allocated.
*/
while (stringcmp(&debug_sync_global.ds_signal, &action->wait_for) &&
!thd->killed && opt_debug_sync_timeout)
{
error= pthread_cond_timedwait(&debug_sync_global.ds_cond,
&debug_sync_global.ds_mutex,
&abstime);
DBUG_EXECUTE("debug_sync", {
/* Functions as DBUG_PRINT args can change keyword and line nr. */
const char *sig_glob= debug_sync_global.ds_signal.c_ptr();
DBUG_PRINT("debug_sync",
("awoke from %s global: %s error: %d",
sig_wait, sig_glob, error));});
if (error == ETIMEDOUT || error == ETIME)
{
push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
ER_DEBUG_SYNC_TIMEOUT, ER(ER_DEBUG_SYNC_TIMEOUT));
break;
}
error= 0;
}
DBUG_EXECUTE("debug_sync_exec",
if (thd->killed)
DBUG_PRINT("debug_sync_exec",
("killed %d from '%s' at: '%s'",
thd->killed, sig_wait, dsp_name));
else
DBUG_PRINT("debug_sync_exec",
("%s from '%s' at: '%s'",
error ? "timeout" : "resume",
sig_wait, dsp_name)););
/*
We don't use enter_cond()/exit_cond(). They do not save old
mutex and cond. This would prohibit the use of DEBUG_SYNC
between other places of enter_cond() and exit_cond(). The
protected mutex must always unlocked _before_ mysys_var->mutex
is locked. (See comment in THD::exit_cond().)
*/
pthread_mutex_unlock(&debug_sync_global.ds_mutex);
pthread_mutex_lock(&thd->mysys_var->mutex);
thd->mysys_var->current_mutex= old_mutex;
thd->mysys_var->current_cond= old_cond;
thd_proc_info(thd, old_proc_info);
pthread_mutex_unlock(&thd->mysys_var->mutex);
}
else
{
/* In case we don't wait, we just release the mutex. */
pthread_mutex_unlock(&debug_sync_global.ds_mutex);
} /* end if (action->wait_for.length()) */
} /* end if (action->execute) */
/* hit_limit is zero for infinite. Don't decrement unconditionally. */
if (action->hit_limit)
{
if (!--action->hit_limit)
{
thd->killed= THD::KILL_QUERY;
my_error(ER_DEBUG_SYNC_HIT_LIMIT, MYF(0));
}
DBUG_PRINT("debug_sync_exec", ("hit_limit: %lu at: '%s'",
action->hit_limit, dsp_name));
}
DBUG_VOID_RETURN;
}
/**
Execute requested action at a synchronization point.
@param[in] thd thread handle
@param[in] sync_point_name name of synchronization point
@param[in] name_len length of sync point name
*/
void debug_sync(THD *thd, const char *sync_point_name, size_t name_len)
{
st_debug_sync_control *ds_control= thd->debug_sync_control;
st_debug_sync_action *action;
DBUG_ENTER("debug_sync");
DBUG_ASSERT(thd);
DBUG_ASSERT(sync_point_name);
DBUG_ASSERT(name_len);
DBUG_ASSERT(ds_control);
DBUG_PRINT("debug_sync_point", ("hit: '%s'", sync_point_name));
/* Statistics. */
ds_control->dsp_hits++;
if (ds_control->ds_active &&
(action= debug_sync_find(ds_control->ds_action, ds_control->ds_active,
sync_point_name, name_len)) &&
action->activation_count)
{
/* Sync point is active (action exists). */
debug_sync_execute(thd, action);
/* Statistics. */
ds_control->dsp_executed++;
/* If action became inactive, remove it to shrink the search array. */
if (!action->activation_count)
debug_sync_remove_action(ds_control, action);
}
DBUG_VOID_RETURN;
}
#endif /* defined(ENABLED_DEBUG_SYNC) */
sql/debug_sync.h 0 → 100644
View file @ 21586dfb
#ifndef DEBUG_SYNC_INCLUDED
#define DEBUG_SYNC_INCLUDED
/* Copyright (C) 2008 Sun Microsystems, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
@file
Declarations for the Debug Sync Facility. See debug_sync.cc for details.
*/
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
#include <my_global.h>
class THD;
#if defined(ENABLED_DEBUG_SYNC)
/* Macro to be put in the code at synchronization points. */
#define DEBUG_SYNC(_thd_, _sync_point_name_) \
do { if (unlikely(opt_debug_sync_timeout)) \
debug_sync(_thd_, STRING_WITH_LEN(_sync_point_name_)); \
} while (0)
/* Command line option --debug-sync-timeout. See mysqld.cc. */
extern uint opt_debug_sync_timeout;
/* Default WAIT_FOR timeout if command line option is given without argument. */
#define DEBUG_SYNC_DEFAULT_WAIT_TIMEOUT 300
/* Debug Sync prototypes. See debug_sync.cc. */
extern int debug_sync_init(void);
extern void debug_sync_end(void);
extern void debug_sync_init_thread(THD *thd);
extern void debug_sync_end_thread(THD *thd);
extern void debug_sync(THD *thd, const char *sync_point_name, size_t name_len);
#else /* defined(ENABLED_DEBUG_SYNC) */
#define DEBUG_SYNC(_thd_, _sync_point_name_) /* disabled DEBUG_SYNC */
#endif /* defined(ENABLED_DEBUG_SYNC) */
#endif /* DEBUG_SYNC_INCLUDED */
sql/mysqld.cc
View file @ 21586dfb
......@@ -26,6 +26,7 @@
#include "mysqld_suffix.h"
#include "mysys_err.h"
#include "events.h"
#include "debug_sync.h"
#include "../storage/myisam/ha_myisam.h"
......@@ -486,6 +487,9 @@ my_bool lower_case_file_system= 0;
my_bool opt_large_pages= 0;
my_bool opt_myisam_use_mmap= 0;
uint opt_large_page_size= 0;
#if defined(ENABLED_DEBUG_SYNC)
uint opt_debug_sync_timeout= 0;
#endif /* defined(ENABLED_DEBUG_SYNC) */
my_bool opt_old_style_user_limits= 0, trust_function_creators= 0;
/*
True if there is at least one per-hour limit for some user, so we should
......@@ -1333,6 +1337,10 @@ void clean_up(bool print_message)
#ifdef USE_REGEX
my_regex_end();
#endif
#if defined(ENABLED_DEBUG_SYNC)
/* End the debug sync facility. See debug_sync.cc. */
debug_sync_end();
#endif /* defined(ENABLED_DEBUG_SYNC) */
#if !defined(EMBEDDED_LIBRARY)
if (!opt_bootstrap)
......@@ -3464,6 +3472,12 @@ static int init_common_variables(const char *conf_file_name, int argc,
sys_var_slow_log_path.value= my_strdup(s, MYF(0));
sys_var_slow_log_path.value_length= strlen(s);
#if defined(ENABLED_DEBUG_SYNC)
/* Initialize the debug sync facility. See debug_sync.cc. */
if (debug_sync_init())
return 1; /* purecov: tested */
#endif /* defined(ENABLED_DEBUG_SYNC) */
#if (ENABLE_TEMP_POOL)
if (use_temp_pool && bitmap_init(&temp_pool,0,1024,1))
return 1;
......@@ -4858,7 +4872,7 @@ void create_thread_to_handle_connection(THD *thd)
handle_one_connection,
(void*) thd)))
{
/* purify: begin inspected */
/* purecov: begin inspected */
DBUG_PRINT("error",
("Can't create thread to handle request (error %d)",
error));
......@@ -5671,6 +5685,9 @@ enum options_mysqld
OPT_SECURE_FILE_PRIV,
OPT_MIN_EXAMINED_ROW_LIMIT,
OPT_LOG_SLOW_SLAVE_STATEMENTS,
#if defined(ENABLED_DEBUG_SYNC)
OPT_DEBUG_SYNC_TIMEOUT,
#endif /* defined(ENABLED_DEBUG_SYNC) */
OPT_OLD_MODE,
OPT_SLAVE_EXEC_MODE,
OPT_GENERAL_LOG_FILE,
......@@ -6442,6 +6459,14 @@ log and this option does nothing anymore.",
"Decision to use in heuristic recover process. Possible values are COMMIT or ROLLBACK.",
(uchar**) &opt_tc_heuristic_recover, (uchar**) &opt_tc_heuristic_recover,
0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
#if defined(ENABLED_DEBUG_SYNC)
{"debug-sync-timeout", OPT_DEBUG_SYNC_TIMEOUT,
"Enable the debug sync facility "
"and optionally specify a default wait timeout in seconds. "
"A zero value keeps the facility disabled.",
(uchar**) &opt_debug_sync_timeout, 0,
0, GET_UINT, OPT_ARG, 0, 0, UINT_MAX, 0, 0, 0},
#endif /* defined(ENABLED_DEBUG_SYNC) */
{"temp-pool", OPT_TEMP_POOL,
#if (ENABLE_TEMP_POOL)
"Using this option will cause most temporary files created to use a small set of names, rather than a unique name for each new file.",
......@@ -7626,6 +7651,9 @@ static int mysql_init_variables(void)
bzero((uchar*) &mysql_tmpdir_list, sizeof(mysql_tmpdir_list));
bzero((char *) &global_status_var, sizeof(global_status_var));
opt_large_pages= 0;
#if defined(ENABLED_DEBUG_SYNC)
opt_debug_sync_timeout= 0;
#endif /* defined(ENABLED_DEBUG_SYNC) */
key_map_full.set_all();
/* Character sets */
......@@ -8360,6 +8388,22 @@ mysqld_get_one_option(int optid,
lower_case_table_names= argument ? atoi(argument) : 1;
lower_case_table_names_used= 1;
break;
#if defined(ENABLED_DEBUG_SYNC)
case OPT_DEBUG_SYNC_TIMEOUT:
/*
Debug Sync Facility. See debug_sync.cc.
Default timeout for WAIT_FOR action.
Default value is zero (facility disabled).
If option is given without an argument, supply a non-zero value.
*/
if (!argument)
{
/* purecov: begin tested */
opt_debug_sync_timeout= DEBUG_SYNC_DEFAULT_WAIT_TIMEOUT;
/* purecov: end */
}
break;
#endif /* defined(ENABLED_DEBUG_SYNC) */
}
return 0;
}
......
sql/set_var.cc
View file @ 21586dfb
......@@ -625,6 +625,12 @@ static sys_var_long_ptr sys_table_cache_size(&vars, "table_open_cache",
&table_cache_size);
static sys_var_long_ptr sys_table_lock_wait_timeout(&vars, "table_lock_wait_timeout",
&table_lock_wait_timeout);
#if defined(ENABLED_DEBUG_SYNC)
/* Debug Sync Facility. Implemented in debug_sync.cc. */
static sys_var_debug_sync sys_debug_sync(&vars, "debug_sync");
#endif /* defined(ENABLED_DEBUG_SYNC) */
static sys_var_long_ptr sys_thread_cache_size(&vars, "thread_cache_size",
&thread_cache_size);
#if HAVE_POOL_OF_THREADS == 1
......
sql/set_var.h
View file @ 21586dfb
......@@ -637,6 +637,21 @@ public:
};
#endif /* DBUG_OFF */
#if defined(ENABLED_DEBUG_SYNC)
/* Debug Sync Facility. Implemented in debug_sync.cc. */
class sys_var_debug_sync :public sys_var_thd
{
public:
sys_var_debug_sync(sys_var_chain *chain, const char *name_arg)
:sys_var_thd(name_arg)
{ chain_sys_var(chain); }
bool check(THD *thd, set_var *var);
bool update(THD *thd, set_var *var);
SHOW_TYPE show_type() { return SHOW_CHAR; }
bool check_update_type(Item_result type) { return type != STRING_RESULT; }
uchar *value_ptr(THD *thd, enum_var_type type, LEX_STRING *base);
};
#endif /* defined(ENABLED_DEBUG_SYNC) */
/* some variables that require special handling */
......
sql/share/errmsg.txt
View file @ 21586dfb
......@@ -6206,3 +6206,10 @@ ER_TOO_MANY_CONCURRENT_TRXS
WARN_NON_ASCII_SEPARATOR_NOT_IMPLEMENTED
eng "Non-ASCII separator arguments are not fully supported"
ER_DEBUG_SYNC_TIMEOUT
eng "debug sync point wait timed out"
ger "Debug Sync Point Wartezeit berschritten"
ER_DEBUG_SYNC_HIT_LIMIT
eng "debug sync point hit limit reached"
ger "Debug Sync Point Hit Limit erreicht"
sql/sql_base.cc
View file @ 21586dfb
......@@ -17,6 +17,7 @@
/* Basic functions needed by many modules */
#include "mysql_priv.h"
#include "debug_sync.h"
#include "sql_select.h"
#include "sp_head.h"
#include "sp.h"
......@@ -950,6 +951,7 @@ bool close_cached_tables(THD *thd, TABLE_LIST *tables, bool have_lock,
close_old_data_files(thd,thd->open_tables,1,1);
mysql_ha_flush(thd);
DEBUG_SYNC(thd, "after_flush_unlock");
bool found=1;
/* Wait until all threads has closed all the tables we had locked */
......@@ -5289,6 +5291,8 @@ int lock_tables(THD *thd, TABLE_LIST *tables, uint count, bool *need_reopen)
}
}
DEBUG_SYNC(thd, "before_lock_tables_takes_lock");
if (! (thd->lock= mysql_lock_tables(thd, start, (uint) (ptr - start),
lock_flag, need_reopen)))
{
......
sql/sql_class.cc
View file @ 21586dfb
......@@ -42,6 +42,7 @@
#include "sp_rcontext.h"
#include "sp_cache.h"
#include "debug_sync.h"
/*
The following is used to initialise Table_ident with a internal
......@@ -584,6 +585,9 @@ THD::THD()
derived_tables_processing(FALSE),
spcont(NULL),
m_parser_state(NULL)
#if defined(ENABLED_DEBUG_SYNC)
, debug_sync_control(0)
#endif /* defined(ENABLED_DEBUG_SYNC) */
{
ulong tmp;
......@@ -832,6 +836,11 @@ void THD::init(void)
reset_current_stmt_binlog_row_based();
bzero((char *) &status_var, sizeof(status_var));
sql_log_bin_toplevel= options & OPTION_BIN_LOG;
#if defined(ENABLED_DEBUG_SYNC)
/* Initialize the Debug Sync Facility. See debug_sync.cc. */
debug_sync_init_thread(this);
#endif /* defined(ENABLED_DEBUG_SYNC) */
}
......@@ -911,6 +920,12 @@ void THD::cleanup(void)
lock=locked_tables; locked_tables=0;
close_thread_tables(this);
}
#if defined(ENABLED_DEBUG_SYNC)
/* End the Debug Sync Facility. See debug_sync.cc. */
debug_sync_end_thread(this);
#endif /* defined(ENABLED_DEBUG_SYNC) */
mysql_ha_cleanup(this);
delete_dynamic(&user_var_events);
hash_free(&user_vars);
......
sql/sql_class.h
View file @ 21586dfb
......@@ -1896,6 +1896,11 @@ public:
partition_info *work_part_info;
#endif
#if defined(ENABLED_DEBUG_SYNC)
/* Debug Sync facility. See debug_sync.cc. */
struct st_debug_sync_control *debug_sync_control;
#endif /* defined(ENABLED_DEBUG_SYNC) */
THD();
~THD();
......
storage/myisam/myisamchk.c
View file @ 21586dfb
......@@ -837,7 +837,7 @@ static int myisamchk(MI_CHECK *param, char * filename)
mi_check_print_error(param,"'%s' is marked as crashed after last repair",filename);
break;
case HA_ERR_OLD_FILE:
mi_check_print_error(param,"'%s' is a old type of MyISAM-table", filename);
mi_check_print_error(param,"'%s' is an old type of MyISAM-table", filename);
break;
case HA_ERR_END_OF_FILE:
mi_check_print_error(param,"Couldn't read complete header from '%s'", filename);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7