Introduce pthread_condattr_setclock()

This is one of the few POSIX APIs that was missing. It lets you choose a
monotonic clock for your condition variables. This might improve perf on
some platforms. It might also grant more flexibility with NTP configs. I
know Qt is one project that believes it needs this. To introduce this, I
needed to change some the *NSYNC APIs, to support passing a clock param.
There's also new benchmarks, demonstrating Cosmopolitan's supremacy over
many libc implementations when it comes to mutex performance. Cygwin has
an alarmingly bad pthread_mutex_t implementation. It is so bad that they
would have been significantly better off if they'd used naive spinlocks.
This commit is contained in:
Justine Tunney 2024-09-02 23:37:50 -07:00
parent 79516bf08e
commit 3c61a541bd
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
55 changed files with 449 additions and 155 deletions

View file

@ -24,6 +24,7 @@
#include "third_party/nsync/testing/closure.h"
#include "third_party/nsync/testing/smprintf.h"
#include "third_party/nsync/testing/testing.h"
#include "libc/sysv/consts/clock.h"
#include "third_party/nsync/testing/time_extra.h"
/* The state shared between the threads in each of the tests below. */
@ -67,6 +68,7 @@ static void test_data_wait_for_all_threads (test_data *td) {
while (td->finished_threads != td->n_threads) {
nsync_cv_wait_with_deadline_generic (&td->done, td->mu_in_use,
td->lock, td->unlock,
CLOCK_REALTIME,
nsync_time_no_deadline, NULL);
}
(*td->unlock) (td->mu_in_use);
@ -303,7 +305,7 @@ static int counter_wait_for_zero_with_deadline (counter *c, nsync_time abs_deadl
int value;
nsync_mu_rlock (&c->mu);
while (c->value != 0 &&
nsync_cv_wait_with_deadline (&c->cv, &c->mu, abs_deadline, NULL) == 0) {
nsync_cv_wait_with_deadline (&c->cv, &c->mu, CLOCK_REALTIME, abs_deadline, NULL) == 0) {
}
value = c->value;
nsync_mu_runlock (&c->mu);