[haiku-commits] r42064 - haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread
- From: ingo_weinhold@xxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Thu, 9 Jun 2011 01:06:55 +0200 (CEST)
Author: bonefish
Date: 2011-06-09 01:06:55 +0200 (Thu, 09 Jun 2011)
New Revision: 42064
Changeset: https://dev.haiku-os.org/changeset/42064
Modified:
haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread/pthread_once.cpp
Log:
pthread_once(): The initialization function may be a cancellation point. So
push a cleanup function that resets the control state before executing it. The
whole function must loop now for that to work.
Modified:
haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread/pthread_once.cpp
===================================================================
---
haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread/pthread_once.cpp
2011-06-08 22:25:04 UTC (rev 42063)
+++
haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread/pthread_once.cpp
2011-06-08 23:06:55 UTC (rev 42064)
@@ -1,5 +1,5 @@
/*
- * Copyright 2008, Ingo Weinhold, ingo_weinhold@xxxxxxx
+ * Copyright 2008-2011, Ingo Weinhold, ingo_weinhold@xxxxxxx
* Distributed under the terms of the MIT License.
*/
@@ -16,6 +16,27 @@
};
+/*! Called when the thread performing the initialization function was
canceled.
+
+ \param data Pointer to the \c pthread_once_t structure in question.
+*/
+static void
+init_function_canceled(void* data)
+{
+ pthread_once_t* onceControl = (pthread_once_t*)data;
+
+ // reset the control state to uninitialized
+ int32 value = atomic_set((vint32*)&onceControl->state,
STATE_UNINITIALIZED);
+
+ // If someone has set a semaphore, delete it.
+ if (value >= 0)
+ delete_sem(value);
+}
+
+
+// #pragma mark -
+
+
int
pthread_once(pthread_once_t* onceControl, void (*initRoutine)(void))
{
@@ -32,57 +53,59 @@
// STATE_INITIALIZED: Set by the first thread when it returns from
// initRoutine. All following threads will return right away.
- int32 value = atomic_test_and_set((vint32*)&onceControl->state,
- STATE_INITIALIZING, STATE_UNINITIALIZED);
+ while (true) {
+ int32 value = atomic_test_and_set((vint32*)&onceControl->state,
+ STATE_INITIALIZING, STATE_UNINITIALIZED);
- if (value == STATE_INITIALIZED)
- return 0;
+ if (value == STATE_INITIALIZED)
+ return 0;
- if (value == STATE_UNINITIALIZED) {
- // we're the first -- perform the initialization
- initRoutine();
+ if (value == STATE_UNINITIALIZED) {
+ // we're the first -- perform the initialization
+ pthread_cleanup_push(&init_function_canceled,
onceControl);
+ initRoutine();
+ pthread_cleanup_pop(false);
- value = atomic_set((vint32*)&onceControl->state,
STATE_INITIALIZED);
+ value = atomic_set((vint32*)&onceControl->state,
STATE_INITIALIZED);
- // If someone else is waiting, we need to delete the semaphore.
- if (value >= 0)
- delete_sem(value);
+ // If someone else is waiting, we need to delete the
semaphore.
+ if (value >= 0)
+ delete_sem(value);
- return 0;
- }
+ return 0;
+ }
- if (value == STATE_INITIALIZING) {
- // someone is initializing -- we need to create a semaphore we
can wait
- // on
- sem_id semaphore = create_sem(0, "pthread once");
- if (semaphore >= 0) {
- // successfully created -- set it
- value =
atomic_test_and_set((vint32*)&onceControl->state,
- semaphore, STATE_INITIALIZING);
- if (value == STATE_INITIALIZING)
- value = semaphore;
- else
- delete_sem(semaphore);
- } else {
- // Failed to create the semaphore. Can only happen when
the system
- // runs out of semaphores, but we can still handle the
situation
- // gracefully by spinning.
- value =
atomic_test_and_set((vint32*)&onceControl->state,
- STATE_SPINNING, STATE_INITIALIZING);
- if (value == STATE_INITIALIZING)
- value = STATE_SPINNING;
+ if (value == STATE_INITIALIZING) {
+ // someone is initializing -- we need to create a
semaphore we can
+ // wait on
+ sem_id semaphore = create_sem(0, "pthread once");
+ if (semaphore >= 0) {
+ // successfully created -- set it
+ value =
atomic_test_and_set((vint32*)&onceControl->state,
+ semaphore, STATE_INITIALIZING);
+ if (value == STATE_INITIALIZING)
+ value = semaphore;
+ else
+ delete_sem(semaphore);
+ } else {
+ // Failed to create the semaphore. Can only
happen when the
+ // system runs out of semaphores, but we can
still handle the
+ // situation gracefully by spinning.
+ value =
atomic_test_and_set((vint32*)&onceControl->state,
+ STATE_SPINNING, STATE_INITIALIZING);
+ if (value == STATE_INITIALIZING)
+ value = STATE_SPINNING;
+ }
}
- }
- if (value >= 0) {
- // wait on the semaphore
- while (acquire_sem(value) == B_INTERRUPTED);
+ if (value >= 0) {
+ // wait on the semaphore
+ while (acquire_sem(value) == B_INTERRUPTED);
- return 0;
- } else if (value == STATE_SPINNING) {
- // out of semaphores -- spin
- while (atomic_get((vint32*)&onceControl->state) ==
STATE_SPINNING);
+ return 0;
+ } else if (value == STATE_SPINNING) {
+ // out of semaphores -- spin
+ while (atomic_get((vint32*)&onceControl->state) ==
STATE_SPINNING);
+ }
}
-
- return 0;
}
Other related posts:
- » [haiku-commits] r42064 - haiku/branches/developer/bonefish/signals/src/system/libroot/posix/pthread - ingo_weinhold
