merge

Doc/c-api/init.rst

@@ -892,7 +892,7 @@ a worker thread and the actual call than made at the earliest convenience by the
 main thread where it has possession of the global interpreter lock and can
 perform any Python API calls.
 
-.. cfunction:: void Py_AddPendingCall( int (*func)(void *, void *arg) )
+.. cfunction:: void Py_AddPendingCall(int (*func)(void *), void *arg)
 
    .. index:: single: Py_AddPendingCall()
 

Lib/test/test_startfile.py

@@ -11,6 +11,7 @@ import unittest
 from test import support
 import os
 from os import path
+from time import sleep
 
 startfile = support.get_attribute(os, 'startfile')
 
@@ -23,6 +24,10 @@ class TestCase(unittest.TestCase):
         empty = path.join(path.dirname(__file__), "empty.vbs")
         startfile(empty)
         startfile(empty, "open")
+        # Give the child process some time to exit before we finish.
+        # Otherwise the cleanup code will not be able to delete the cwd,
+        # because it is still in use.
+        sleep(0.1)
 
 def test_main():
     support.run_unittest(TestCase)

Misc/NEWS

@@ -55,6 +55,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #11768: The signal handler of the signal module only calls
+  Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or
+  parallel calls. PyErr_SetInterrupt() writes also into the wake up file.
+
 - Issue #11467: Fix urlparse behavior when handling urls which contains scheme
   specific part only digits. Patch by Santoso Wijaya.
 
@@ -314,6 +318,8 @@ Build
 Tests
 -----
 
+- Fix test_startfile to wait for child process to terminate before finishing.
+
 - Issue #11719: Fix message about unexpected test_msilib skip on non-Windows
   platforms. Patch by Nadeem Vawda.
 

Modules/signalmodule.c

@@ -163,6 +163,20 @@ checksignals_witharg(void * unused)
     return PyErr_CheckSignals();
 }
 
+static void
+trip_signal(int sig_num)
+{
+    Handlers[sig_num].tripped = 1;
+    if (is_tripped)
+        return;
+    /* Set is_tripped after setting .tripped, as it gets
+       cleared in PyErr_CheckSignals() before .tripped. */
+    is_tripped = 1;
+    Py_AddPendingCall(checksignals_witharg, NULL);
+    if (wakeup_fd != -1)
+        write(wakeup_fd, "\0", 1);
+}
+
 static void
 signal_handler(int sig_num)
 {
@@ -180,13 +194,7 @@ signal_handler(int sig_num)
     if (getpid() == main_pid)
 #endif
     {
-        Handlers[sig_num].tripped = 1;
-        /* Set is_tripped after setting .tripped, as it gets
-           cleared in PyErr_CheckSignals() before .tripped. */
-        is_tripped = 1;
-        Py_AddPendingCall(checksignals_witharg, NULL);
-        if (wakeup_fd != -1)
-            write(wakeup_fd, "\0", 1);
+        trip_signal(sig_num);
     }
 
 #ifndef HAVE_SIGACTION
@@ -932,9 +940,7 @@ PyErr_CheckSignals(void)
 void
 PyErr_SetInterrupt(void)
 {
-    is_tripped = 1;
-    Handlers[SIGINT].tripped = 1;
-    Py_AddPendingCall((int (*)(void *))PyErr_CheckSignals, NULL);
+    trip_signal(SIGINT);
 }
 
 void