Issue #7544: Preallocate thread memory before creating the thread to avoid a

fatal error in low memory condition.

diff --git a/Include/pystate.h b/Include/pystate.h
index 4919d99b6c76bca1664b3e48f7977c29397ef68d..b9fe61e7210b672a811baef504ad4b1dab8e5f1a 100644 (file)
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -105,6 +105,8 @@ PyAPI_FUNC(void) PyInterpreterState_Clear(PyInterpreterState *);
 PyAPI_FUNC(void) PyInterpreterState_Delete(PyInterpreterState *);
 
 PyAPI_FUNC(PyThreadState *) PyThreadState_New(PyInterpreterState *);
+PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *);
+PyAPI_FUNC(void) _PyThreadState_Init(PyThreadState *);
 PyAPI_FUNC(void) PyThreadState_Clear(PyThreadState *);
 PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *);
 #ifdef WITH_THREAD

diff --git a/Misc/NEWS b/Misc/NEWS
index 5636528d73f33fbe745d66489238c3d2367859e8..cfdd364096eb7f050bdecbf478b72402b992977c 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 2.7 alpha 4?
 Core and Builtins
 -----------------
 
+- Issue #7544: Preallocate thread memory before creating the thread to avoid
+  a fatal error in low memory condition.
+
 - Issue #7820: The parser tokenizer restores all bytes in the right if
   the BOM check fails.
 

diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c
index b65360e375f895ade24c0c5d9f12270cee6ce2f2..6494f497951d9e7260d4e882553131345a23f446 100644 (file)
--- a/Modules/threadmodule.c
+++ b/Modules/threadmodule.c
@@ -428,6 +428,7 @@ struct bootstate {
        PyObject *func;
        PyObject *args;
        PyObject *keyw;
+       PyThreadState *tstate;
 };
 
 static void
@@ -437,8 +438,9 @@ t_bootstrap(void *boot_raw)
        PyThreadState *tstate;
        PyObject *res;
 
-       tstate = PyThreadState_New(boot->interp);
-
+       tstate = boot->tstate;
+       tstate->thread_id = PyThread_get_thread_ident();
+       _PyThreadState_Init(tstate);
        PyEval_AcquireThread(tstate);
        nb_threads++;
        res = PyEval_CallObjectWithKeywords(
@@ -503,6 +505,11 @@ thread_PyThread_start_new_thread(PyObject *self, PyObject *fargs)
        boot->func = func;
        boot->args = args;
        boot->keyw = keyw;
+       boot->tstate = _PyThreadState_Prealloc(boot->interp);
+       if (boot->tstate == NULL) {
+               PyMem_DEL(boot);
+               return PyErr_NoMemory();
+       }
        Py_INCREF(func);
        Py_INCREF(args);
        Py_XINCREF(keyw);
@@ -513,6 +520,7 @@ thread_PyThread_start_new_thread(PyObject *self, PyObject *fargs)
                Py_DECREF(func);
                Py_DECREF(args);
                Py_XDECREF(keyw);
+               PyThreadState_Clear(boot->tstate);
                PyMem_DEL(boot);
                return NULL;
        }

diff --git a/Python/pystate.c b/Python/pystate.c
index da417c103202f792fefd42ea3fcb617ceb36585c..343a97b00d15af2d4764101f09a76d39b8582132 100644 (file)
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -154,8 +154,8 @@ threadstate_getframe(PyThreadState *self)
        return self->frame;
 }
 
-PyThreadState *
-PyThreadState_New(PyInterpreterState *interp)
+static PyThreadState *
+new_threadstate(PyInterpreterState *interp, int init)
 {
        PyThreadState *tstate = (PyThreadState *)malloc(sizeof(PyThreadState));
 
@@ -193,9 +193,8 @@ PyThreadState_New(PyInterpreterState *interp)
                tstate->c_profileobj = NULL;
                tstate->c_traceobj = NULL;
 
-#ifdef WITH_THREAD
-               _PyGILState_NoteThreadState(tstate);
-#endif
+               if (init)
+                       _PyThreadState_Init(tstate);
 
                HEAD_LOCK();
                tstate->next = interp->tstate_head;
@@ -206,6 +205,25 @@ PyThreadState_New(PyInterpreterState *interp)
        return tstate;
 }
 
+PyThreadState *
+PyThreadState_New(PyInterpreterState *interp)
+{
+       return new_threadstate(interp, 1);
+}
+
+PyThreadState *
+_PyThreadState_Prealloc(PyInterpreterState *interp)
+{
+       return new_threadstate(interp, 0);
+}
+
+void
+_PyThreadState_Init(PyThreadState *tstate)
+{
+#ifdef WITH_THREAD
+       _PyGILState_NoteThreadState(tstate);
+#endif
+}
 
 void
 PyThreadState_Clear(PyThreadState *tstate)