mirror of
https://github.com/jart/cosmopolitan.git
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8c645fa1ee
It's now possible to create thousands of thousands of sparse independent memory mappings, without any slowdown. The memory manager is better with tracking memory protection now, particularly on Windows in a precise way that can be restored during fork(). You now have the highest quality mem manager possible. It's even better than some OSes like XNU, where mmap() is implemented as an O(n) operation which means sadly things aren't much improved over there. With this change the llamafile HTTP server endpoint at /tokenize with a prompt of 50 tokens is now able to handle 2.6m r/sec
100 lines
4.3 KiB
C
100 lines
4.3 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2023 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/dce.h"
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#include "libc/errno.h"
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#include "libc/intrin/atomic.h"
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#include "libc/intrin/weaken.h"
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#include "libc/runtime/internal.h"
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#include "libc/thread/lock.h"
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#include "libc/thread/thread.h"
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#include "third_party/nsync/mu.h"
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/**
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* Attempts acquiring lock.
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*
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* Unlike pthread_mutex_lock() this function won't block and instead
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* returns an error immediately if the lock couldn't be acquired.
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*
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* @return 0 if lock was acquired, otherwise an errno
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* @raise EAGAIN if maximum number of recursive locks is held
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* @raise EBUSY if lock is currently held in read or write mode
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* @raise EINVAL if `mutex` doesn't refer to an initialized lock
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* @raise EDEADLK if `mutex` is `PTHREAD_MUTEX_ERRORCHECK` and the
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* current thread already holds this mutex
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*/
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errno_t pthread_mutex_trylock(pthread_mutex_t *mutex) {
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int me;
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uint64_t word, lock;
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// get current state of lock
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word = atomic_load_explicit(&mutex->_word, memory_order_relaxed);
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// delegate to *NSYNC if possible
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if (MUTEX_TYPE(word) == PTHREAD_MUTEX_NORMAL &&
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MUTEX_PSHARED(word) == PTHREAD_PROCESS_PRIVATE && //
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_weaken(nsync_mu_trylock)) {
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if (_weaken(nsync_mu_trylock)((nsync_mu *)mutex)) {
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return 0;
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} else {
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return EBUSY;
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}
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}
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// handle normal mutexes
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if (MUTEX_TYPE(word) == PTHREAD_MUTEX_NORMAL) {
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word = MUTEX_UNLOCK(word);
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lock = MUTEX_LOCK(word);
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if (atomic_compare_exchange_weak_explicit(&mutex->_word, &word, lock,
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memory_order_acquire,
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memory_order_relaxed))
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return 0;
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return EBUSY;
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}
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// handle recursive and error check mutexes
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me = gettid();
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for (;;) {
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if (MUTEX_OWNER(word) == me) {
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if (MUTEX_TYPE(word) != PTHREAD_MUTEX_ERRORCHECK) {
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if (MUTEX_DEPTH(word) < MUTEX_DEPTH_MAX) {
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if (atomic_compare_exchange_weak_explicit(
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&mutex->_word, &word, MUTEX_INC_DEPTH(word),
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memory_order_relaxed, memory_order_relaxed))
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return 0;
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continue;
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} else {
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return EAGAIN;
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}
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} else {
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return EDEADLK;
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}
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}
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word = MUTEX_UNLOCK(word);
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lock = MUTEX_LOCK(word);
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lock = MUTEX_SET_OWNER(lock, me);
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if (atomic_compare_exchange_weak_explicit(&mutex->_word, &word, lock,
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memory_order_acquire,
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memory_order_relaxed)) {
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mutex->_pid = __pid;
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return 0;
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}
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return EBUSY;
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}
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}
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