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Use *NSYNC for POSIX threads locking APIs

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Condition variables, barriers, and r/w locks now work very well.
This commit is contained in:
Justine Tunney 2022-09-11 11:02:07 -07:00
parent 3de35e196c
commit b5cb71ab84
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GPG key ID: BE714B4575D6E328
197 changed files with 3734 additions and 3817 deletions
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85
libc/thread/nsync_sem_wait.c Normal file
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/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2016 Google Inc. │
│ │
│ Licensed under the Apache License, Version 2.0 (the "License"); │
│ you may not use this file except in compliance with the License. │
│ You may obtain a copy of the License at │
│ │
│ http://www.apache.org/licenses/LICENSE-2.0 │
│ │
│ Unless required by applicable law or agreed to in writing, software │
│ distributed under the License is distributed on an "AS IS" BASIS, │
│ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. │
│ See the License for the specific language governing permissions and │
│ limitations under the License. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/errno.h"
#include "third_party/nsync/atomic.h"
#include "third_party/nsync/atomic.internal.h"
#include "third_party/nsync/common.internal.h"
#include "third_party/nsync/dll.h"
#include "third_party/nsync/mu_semaphore.h"
#include "third_party/nsync/wait_s.internal.h"
asm(".ident\t\"\\n\\n\
*NSYNC (Apache 2.0)\\n\
Copyright 2016 Google, Inc.\\n\
https://github.com/google/nsync\"");
// clang-format off
/* Wait until one of:
w->sem is non-zero----decrement it and return 0.
abs_deadline expires---return ETIMEDOUT.
cancel_note is non-NULL and *cancel_note becomes notified---return ECANCELED. */
int nsync_sem_wait_with_cancel_ (waiter *w, nsync_time abs_deadline,
nsync_note cancel_note) {
int sem_outcome;
if (cancel_note == NULL) {
sem_outcome = nsync_mu_semaphore_p_with_deadline (&w->sem, abs_deadline);
} else {
nsync_time cancel_time;
cancel_time = nsync_note_notified_deadline_ (cancel_note);
sem_outcome = ECANCELED;
if (nsync_time_cmp (cancel_time, nsync_time_zero) > 0) {
struct nsync_waiter_s nw;
nw.tag = NSYNC_WAITER_TAG;
nw.sem = &w->sem;
nsync_dll_init_ (&nw.q, &nw);
ATM_STORE (&nw.waiting, 1);
nw.flags = 0;
nsync_mu_lock (&cancel_note->note_mu);
cancel_time = NOTIFIED_TIME (cancel_note);
if (nsync_time_cmp (cancel_time, nsync_time_zero) > 0) {
nsync_time local_abs_deadline;
int deadline_is_nearer = 0;
cancel_note->waiters = nsync_dll_make_last_in_list_ (
cancel_note->waiters, &nw.q);
local_abs_deadline = cancel_time;
if (nsync_time_cmp (abs_deadline, cancel_time) < 0) {
local_abs_deadline = abs_deadline;
deadline_is_nearer = 1;
}
nsync_mu_unlock (&cancel_note->note_mu);
sem_outcome = nsync_mu_semaphore_p_with_deadline (&w->sem,
local_abs_deadline);
if (sem_outcome == ETIMEDOUT && !deadline_is_nearer) {
sem_outcome = ECANCELED;
nsync_note_notify (cancel_note);
}
nsync_mu_lock (&cancel_note->note_mu);
cancel_time = NOTIFIED_TIME (cancel_note);
if (nsync_time_cmp (cancel_time,
nsync_time_zero) > 0) {
cancel_note->waiters = nsync_dll_remove_ (
cancel_note->waiters, &nw.q);
}
}
nsync_mu_unlock (&cancel_note->note_mu);
}
}
return (sem_outcome);
}