commit 82d7ab6c7e0cf971e515134ccf072682dd1a2cdb
author Mathias Agopian <mathias@google.com> Thu Jan 19 18:34:40 2012 -0800
committer Mathias Agopian <mathias@google.com> Tue Jan 24 18:22:56 2012 -0800
tree 1e8929040b814a6648119145260d7c8edfadde1f
parent e8696a40e09b24b634214684d18526187b316a2f

improve SurfaceFlinger dumpsys

It is now possible to say:

dumpsys SurfaceFlinger --latency

to print latency information about all windows

dumpsys SurfaceFlinger --latency window-name

to print the latency stats of the specified window

for instance: dumpsys SurfaceFlinger --latency SurfaceView

The data consists of one line containing global stats, followed by
128 lines of tab separated timestamps in nanosecond.

The first line currently contains the refresh period in nanosecond.
Each 128 following line contains 3 timestamps, of respectively
the app draw time, the vsync timestamp just prior the call to set and
the timestamp of the call to set.

Change-Id: Ib6b6da1d7e2e6ba49c282bdbc0b56a7dc203343a

services/surfaceflinger/DisplayHardware/DisplayHardware.cpp

diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index 438a6da..986aec5 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -350,15 +350,28 @@
 }
 
 // this needs to be thread safe
-nsecs_t DisplayHardware::waitForVSync() const {
+nsecs_t DisplayHardware::waitForRefresh() const {
     nsecs_t timestamp;
     if (mVSync.wait(&timestamp) < 0) {
         // vsync not supported!
         usleep( getDelayToNextVSyncUs(&timestamp) );
     }
+    mLastHwVSync = timestamp; // FIXME: Not thread safe
     return timestamp;
 }
 
+nsecs_t DisplayHardware::getRefreshTimestamp() const {
+    // this returns the last refresh timestamp.
+    // if the last one is not available, we estimate it based on
+    // the refresh period and whatever closest timestamp we have.
+    nsecs_t now = systemTime();
+    return now - ((now - mLastHwVSync) %  mRefreshPeriod);
+}
+
+nsecs_t DisplayHardware::getRefreshPeriod() const {
+    return mRefreshPeriod;
+}
+
 int32_t DisplayHardware::getDelayToNextVSyncUs(nsecs_t* timestamp) const {
     Mutex::Autolock _l(mFakeVSyncMutex);
     const nsecs_t period = mRefreshPeriod;

services/surfaceflinger/DisplayHardware/DisplayHardware.h

diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.h b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
index 77da272..02be4dc 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
@@ -76,7 +76,9 @@
     uint32_t    getMaxViewportDims() const;
 
     // waits for the next vsync and returns the timestamp of when it happened
-    nsecs_t        waitForVSync() const;
+    nsecs_t     waitForRefresh() const;
+    nsecs_t     getRefreshPeriod() const;
+    nsecs_t     getRefreshTimestamp() const;
 
     uint32_t getPageFlipCount() const;
     EGLDisplay getEGLDisplay() const { return mDisplay; }
@@ -119,6 +121,7 @@
     mutable Mutex   mFakeVSyncMutex;
     mutable nsecs_t mNextFakeVSync;
     nsecs_t         mRefreshPeriod;
+    mutable nsecs_t mLastHwVSync;
 
     HWComposer*     mHwc;