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
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55 changed files with 449 additions and 155 deletions

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@ -8,7 +8,8 @@ extern const int CLOCK_MONOTONIC;
extern const int CLOCK_MONOTONIC_COARSE;
extern const int CLOCK_MONOTONIC_FAST;
extern const int CLOCK_MONOTONIC_PRECISE;
extern const int CLOCK_MONOTONIC_RAW;
extern int CLOCK_MONOTONIC_RAW;
extern int CLOCK_MONOTONIC_RAW_APPROX;
extern const int CLOCK_PROCESS_CPUTIME_ID;
extern const int CLOCK_PROF;
extern const int CLOCK_REALTIME_ALARM;
@ -24,9 +25,19 @@ extern const int CLOCK_UPTIME_PRECISE;
COSMOPOLITAN_C_END_
#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC CLOCK_MONOTONIC
#define CLOCK_PROCESS_CPUTIME_ID CLOCK_PROCESS_CPUTIME_ID
#define CLOCK_REALTIME 0
#define CLOCK_REALTIME_FAST CLOCK_REALTIME_FAST
#define CLOCK_REALTIME_PRECISE CLOCK_REALTIME_PRECISE
#define CLOCK_REALTIME_COARSE CLOCK_REALTIME_COARSE
#define CLOCK_MONOTONIC CLOCK_MONOTONIC
#define CLOCK_MONOTONIC_RAW CLOCK_MONOTONIC_RAW
#define CLOCK_MONOTONIC_RAW_APPROX CLOCK_MONOTONIC_RAW_APPROX
#define CLOCK_MONOTONIC_FAST CLOCK_MONOTONIC_FAST
#define CLOCK_MONOTONIC_PRECISE CLOCK_MONOTONIC_PRECISE
#define CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC_COARSE
#define CLOCK_THREAD_CPUTIME_ID CLOCK_THREAD_CPUTIME_ID
#define CLOCK_PROCESS_CPUTIME_ID CLOCK_PROCESS_CPUTIME_ID
#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_CLOCK_H_ */