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/* Copyright 2016-present Facebook, Inc.
* Licensed under the Apache License, Version 2.0 */
#include "watchman.h"
#ifdef __APPLE__
// We get to emulate these functions because Darwin doesn't implement them
#define timed_helper(func_name, object_type, try_func) \
int func_name(object_type* lock, const struct timespec* deadline_ts) { \
int result; \
struct timeval now, deadline; \
int usec = 1; \
w_timespec_to_timeval(*deadline_ts, &deadline); \
while (true) { \
gettimeofday(&now, nullptr); \
if (w_timeval_compare(now, deadline) >= 0) { \
return ETIMEDOUT; \
} \
result = try_func(lock); \
if (result != EBUSY) { \
return result; \
} \
/* Exponential backoff on the sleep period */ \
usec = std::min(usec * 2, 1024); \
if (now.tv_sec == deadline.tv_sec) { \
/* Cap the sleep if we are close to the deadline */ \
usec = std::min(usec, deadline.tv_usec - now.tv_usec); \
} \
/* sleep override */ usleep(usec); \
} \
}
timed_helper(pthread_mutex_timedlock, pthread_mutex_t, pthread_mutex_trylock)
timed_helper(pthread_rwlock_timedwrlock, pthread_rwlock_t,
pthread_rwlock_trywrlock)
timed_helper(pthread_rwlock_timedrdlock, pthread_rwlock_t,
pthread_rwlock_tryrdlock)
#endif
/* vim:ts=2:sw=2:et:
*/
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