1. add support to join main task
| static pthread_t self;
|
| static void *join_task(void *arg)
| {
| int ret;
| ret = pthread_join(self, NULL); <--- /* Fix Task could not be joined */
| return NULL;
| }
|
| int main(int argc, char *argv[])
| {
| pthread_t thread;
|
| self = pthread_self();
|
| pthread_create(&thread, NULL, join_task, NULL);
| sleep(1);
|
| pthread_exit(NULL);
| return 0;
| }
2. Detach active thread will not alloc for additional join, just update the task flag.
3. Remove the return value waiting lock logic (data_sem),
the return value will be stored in the waiting tcb.
4. Revise the return value of pthread_join(), consistent with linux
e.g:
Joining a detached and canceled thread should return EINVAL, not ESRCH
https://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_join.html
[EINVAL]
The value specified by thread does not refer to a joinable thread.
NOTE:
This PR will not increase stack usage, but struct tcb_s will increase 32 bytes.
Signed-off-by: chao an <anchao@lixiang.com>
Resolving the issue with the ltp_interfaces_pthread_join_6_2 test case.
In SMP mode, the pthread may still be in the process of exiting when
pthread_join returns, and calling pthread_join again at this time will
result in an error. The error code returned should be ESRCH.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
if a pthread set attr is detach,and when call pthread_create,
new thread exit quikly,new thread's tcb be free,then pthread_create
use new thread's tcb will crash.
Signed-off-by: anjiahao <anjiahao@xiaomi.com>
This commit backs out most of commit b4747286b1. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point.
In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable.
In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable.
sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
This was a consequence of the recent robust mutex changes. If robust mutexes are selected, then each mutex that a thread takes is retained in a list in threads TCB. If the thread exits and that list is not empty, then we know that the thread exitted while holding mutexes. And, in that case, each will be marked as inconsistent and the any waiter for the thread is awakened.
For the case of pthread_mutex_trywait(), the mutex was not being added to the list! while not usually a fatal error, this was caught by an assertion when pthread_mutex_unlock() was called: It tried to remove the mutex from the TCB list and it was not there when, of course, it shoule be.
The fix was to add pthread_mutex_trytake() which does sem_trywait() and if successful, does correctly add the mutext to the TCB list. This should eliminated the assertion.
