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Add posix semaphores support

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There's still some bugs to work out on Windows and OpenBSD.
This commit is contained in:
Justine Tunney 2022-10-14 08:25:47 -07:00
parent f52f65b2e3
commit 8111462789
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
36 changed files with 779 additions and 59 deletions
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2
libc/thread/freebsd.internal.h
View file

@ -46,7 +46,7 @@ struct _umtx_time {
};
int sys_umtx_op(void *, int, unsigned long, void *, void *);
int sys_umtx_timedwait_uint(int *, int, bool, const struct timespec *);
int sys_umtx_timedwait_uint(_Atomic(int) *, int, bool, const struct timespec *);
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

2
libc/thread/pthread_exit.c
View file

@ -86,7 +86,7 @@ wontreturn void pthread_exit(void *rc) {
// set_tid_address() upon every program startup which isn't possible
// on non-linux platforms anyway.
atomic_store_explicit(&__get_tls()->tib_tid, 0, memory_order_release);
nsync_futex_wake_((int *)&__get_tls()->tib_tid, INT_MAX, !IsWindows());
nsync_futex_wake_(&__get_tls()->tib_tid, INT_MAX, !IsWindows());
_Exit1(0);
}
}

4
libc/thread/pthread_getname_np.c
View file

@ -45,7 +45,7 @@
* @raise ENOSYS on MacOS, Windows, FreeBSD, and OpenBSD
*/
errno_t pthread_getname_np(pthread_t thread, char *name, size_t size) {
int e, fd, rc, tid, len;
int fd, rc, tid, len, e = errno;
if (!size) return 0;
bzero(name, size);
@ -55,7 +55,6 @@ errno_t pthread_getname_np(pthread_t thread, char *name, size_t size) {
// TASK_COMM_LEN is 16 on Linux so we're just being paranoid.
char buf[256] = {0};
if (tid == gettid()) {
e = errno;
if (prctl(PR_GET_NAME, buf) == -1) {
rc = errno;
errno = e;
@ -66,7 +65,6 @@ errno_t pthread_getname_np(pthread_t thread, char *name, size_t size) {
p = stpcpy(p, "/proc/self/task/");
p = FormatUint32(p, tid);
p = stpcpy(p, "/comm");
e = errno;
if ((fd = sys_open(path, O_RDONLY | O_CLOEXEC, 0)) == -1) {
rc = errno;
errno = e;

4
libc/thread/pthread_setname_np.c
View file

@ -53,14 +53,13 @@
*/
errno_t pthread_setname_np(pthread_t thread, const char *name) {
char path[128], *p;
int e, fd, rc, tid, len;
int fd, rc, tid, len, e = errno;
tid = ((struct PosixThread *)thread)->tid;
len = strlen(name);
if (IsLinux()) {
if (tid == gettid()) {
e = errno;
if (prctl(PR_SET_NAME, name) == -1) {
rc = errno;
errno = e;
@ -71,7 +70,6 @@ errno_t pthread_setname_np(pthread_t thread, const char *name) {
p = stpcpy(p, "/proc/self/task/");
p = FormatUint32(p, tid);
p = stpcpy(p, "/comm");
e = errno;
if ((fd = sys_open(path, O_WRONLY | O_CLOEXEC, 0)) == -1) {
rc = errno;
errno = e;

12
libc/thread/pthread_sigmask.c
View file

@ -17,10 +17,20 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/struct/sigset.h"
#include "libc/errno.h"
/**
* Examines and/or changes blocked signals on current thread.
*
* @return 0 on success, or errno on error
*/
int pthread_sigmask(int how, const sigset_t *set, sigset_t *old) {
return sigprocmask(how, set, old);
int rc, e = errno;
if (!sigprocmask(how, set, old)) {
rc = 0;
} else {
rc = errno;
errno = e;
}
return rc;
}

32
libc/thread/sem_close.c Normal file
View file

@ -0,0 +1,32 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/runtime/runtime.h"
#include "libc/thread/semaphore.h"
/**
* Closes named semaphore.
*
* @param sem was created with sem_open()
* @return 0 on success, or -1 w/ errno
*/
int sem_close(sem_t *sem) {
_npassert(!munmap(sem, FRAMESIZE));
return 0;
}

32
libc/thread/sem_destroy.c Normal file
View file

@ -0,0 +1,32 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/atomic.h"
#include "libc/limits.h"
#include "libc/thread/semaphore.h"
/**
* Destroys unnamed semaphore.
*
* @param sem was created by sem_init()
* @return 0 on success, or -1 w/ errno
*/
int sem_destroy(sem_t *sem) {
atomic_store_explicit(&sem->sem_value, INT_MIN, memory_order_relaxed);
return 0;
}

32
libc/thread/sem_getvalue.c Normal file
View file

@ -0,0 +1,32 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/atomic.h"
#include "libc/thread/semaphore.h"
/**
* Destroys unnamed semaphore.
*
* @param sem was created by sem_init()
* @param sval receives output value
* @return 0 on success, or -1 w/ errno
*/
int sem_getvalue(sem_t *sem, int *sval) {
*sval = atomic_load_explicit(&sem->sem_value, memory_order_relaxed);
return 0;
}

39
libc/thread/sem_init.c Normal file
View file

@ -0,0 +1,39 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/atomic.h"
#include "libc/limits.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/semaphore.h"
#include "third_party/nsync/mu_semaphore.h"
/**
* Initializes unnamed semaphore.
*
* @param sem should make its way to sem_destroy() if this succeeds
* @param pshared if semaphore may be shared between processes
* @param value is initial count of semaphore
* @return 0 on success, or -1 w/ errno
* @raise EINVAL if `value` exceeds `SEM_VALUE_MAX`
*/
int sem_init(sem_t *sem, int pshared, unsigned value) {
if (value > SEM_VALUE_MAX) return einval();
atomic_store_explicit(&sem->sem_value, value, memory_order_relaxed);
sem->sem_pshared = pshared;
return 0;
}

34
libc/thread/sem_name.c Normal file
View file

@ -0,0 +1,34 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/runtime/runtime.h"
#include "libc/str/path.h"
#include "libc/str/str.h"
#include "libc/thread/semaphore.internal.h"
#include "libc/thread/thread.h"
const char *__sem_name(const char *name, char path[hasatleast PATH_MAX]) {
if (_isabspath(name)) {
return name;
} else {
strlcpy(path, kTmpPath, PATH_MAX);
strlcat(path, ".sem-", PATH_MAX);
strlcat(path, name, PATH_MAX);
return path;
}
}

72
libc/thread/sem_open.c Normal file
View file

@ -0,0 +1,72 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/calls.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/at.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "libc/thread/semaphore.h"
#include "libc/thread/semaphore.internal.h"
/**
* Initializes and opens named semaphore.
*
* @param name can be absolute path or should be component w/o slashes
* @param oflga can have `O_CREAT` and/or `O_EXCL`
* @return semaphore object which needs sem_close(), or SEM_FAILED w/ errno
* @raise ENOTDIR if a directory component in `name` exists as non-directory
* @raise ENAMETOOLONG if symlink-resolved `name` length exceeds `PATH_MAX`
* @raise ENAMETOOLONG if component in `name` exists longer than `NAME_MAX`
* @raise ELOOP if `flags` had `O_NOFOLLOW` and `name` is a symbolic link
* @raise ENOSPC if file system is full when `name` would be `O_CREAT`ed
* @raise ELOOP if a loop was detected resolving components of `name`
* @raise EEXIST if `O_CREAT|O_EXCL` is used and semaphore exists
* @raise EACCES if we didn't have permission to create semaphore
* @raise EMFILE if process `RLIMIT_NOFILE` has been reached
* @raise ENFILE if system-wide file limit has been reached
* @raise EINTR if signal was delivered instead
*/
sem_t *sem_open(const char *name, int oflag, ...) {
int fd;
sem_t *sem;
va_list va;
unsigned mode;
char path[PATH_MAX];
va_start(va, oflag);
mode = va_arg(va, unsigned);
va_end(va);
oflag |= O_RDWR | O_CLOEXEC;
if ((fd = openat(AT_FDCWD, __sem_name(name, path), oflag, mode)) == -1) {
return SEM_FAILED;
}
if (ftruncate(fd, sizeof(sem_t)) == -1) {
_npassert(!close(fd));
return SEM_FAILED;
}
sem = mmap(0, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (sem != MAP_FAILED) sem->sem_pshared = true;
_npassert(!close(fd));
return sem;
}

44
libc/thread/sem_post.c Normal file
View file

@ -0,0 +1,44 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/errno.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/semaphore.h"
#include "third_party/nsync/futex.internal.h"
/**
* Unlocks semaphore.
*
* @return 0 on success, or -1 w/ errno
* @raise EINVAL if `sem` isn't valid
*/
int sem_post(sem_t *sem) {
int rc;
int old = atomic_fetch_add_explicit(&sem->sem_value, 1, memory_order_relaxed);
if (old >= 0) {
_npassert(nsync_futex_wake_(&sem->sem_value, 1, sem->sem_pshared) >= 0);
rc = 0;
} else {
rc = einval();
}
STRACE("sem_post(%p) → %d% m", sem, rc);
return rc;
}

113
libc/thread/sem_timedwait.c Normal file
View file

@ -0,0 +1,113 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/struct/timespec.h"
#include "libc/calls/struct/timespec.internal.h"
#include "libc/errno.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/semaphore.h"
#include "libc/thread/semaphore.internal.h"
#include "third_party/nsync/futex.internal.h"
static void sem_delay(int n) {
volatile int i;
for (i = 0; i != 1 << n; i++) donothing;
}
// TODO(jart): This should be abstracted by polyfill.
static struct timespec *sem_timeout(struct timespec *memory,
const struct timespec *abstime) {
struct timespec now;
if (!abstime) {
return 0;
} else if (FUTEX_TIMEOUT_IS_ABSOLUTE) {
*memory = *abstime;
return memory;
} else {
now = _timespec_real();
if (_timespec_cmp(now, *abstime) > 0) {
*memory = (struct timespec){0};
} else {
*memory = _timespec_sub(*abstime, now);
}
return memory;
}
}
/**
* Locks semaphore w/ deadline.
*
* @param abstime is absolute deadline or null to wait forever
* @return 0 on success, or -1 w/ errno
* @raise EINTR if signal was delivered instead
* @raise EDEADLK if deadlock was detected
* @raise ETIMEDOUT if deadline expired
* @raise EINVAL if `sem` is invalid
*/
int sem_timedwait(sem_t *sem, const struct timespec *abstime) {
int e, i, v, rc;
struct timespec ts;
e = errno;
for (i = 0; i < 7; ++i) {
rc = sem_trywait(sem);
if (!rc) {
return rc;
} else if (errno == EAGAIN) {
errno = e;
sem_delay(i);
} else {
return rc;
}
}
do {
if (!(v = atomic_load_explicit(&sem->sem_value, memory_order_relaxed))) {
rc = nsync_futex_wait_(&sem->sem_value, v, sem->sem_pshared,
sem_timeout(&ts, abstime));
if (rc == -EINTR) {
rc = eintr();
} else if (rc == -EAGAIN || rc == -EWOULDBLOCK) {
rc = 0;
} else if (rc == -ETIMEDOUT) {
_npassert(abstime);
if (_timespec_cmp(*abstime, _timespec_real()) <= 0) {
rc = etimedout();
} else {
rc = 0;
}
} else {
_npassert(!rc);
rc = 0;
}
} else if (v > 0) {
rc = 0;
} else {
rc = einval();
}
} while (!rc && (!v || !atomic_compare_exchange_weak_explicit(
&sem->sem_value, &v, v - 1, memory_order_acquire,
memory_order_relaxed)));
STRACE("sem_timedwait(%p, %s) → %d% m", sem, DescribeTimespec(0, abstime),
rc);
return rc;
}

42
libc/thread/sem_trywait.c Normal file
View file

@ -0,0 +1,42 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/errno.h"
#include "libc/intrin/atomic.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/semaphore.h"
/**
* Locks semaphore only if it's currently not locked.
*
* @return 0 on success, or -1 w/ errno
* @raise EAGAIN if semaphore is locked
* @raise EDEADLK if deadlock was detected
* @raise EINVAL if `sem` is invalid
*/
int sem_trywait(sem_t *sem) {
int v;
v = atomic_load_explicit(&sem->sem_value, memory_order_relaxed);
do {
if (!v) return eagain();
if (v < 0) return einval();
} while (!atomic_compare_exchange_weak_explicit(
&sem->sem_value, &v, v - 1, memory_order_acquire, memory_order_relaxed));
return 0;
}

35
libc/thread/sem_unlink.c Normal file
View file

@ -0,0 +1,35 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/thread/semaphore.h"
#include "libc/thread/semaphore.internal.h"
/**
* Removes named semaphore.
*
* @param name can be absolute path or should be component w/o slashes
* @return 0 on success, or -1 w/ errno
* @raise EPERM if pledge() is in play w/o `cpath` promise
* @raise ENOENT if named semaphore doesn't exist
* @raise EACCES if permission is denied
*/
int sem_unlink(const char *name) {
char path[PATH_MAX];
return unlink(__sem_name(name, path));
}

31
libc/thread/sem_wait.c Normal file
View file

@ -0,0 +1,31 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/thread/semaphore.h"
/**
* Locks semaphore.
*
* @return 0 on success, or -1 w/ errno
* @raise EINTR if signal was delivered instead
* @raise EDEADLK if deadlock was detected
* @raise EINVAL if `sem` is invalid
*/
int sem_wait(sem_t *sem) {
return sem_timedwait(sem, 0);
}

32
libc/thread/semaphore.h Normal file
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@ -0,0 +1,32 @@
#ifndef COSMOPOLITAN_LIBC_CALLS_SEMAPHORE_H_
#define COSMOPOLITAN_LIBC_CALLS_SEMAPHORE_H_
#include "libc/calls/struct/timespec.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
#define SEM_FAILED ((sem_t *)0)
typedef struct {
union {
struct {
_Atomic(int) sem_value;
bool sem_pshared;
};
void *sem_space[32];
};
} sem_t;
int sem_init(sem_t *, int, unsigned);
int sem_destroy(sem_t *);
int sem_post(sem_t *);
int sem_wait(sem_t *);
int sem_trywait(sem_t *);
int sem_timedwait(sem_t *, const struct timespec *);
int sem_getvalue(sem_t *, int *);
sem_t *sem_open(const char *, int, ...);
int sem_close(sem_t *);
int sem_unlink(const char *);
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_CALLS_SEMAPHORE_H_ */

10
libc/thread/semaphore.internal.h Normal file
View file

@ -0,0 +1,10 @@
#ifndef COSMOPOLITAN_LIBC_THREAD_SEMAPHORE_INTERNAL_H_
#define COSMOPOLITAN_LIBC_THREAD_SEMAPHORE_INTERNAL_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
const char *__sem_name(const char *, char[hasatleast PATH_MAX]) hidden;
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_THREAD_SEMAPHORE_INTERNAL_H_ */

6
libc/thread/thread.h
View file

@ -200,8 +200,6 @@ void _pthread_cleanup_push(struct _pthread_cleanup_buffer *, void (*)(void *),
_pthread_cleanup_pop(&_buffer, (execute)); \
}
#define pthread_spin_init(pSpin, multiprocess) ((pSpin)->_lock = 0, 0)
#define pthread_spin_destroy(pSpin) ((pSpin)->_lock = -1, 0)
#if (__GNUC__ + 0) * 100 + (__GNUC_MINOR__ + 0) >= 407 && \
!defined(__STRICT_ANSI__)
extern const errno_t EBUSY;
@ -222,6 +220,10 @@ extern const errno_t EBUSY;
pthread_spinlock_t *_s = pSpin; \
__atomic_test_and_set(&_s->_lock, __ATOMIC_ACQUIRE) ? EBUSY : 0; \
})
#define pthread_spin_init(pSpin, multiprocess) \
(__atomic_store_n(&(pSpin)->_lock, 0, __ATOMIC_RELAXED), 0)
#define pthread_spin_destroy(pSpin) \
(__atomic_store_n(&(pSpin)->_lock, -1, __ATOMIC_RELAXED), 0)
#endif /* GCC 4.7+ */
COSMOPOLITAN_C_END_

2
libc/thread/wait0.c
View file

@ -33,6 +33,6 @@
void _wait0(const atomic_int *ctid) {
int x;
while ((x = atomic_load_explicit(ctid, memory_order_relaxed))) {
nsync_futex_wait_((int *)ctid, x, !IsWindows(), 0);
nsync_futex_wait_(ctid, x, !IsWindows(), 0);
}
}