DTrace support: function calls, GC activity, line execution

Tested on macOS 10.11 dtrace, Ubuntu 16.04 SystemTap, and libbcc.

Largely based by an initial patch by Jesús Cea Avión, with some
influence from Dave Malcolm's SystemTap patch and Nikhil Benesch's
unification patch.

Things deliberately left out for simplicity:
- ustack helpers, I have no way of testing them at this point since
they are Solaris-specific
- PyFrameObject * in function__entry/function__return, this is
SystemTap-specific
- SPARC support
- dynamic tracing
- sys module dtrace facility introspection

All of those might be added later.

.hgignore

@@ -56,6 +56,7 @@ libpython*.dylib
 *.profclang?
 *.profraw
 *.dyn
+Include/pydtrace_probes.h
 Lib/distutils/command/*.pdb
 Lib/lib2to3/*.pickle
 Lib/test/data/*

Doc/howto/index.rst

@@ -28,4 +28,5 @@ Currently, the HOWTOs are:
    argparse.rst
    ipaddress.rst
    clinic.rst
+   instrumentation.rst
 

Doc/whatsnew/3.6.rst

@@ -407,6 +407,31 @@ Example of fatal error on buffer overflow using
 (Contributed by Victor Stinner in :issue:`26516` and :issue:`26564`.)
 
 
+DTrace and SystemTap probing support
+------------------------------------
+
+Python can now be built ``--with-dtrace`` which enables static markers
+for the following events in the interpreter:
+
+* function call/return
+
+* garbage collection started/finished
+
+* line of code executed.
+
+This can be used to instrument running interpreters in production,
+without the need to recompile specific debug builds or providing
+application-specific profiling/debugging code.
+
+More details in:ref:`instrumentation`.
+
+The current implementation is tested on Linux and macOS.  Additional
+markers may be added in the future.
+
+(Contributed by Łukasz Langa in :issue:`21590`, based on patches by
+Jesús Cea Avión, David Malcolm, and Nikhil Benesch.)
+
+
 .. _whatsnew-deforder:
 
 PEP 520: Preserving Class Attribute Definition Order

Include/pydtrace.d

+/* Python DTrace provider */
+
+provider python {
+    probe function__entry(const char *, const char *, int);
+    probe function__return(const char *, const char *, int);
+    probe instance__new__start(const char *, const char *);
+    probe instance__new__done(const char *, const char *);
+    probe instance__delete__start(const char *, const char *);
+    probe instance__delete__done(const char *, const char *);
+    probe line(const char *, const char *, int);
+    probe gc__start(int);
+    probe gc__done(long);
+};
+
+#pragma D attributes Evolving/Evolving/Common provider python provider
+#pragma D attributes Evolving/Evolving/Common provider python module
+#pragma D attributes Evolving/Evolving/Common provider python function
+#pragma D attributes Evolving/Evolving/Common provider python name
+#pragma D attributes Evolving/Evolving/Common provider python args

Include/pydtrace.h

+/* Static DTrace probes interface */
+
+#ifndef Py_DTRACE_H
+#define Py_DTRACE_H
+
+#ifdef WITH_DTRACE
+
+#include "pydtrace_probes.h"
+
+/* pydtrace_probes.h, on systems with DTrace, is auto-generated to include
+   `PyDTrace_{PROBE}` and `PyDTrace_{PROBE}_ENABLED()` macros for every probe
+   defined in pydtrace_provider.d.
+
+   Calling these functions must be guarded by a `PyDTrace_{PROBE}_ENABLED()`
+   check to minimize performance impact when probing is off. For example:
+
+       if (PyDTrace_FUNCTION_ENTRY_ENABLED())
+           PyDTrace_FUNCTION_ENTRY(f);
+*/
+
+#else
+
+/* Without DTrace, compile to nothing. */
+
+#define PyDTrace_LINE(arg0, arg1, arg2, arg3) do ; while (0)
+#define PyDTrace_FUNCTION_ENTRY(arg0, arg1, arg2)  do ; while (0)
+#define PyDTrace_FUNCTION_RETURN(arg0, arg1, arg2) do ; while (0)
+#define PyDTrace_GC_START(arg0)               do ; while (0)
+#define PyDTrace_GC_DONE(arg0)                do ; while (0)
+#define PyDTrace_INSTANCE_NEW_START(arg0)     do ; while (0)
+#define PyDTrace_INSTANCE_NEW_DONE(arg0)      do ; while (0)
+#define PyDTrace_INSTANCE_DELETE_START(arg0)  do ; while (0)
+#define PyDTrace_INSTANCE_DELETE_DONE(arg0)   do ; while (0)
+
+#define PyDTrace_LINE_ENABLED()                  (0)
+#define PyDTrace_FUNCTION_ENTRY_ENABLED()        (0)
+#define PyDTrace_FUNCTION_RETURN_ENABLED()       (0)
+#define PyDTrace_GC_START_ENABLED()              (0)
+#define PyDTrace_GC_DONE_ENABLED()               (0)
+#define PyDTrace_INSTANCE_NEW_START_ENABLED()    (0)
+#define PyDTrace_INSTANCE_NEW_DONE_ENABLED()     (0)
+#define PyDTrace_INSTANCE_DELETE_START_ENABLED() (0)
+#define PyDTrace_INSTANCE_DELETE_DONE_ENABLED()  (0)
+
+#endif /* !WITH_DTRACE */
+
+#endif /* !Py_DTRACE_H */

Lib/test/dtracedata/assert_usable.d

+BEGIN
+{
+    printf("probe: success\n");
+    exit(0);
+}

Lib/test/dtracedata/assert_usable.stp

+probe begin
+{
+  println("probe: success")
+  exit ()
+}

Lib/test/dtracedata/call_stack.d

+self int indent;
+
+python$target:::function-entry
+/copyinstr(arg1) == "start"/
+{
+    self->trace = 1;
+}
+
+python$target:::function-entry
+/self->trace/
+{
+    printf("%d\t%*s:", timestamp, 15, probename);
+    printf("%*s", self->indent, ""); 
+    printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2);
+    self->indent++;
+}
+
+python$target:::function-return
+/self->trace/
+{
+    self->indent--;
+    printf("%d\t%*s:", timestamp, 15, probename);
+    printf("%*s", self->indent, ""); 
+    printf("%s:%s:%d\n", basename(copyinstr(arg0)), copyinstr(arg1), arg2);
+}
+
+python$target:::function-return
+/copyinstr(arg1) == "start"/
+{
+    self->trace = 0;
+}

Lib/test/dtracedata/call_stack.d.expected

+ function-entry:call_stack.py:start:23
+ function-entry: call_stack.py:function_1:1
+ function-entry:  call_stack.py:function_3:9
+function-return:  call_stack.py:function_3:10
+function-return: call_stack.py:function_1:2
+ function-entry: call_stack.py:function_2:5
+ function-entry:  call_stack.py:function_1:1
+ function-entry:   call_stack.py:function_3:9
+function-return:   call_stack.py:function_3:10
+function-return:  call_stack.py:function_1:2
+function-return: call_stack.py:function_2:6
+ function-entry: call_stack.py:function_3:9
+function-return: call_stack.py:function_3:10
+ function-entry: call_stack.py:function_4:13
+function-return: call_stack.py:function_4:14
+ function-entry: call_stack.py:function_5:18
+function-return: call_stack.py:function_5:21
+function-return:call_stack.py:start:28

Lib/test/dtracedata/call_stack.py

+def function_1():
+    function_3(1, 2)
+
+# Check stacktrace
+def function_2():
+    function_1()
+
+# CALL_FUNCTION_VAR
+def function_3(dummy, dummy2):
+    pass
+
+# CALL_FUNCTION_KW
+def function_4(**dummy):
+    return 1
+    return 2  # unreachable
+
+# CALL_FUNCTION_VAR_KW
+def function_5(dummy, dummy2, **dummy3):
+    if False:
+        return 7
+    return 8
+
+def start():
+    function_1()
+    function_2()
+    function_3(1, 2)
+    function_4(test=42)
+    function_5(*(1, 2), **{"test": 42})
+
+start()

Lib/test/dtracedata/call_stack.stp

+global tracing
+
+function basename:string(path:string)
+{
+    last_token = token = tokenize(path, "/");
+    while (token != "") {
+        last_token = token;
+        token = tokenize("", "/");
+    }
+    return last_token;
+}
+
+probe process.mark("function__entry")
+{
+    funcname = user_string($arg2);
+
+    if (funcname == "start") {
+        tracing = 1;
+    }
+}
+
+probe process.mark("function__entry"), process.mark("function__return")
+{
+    filename = user_string($arg1);
+    funcname = user_string($arg2);
+    lineno = $arg3;
+
+    if (tracing) {
+        printf("%d\t%s:%s:%s:%d\n", gettimeofday_us(), $$name,
+               basename(filename), funcname, lineno);
+    }
+}
+
+probe process.mark("function__return")
+{
+    funcname = user_string($arg2);
+
+    if (funcname == "start") {
+        tracing = 0;
+    }
+}

Lib/test/dtracedata/call_stack.stp.expected

+function__entry:call_stack.py:start:23
+function__entry:call_stack.py:function_1:1
+function__return:call_stack.py:function_1:2
+function__entry:call_stack.py:function_2:5
+function__entry:call_stack.py:function_1:1
+function__return:call_stack.py:function_1:2
+function__return:call_stack.py:function_2:6
+function__entry:call_stack.py:function_3:9
+function__return:call_stack.py:function_3:10
+function__entry:call_stack.py:function_4:13
+function__return:call_stack.py:function_4:14
+function__entry:call_stack.py:function_5:18
+function__return:call_stack.py:function_5:21
+function__return:call_stack.py:start:28

Lib/test/dtracedata/gc.d

+python$target:::function-entry
+/copyinstr(arg1) == "start"/
+{
+    self->trace = 1;
+}
+
+python$target:::gc-start,
+python$target:::gc-done
+/self->trace/
+{
+    printf("%d\t%s:%ld\n", timestamp, probename, arg0);
+}
+
+python$target:::function-return
+/copyinstr(arg1) == "start"/
+{
+    self->trace = 0;
+}

Lib/test/dtracedata/gc.d.expected

+gc-start:0
+gc-done:0
+gc-start:1
+gc-done:0
+gc-start:2
+gc-done:0
+gc-start:2
+gc-done:1

Lib/test/dtracedata/gc.py

+import gc
+
+def start():
+    gc.collect(0)
+    gc.collect(1)
+    gc.collect(2)
+    l = []
+    l.append(l)
+    del l
+    gc.collect(2)
+
+gc.collect()
+start()

Lib/test/dtracedata/gc.stp

+global tracing
+
+probe process.mark("function__entry")
+{
+    funcname = user_string($arg2);
+
+    if (funcname == "start") {
+        tracing = 1;
+    }
+}
+
+probe process.mark("gc__start"), process.mark("gc__done")
+{
+    if (tracing) {
+        printf("%d\t%s:%ld\n", gettimeofday_us(), $$name, $arg1);
+    }
+}
+
+probe process.mark("function__return")
+{
+    funcname = user_string($arg2);
+
+    if (funcname == "start") {
+        tracing = 0;
+    }
+}

Lib/test/dtracedata/gc.stp.expected

+gc__start:0
+gc__done:0
+gc__start:1
+gc__done:0
+gc__start:2
+gc__done:0
+gc__start:2
+gc__done:1

Lib/test/dtracedata/instance.py

+import gc
+
+class old_style_class():
+    pass
+class new_style_class(object):
+    pass
+
+a = old_style_class()
+del a
+gc.collect()
+b = new_style_class()
+del b
+gc.collect()
+
+a = old_style_class()
+del old_style_class
+gc.collect()
+b = new_style_class()
+del new_style_class
+gc.collect()
+del a
+gc.collect()
+del b
+gc.collect()

Lib/test/dtracedata/line.d

+python$target:::line
+/(copyinstr(arg1)=="test_line")/
+{
+    printf("%d\t%s:%s:%s:%d\n", timestamp,
+        probename, basename(copyinstr(arg0)),
+        copyinstr(arg1), arg2);
+}

Lib/test/dtracedata/line.d.expected

+line:line.py:test_line:2
+line:line.py:test_line:3
+line:line.py:test_line:4
+line:line.py:test_line:5
+line:line.py:test_line:6
+line:line.py:test_line:7
+line:line.py:test_line:8
+line:line.py:test_line:9
+line:line.py:test_line:10
+line:line.py:test_line:11
+line:line.py:test_line:4
+line:line.py:test_line:5
+line:line.py:test_line:6
+line:line.py:test_line:7
+line:line.py:test_line:8
+line:line.py:test_line:10
+line:line.py:test_line:11
+line:line.py:test_line:4
+line:line.py:test_line:12
+line:line.py:test_line:13

Lib/test/dtracedata/line.py

+def test_line():
+    a = 1
+    print('# Preamble', a)
+    for i in range(2):
+        a = i
+        b = i+2
+        c = i+3
+        if c < 4:
+            a = c
+        d = a + b +c
+        print('#', a, b, c, d)
+    a = 1
+    print('# Epilogue', a)
+
+
+if __name__ == '__main__':
+    test_line()

Lib/test/test_dtrace.py

+import dis
+import os.path
+import re
+import subprocess
+import sys
+import types
+import unittest
+
+from test.support import findfile, run_unittest
+
+
+def abspath(filename):
+    return os.path.abspath(findfile(filename, subdir="dtracedata"))
+
+
+def normalize_trace_output(output):
+    """Normalize DTrace output for comparison.
+
+    DTrace keeps a per-CPU buffer, and when showing the fired probes, buffers
+    are concatenated. So if the operating system moves our thread around, the
+    straight result can be "non-causal". So we add timestamps to the probe
+    firing, sort by that field, then strip it from the output"""
+
+    # When compiling with '--with-pydebug', strip '[# refs]' debug output.
+    output = re.sub(r"\[[0-9]+ refs\]", "", output)
+    try:
+        result = [
+            row.split("\t")
+            for row in output.splitlines()
+            if row and not row.startswith('#')
+        ]
+        result.sort(key=lambda row: int(row[0]))
+        result = [row[1] for row in result]
+        return "\n".join(result)
+    except (IndexError, ValueError):
+        raise AssertionError(
+            "tracer produced unparseable output:\n{}".format(output)
+        )
+
+
+class TraceBackend:
+    EXTENSION = None
+    COMMAND = None
+    COMMAND_ARGS = []
+
+    def run_case(self, name, optimize_python=None):
+        actual_output = normalize_trace_output(self.trace_python(
+            script_file=abspath(name + self.EXTENSION),
+            python_file=abspath(name + ".py"),
+            optimize_python=optimize_python))
+
+        with open(abspath(name + self.EXTENSION + ".expected")) as f:
+            expected_output = f.read().rstrip()
+
+        return (expected_output, actual_output)
+
+    def generate_trace_command(self, script_file, subcommand=None):
+        command = self.COMMAND + [script_file]
+        if subcommand:
+            command += ["-c", subcommand]
+        return command
+
+    def trace(self, script_file, subcommand=None):
+        command = self.generate_trace_command(script_file, subcommand)
+        stdout, _ = subprocess.Popen(command,
+                                     stdout=subprocess.PIPE,
+                                     stderr=subprocess.STDOUT,
+                                     universal_newlines=True).communicate()
+        return stdout
+
+    def trace_python(self, script_file, python_file, optimize_python=None):
+        python_flags = []
+        if optimize_python:
+            python_flags.extend(["-O"] * optimize_python)
+        subcommand = " ".join([sys.executable] + python_flags + [python_file])
+        return self.trace(script_file, subcommand)
+
+    def assert_usable(self):
+        try:
+            output = self.trace(abspath("assert_usable" + self.EXTENSION))
+            output = output.strip()
+        except FileNotFoundError as fnfe:
+            output = str(fnfe)
+        if output != "probe: success":
+            raise unittest.SkipTest(
+                "{}(1) failed: {}".format(self.COMMAND[0], output)
+            )
+
+
+class DTraceBackend(TraceBackend):
+    EXTENSION = ".d"
+    COMMAND = ["dtrace", "-q", "-s"]
+
+
+class SystemTapBackend(TraceBackend):
+    EXTENSION = ".stp"
+    COMMAND = ["stap", "-g"]
+
+
+class TraceTests(unittest.TestCase):
+    # unittest.TestCase options
+    maxDiff = None
+
+    # TraceTests options
+    backend = None
+    optimize_python = 0
+
+    @classmethod
+    def setUpClass(self):
+        self.backend.assert_usable()
+
+    def run_case(self, name):
+        actual_output, expected_output = self.backend.run_case(
+            name, optimize_python=self.optimize_python)
+        self.assertEqual(actual_output, expected_output)
+
+    def test_function_entry_return(self):
+        self.run_case("call_stack")
+
+    def test_verify_call_opcodes(self):
+        """Ensure our call stack test hits all function call opcodes"""
+
+        opcodes = set(["CALL_FUNCTION", "CALL_FUNCTION_EX", "CALL_FUNCTION_KW"])
+
+        with open(abspath("call_stack.py")) as f:
+            code_string = f.read()
+
+        def get_function_instructions(funcname):
+            # Recompile with appropriate optimization setting
+            code = compile(source=code_string,
+                           filename="<string>",
+                           mode="exec",
+                           optimize=self.optimize_python)
+
+            for c in code.co_consts:
+                if isinstance(c, types.CodeType) and c.co_name == funcname:
+                    return dis.get_instructions(c)
+            return []
+
+        for instruction in get_function_instructions('start'):
+            opcodes.discard(instruction.opname)
+
+        self.assertEqual(set(), opcodes)
+
+    def test_gc(self):
+        self.run_case("gc")
+
+    def test_line(self):
+        self.run_case("line")
+
+
+class DTraceNormalTests(TraceTests):
+    backend = DTraceBackend()
+    optimize_python = 0
+
+
+class DTraceOptimizedTests(TraceTests):
+    backend = DTraceBackend()
+    optimize_python = 2
+
+
+class SystemTapNormalTests(TraceTests):
+    backend = SystemTapBackend()
+    optimize_python = 0
+
+
+class SystemTapOptimizedTests(TraceTests):
+    backend = SystemTapBackend()
+    optimize_python = 2
+
+
+def test_main():
+    run_unittest(DTraceNormalTests, DTraceOptimizedTests, SystemTapNormalTests,
+                 SystemTapOptimizedTests)
+
+
+if __name__ == '__main__':
+    test_main()

Makefile.pre.in

@@ -48,6 +48,10 @@ PGO_PROF_USE_FLAG=@PGO_PROF_USE_FLAG@
 LLVM_PROF_MERGER=@LLVM_PROF_MERGER@
 LLVM_PROF_FILE=@LLVM_PROF_FILE@
 LLVM_PROF_ERR=@LLVM_PROF_ERR@
+DTRACE=         @DTRACE@
+DFLAGS=         @DFLAGS@
+DTRACE_HEADERS= @DTRACE_HEADERS@
+DTRACE_OBJS=    @DTRACE_OBJS@
 
 GNULD=		@GNULD@
 
@@ -315,7 +319,7 @@ OPCODE_H_DIR= 	$(srcdir)/Include
 OPCODE_H_SCRIPT= $(srcdir)/Tools/scripts/generate_opcode_h.py
 OPCODE_H=	$(OPCODE_H_DIR)/opcode.h
 OPCODE_H_GEN=	$(PYTHON_FOR_GEN) $(OPCODE_H_SCRIPT) $(srcdir)/Lib/opcode.py $(OPCODE_H)
-#
+
 ##########################################################################
 # AST
 AST_H_DIR=	Include
@@ -391,7 +395,8 @@ PYTHON_OBJS=	\
 		Python/$(DYNLOADFILE) \
 		$(LIBOBJS) \
 		$(MACHDEP_OBJS) \
-		$(THREADOBJ)
+		$(THREADOBJ) \
+		$(DTRACE_OBJS)
 
 
 ##########################################################################
@@ -451,6 +456,15 @@ LIBRARY_OBJS=	\
 		$(LIBRARY_OBJS_OMIT_FROZEN) \
 		Python/frozen.o
 
+##########################################################################
+# DTrace
+
+# On some systems, object files that reference DTrace probes need to be modified
+# in-place by dtrace(1).
+DTRACE_DEPS = \
+	Python/ceval.o
+# XXX: should gcmodule, etc. be here, too?
+
 #########################################################################
 # Rules
 
@@ -852,6 +866,18 @@ Python/ceval.o: $(OPCODETARGETS_H) $(srcdir)/Python/ceval_gil.h
 
 Python/frozen.o: Python/importlib.h Python/importlib_external.h
 
+# Generate DTrace probe macros, then rename them (PYTHON_ -> PyDTrace_) to
+# follow our naming conventions. dtrace(1) uses the output filename to generate
+# an include guard, so we can't use a pipeline to transform its output.
+Include/pydtrace_probes.h: $(srcdir)/Include/pydtrace.d
+	$(DTRACE) $(DFLAGS) -o $@ -h -s $<
+	: sed in-place edit with POSIX-only tools
+	sed 's/PYTHON_/PyDTrace_/' $@ > $@.tmp
+	mv $@.tmp $@
+
+Python/pydtrace.o: $(srcdir)/Include/pydtrace.d $(DTRACE_DEPS)
+	$(DTRACE) $(DFLAGS) -o $@ -G -s $< $(DTRACE_DEPS)
+
 Objects/typeobject.o: Objects/typeslots.inc
 Objects/typeslots.inc: $(srcdir)/Include/typeslots.h $(srcdir)/Objects/typeslots.py
 	$(PYTHON_FOR_GEN) $(srcdir)/Objects/typeslots.py < $(srcdir)/Include/typeslots.h Objects/typeslots.inc
@@ -918,6 +944,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/pycapsule.h \
 		$(srcdir)/Include/pyctype.h \
 		$(srcdir)/Include/pydebug.h \
+		$(srcdir)/Include/pydtrace.h \
 		$(srcdir)/Include/pyerrors.h \
 		$(srcdir)/Include/pyfpe.h \
 		$(srcdir)/Include/pyhash.h \
@@ -949,7 +976,8 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/weakrefobject.h \
 		pyconfig.h \
 		$(PARSER_HEADERS) \
-		$(AST_H)
+		$(AST_H) \
+		$(DTRACE_HEADERS)
 
 $(LIBRARY_OBJS) $(MODOBJS) Programs/python.o: $(PYTHON_HEADERS)
 
@@ -1158,6 +1186,7 @@ LIBSUBDIRS=	tkinter tkinter/test tkinter/test/test_tkinter \
 		test/audiodata \
 		test/capath test/data \
 		test/cjkencodings test/decimaltestdata test/xmltestdata \
+		test/dtracedata \
 		test/eintrdata \
 		test/imghdrdata \
 		test/libregrtest \
@@ -1569,6 +1598,7 @@ clean: pycremoval
 	-rm -f Lib/lib2to3/*Grammar*.pickle
 	-rm -f Programs/_testembed Programs/_freeze_importlib
 	-find build -type f -a ! -name '*.gc??' -exec rm -f {} ';'
+	-rm -f Include/pydtrace_probes.h
 
 profile-removal:
 	find . -name '*.gc??' -exec rm -f {} ';'

Misc/ACKS

@@ -120,6 +120,7 @@ Ben Bell
 Thomas Bellman
 Alexander “Саша” Belopolsky
 Eli Bendersky
+Nikhil Benesch
 David Benjamin
 Oscar Benjamin
 Andrew Bennetts

Misc/NEWS

@@ -329,6 +329,8 @@ Build
   make time when --with-optimizations is enabled.  Also improve our
   ability to find the llvm-profdata tool on MacOS and some Linuxes.
 
+- Issue #21590: Support for DTrace and SystemTap probes.
+
 - Issue #26307: The profile-opt build now applys PGO to the built-in modules.
 
 - Issue #26539: Add the --with-optimizations flag to turn on LTO and PGO build

Modules/gcmodule.c

@@ -25,6 +25,7 @@
 
 #include "Python.h"
 #include "frameobject.h"        /* for PyFrame_ClearFreeList */
+#include "pydtrace.h"
 #include "pytime.h"             /* for _PyTime_GetMonotonicClock() */
 
 /* Get an object's GC head */
@@ -925,6 +926,9 @@ collect(int generation, Py_ssize_t *n_collected, Py_ssize_t *n_uncollectable,
         PySys_WriteStderr("\n");
     }
 
+    if (PyDTrace_GC_START_ENABLED())
+        PyDTrace_GC_START(generation);
+
     /* update collection and allocation counters */
     if (generation+1 < NUM_GENERATIONS)
         generations[generation+1].count += 1;
@@ -1069,6 +1073,10 @@ collect(int generation, Py_ssize_t *n_collected, Py_ssize_t *n_uncollectable,
     stats->collections++;
     stats->collected += m;
     stats->uncollectable += n;
+
+    if (PyDTrace_GC_DONE_ENABLED())
+        PyDTrace_GC_DONE(n+m);
+
     return n+m;
 }
 

Python/ceval.c

@@ -15,6 +15,7 @@
 #include "dictobject.h"
 #include "frameobject.h"
 #include "opcode.h"
+#include "pydtrace.h"
 #include "setobject.h"
 #include "structmember.h"
 
@@ -50,6 +51,9 @@ static void call_exc_trace(Py_tracefunc, PyObject *,
                            PyThreadState *, PyFrameObject *);
 static int maybe_call_line_trace(Py_tracefunc, PyObject *,
                                  PyThreadState *, PyFrameObject *, int *, int *, int *);
+static void maybe_dtrace_line(PyFrameObject *, int *, int *, int *);
+static void dtrace_function_entry(PyFrameObject *);
+static void dtrace_function_return(PyFrameObject *);
 
 static PyObject * cmp_outcome(int, PyObject *, PyObject *);
 static PyObject * import_name(PyFrameObject *, PyObject *, PyObject *, PyObject *);
@@ -822,7 +826,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
 #ifdef LLTRACE
 #define FAST_DISPATCH() \
     { \
-        if (!lltrace && !_Py_TracingPossible) { \
+        if (!lltrace && !_Py_TracingPossible && !PyDTrace_LINE_ENABLED()) { \
             f->f_lasti = INSTR_OFFSET(); \
             NEXTOPARG(); \
             goto *opcode_targets[opcode]; \
@@ -832,7 +836,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
 #else
 #define FAST_DISPATCH() \
     { \
-        if (!_Py_TracingPossible) { \
+        if (!_Py_TracingPossible && !PyDTrace_LINE_ENABLED()) { \
             f->f_lasti = INSTR_OFFSET(); \
             NEXTOPARG(); \
             goto *opcode_targets[opcode]; \
@@ -1042,6 +1046,9 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
         }
     }
 
+    if (PyDTrace_FUNCTION_ENTRY_ENABLED())
+        dtrace_function_entry(f);
+
     co = f->f_code;
     names = co->co_names;
     consts = co->co_consts;
@@ -1162,6 +1169,9 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
     fast_next_opcode:
         f->f_lasti = INSTR_OFFSET();
 
+        if (PyDTrace_LINE_ENABLED())
+            maybe_dtrace_line(f, &instr_lb, &instr_ub, &instr_prev);
+
         /* line-by-line tracing support */
 
         if (_Py_TracingPossible &&
@@ -3620,6 +3630,8 @@ fast_yield:
 
     /* pop frame */
 exit_eval_frame:
+    if (PyDTrace_FUNCTION_RETURN_ENABLED())
+        dtrace_function_return(f);
     Py_LeaveRecursiveCall();
     f->f_executing = 0;
     tstate->frame = f->f_back;
@@ -5415,3 +5427,65 @@ _PyEval_RequestCodeExtraIndex(freefunc free)
     tstate->co_extra_freefuncs[new_index] = free;
     return new_index;
 }
+
+static void
+dtrace_function_entry(PyFrameObject *f)
+{
+    char* filename;
+    char* funcname;
+    int lineno;
+
+    filename = PyUnicode_AsUTF8(f->f_code->co_filename);
+    funcname = PyUnicode_AsUTF8(f->f_code->co_name);
+    lineno = PyCode_Addr2Line(f->f_code, f->f_lasti);
+
+    PyDTrace_FUNCTION_ENTRY(filename, funcname, lineno);
+}
+
+static void
+dtrace_function_return(PyFrameObject *f)
+{
+    char* filename;
+    char* funcname;
+    int lineno;
+
+    filename = PyUnicode_AsUTF8(f->f_code->co_filename);
+    funcname = PyUnicode_AsUTF8(f->f_code->co_name);
+    lineno = PyCode_Addr2Line(f->f_code, f->f_lasti);
+
+    PyDTrace_FUNCTION_RETURN(filename, funcname, lineno);
+}
+
+/* DTrace equivalent of maybe_call_line_trace. */
+static void
+maybe_dtrace_line(PyFrameObject *frame,
+                  int *instr_lb, int *instr_ub, int *instr_prev)
+{
+    int line = frame->f_lineno;
+    char *co_filename, *co_name;
+
+    /* If the last instruction executed isn't in the current
+       instruction window, reset the window.
+    */
+    if (frame->f_lasti < *instr_lb || frame->f_lasti >= *instr_ub) {
+        PyAddrPair bounds;
+        line = _PyCode_CheckLineNumber(frame->f_code, frame->f_lasti,
+                                       &bounds);
+        *instr_lb = bounds.ap_lower;
+        *instr_ub = bounds.ap_upper;
+    }
+    /* If the last instruction falls at the start of a line or if
+       it represents a jump backwards, update the frame's line
+       number and call the trace function. */
+    if (frame->f_lasti == *instr_lb || frame->f_lasti < *instr_prev) {
+        frame->f_lineno = line;
+        co_filename = PyUnicode_AsUTF8(frame->f_code->co_filename);
+        if (!co_filename)
+            co_filename = "?";
+        co_name = PyUnicode_AsUTF8(frame->f_code->co_name);
+        if (!co_name)
+            co_name = "?";
+        PyDTrace_LINE(co_filename, co_name, line);
+    }
+    *instr_prev = frame->f_lasti;
+}

configure

@@ -642,6 +642,10 @@ TRUE
 MACHDEP_OBJS
 DYNLOADFILE
 DLINCLDIR
+DTRACE_OBJS
+DTRACE_HEADERS
+DFLAGS
+DTRACE
 THREADOBJ
 LDLAST
 USE_THREAD_MODULE
@@ -713,6 +717,7 @@ MULTIARCH
 ac_ct_CXX
 MAINCC
 CXX
+SED
 GREP
 CPP
 OBJEXT
@@ -780,7 +785,6 @@ infodir
 docdir
 oldincludedir
 includedir
-runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -832,6 +836,7 @@ enable_ipv6
 with_doc_strings
 with_pymalloc
 with_valgrind
+with_dtrace
 with_fpectl
 with_libm
 with_libc
@@ -890,7 +895,6 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
-runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1143,15 +1147,6 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
-  -runstatedir | --runstatedir | --runstatedi | --runstated \
-  | --runstate | --runstat | --runsta | --runst | --runs \
-  | --run | --ru | --r)
-    ac_prev=runstatedir ;;
-  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
-  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
-  | --run=* | --ru=* | --r=*)
-    runstatedir=$ac_optarg ;;
-
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1289,7 +1284,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir runstatedir
+		libdir localedir mandir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1442,7 +1437,6 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
-  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -1535,6 +1529,7 @@ Optional Packages:
   --with(out)-doc-strings disable/enable documentation strings
   --with(out)-pymalloc    disable/enable specialized mallocs
   --with-valgrind         Enable Valgrind support
+  --with(out)-dtrace      disable/enable DTrace support
   --with-fpectl           enable SIGFPE catching
   --with-libm=STRING      math library
   --with-libc=STRING      C library
@@ -4581,6 +4576,75 @@ $as_echo "$ac_cv_path_GREP" >&6; }
  GREP="$ac_cv_path_GREP"
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for a sed that does not truncate output" >&5
+$as_echo_n "checking for a sed that does not truncate output... " >&6; }
+if ${ac_cv_path_SED+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+            ac_script=s/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/
+     for ac_i in 1 2 3 4 5 6 7; do
+       ac_script="$ac_script$as_nl$ac_script"
+     done
+     echo "$ac_script" 2>/dev/null | sed 99q >conftest.sed
+     { ac_script=; unset ac_script;}
+     if test -z "$SED"; then
+  ac_path_SED_found=false
+  # Loop through the user's path and test for each of PROGNAME-LIST
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_prog in sed gsed; do
+    for ac_exec_ext in '' $ac_executable_extensions; do
+      ac_path_SED="$as_dir/$ac_prog$ac_exec_ext"
+      as_fn_executable_p "$ac_path_SED" || continue
+# Check for GNU ac_path_SED and select it if it is found.
+  # Check for GNU $ac_path_SED
+case `"$ac_path_SED" --version 2>&1` in
+*GNU*)
+  ac_cv_path_SED="$ac_path_SED" ac_path_SED_found=:;;
+*)
+  ac_count=0
+  $as_echo_n 0123456789 >"conftest.in"
+  while :
+  do
+    cat "conftest.in" "conftest.in" >"conftest.tmp"
+    mv "conftest.tmp" "conftest.in"
+    cp "conftest.in" "conftest.nl"
+    $as_echo '' >> "conftest.nl"
+    "$ac_path_SED" -f conftest.sed < "conftest.nl" >"conftest.out" 2>/dev/null || break
+    diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
+    as_fn_arith $ac_count + 1 && ac_count=$as_val
+    if test $ac_count -gt ${ac_path_SED_max-0}; then
+      # Best one so far, save it but keep looking for a better one
+      ac_cv_path_SED="$ac_path_SED"
+      ac_path_SED_max=$ac_count
+    fi
+    # 10*(2^10) chars as input seems more than enough
+    test $ac_count -gt 10 && break
+  done
+  rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
+esac
+
+      $ac_path_SED_found && break 3
+    done
+  done
+  done
+IFS=$as_save_IFS
+  if test -z "$ac_cv_path_SED"; then
+    as_fn_error $? "no acceptable sed could be found in \$PATH" "$LINENO" 5
+  fi
+else
+  ac_cv_path_SED=$SED
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_SED" >&5
+$as_echo "$ac_cv_path_SED" >&6; }
+ SED="$ac_cv_path_SED"
+  rm -f conftest.sed
+
 
 
 
@@ -10864,6 +10928,102 @@ fi
     OPT="-DDYNAMIC_ANNOTATIONS_ENABLED=1 $OPT"
 fi
 
+# Check for DTrace support
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-dtrace" >&5
+$as_echo_n "checking for --with-dtrace... " >&6; }
+
+# Check whether --with-dtrace was given.
+if test "${with_dtrace+set}" = set; then :
+  withval=$with_dtrace;
+else
+  with_dtrace=no
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $with_dtrace" >&5
+$as_echo "$with_dtrace" >&6; }
+
+
+
+
+
+DTRACE=
+DFLAGS=
+DTRACE_HEADERS=
+DTRACE_OBJS=
+
+if test "$with_dtrace" = "yes"
+then
+    # Extract the first word of "dtrace", so it can be a program name with args.
+set dummy dtrace; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_DTRACE+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $DTRACE in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_DTRACE="$DTRACE" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_DTRACE="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_path_DTRACE" && ac_cv_path_DTRACE="not found"
+  ;;
+esac
+fi
+DTRACE=$ac_cv_path_DTRACE
+if test -n "$DTRACE"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $DTRACE" >&5
+$as_echo "$DTRACE" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+    if test "$DTRACE" = "not found"; then
+        as_fn_error $? "dtrace command not found on \$PATH" "$LINENO" 5
+    fi
+
+$as_echo "#define WITH_DTRACE 1" >>confdefs.h
+
+    DTRACE_HEADERS="Include/pydtrace_probes.h"
+
+    # On OS X, DTrace providers do not need to be explicitly compiled and
+    # linked into the binary. Correspondingly, dtrace(1) is missing the ELF
+    # generation flag '-G'. We check for presence of this flag, rather than
+    # hardcoding support by OS, in the interest of robustness.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether DTrace probes require linking" >&5
+$as_echo_n "checking whether DTrace probes require linking... " >&6; }
+if ${ac_cv_dtrace_link+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+              ac_cv_dtrace_link=no
+            echo 'BEGIN' > conftest.d
+            "$DTRACE" -G -s conftest.d -o conftest.o > /dev/null 2>&1 && \
+                ac_cv_dtrace_link=yes
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_dtrace_link" >&5
+$as_echo "$ac_cv_dtrace_link" >&6; }
+    if test "$ac_cv_dtrace_link" = "yes"; then
+        DTRACE_OBJS="Python/pydtrace.o"
+    fi
+fi
+
 # -I${DLINCLDIR} is added to the compile rule for importdl.o
 
 DLINCLDIR=.

configure.ac

@@ -694,6 +694,7 @@ fi
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_GREP
+AC_PROG_SED
 
 AC_SUBST(CXX)
 AC_SUBST(MAINCC)
@@ -3245,6 +3246,47 @@ if test "$with_valgrind" != no; then
     OPT="-DDYNAMIC_ANNOTATIONS_ENABLED=1 $OPT"
 fi
 
+# Check for DTrace support
+AC_MSG_CHECKING(for --with-dtrace)
+AC_ARG_WITH(dtrace,
+  AC_HELP_STRING(--with(out)-dtrace, [disable/enable DTrace support]),,
+  with_dtrace=no)
+AC_MSG_RESULT($with_dtrace)
+
+AC_SUBST(DTRACE)
+AC_SUBST(DFLAGS)
+AC_SUBST(DTRACE_HEADERS)
+AC_SUBST(DTRACE_OBJS)
+DTRACE=
+DFLAGS=
+DTRACE_HEADERS=
+DTRACE_OBJS=
+
+if test "$with_dtrace" = "yes"
+then
+    AC_PATH_PROG(DTRACE, [dtrace], [not found])
+    if test "$DTRACE" = "not found"; then
+        AC_MSG_ERROR([dtrace command not found on \$PATH])
+    fi
+    AC_DEFINE(WITH_DTRACE, 1, [Define if you want to compile in DTrace support])
+    DTRACE_HEADERS="Include/pydtrace_probes.h"
+
+    # On OS X, DTrace providers do not need to be explicitly compiled and
+    # linked into the binary. Correspondingly, dtrace(1) is missing the ELF
+    # generation flag '-G'. We check for presence of this flag, rather than
+    # hardcoding support by OS, in the interest of robustness.
+    AC_CACHE_CHECK([whether DTrace probes require linking],
+        [ac_cv_dtrace_link], [dnl
+            ac_cv_dtrace_link=no
+            echo 'BEGIN' > conftest.d
+            "$DTRACE" -G -s conftest.d -o conftest.o > /dev/null 2>&1 && \
+                ac_cv_dtrace_link=yes
+      ])
+    if test "$ac_cv_dtrace_link" = "yes"; then
+        DTRACE_OBJS="Python/pydtrace.o"
+    fi
+fi
+
 # -I${DLINCLDIR} is added to the compile rule for importdl.o
 AC_SUBST(DLINCLDIR)
 DLINCLDIR=.

pyconfig.h.in

@@ -1370,6 +1370,9 @@
 /* Define if you want documentation strings in extension modules */
 #undef WITH_DOC_STRINGS
 
+/* Define if you want to compile in DTrace support */
+#undef WITH_DTRACE
+
 /* Define if you want to use the new-style (Openstep, Rhapsody, MacOS) dynamic
    linker (dyld) instead of the old-style (NextStep) dynamic linker (rld).
    Dyld is necessary to support frameworks. */