1 files changed, 150 insertions, 33 deletions
diff --git a/core/java/android/hardware/SyncFence.java b/core/java/android/hardware/SyncFence.java
index b0a6f51c2a39..693cda7720e4 100644
--- a/core/java/android/hardware/SyncFence.java
+++ b/core/java/android/hardware/SyncFence.java
@@ -17,12 +17,17 @@
 package android.hardware;
 
 import android.annotation.NonNull;
+import android.opengl.EGLDisplay;
+import android.opengl.EGLSync;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
 
-import java.io.Closeable;
+import libcore.util.NativeAllocationRegistry;
+
+import java.io.FileDescriptor;
 import java.io.IOException;
+import java.time.Duration;
 
 /**
  * A SyncFence represents a synchronization primitive which signals when hardware buffers have
@@ -34,19 +39,57 @@ import java.io.IOException;
  * Once the fence signals, then the backing storage for the framebuffer may be safely read from,
  * such as for display or for media encoding.</p>
  *
- * @see <a href="https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/vkCreateFence.html">
- * VkFence</a>
+ * @see android.opengl.EGLExt#eglDupNativeFenceFDANDROID(EGLDisplay, EGLSync)
+ * @see android.media.Image#getFence()
  */
-public final class SyncFence implements Closeable, Parcelable {
-    private static final String TAG = "SyncFence";
+public final class SyncFence implements AutoCloseable, Parcelable {
+
+    /**
+     * An invalid signal time. Represents either the signal time for a SyncFence that isn't valid
+     * (that is, {@link #isValid()} is false), or if an error occurred while attempting to retrieve
+     * the signal time.
+     */
+    public static final long SIGNAL_TIME_INVALID = -1;
 
     /**
-     * Wrapped {@link android.os.ParcelFileDescriptor}.
+     * A pending signal time. This is equivalent to the max value of a long, representing an
+     * infinitely far point in the future.
      */
-    private ParcelFileDescriptor mWrapped;
+    public static final long SIGNAL_TIME_PENDING = Long.MAX_VALUE;
+
+    private static final NativeAllocationRegistry sRegistry =
+            NativeAllocationRegistry.createNonmalloced(SyncFence.class.getClassLoader(),
+                    nGetDestructor(), 4);
+
+    private long mNativePtr;
+
+    // The destructor for this object
+    // This is also used as our internal lock object. Although SyncFence doesn't claim to be
+    // thread-safe, the cost of doing so to avoid issues around double-close or similar issues
+    // is well worth making.
+    private final Runnable mCloser;
 
     private SyncFence(@NonNull ParcelFileDescriptor wrapped) {
-        mWrapped = wrapped;
+        mNativePtr = nCreate(wrapped.detachFd());
+        mCloser = sRegistry.registerNativeAllocation(this, mNativePtr);
+    }
+
+    private SyncFence(@NonNull Parcel parcel) {
+        boolean valid = parcel.readBoolean();
+        FileDescriptor fileDescriptor = null;
+        if (valid) {
+            fileDescriptor = parcel.readRawFileDescriptor();
+        }
+        if (fileDescriptor != null) {
+            mNativePtr = nCreate(fileDescriptor.getInt$());
+            mCloser = sRegistry.registerNativeAllocation(this, mNativePtr);
+        } else {
+            mCloser = () -> {};
+        }
+    }
+
+    private SyncFence() {
+        mCloser = () -> {};
     }
 
     /***
@@ -56,7 +99,7 @@ public final class SyncFence implements Closeable, Parcelable {
      * @hide
      */
     public static @NonNull SyncFence createEmpty() {
-        return new SyncFence(ParcelFileDescriptor.adoptFd(-1));
+        return new SyncFence();
     }
 
     /**
@@ -75,7 +118,13 @@ public final class SyncFence implements Closeable, Parcelable {
      * @hide
      */
     public @NonNull ParcelFileDescriptor getFdDup() throws IOException {
-        return mWrapped.dup();
+        synchronized (mCloser) {
+            final int fd = mNativePtr != 0 ? nGetFd(mNativePtr) : -1;
+            if (fd == -1) {
+                throw new IllegalStateException("Cannot dup the FD of an invalid SyncFence");
+            }
+            return ParcelFileDescriptor.fromFd(fd);
+        }
     }
 
     /**
@@ -85,29 +134,84 @@ public final class SyncFence implements Closeable, Parcelable {
      *         {@code false} otherwise.
      */
     public boolean isValid() {
-        return mWrapped.getFileDescriptor().valid();
+        synchronized (mCloser) {
+            return mNativePtr != 0 && nIsValid(mNativePtr);
+        }
+    }
+
+    /**
+     * Waits for a SyncFence to signal for up to the timeout duration.
+     *
+     * An invalid SyncFence, that is if {@link #isValid()} is false, is treated equivalently
+     * to a SyncFence that has already signaled. That is, wait() will immediately return true.
+     *
+     * @param timeout The timeout duration. If the duration is negative, then this waits forever.
+     * @return true if the fence signaled or isn't valid, false otherwise.
+     */
+    public boolean await(@NonNull Duration timeout) {
+        final long timeoutNanos;
+        if (timeout.isNegative()) {
+            timeoutNanos = -1;
+        } else {
+            timeoutNanos = timeout.toNanos();
+        }
+        return await(timeoutNanos);
+    }
+
+    /**
+     * Waits forever for a SyncFence to signal.
+     *
+     * An invalid SyncFence, that is if {@link #isValid()} is false, is treated equivalently
+     * to a SyncFence that has already signaled. That is, wait() will immediately return true.
+     *
+     * @return true if the fence signaled or isn't valid, false otherwise.
+     */
+    public boolean awaitForever() {
+        return await(-1);
+    }
+
+    private boolean await(long timeoutNanos) {
+        synchronized (mCloser) {
+            return mNativePtr != 0 && nWait(mNativePtr, timeoutNanos);
+        }
+    }
+
+    /**
+     * Returns the time that the fence signaled in the CLOCK_MONOTONIC time domain.
+     *
+     * If the fence isn't valid, that is if {@link #isValid()} is false, then this returns
+     * {@link #SIGNAL_TIME_INVALID}. Similarly, if an error occurs while trying to access the
+     * signal time, then {@link #SIGNAL_TIME_INVALID} is also returned.
+     *
+     * If the fence hasn't yet signaled, then {@link #SIGNAL_TIME_PENDING} is returned.
+     *
+     * @return The time the fence signaled, {@link #SIGNAL_TIME_INVALID} if there's an error,
+     *         or {@link #SIGNAL_TIME_PENDING} if the fence hasn't signaled yet.
+     */
+    public long getSignalTime() {
+        synchronized (mCloser) {
+            return mNativePtr != 0 ? nGetSignalTime(mNativePtr) : SIGNAL_TIME_INVALID;
+        }
     }
 
     /**
      * Close the SyncFence. This implementation closes the underlying OS resources allocated
      * this stream.
-     *
-     * @throws IOException If an error occurs attempting to close this SyncFence.
      */
     @Override
-    public void close() throws IOException {
-        if (mWrapped != null) {
-            try {
-                mWrapped.close();
-            } finally {
-                // success
+    public void close() {
+        synchronized (mCloser) {
+            if (mNativePtr == 0) {
+                return;
             }
+            mNativePtr = 0;
+            mCloser.run();
         }
     }
 
     @Override
     public int describeContents() {
-        return mWrapped.describeContents();
+        return CONTENTS_FILE_DESCRIPTOR;
     }
 
     /**
@@ -119,23 +223,36 @@ public final class SyncFence implements Closeable, Parcelable {
      */
     @Override
     public void writeToParcel(@NonNull Parcel out, int flags) {
-        try {
-            mWrapped.writeToParcel(out, flags);
-        } finally {
-            // success
+        synchronized (mCloser) {
+            final int fd = mNativePtr != 0 ? nGetFd(mNativePtr) : -1;
+            if (fd == -1) {
+                out.writeBoolean(false);
+            } else {
+                out.writeBoolean(true);
+                FileDescriptor temp = new FileDescriptor();
+                temp.setInt$(fd);
+                out.writeFileDescriptor(temp);
+            }
         }
     }
 
     public static final @NonNull Parcelable.Creator<SyncFence> CREATOR =
             new Parcelable.Creator<SyncFence>() {
-        @Override
-        public SyncFence createFromParcel(Parcel in) {
-            return new SyncFence(ParcelFileDescriptor.CREATOR.createFromParcel(in));
-        }
+                @Override
+                public SyncFence createFromParcel(Parcel in) {
+                    return new SyncFence(in);
+                }
 
-        @Override
-        public SyncFence[] newArray(int size) {
-            return new SyncFence[size];
-        }
-    };
+                @Override
+                public SyncFence[] newArray(int size) {
+                    return new SyncFence[size];
+                }
+            };
+
+    private static native long nGetDestructor();
+    private static native long nCreate(int fd);
+    private static native boolean nIsValid(long nPtr);
+    private static native int nGetFd(long nPtr);
+    private static native boolean nWait(long nPtr, long timeout);
+    private static native long nGetSignalTime(long nPtr);
 }