commit bb641244d7d73312dc65b8e338df18b22e335107
author Mathias Agopian <mathias@google.com> Tue May 18 17:06:55 2010 -0700
committer Mathias Agopian <mathias@google.com> Thu May 20 18:00:42 2010 -0700
tree 4a3e6e847513ad28bedd8de68da4ef2bd6ebf5ff
parent dcf01e6644d0e9eca5aa08ee1b16a0d29d039e5e

fix the threading issue for setBuffercount()

this change introduces R/W locks in the right places.
on the server-side, it guarantees that setBufferCount()
is synchronized with "retire" and "resize".
on the client-side, it guarantees that setBufferCount()
is synchronized with "dequeue", "lockbuffer" and "queue"

libs/surfaceflinger/MessageQueue.cpp

diff --git a/libs/surfaceflinger/MessageQueue.cpp b/libs/surfaceflinger/MessageQueue.cpp
index b43d801..d668e88 100644
--- a/libs/surfaceflinger/MessageQueue.cpp
+++ b/libs/surfaceflinger/MessageQueue.cpp
@@ -60,9 +60,9 @@
 {
 }
 
-MessageList::value_type MessageQueue::waitMessage(nsecs_t timeout)
+sp<MessageBase> MessageQueue::waitMessage(nsecs_t timeout)
 {
-    MessageList::value_type result;
+    sp<MessageBase> result;
 
     bool again;
     do {
@@ -132,6 +132,7 @@
         if (again) {
             // the message has been processed. release our reference to it
             // without holding the lock.
+            result->notify();
             result = 0;
         }
         
@@ -141,7 +142,7 @@
 }
 
 status_t MessageQueue::postMessage(
-        const MessageList::value_type& message, nsecs_t relTime, uint32_t flags)
+        const sp<MessageBase>& message, nsecs_t relTime, uint32_t flags)
 {
     return queueMessage(message, relTime, flags);
 }
@@ -154,7 +155,7 @@
 }
 
 status_t MessageQueue::queueMessage(
-        const MessageList::value_type& message, nsecs_t relTime, uint32_t flags)
+        const sp<MessageBase>& message, nsecs_t relTime, uint32_t flags)
 {
     Mutex::Autolock _l(mLock);
     message->when = systemTime() + relTime;
@@ -167,13 +168,13 @@
     return NO_ERROR;
 }
 
-void MessageQueue::dump(const MessageList::value_type& message)
+void MessageQueue::dump(const sp<MessageBase>& message)
 {
     Mutex::Autolock _l(mLock);
     dumpLocked(message);
 }
 
-void MessageQueue::dumpLocked(const MessageList::value_type& message)
+void MessageQueue::dumpLocked(const sp<MessageBase>& message)
 {
     LIST::const_iterator cur(mMessages.begin());
     LIST::const_iterator end(mMessages.end());