Issue #16230: Fix a crash in select.select() when one the lists changes size while iterated on.

Patch by Serhiy Storchaka.

1 files changed, 11 insertions, 14 deletions

diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index 3cde03567c..5007aaf0b7 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -148,7 +148,7 @@ typedef struct {
  * Initialization.
  */
 
-#ifdef _HAVE_BSDI
+#if defined(_HAVE_BSDI)
 static
 void _noop(void)
 {
@@ -244,8 +244,7 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
    hosed" because:
      - It does not guarantee the promise that a non-zero integer is returned.
      - The cast to long is inherently unsafe.
-     - It is not clear that the 'volatile' (for AIX?) and ugly casting in the
-       latter return statement (for Alpha OSF/1) are any longer necessary.
+     - It is not clear that the 'volatile' (for AIX?) are any longer necessary.
 */
 long
 PyThread_get_thread_ident(void)
@@ -253,13 +252,8 @@ PyThread_get_thread_ident(void)
     volatile pthread_t threadid;
     if (!initialized)
         PyThread_init_thread();
-    /* Jump through some hoops for Alpha OSF/1 */
     threadid = pthread_self();
-#if SIZEOF_PTHREAD_T <= SIZEOF_LONG
     return (long) threadid;
-#else
-    return (long) *(long *) &threadid;
-#endif
 }
 
 void
@@ -449,12 +443,15 @@ PyThread_free_lock(PyThread_type_lock lock)
 
     dprintf(("PyThread_free_lock(%p) called\n", lock));
 
-    status = pthread_mutex_destroy( &thelock->mut );
-    CHECK_STATUS("pthread_mutex_destroy");
-
+    /* some pthread-like implementations tie the mutex to the cond
+     * and must have the cond destroyed first.
+     */
     status = pthread_cond_destroy( &thelock->lock_released );
     CHECK_STATUS("pthread_cond_destroy");
 
+    status = pthread_mutex_destroy( &thelock->mut );
+    CHECK_STATUS("pthread_mutex_destroy");
+
     free((void *)thelock);
 }
 
@@ -537,12 +534,12 @@ PyThread_release_lock(PyThread_type_lock lock)
 
     thelock->locked = 0;
 
-    status = pthread_mutex_unlock( &thelock->mut );
-    CHECK_STATUS("pthread_mutex_unlock[3]");
-
     /* wake up someone (anyone, if any) waiting on the lock */
     status = pthread_cond_signal( &thelock->lock_released );
     CHECK_STATUS("pthread_cond_signal");
+
+    status = pthread_mutex_unlock( &thelock->mut );
+    CHECK_STATUS("pthread_mutex_unlock[3]");
 }
 
 #endif /* USE_SEMAPHORES */