Make threads faster and more reliable

This change doubles the performance of thread spawning. That's thanks to
our new stack manager, which allows us to avoid zeroing stacks. It gives
us 15µs spawns rather than 30µs spawns on Linux. Also, pthread_exit() is
faster now, since it doesn't need to acquire the pthread GIL. On NetBSD,
that helps us avoid allocating too many semaphores. Even if that happens
we're now able to survive semaphores running out and even memory running
out, when allocating *NSYNC waiter objects. I found a lot more rare bugs
in the POSIX threads runtime that could cause things to crash, if you've
got dozens of threads all spawning and joining dozens of threads. I want
cosmo to be world class production worthy for 2025 so happy holidays all
This commit is contained in:
Justine Tunney 2024-12-18 04:59:02 -08:00
parent 906bd06a5a
commit 624573207e
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51 changed files with 1006 additions and 321 deletions

23
libc/thread/itimer.h Normal file
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#ifndef COSMOPOLITAN_LIBC_ITIMER_H_
#define COSMOPOLITAN_LIBC_ITIMER_H_
#include "libc/atomic.h"
#include "libc/calls/struct/itimerval.h"
#include "libc/thread/thread.h"
COSMOPOLITAN_C_START_
struct IntervalTimer {
atomic_uint once;
intptr_t thread;
pthread_mutex_t lock;
pthread_cond_t cond;
struct itimerval it;
};
extern struct IntervalTimer __itimer;
void __itimer_lock(void);
void __itimer_unlock(void);
void __itimer_wipe_and_reset(void);
COSMOPOLITAN_C_END_
#endif /* COSMOPOLITAN_LIBC_ITIMER_H_ */