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Use *NSYNC for POSIX threads locking APIs

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Condition variables, barriers, and r/w locks now work very well.
This commit is contained in:
Justine Tunney 2022-09-11 11:02:07 -07:00
parent 3de35e196c
commit b5cb71ab84
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GPG key ID: BE714B4575D6E328
197 changed files with 3734 additions and 3817 deletions
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70
libc/thread/pthread_cond_broadcast.c
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@ -16,72 +16,17 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dce.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/futex.internal.h"
#include "libc/thread/thread.h"
#include "libc/limits.h"
static dontinline int pthread_cond_signal_impl(pthread_cond_t *cond, int n) {
if (atomic_load_explicit(&cond->waits, memory_order_relaxed)) {
atomic_fetch_add(&cond->seq, 1);
if (IsLinux() || IsOpenbsd()) {
_futex_wake(&cond->seq, n, cond->pshared);
}
}
return 0;
}
/**
* Wakes at least one thread waiting on condition, e.g.
*
* pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
* pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
*
* // thread pool waiters
* pthread_mutex_lock(&lock);
* pthread_cond_wait(&cond, &lock);
* pthread_mutex_unlock(&lock);
*
* // waker upper
* pthread_mutex_lock(&lock);
* pthread_cond_signal(&cond);
* pthread_mutex_unlock(&lock);
*
* This function has no effect if there aren't any threads currently
* waiting on the condition.
*
* @return 0 on success, or errno on error
* @see pthread_cond_broadcast
* @see pthread_cond_wait
*/
int pthread_cond_signal(pthread_cond_t *cond) {
return pthread_cond_signal_impl(cond, 1);
}
#include "third_party/nsync/cv.h"
/**
* Wakes all threads waiting on condition, e.g.
*
* pthread_mutex_t lock;
* pthread_mutexattr_t mattr;
* pthread_mutexattr_init(&mattr);
* pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_ERRORCHECK);
* pthread_mutex_init(&lock, &mattr);
*
* pthread_cond_t cond;
* pthread_condattr_t cattr;
* pthread_condattr_init(&cattr);
* pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
* pthread_cond_init(&cond, &cattr);
*
* // waiting threads
* CHECK_EQ(0, pthread_mutex_lock(&lock));
* CHECK_EQ(0, pthread_cond_wait(&cond, &lock));
* pthread_mutex_unlock(&lock);
*
* // notifying thread
* CHECK_EQ(0, pthread_mutex_lock(&lock));
* pthread_cond_broadcast(&cond);
* pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
* pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
* // ...
* pthread_mutex_lock(&lock);
* pthread_cond_broadcast(&cond, &lock);
* pthread_mutex_unlock(&lock);
*
* This function has no effect if there aren't any threads currently
@ -92,5 +37,6 @@ int pthread_cond_signal(pthread_cond_t *cond) {
* @see pthread_cond_wait
*/
int pthread_cond_broadcast(pthread_cond_t *cond) {
return pthread_cond_signal_impl(cond, INT_MAX);
nsync_cv_broadcast((nsync_cv *)cond);
return 0;
}