Android EGL: Synchronize calls to eglSwapBuffers and eglMakeCurrent

BUG=webrtc:5702
R=glaznev@webrtc.org, perkj@webrtc.org

Review URL: https://codereview.webrtc.org/1848483002 .

Cr-Commit-Position: refs/heads/master@{#12178}

webrtc/api/java/android/org/webrtc/EglBase.java

@@ -25,6 +25,12 @@ public abstract class EglBase {
   public static class Context {
   }
 
+  // According to the documentation, EGL can be used from multiple threads at the same time if each
+  // thread has its own EGLContext, but in practice it deadlocks on some devices when doing this.
+  // Therefore, synchronize on this global lock before calling dangerous EGL functions that might
+  // deadlock. See https://bugs.chromium.org/p/webrtc/issues/detail?id=5702 for more info.
+  public static final Object lock = new Object();
+
   // These constants are taken from EGL14.EGL_OPENGL_ES2_BIT and EGL14.EGL_CONTEXT_CLIENT_VERSION.
   // https://android.googlesource.com/platform/frameworks/base/+/master/opengl/java/android/opengl/EGL14.java
   // This is similar to how GlSurfaceView does:

webrtc/api/java/android/org/webrtc/EglBase10.java

@@ -220,17 +220,21 @@ final class EglBase10 extends EglBase {
     if (eglSurface == EGL10.EGL_NO_SURFACE) {
       throw new RuntimeException("No EGLSurface - can't make current");
     }
+    synchronized (EglBase.lock) {
       if (!egl.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext)) {
         throw new RuntimeException("eglMakeCurrent failed");
       }
     }
+  }
 
   // Detach the current EGL context, so that it can be made current on another thread.
   @Override
   public void detachCurrent() {
+    synchronized (EglBase.lock) {
       if (!egl.eglMakeCurrent(
           eglDisplay, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_CONTEXT)) {
-      throw new RuntimeException("eglMakeCurrent failed");
+        throw new RuntimeException("eglDetachCurrent failed");
+      }
     }
   }
 
@@ -240,8 +244,10 @@ final class EglBase10 extends EglBase {
     if (eglSurface == EGL10.EGL_NO_SURFACE) {
       throw new RuntimeException("No EGLSurface - can't swap buffers");
     }
+    synchronized (EglBase.lock) {
       egl.eglSwapBuffers(eglDisplay, eglSurface);
     }
+  }
 
   // Return an EGLDisplay, or die trying.
   private EGLDisplay getEglDisplay() {

webrtc/api/java/android/org/webrtc/EglBase14.java

@@ -168,17 +168,21 @@ public final class EglBase14 extends EglBase {
     if (eglSurface == EGL14.EGL_NO_SURFACE) {
       throw new RuntimeException("No EGLSurface - can't make current");
     }
+    synchronized (EglBase.lock) {
       if (!EGL14.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext)) {
         throw new RuntimeException("eglMakeCurrent failed");
       }
     }
+  }
 
   // Detach the current EGL context, so that it can be made current on another thread.
   @Override
   public void detachCurrent() {
+    synchronized (EglBase.lock) {
       if (!EGL14.eglMakeCurrent(
           eglDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_CONTEXT)) {
-      throw new RuntimeException("eglMakeCurrent failed");
+        throw new RuntimeException("eglDetachCurrent failed");
+      }
     }
   }
 
@@ -188,18 +192,22 @@ public final class EglBase14 extends EglBase {
     if (eglSurface == EGL14.EGL_NO_SURFACE) {
       throw new RuntimeException("No EGLSurface - can't swap buffers");
     }
+    synchronized (EglBase.lock) {
       EGL14.eglSwapBuffers(eglDisplay, eglSurface);
     }
+  }
 
   public void swapBuffers(long timeStampNs) {
     checkIsNotReleased();
     if (eglSurface == EGL14.EGL_NO_SURFACE) {
       throw new RuntimeException("No EGLSurface - can't swap buffers");
     }
+    synchronized (EglBase.lock) {
       // See https://android.googlesource.com/platform/frameworks/native/+/tools_r22.2/opengl/specs/EGL_ANDROID_presentation_time.txt
       EGLExt.eglPresentationTimeANDROID(eglDisplay, eglSurface, timeStampNs);
       EGL14.eglSwapBuffers(eglDisplay, eglSurface);
     }
+  }
 
   // Return an EGLDisplay, or die trying.
   private static EGLDisplay getEglDisplay() {

webrtc/api/java/android/org/webrtc/SurfaceTextureHelper.java

@@ -451,8 +451,12 @@ class SurfaceTextureHelper {
     isTextureInUse = true;
     hasPendingTexture = false;
 
-    eglBase.makeCurrent();
+    // SurfaceTexture.updateTexImage apparently can compete and deadlock with eglSwapBuffers,
+    // as observed on Nexus 5. Therefore, synchronize it with the EGL functions.
+    // See https://bugs.chromium.org/p/webrtc/issues/detail?id=5702 for more info.
+    synchronized (EglBase.lock) {
       surfaceTexture.updateTexImage();
+    }
 
     final float[] transformMatrix = new float[16];
     surfaceTexture.getTransformMatrix(transformMatrix);
@@ -473,7 +477,6 @@ class SurfaceTextureHelper {
       if (yuvConverter != null)
         yuvConverter.release();
     }
-    eglBase.makeCurrent();
     GLES20.glDeleteTextures(1, new int[] {oesTextureId}, 0);
     surfaceTexture.release();
     eglBase.release();