Rewrite of sigslot that avoids vtables.

webrtc/base/sigslot.cc

Index: webrtc/base/sigslot.cc
diff --git a/webrtc/base/sigslot.cc b/webrtc/base/sigslot.cc
index 9628217dc0729b0847c97a4567650beae235afd8..2fdb214b5200f76e4503c4aa4dd92fe250312696 100644
--- a/webrtc/base/sigslot.cc
+++ b/webrtc/base/sigslot.cc
@@ -12,43 +12,11 @@ namespace sigslot {
 
 #ifdef _SIGSLOT_HAS_POSIX_THREADS
 
-multi_threaded_global::multi_threaded_global() {
-  pthread_mutex_init(get_mutex(), NULL);
-}
-
-multi_threaded_global::multi_threaded_global(const multi_threaded_global&) {
-}
-
-multi_threaded_global::~multi_threaded_global() = default;
-
-void multi_threaded_global::lock() {
-  pthread_mutex_lock(get_mutex());
-}
-
-void multi_threaded_global::unlock() {
-  pthread_mutex_unlock(get_mutex());
-}
-
-multi_threaded_local::multi_threaded_local() {
-  pthread_mutex_init(&m_mutex, NULL);
-}
-
-multi_threaded_local::multi_threaded_local(const multi_threaded_local&) {
-  pthread_mutex_init(&m_mutex, NULL);
-}
-
-multi_threaded_local::~multi_threaded_local() {
-  pthread_mutex_destroy(&m_mutex);
-}
-
-void multi_threaded_local::lock() {
-  pthread_mutex_lock(&m_mutex);
-}
-
-void multi_threaded_local::unlock() {
-  pthread_mutex_unlock(&m_mutex);
+pthread_mutex_t* multi_threaded_global::get_mutex() {
+  static pthread_mutex_t g_mutex = PTHREAD_MUTEX_INITIALIZER;
+  return &g_mutex;
 }
 
 #endif  // _SIGSLOT_HAS_POSIX_THREADS
 
-};  // namespace sigslot
+}  // namespace sigslot