commit a7ec12f7efc032211e54aa1ce28c698413f02b8d
author Leon Scroggins III <scroggo@google.com> Wed Sep 11 12:33:00 2019 -0400
committer Leon Scroggins III <scroggo@google.com> Mon Sep 16 16:29:58 2019 -0400
tree da3ec860c6f4c2d898785540be5da747f563099b
parent 081deafca597c61d4e7e73083ff685e64034c9cc

Fix AnimatedImageDrawables using ByteBuffers

Bug: 140715166
Test: I56dc6e9865c2701746c95ea584bcc70fe4d62a6c

AnimatedImageDrawable, when created from a ByteBuffer, needs to get a
pointer to the JNI interface in order to read the ByteBuffer (or
byte[]). But the AnimatedImageThread is not attached to the JVM. Attach
it as necessary.

Change-Id: I51b69b5b70f8c5865d5e5ed065e42267fa556202

core/jni/android/graphics/ByteBufferStreamAdaptor.cpp

diff --git a/core/jni/android/graphics/ByteBufferStreamAdaptor.cpp b/core/jni/android/graphics/ByteBufferStreamAdaptor.cpp
index 173818b..d443fd8 100644
--- a/core/jni/android/graphics/ByteBufferStreamAdaptor.cpp
+++ b/core/jni/android/graphics/ByteBufferStreamAdaptor.cpp
@@ -1,6 +1,7 @@
 #include "ByteBufferStreamAdaptor.h"
 #include "core_jni_helpers.h"
 #include "Utils.h"
+#include <jni.h>
 
 #include <SkStream.h>
 
@@ -9,6 +10,24 @@
 static jmethodID gByteBuffer_getMethodID;
 static jmethodID gByteBuffer_setPositionMethodID;
 
+/**
+ * Helper method for accessing the JNI interface pointer.
+ *
+ * Image decoding (which this supports) is started on a thread that is already
+ * attached to the Java VM. But an AnimatedImageDrawable continues decoding on
+ * the AnimatedImageThread, which is not attached. This will attach if
+ * necessary.
+ */
+static JNIEnv* requireEnv(JavaVM* jvm) {
+    JNIEnv* env;
+    if (jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
+        if (jvm->AttachCurrentThreadAsDaemon(&env, nullptr) != JNI_OK) {
+            LOG_ALWAYS_FATAL("Failed to AttachCurrentThread!");
+        }
+    }
+    return env;
+}
+
 class ByteBufferStream : public SkStreamAsset {
 private:
     ByteBufferStream(JavaVM* jvm, jobject jbyteBuffer, size_t initialPosition, size_t length,
@@ -46,7 +65,7 @@
     }
 
     ~ByteBufferStream() override {
-        auto* env = get_env_or_die(mJvm);
+        auto* env = requireEnv(mJvm);
         env->DeleteGlobalRef(mByteBuffer);
         env->DeleteGlobalRef(mStorage);
     }
@@ -63,7 +82,7 @@
             return this->setPosition(mPosition + size) ? size : 0;
         }
 
-        auto* env = get_env_or_die(mJvm);
+        auto* env = requireEnv(mJvm);
         size_t bytesRead = 0;
         do {
             const size_t requested = (size > kStorageSize) ? kStorageSize : size;
@@ -146,7 +165,7 @@
 
     // Range has already been checked by the caller.
     bool setPosition(size_t newPosition) {
-        auto* env = get_env_or_die(mJvm);
+        auto* env = requireEnv(mJvm);
         env->CallObjectMethod(mByteBuffer, gByteBuffer_setPositionMethodID,
                               newPosition + mInitialPosition);
         if (env->ExceptionCheck()) {
@@ -185,7 +204,7 @@
     }
 
     ~ByteArrayStream() override {
-        auto* env = get_env_or_die(mJvm);
+        auto* env = requireEnv(mJvm);
         env->DeleteGlobalRef(mByteArray);
     }
 
@@ -197,7 +216,7 @@
             return 0;
         }
 
-        auto* env = get_env_or_die(mJvm);
+        auto* env = requireEnv(mJvm);
         if (buffer) {
             env->GetByteArrayRegion(mByteArray, mPosition + mOffset, size,
                                     reinterpret_cast<jbyte*>(buffer));