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-rw-r--r--mozglue/misc/Mutex_posix.cpp133
1 files changed, 133 insertions, 0 deletions
diff --git a/mozglue/misc/Mutex_posix.cpp b/mozglue/misc/Mutex_posix.cpp
new file mode 100644
index 0000000000..7378a544f2
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+++ b/mozglue/misc/Mutex_posix.cpp
@@ -0,0 +1,133 @@
+/* -*- 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_);
+}