MemoryIntArray: dup in writeToParcel.

Previously, if a MemoryIntArray is written to a parcel from multiple
threads, we'll create multiple ParcelFileDescriptors that own the same
file descriptor, which fdsan doesn't like. Instead of adopting and then
detaching, use ParcelFileDescriptor::fromFd which dups behind the scenes.

Bug: http://b/132720476
Test: treehugger
Change-Id: Iad4930cc2d8c59a9348fedb0889d24cb566afa62

1 files changed, 4 insertions, 6 deletions

diff --git a/core/java/android/util/MemoryIntArray.java b/core/java/android/util/MemoryIntArray.java
index 80b16075cdf6..7d287e38ba86 100644
--- a/core/java/android/util/MemoryIntArray.java
+++ b/core/java/android/util/MemoryIntArray.java
@@ -175,12 +175,10 @@ public final class MemoryIntArray implements Parcelable, Closeable {
 
     @Override
     public void writeToParcel(Parcel parcel, int flags) {
-        ParcelFileDescriptor pfd = ParcelFileDescriptor.adoptFd(mFd);
-        try {
-            // Don't let writing to a parcel to close our fd - plz
-            parcel.writeParcelable(pfd, flags & ~Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
-        } finally {
-            pfd.detachFd();
+        try (ParcelFileDescriptor pfd = ParcelFileDescriptor.fromFd(mFd)) {
+            parcel.writeParcelable(pfd, flags);
+        } catch (IOException ex) {
+            throw new RuntimeException(ex);
         }
     }