gecko-dev/mozglue/misc/Mutex_posix.cpp

134 строки
4.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Assertions.h"
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#if defined(XP_DARWIN)
# include <pthread_spis.h>
#endif
#include "mozilla/PlatformMutex.h"
#include "MutexPlatformData_posix.h"
#define REPORT_PTHREADS_ERROR(result, msg) \
{ \
errno = result; \
perror(msg); \
MOZ_CRASH(msg); \
}
#define TRY_CALL_PTHREADS(call, msg) \
{ \
int result = (call); \
if (result != 0) { \
REPORT_PTHREADS_ERROR(result, msg); \
} \
}
mozilla::detail::MutexImpl::MutexImpl() {
pthread_mutexattr_t* attrp = nullptr;
#if defined(DEBUG)
# define MUTEX_KIND PTHREAD_MUTEX_ERRORCHECK
// Linux with glibc, FreeBSD and macOS 10.14+ support adaptive mutexes that
// spin for a short number of tries before sleeping. NSPR's locks did this,
// too, and it seems like a reasonable thing to do.
#elif (defined(__linux__) && defined(__GLIBC__)) || defined(__FreeBSD__)
# define MUTEX_KIND PTHREAD_MUTEX_ADAPTIVE_NP
#elif defined(XP_DARWIN)
# if defined(PTHREAD_MUTEX_POLICY_FIRSTFIT_NP)
# define POLICY_KIND PTHREAD_MUTEX_POLICY_FIRSTFIT_NP
# else
# define POLICY_KIND (3) // The definition is missing in old SDKs
# endif
#endif
#if defined(MUTEX_KIND) || defined(POLICY_KIND)
# define ATTR_REQUIRED
#endif
#if defined(ATTR_REQUIRED)
pthread_mutexattr_t attr;
TRY_CALL_PTHREADS(
pthread_mutexattr_init(&attr),
"mozilla::detail::MutexImpl::MutexImpl: pthread_mutexattr_init failed");
# if defined(MUTEX_KIND)
TRY_CALL_PTHREADS(pthread_mutexattr_settype(&attr, MUTEX_KIND),
"mozilla::detail::MutexImpl::MutexImpl: "
"pthread_mutexattr_settype failed");
# elif defined(POLICY_KIND)
if (__builtin_available(macOS 10.14, *)) {
TRY_CALL_PTHREADS(pthread_mutexattr_setpolicy_np(&attr, POLICY_KIND),
"mozilla::detail::MutexImpl::MutexImpl: "
"pthread_mutexattr_setpolicy_np failed");
}
# endif
attrp = &attr;
#endif
TRY_CALL_PTHREADS(
pthread_mutex_init(&platformData()->ptMutex, attrp),
"mozilla::detail::MutexImpl::MutexImpl: pthread_mutex_init failed");
#if defined(ATTR_REQUIRED)
TRY_CALL_PTHREADS(pthread_mutexattr_destroy(&attr),
"mozilla::detail::MutexImpl::MutexImpl: "
"pthread_mutexattr_destroy failed");
#endif
}
mozilla::detail::MutexImpl::~MutexImpl() {
TRY_CALL_PTHREADS(
pthread_mutex_destroy(&platformData()->ptMutex),
"mozilla::detail::MutexImpl::~MutexImpl: pthread_mutex_destroy failed");
}
inline void mozilla::detail::MutexImpl::mutexLock() {
TRY_CALL_PTHREADS(
pthread_mutex_lock(&platformData()->ptMutex),
"mozilla::detail::MutexImpl::mutexLock: pthread_mutex_lock failed");
}
bool mozilla::detail::MutexImpl::tryLock() { return mutexTryLock(); }
bool mozilla::detail::MutexImpl::mutexTryLock() {
int result = pthread_mutex_trylock(&platformData()->ptMutex);
if (result == 0) {
return true;
}
if (result == EBUSY) {
return false;
}
REPORT_PTHREADS_ERROR(
result,
"mozilla::detail::MutexImpl::mutexTryLock: pthread_mutex_trylock failed");
}
void mozilla::detail::MutexImpl::lock() { mutexLock(); }
void mozilla::detail::MutexImpl::unlock() {
TRY_CALL_PTHREADS(
pthread_mutex_unlock(&platformData()->ptMutex),
"mozilla::detail::MutexImpl::unlock: pthread_mutex_unlock failed");
}
#undef TRY_CALL_PTHREADS
mozilla::detail::MutexImpl::PlatformData*
mozilla::detail::MutexImpl::platformData() {
static_assert(sizeof(platformData_) >= sizeof(PlatformData),
"platformData_ is too small");
return reinterpret_cast<PlatformData*>(platformData_);
}