Android13 Surface UnlockCanvasAndPost流程分析-CSDN博客

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15

//frameworks/base/core/java/android/view/Surface.java
public class Surface implements Parcelable {
    public void unlockCanvasAndPost(Canvas canvas) {
        synchronized (mLock) {
            checkNotReleasedLocked();
 
 
            if (mHwuiContext != null) {
                mHwuiContext.unlockAndPost(canvas);
            } else {
                unlockSwCanvasAndPost(canvas);
            }
        }
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23

//frameworks/base/core/java/android/view/Surface.java
public class Surface implements Parcelable {
    private void unlockSwCanvasAndPost(Canvas canvas) {
        if (canvas != mCanvas) {
            throw new IllegalArgumentException("canvas object must be the same instance that "
                    + "was previously returned by lockCanvas");
        }
        if (mNativeObject != mLockedObject) {
            Log.w(TAG, "WARNING: Surface's mNativeObject (0x" +
                    Long.toHexString(mNativeObject) + ") != mLockedObject (0x" +
                    Long.toHexString(mLockedObject) +")");
        }
        if (mLockedObject == 0) {
            throw new IllegalStateException("Surface was not locked");
        }
        try {
            nativeUnlockCanvasAndPost(mLockedObject, canvas);
        } finally {
            nativeRelease(mLockedObject);
            mLockedObject = 0;
        }
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20

//frameworks/base/core/jni/android_view_Surface.cpp
static void nativeUnlockCanvasAndPost(JNIEnv* env, jclass clazz,
        jlong nativeObject, jobject canvasObj) {
    sp<Surface> surface(reinterpret_cast<Surface *>(nativeObject));
    if (!isSurfaceValid(surface)) {
        return;
    }
 
 
    // detach the canvas from the surface
    graphics::Canvas canvas(env, canvasObj);
    canvas.setBuffer(nullptr, ADATASPACE_UNKNOWN);
 
 
    // unlock surface
    status_t err = surface->unlockAndPost();
    if (err < 0) {
        jniThrowException(env, IllegalArgumentException, NULL);
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

//framework/native/libs/gui/Surface.cpp
class Surface : public ANativeObjectBase<ANativeWindow, Surface, RefBase> {
status_t Surface::unlockAndPost()
{
    if (mLockedBuffer == nullptr) {
        ALOGE("Surface::unlockAndPost failed, no locked buffer");
        return INVALID_OPERATION;
    }
 
 
    int fd = -1;
    status_t err = mLockedBuffer->unlockAsync(&fd);
    ALOGE_IF(err, "failed unlocking buffer (%p)", mLockedBuffer->handle);
 
 
    err = queueBuffer(mLockedBuffer.get(), fd);
    ALOGE_IF(err, "queueBuffer (handle=%p) failed (%s)",
            mLockedBuffer->handle, strerror(-err));
 
 
    mPostedBuffer = mLockedBuffer;
    mLockedBuffer = nullptr;
    return err;
}
}