mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 03:27:39 +00:00
3c61a541bd
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.
26 lines
833 B
C
26 lines
833 B
C
#ifndef NSYNC_SEM_H_
|
|
#define NSYNC_SEM_H_
|
|
#include "third_party/nsync/time.h"
|
|
COSMOPOLITAN_C_START_
|
|
|
|
typedef struct nsync_semaphore_s_ {
|
|
void *sem_space[3];
|
|
} nsync_semaphore;
|
|
|
|
/* Initialize *s; the initial value is 0. */
|
|
bool nsync_mu_semaphore_init(nsync_semaphore *s);
|
|
|
|
/* Wait until the count of *s exceeds 0, and decrement it. */
|
|
errno_t nsync_mu_semaphore_p(nsync_semaphore *s);
|
|
|
|
/* Wait until one of: the count of *s is non-zero, in which case
|
|
decrement *s and return 0; or abs_deadline expires, in which case
|
|
return ETIMEDOUT. */
|
|
errno_t nsync_mu_semaphore_p_with_deadline(nsync_semaphore *s, int clock,
|
|
nsync_time abs_deadline);
|
|
|
|
/* Ensure that the count of *s is at least 1. */
|
|
void nsync_mu_semaphore_v(nsync_semaphore *s);
|
|
|
|
COSMOPOLITAN_C_END_
|
|
#endif /* NSYNC_SEM_H_ */
|