renderer: take separate lock instead of exclusive lock for present queue

This looks rather messy. But is solves an important performance issue
where decode thread would be blocked waiting flip by render thread while
it was rendering current frame.

Without this faster than display rate decode is not possible

diff --git a/xbmc/cores/VideoRenderers/RenderManager.cpp b/xbmc/cores/VideoRenderers/RenderManager.cpp
index 0acb3ea..1c8cdaa 100644 (file)
--- a/xbmc/cores/VideoRenderers/RenderManager.cpp
+++ b/xbmc/cores/VideoRenderers/RenderManager.cpp
@@ -329,7 +329,7 @@ void CXBMCRenderManager::Update()
 bool CXBMCRenderManager::FrameWait(int ms)
 {
   XbmcThreads::EndTime timeout(ms);
-  CRetakeLock<CExclusiveLock> lock(m_sharedSection);
+  CSingleLock lock(m_presentlock);
   while(m_presentstep == PRESENT_IDLE && !timeout.IsTimePast())
   {
     lock.Leave();
@@ -341,7 +341,9 @@ bool CXBMCRenderManager::FrameWait(int ms)
 
 void CXBMCRenderManager::FrameMove()
 {
-  { CRetakeLock<CExclusiveLock> lock(m_sharedSection);
+  { CSharedLock lock(m_sharedSection);
+    CSingleLock lock2(m_presentlock);
+
     if (!m_pRenderer)
       return;
 
@@ -387,7 +389,7 @@ void CXBMCRenderManager::FrameFinish()
   if(g_graphicsContext.IsFullScreenVideo())
     WaitPresentTime(m_presenttime);
 
-  { CRetakeLock<CExclusiveLock> lock(m_sharedSection);
+  { CSingleLock lock(m_presentlock);
 
     if(m_presentstep == PRESENT_FRAME)
     {
@@ -640,7 +642,7 @@ void CXBMCRenderManager::SetViewMode(int iViewMode)
 
 void CXBMCRenderManager::FlipPage(volatile bool& bStop, double timestamp /* = 0LL*/, int source /*= -1*/, EFIELDSYNC sync /*= FS_NONE*/)
 {
-  { CRetakeLock<CExclusiveLock> lock(m_sharedSection);
+  { CSharedLock lock(m_sharedSection);
 
     if(bStop)
       return;
@@ -692,6 +694,8 @@ void CXBMCRenderManager::FlipPage(volatile bool& bStop, double timestamp /* = 0L
     if(timestamp > GetPresentTime() + 5.0)
       timestamp = GetPresentTime() + 5.0;
 
+    CSingleLock lock2(m_presentlock);
+
     if(source < 0)
       source = GetNextDecode();
 
@@ -978,12 +982,14 @@ EINTERLACEMETHOD CXBMCRenderManager::AutoInterlaceMethodInternal(EINTERLACEMETHO
 int CXBMCRenderManager::WaitForBuffer(volatile bool& bStop, int timeout)
 {
   CSharedLock lock(m_sharedSection);
+  CSingleLock lock2(m_presentlock);
   if (!m_pRenderer)
     return -1;
 
   XbmcThreads::EndTime endtime(timeout);
   while(GetNextDecode() < 0)
   {
+    lock2.Leave();
     lock.Leave();
     m_presentevent.WaitMSec(std::min(50, timeout));
     if(endtime.IsTimePast() || bStop)
@@ -993,6 +999,7 @@ int CXBMCRenderManager::WaitForBuffer(volatile bool& bStop, int timeout)
       return -1;
     }
     lock.Enter();
+    lock2.Enter();
   }
 
   // make sure overlay buffer is released, this won't happen on AddOverlay
@@ -1020,6 +1027,8 @@ int CXBMCRenderManager::GetNextDecode()
 
 void CXBMCRenderManager::PrepareNextRender()
 {
+  CSingleLock lock(m_presentlock);
+
   int nxt = GetNextRender();
   if (nxt < 0)
     return;
@@ -1058,7 +1067,8 @@ void CXBMCRenderManager::PrepareNextRender()
 
 void CXBMCRenderManager::DiscardBuffer()
 {
-  CRetakeLock<CExclusiveLock> lock(m_sharedSection);
+  CSharedLock lock(m_sharedSection);
+  CSingleLock lock2(m_presentlock);
   while(m_QueueOutput != m_QueueRender)
   {
     m_pRenderer->ReleaseBuffer(m_QueueOutput);

diff --git a/xbmc/cores/VideoRenderers/RenderManager.h b/xbmc/cores/VideoRenderers/RenderManager.h
index 1a4adc9..4efabde 100644 (file)
--- a/xbmc/cores/VideoRenderers/RenderManager.h
+++ b/xbmc/cores/VideoRenderers/RenderManager.h
@@ -248,6 +248,7 @@ protected:
   EPRESENTSTEP     m_presentstep;
   int        m_presentsource;
   CEvent     m_presentevent;
+  CCriticalSection m_presentlock;
   CEvent     m_flushEvent;