cosmopolitan/third_party/nsync/mu_semaphore.internal.h
Justine Tunney e398f3887c
Make more improvements to threads and mappings
- NetBSD should now have faster synchronization
- POSIX barriers may now be shared across processes
- An edge case with memory map tracking has been fixed
- Grand Central Dispatch is no longer used on MacOS ARM64
- POSIX mutexes in normal mode now use futexes across processes
2024-07-24 01:19:54 -07:00

37 lines
1.6 KiB
C
Executable file

#ifndef COSMOPOLITAN_THIRD_PARTY_NSYNC_MU_SEMAPHORE_INTERNAL_H_
#define COSMOPOLITAN_THIRD_PARTY_NSYNC_MU_SEMAPHORE_INTERNAL_H_
#include "third_party/nsync/mu_semaphore.h"
#include "third_party/nsync/time.h"
COSMOPOLITAN_C_START_
/* XNU ulock (used by cosmo futexes) is an internal API, however:
1. Unlike GCD it's cancelable i.e. can be EINTR'd by signals
2. We have no choice but to use ulock for joining threads
3. Grand Central Dispatch requires a busy loop workaround
4. ulock makes our mutexes use 20% more system time (meh)
5. ulock makes our mutexes use 40% less wall time (good)
6. ulock makes our mutexes use 64% less user time (woop)
ulock is an outstanding system call that must be used.
gcd is not an acceptable alternative to ulock. */
#define NSYNC_USE_GRAND_CENTRAL 0
bool nsync_mu_semaphore_init_futex(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_futex(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_with_deadline_futex(nsync_semaphore *, nsync_time);
void nsync_mu_semaphore_v_futex(nsync_semaphore *);
bool nsync_mu_semaphore_init_sem(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_sem(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_with_deadline_sem(nsync_semaphore *, nsync_time);
void nsync_mu_semaphore_v_sem(nsync_semaphore *);
bool nsync_mu_semaphore_init_gcd(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_gcd(nsync_semaphore *);
errno_t nsync_mu_semaphore_p_with_deadline_gcd(nsync_semaphore *, nsync_time);
void nsync_mu_semaphore_v_gcd(nsync_semaphore *);
COSMOPOLITAN_C_END_
#endif /* COSMOPOLITAN_THIRD_PARTY_NSYNC_MU_SEMAPHORE_INTERNAL_H_ */