1 files changed, 64 insertions, 0 deletions
diff --git a/mozglue/misc/RWLock_posix.cpp b/mozglue/misc/RWLock_posix.cpp
new file mode 100644
index 0000000000..970bddd1aa
--- /dev/null
+++ b/mozglue/misc/RWLock_posix.cpp
@@ -0,0 +1,64 @@
+/* -*- 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/. */
+
+#ifdef XP_WIN
+#  error This file should only be compiled on non-Windows platforms.
+#endif
+
+#include "mozilla/PlatformRWLock.h"
+
+#include "mozilla/Assertions.h"
+
+#include <errno.h>
+
+// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
+mozilla::detail::RWLockImpl::RWLockImpl() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_init(&mRWLock, nullptr) == 0,
+                     "pthread_rwlock_init failed");
+}
+
+mozilla::detail::RWLockImpl::~RWLockImpl() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_destroy(&mRWLock) == 0,
+                     "pthread_rwlock_destroy failed");
+}
+
+bool mozilla::detail::RWLockImpl::tryReadLock() {
+  int rv = pthread_rwlock_tryrdlock(&mRWLock);
+  // We allow EDEADLK here because it has been observed returned on macos when
+  // the write lock is held by the current thread.
+  MOZ_RELEASE_ASSERT(rv == 0 || rv == EBUSY || rv == EDEADLK,
+                     "pthread_rwlock_tryrdlock failed");
+  return rv == 0;
+}
+
+void mozilla::detail::RWLockImpl::readLock() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_rdlock(&mRWLock) == 0,
+                     "pthread_rwlock_rdlock failed");
+}
+
+void mozilla::detail::RWLockImpl::readUnlock() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(&mRWLock) == 0,
+                     "pthread_rwlock_unlock failed");
+}
+
+bool mozilla::detail::RWLockImpl::tryWriteLock() {
+  int rv = pthread_rwlock_trywrlock(&mRWLock);
+  // We allow EDEADLK here because it has been observed returned on macos when
+  // the write lock is held by the current thread.
+  MOZ_RELEASE_ASSERT(rv == 0 || rv == EBUSY || rv == EDEADLK,
+                     "pthread_rwlock_trywrlock failed");
+  return rv == 0;
+}
+
+void mozilla::detail::RWLockImpl::writeLock() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_wrlock(&mRWLock) == 0,
+                     "pthread_rwlock_wrlock failed");
+}
+
+void mozilla::detail::RWLockImpl::writeUnlock() {
+  MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(&mRWLock) == 0,
+                     "pthread_rwlock_unlock failed");
+}