Add support for sending VSYNC events to the framework

use gui/DisplayEvent to receive the events. Events are
dispatched through a unix pipe, so the API is compatible
with utils/Looper. see gui/DisplayEvent.h for more info.

Bug: 1475048
Change-Id: If4126023fc9c067e56087ec7d16a8fd542ce1794

8 files changed, 153 insertions, 28 deletions

diff --git a/include/surfaceflinger/ISurfaceComposer.h b/include/surfaceflinger/ISurfaceComposer.h
index 5eb09c79666a..58fd89d3b62c 100644
--- a/include/surfaceflinger/ISurfaceComposer.h
+++ b/include/surfaceflinger/ISurfaceComposer.h
@@ -33,8 +33,9 @@
 namespace android {
 // ----------------------------------------------------------------------------
 
-class IMemoryHeap;
 class ComposerState;
+class IDisplayEventConnection;
+class IMemoryHeap;
 
 class ISurfaceComposer : public IInterface
 {
@@ -124,13 +125,19 @@ public:
             uint32_t reqWidth, uint32_t reqHeight,
             uint32_t minLayerZ, uint32_t maxLayerZ) = 0;
 
+    /* triggers screen off animation */
     virtual status_t turnElectronBeamOff(int32_t mode) = 0;
+
+    /* triggers screen on animation */
     virtual status_t turnElectronBeamOn(int32_t mode) = 0;
 
     /* verify that an ISurfaceTexture was created by SurfaceFlinger.
      */
     virtual bool authenticateSurfaceTexture(
             const sp<ISurfaceTexture>& surface) const = 0;
+
+    /* return an IDisplayEventConnection */
+    virtual sp<IDisplayEventConnection> createDisplayEventConnection() = 0;
 };
 
 // ----------------------------------------------------------------------------
@@ -151,6 +158,7 @@ public:
         TURN_ELECTRON_BEAM_OFF,
         TURN_ELECTRON_BEAM_ON,
         AUTHENTICATE_SURFACE,
+        CREATE_DISPLAY_EVENT_CONNECTION,
     };
 
     virtual status_t    onTransact( uint32_t code,
diff --git a/libs/gui/Android.mk b/libs/gui/Android.mk
index b7e3ee32c62f..b8be67d446ce 100644
--- a/libs/gui/Android.mk
+++ b/libs/gui/Android.mk
@@ -3,6 +3,8 @@ include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= \
 	BitTube.cpp \
+	DisplayEventReceiver.cpp \
+	IDisplayEventConnection.cpp \
 	ISensorEventConnection.cpp \
 	ISensorServer.cpp \
 	ISurfaceTexture.cpp \
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 86bc62aa2806..db3282781ab3 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -29,6 +29,9 @@
 
 #include <surfaceflinger/ISurfaceComposer.h>
 
+#include <gui/BitTube.h>
+#include <gui/IDisplayEventConnection.h>
+
 #include <ui/DisplayInfo.h>
 
 #include <gui/ISurfaceTexture.h>
@@ -44,6 +47,8 @@
 
 namespace android {
 
+class IDisplayEventConnection;
+
 class BpSurfaceComposer : public BpInterface<ISurfaceComposer>
 {
 public:
@@ -174,6 +179,27 @@ public:
         }
         return result != 0;
     }
+
+    virtual sp<IDisplayEventConnection> createDisplayEventConnection()
+    {
+        Parcel data, reply;
+        sp<IDisplayEventConnection> result;
+        int err = data.writeInterfaceToken(
+                ISurfaceComposer::getInterfaceDescriptor());
+        if (err != NO_ERROR) {
+            return result;
+        }
+        err = remote()->transact(
+                BnSurfaceComposer::CREATE_DISPLAY_EVENT_CONNECTION,
+                data, &reply);
+        if (err != NO_ERROR) {
+            LOGE("ISurfaceComposer::createDisplayEventConnection: error performing "
+                    "transaction: %s (%d)", strerror(-err), -err);
+            return result;
+        }
+        result = interface_cast<IDisplayEventConnection>(reply.readStrongBinder());
+        return result;
+    }
 };
 
 IMPLEMENT_META_INTERFACE(SurfaceComposer, "android.ui.ISurfaceComposer");
@@ -254,6 +280,12 @@ status_t BnSurfaceComposer::onTransact(
             int32_t result = authenticateSurfaceTexture(surfaceTexture) ? 1 : 0;
             reply->writeInt32(result);
         } break;
+        case CREATE_DISPLAY_EVENT_CONNECTION: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            sp<IDisplayEventConnection> connection(createDisplayEventConnection());
+            reply->writeStrongBinder(connection->asBinder());
+            return NO_ERROR;
+        } break;
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 61a8358332eb..17bf375a1d7d 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -2,19 +2,22 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES:= \
-    Layer.cpp 								\
-    LayerBase.cpp 							\
-    LayerDim.cpp 							\
-    LayerScreenshot.cpp						\
-    DdmConnection.cpp						\
-    DisplayHardware/DisplayHardware.cpp 	\
+    EventThread.cpp                         \
+    Layer.cpp                               \
+    LayerBase.cpp                           \
+    LayerDim.cpp                            \
+    LayerScreenshot.cpp                     \
+    DdmConnection.cpp                       \
+    DisplayHardware/DisplayHardware.cpp     \
     DisplayHardware/DisplayHardwareBase.cpp \
-    DisplayHardware/HWComposer.cpp 			\
-    GLExtensions.cpp 						\
-    MessageQueue.cpp 						\
-    SurfaceFlinger.cpp 						\
-    SurfaceTextureLayer.cpp 				\
-    Transform.cpp 							\
+    DisplayHardware/HWComposer.cpp          \
+    DisplayHardware/VSyncBarrier.cpp        \
+    DisplayEventConnection.cpp              \
+    GLExtensions.cpp                        \
+    MessageQueue.cpp                        \
+    SurfaceFlinger.cpp                      \
+    SurfaceTextureLayer.cpp                 \
+    Transform.cpp                           \
     
 
 LOCAL_CFLAGS:= -DLOG_TAG=\"SurfaceFlinger\"
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index f94d32149b0f..3bbc75e6f8a6 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -140,6 +140,7 @@ void DisplayHardware::init(uint32_t dpy)
     mDpiX = mNativeWindow->xdpi;
     mDpiY = mNativeWindow->ydpi;
     mRefreshRate = fbDev->fps;
+    mNextFakeVSync = 0;
 
 
 /* FIXME: this is a temporary HACK until we are able to report the refresh rate
@@ -152,6 +153,8 @@ void DisplayHardware::init(uint32_t dpy)
 #warning "refresh rate set via makefile to REFRESH_RATE"
 #endif
 
+    mRefreshPeriod = nsecs_t(1e9 / mRefreshRate);
+
     EGLint w, h, dummy;
     EGLint numConfigs=0;
     EGLSurface surface;
@@ -346,6 +349,37 @@ uint32_t DisplayHardware::getPageFlipCount() const {
     return mPageFlipCount;
 }
 
+// this needs to be thread safe
+nsecs_t DisplayHardware::waitForVSync() const {
+    nsecs_t timestamp;
+    if (mVSync.wait(&timestamp) < 0) {
+        // vsync not supported!
+        usleep( getDelayToNextVSyncUs(&timestamp) );
+    }
+    return timestamp;
+}
+
+int32_t DisplayHardware::getDelayToNextVSyncUs(nsecs_t* timestamp) const {
+    Mutex::Autolock _l(mFakeVSyncMutex);
+    const nsecs_t period = mRefreshPeriod;
+    const nsecs_t now = systemTime(CLOCK_MONOTONIC);
+    nsecs_t next_vsync = mNextFakeVSync;
+    nsecs_t sleep = next_vsync - now;
+    if (sleep < 0) {
+        // we missed, find where the next vsync should be
+        sleep = (period - ((now - next_vsync) % period));
+        next_vsync = now + sleep;
+    }
+    mNextFakeVSync = next_vsync + period;
+    timestamp[0] = next_vsync;
+
+    // round to next microsecond
+    int32_t sleep_us = (sleep + 999LL) / 1000LL;
+
+    // guaranteed to be > 0
+    return sleep_us;
+}
+
 status_t DisplayHardware::compositionComplete() const {
     return mNativeWindow->compositionComplete();
 }
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.h b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
index f02c95414fae..45d4b45ad934 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.h
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.h
@@ -32,6 +32,7 @@
 #include "GLExtensions.h"
 
 #include "DisplayHardware/DisplayHardwareBase.h"
+#include "DisplayHardware/VSyncBarrier.h"
 
 namespace android {
 
@@ -74,6 +75,9 @@ public:
     uint32_t    getMaxTextureSize() const;
     uint32_t    getMaxViewportDims() const;
 
+    // waits for the next vsync and returns the timestamp of when it happened
+    nsecs_t        waitForVSync() const;
+
     uint32_t getPageFlipCount() const;
     EGLDisplay getEGLDisplay() const { return mDisplay; }
 
@@ -95,6 +99,7 @@ public:
 private:
     void init(uint32_t displayIndex) __attribute__((noinline));
     void fini() __attribute__((noinline));
+    int32_t getDelayToNextVSyncUs(nsecs_t* timestamp) const;
 
     sp<SurfaceFlinger> mFlinger;
     EGLDisplay      mDisplay;
@@ -112,7 +117,12 @@ private:
     mutable uint32_t mPageFlipCount;
     GLint           mMaxViewportDims[2];
     GLint           mMaxTextureSize;
-    
+    VSyncBarrier    mVSync;
+
+    mutable Mutex   mFakeVSyncMutex;
+    mutable nsecs_t mNextFakeVSync;
+    nsecs_t         mRefreshPeriod;
+
     HWComposer*     mHwc;
 
     sp<FramebufferNativeWindow> mNativeWindow;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 39f0f401b4f9..d5a8d083e8c2 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -34,6 +34,8 @@
 #include <binder/MemoryHeapBase.h>
 #include <binder/PermissionCache.h>
 
+#include <gui/IDisplayEventConnection.h>
+
 #include <utils/String8.h>
 #include <utils/String16.h>
 #include <utils/StopWatch.h>
@@ -46,6 +48,8 @@
 #include <GLES/gl.h>
 
 #include "clz.h"
+#include "DisplayEventConnection.h"
+#include "EventThread.h"
 #include "GLExtensions.h"
 #include "DdmConnection.h"
 #include "Layer.h"
@@ -293,12 +297,16 @@ status_t SurfaceFlinger::readyToRun()
     // put the origin in the left-bottom corner
     glOrthof(0, w, 0, h, 0, 1); // l=0, r=w ; b=0, t=h
 
-    mReadyToRunBarrier.open();
+
+    // start the EventThread
+    mEventThread = new EventThread(this);
 
     /*
      *  We're now ready to accept clients...
      */
 
+    mReadyToRunBarrier.open();
+
     // start boot animation
     property_set("ctl.start", "bootanim");
 
@@ -319,6 +327,22 @@ void SurfaceFlinger::signalEvent() {
     mEventQueue.invalidate();
 }
 
+status_t SurfaceFlinger::postMessageAsync(const sp<MessageBase>& msg,
+        nsecs_t reltime, uint32_t flags) {
+    return mEventQueue.postMessage(msg, reltime);
+}
+
+status_t SurfaceFlinger::postMessageSync(const sp<MessageBase>& msg,
+        nsecs_t reltime, uint32_t flags) {
+    status_t res = mEventQueue.postMessage(msg, reltime);
+    if (res == NO_ERROR) {
+        msg->wait();
+    }
+    return res;
+}
+
+// ----------------------------------------------------------------------------
+
 bool SurfaceFlinger::authenticateSurfaceTexture(
         const sp<ISurfaceTexture>& surfaceTexture) const {
     Mutex::Autolock _l(mStateLock);
@@ -360,20 +384,17 @@ bool SurfaceFlinger::authenticateSurfaceTexture(
     return false;
 }
 
-status_t SurfaceFlinger::postMessageAsync(const sp<MessageBase>& msg,
-        nsecs_t reltime, uint32_t flags)
-{
-    return mEventQueue.postMessage(msg, reltime, flags);
+// ----------------------------------------------------------------------------
+
+sp<IDisplayEventConnection> SurfaceFlinger::createDisplayEventConnection() {
+    sp<DisplayEventConnection> result(new DisplayEventConnection(this));
+    mEventThread->registerDisplayEventConnection(result);
+    return result;
 }
 
-status_t SurfaceFlinger::postMessageSync(const sp<MessageBase>& msg,
-        nsecs_t reltime, uint32_t flags)
-{
-    status_t res = mEventQueue.postMessage(msg, reltime, flags);
-    if (res == NO_ERROR) {
-        msg->wait();
-    }
-    return res;
+void SurfaceFlinger::cleanupDisplayEventConnection(
+        const wp<DisplayEventConnection>& connection) {
+    mEventThread->unregisterDisplayEventConnection(connection);
 }
 
 // ----------------------------------------------------------------------------
@@ -432,7 +453,7 @@ bool SurfaceFlinger::threadLoop()
     } else {
         // pretend we did the post
         hw.compositionComplete();
-        usleep(16667); // 60 fps period
+        hw.waitForVSync();
     }
     return true;
 }
@@ -1572,9 +1593,16 @@ status_t SurfaceFlinger::dump(int fd, const Vector<String16>& args)
         }
 
         /*
+         * VSYNC state
+         */
+        mEventThread->dump(result, buffer, SIZE);
+
+        /*
          * Dump HWComposer state
          */
         HWComposer& hwc(hw.getHwComposer());
+        snprintf(buffer, SIZE, "h/w composer state:\n");
+        result.append(buffer);
         snprintf(buffer, SIZE, "  h/w composer %s and %s\n",
                 hwc.initCheck()==NO_ERROR ? "present" : "not present",
                 (mDebugDisableHWC || mDebugRegion) ? "disabled" : "enabled");
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 17028dbb64fa..1039f471e5a3 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -46,6 +46,8 @@ namespace android {
 
 class Client;
 class DisplayHardware;
+class DisplayEventConnection;
+class EventThread;
 class Layer;
 class LayerDim;
 class LayerScreenshot;
@@ -171,6 +173,7 @@ public:
                                                             int orientation, uint32_t flags);
     virtual int                         setOrientation(DisplayID dpy, int orientation, uint32_t flags);
     virtual bool                        authenticateSurfaceTexture(const sp<ISurfaceTexture>& surface) const;
+    virtual sp<IDisplayEventConnection> createDisplayEventConnection();
 
     virtual status_t captureScreen(DisplayID dpy,
             sp<IMemoryHeap>* heap,
@@ -222,6 +225,7 @@ private:
 
 private:
     friend class Client;
+    friend class DisplayEventConnection;
     friend class LayerBase;
     friend class LayerBaseClient;
     friend class Layer;
@@ -331,6 +335,9 @@ private:
             status_t electronBeamOffAnimationImplLocked();
             status_t electronBeamOnAnimationImplLocked();
 
+            void cleanupDisplayEventConnection(
+                    const wp<DisplayEventConnection>& connection);
+
             void        debugFlashRegions();
             void        debugShowFPS() const;
             void        drawWormhole() const;
@@ -361,6 +368,7 @@ private:
                 GLuint                      mWormholeTexName;
                 GLuint                      mProtectedTexName;
                 nsecs_t                     mBootTime;
+                sp<EventThread>             mEventThread;
 
                 // Can only accessed from the main thread, these members
                 // don't need synchronization