[Python-checkins] cpython: Close #19576: PyGILState_Ensure() now initializes threads. At startup, Python

[victor.stinner]

http://hg.python.org/cpython/rev/dc4e805ec68a
changeset:   87916:dc4e805ec68a
user:        Victor Stinner <victor.stinner at gmail.com>
date:        Fri Dec 13 01:46:43 2013 +0100
summary:
  Close #19576: PyGILState_Ensure() now initializes threads. At startup, Python
has no concrete GIL. If PyGILState_Ensure() is called from a new thread for the
first time and PyEval_InitThreads() was not called yet, a GIL needs to be
created.

files:
  Misc/NEWS        |  5 +++++
  Python/pystate.c |  5 +++++
  2 files changed, 10 insertions(+), 0 deletions(-)


diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,11 @@
 Core and Builtins
 -----------------
 
+- Issue #19576: PyGILState_Ensure() now initializes threads. At startup, Python
+  has no concrete GIL. If PyGILState_Ensure() is called from a new thread for
+  the first time and PyEval_InitThreads() was not called yet, a GIL needs to be
+  created.
+
 - Issue #17576: Deprecation warning emitted now when __int__() or __index__()
   return not int instance.
 
diff --git a/Python/pystate.c b/Python/pystate.c
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -771,6 +771,11 @@
     assert(autoInterpreterState); /* Py_Initialize() hasn't been called! */
     tcur = (PyThreadState *)PyThread_get_key_value(autoTLSkey);
     if (tcur == NULL) {
+        /* At startup, Python has no concrete GIL. If PyGILState_Ensure() is
+           called from a new thread for the first time, we need the create the
+           GIL. */
+        PyEval_InitThreads();
+
         /* Create a new thread state for this thread */
         tcur = PyThreadState_New(autoInterpreterState);
         if (tcur == NULL)

-- 
Repository URL: http://hg.python.org/cpython