From fb4f266a1b9f6a20e256d192a940ae4ccc510fad Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Mon, 13 Jul 2009 21:59:37 -0700
Subject: [PATCH] add a ctor to Mutex to specify the type, which can be shared.
 This is used by sf and af an soon will allow some optimization in the kernel
 for non shared mutexes

---
 include/private/ui/SharedState.h |  2 ++
 include/utils/threads.h          | 17 +++++++++++++++++
 media/libmedia/AudioTrack.cpp    |  2 +-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/include/private/ui/SharedState.h b/include/private/ui/SharedState.h
index 3bc7979ca8109..c9f6b5edb9ab4 100644
--- a/include/private/ui/SharedState.h
+++ b/include/private/ui/SharedState.h
@@ -98,6 +98,8 @@ struct layer_cblk_t     // (128 bytes)
 
 struct per_client_cblk_t   // 4KB max
 {
+    per_client_cblk_t() : lock(Mutex::SHARED) { }
+
                 Mutex           lock;
                 Condition       cv;
                 layer_cblk_t    layers[NUM_LAYERS_MAX] __attribute__((aligned(32)));
diff --git a/include/utils/threads.h b/include/utils/threads.h
index 5c03965960746..e9b0788895e2f 100644
--- a/include/utils/threads.h
+++ b/include/utils/threads.h
@@ -190,8 +190,14 @@ inline thread_id_t getThreadId() {
  */
 class Mutex {
 public:
+    enum {
+        NORMAL = 0,
+        SHARED = 1
+    };
+    
                 Mutex();
                 Mutex(const char* name);
+                Mutex(int type, const char* name = NULL);
                 ~Mutex();
 
     // lock or unlock the mutex
@@ -235,6 +241,17 @@ inline Mutex::Mutex() {
 inline Mutex::Mutex(const char* name) {
     pthread_mutex_init(&mMutex, NULL);
 }
+inline Mutex::Mutex(int type, const char* name) {
+    if (type == SHARED) {
+        pthread_mutexattr_t attr;
+        pthread_mutexattr_init(&attr);
+        pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
+        pthread_mutex_init(&mMutex, &attr);
+        pthread_mutexattr_destroy(&attr);
+    } else {
+        pthread_mutex_init(&mMutex, NULL);
+    }
+}
 inline Mutex::~Mutex() {
     pthread_mutex_destroy(&mMutex);
 }
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index af7dae5f502f9..7b9eda76d8200 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -891,7 +891,7 @@ void AudioTrack::AudioTrackThread::onFirstRef()
 // =========================================================================
 
 audio_track_cblk_t::audio_track_cblk_t()
-    : user(0), server(0), userBase(0), serverBase(0), buffers(0), frameCount(0),
+    : lock(Mutex::SHARED), user(0), server(0), userBase(0), serverBase(0), buffers(0), frameCount(0),
     loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0), flowControlFlag(1), forceReady(0)
 {
 }