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
--- /dev/null
+++ 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_);
+}