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Add pthread attributes and other libc functions

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Justine Tunney 2022-09-07 05:23:44 -07:00
parent d5c9308a43
commit 4339d9f15e
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GPG key ID: BE714B4575D6E328
81 changed files with 1111 additions and 428 deletions
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24
libc/intrin/pthread_mutex_lock.c
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@ -39,7 +39,7 @@ static int pthread_mutex_lock_spin(pthread_mutex_t *mutex, int expect,
tries++;
} else if (IsLinux() || IsOpenbsd()) {
atomic_fetch_add(&mutex->waits, 1);
_futex_wait_private(&mutex->lock, expect, &(struct timespec){1});
_futex_wait(&mutex->lock, expect, mutex->pshared, &(struct timespec){1});
atomic_fetch_sub(&mutex->waits, 1);
} else {
pthread_yield();
@ -87,24 +87,24 @@ static int pthread_mutex_lock_spin(pthread_mutex_t *mutex, int expect,
*
* Microbenchmarks for single-threaded lock + unlock:
*
* pthread_spinlock_t : 12c ( 4ns)
* PTHREAD_MUTEX_NORMAL : 37c ( 12ns)
* PTHREAD_MUTEX_RECURSIVE : 22c ( 7ns)
* PTHREAD_MUTEX_ERRORCHECK : 27c ( 9ns)
* pthread_spinlock_t : 12c ( 4ns)
* PTHREAD_MUTEX_NORMAL : 37c ( 12ns)
* PTHREAD_MUTEX_RECURSIVE : 22c ( 7ns)
* PTHREAD_MUTEX_ERRORCHECK : 27c ( 9ns)
*
* Microbenchmarks for multi-threaded lock + unlock:
*
* pthread_spinlock_t : 6,162c (1,990ns)
* PTHREAD_MUTEX_NORMAL : 780c ( 252ns)
* PTHREAD_MUTEX_RECURSIVE : 1,047c ( 338ns)
* PTHREAD_MUTEX_ERRORCHECK : 1,044c ( 337ns)
* pthread_spinlock_t : 2,396c (774ns)
* PTHREAD_MUTEX_NORMAL : 535c (173ns)
* PTHREAD_MUTEX_RECURSIVE : 1,045c (338ns)
* PTHREAD_MUTEX_ERRORCHECK : 917c (296ns)
*
* @return 0 on success, or error number on failure
* @see pthread_spin_lock
*/
int pthread_mutex_lock(pthread_mutex_t *mutex) {
int c, me, owner, tries;
switch (mutex->attr) {
switch (mutex->type) {
case PTHREAD_MUTEX_NORMAL:
// From Futexes Are Tricky Version 1.1 § Mutex, Take 3;
// Ulrich Drepper, Red Hat Incorporated, June 27, 2004.
@ -116,7 +116,7 @@ int pthread_mutex_lock(pthread_mutex_t *mutex) {
c = atomic_exchange_explicit(&mutex->lock, 2, memory_order_acquire);
}
while (c) {
_futex_wait_private(&mutex->lock, 2, 0);
_futex_wait(&mutex->lock, 2, mutex->pshared, 0);
c = atomic_exchange_explicit(&mutex->lock, 2, memory_order_acquire);
}
}
@ -130,7 +130,7 @@ int pthread_mutex_lock(pthread_mutex_t *mutex) {
memory_order_relaxed)) {
break;
} else if (owner == me) {
if (mutex->attr != PTHREAD_MUTEX_ERRORCHECK) {
if (mutex->type != PTHREAD_MUTEX_ERRORCHECK) {
break;
} else {
assert(!"deadlock");