android_jni: Handle JNI exceptions
When calling JNI functions, the default behavior is that the native
code execution will continue and a pending exception will be queued
to be thrown when the control goes back to the Java layer.
This is not desirable when multiple JNI calls are being made and the
second one depends on the successful execution of the first. Suppress
JNI level exceptions and simply return an error from those functions
instead of throwing a JNI exception in the java layer. This also
avoids some SIGABRTs in the native code.
Also, add nullptr checks for return values of FindClass and
GetFieldID.
diff --git a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
index 01c6181..b257e4e 100644
--- a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
+++ b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
@@ -158,6 +158,19 @@
return (threads == 0) ? android_getCpuCount() : threads;
}
+// Checks if there is a pending JNI exception that will be thrown when the
+// control returns to the java layer. If there is none, it will return false. If
+// there is one, then it will clear the pending exception and return true.
+// Whenever this function returns true, the caller should treat it as a fatal
+// error and return with a failure status at the earliest instance possible.
+bool JniExceptionCheck(JNIEnv* env) {
+ if (!env->ExceptionCheck()) {
+ return false;
+ }
+ env->ExceptionClear();
+ return true;
+}
+
} // namespace
jint JNI_OnLoad(JavaVM* vm, void* /*reserved*/) {
@@ -175,6 +188,21 @@
return avifPeekCompatibleFileType(&avif);
}
+#define CHECK_EXCEPTION(ret) \
+ do { \
+ if (JniExceptionCheck(env)) return ret; \
+ } while (false)
+
+#define FIND_CLASS(var, class_name, ret) \
+ const jclass var = env->FindClass(class_name); \
+ CHECK_EXCEPTION(ret); \
+ if (var == nullptr) return ret
+
+#define GET_FIELD_ID(var, class_name, field_name, signature, ret) \
+ const jfieldID var = env->GetFieldID(class_name, field_name, signature); \
+ CHECK_EXCEPTION(ret); \
+ if (var == nullptr) return ret
+
FUNC(jboolean, getInfo, jobject encoded, int length, jobject info) {
const uint8_t* const buffer =
static_cast<const uint8_t*>(env->GetDirectBufferAddress(encoded));
@@ -182,17 +210,19 @@
if (!CreateDecoderAndParse(&decoder, buffer, length, /*threads=*/1)) {
return false;
}
- const jclass info_class =
- env->FindClass("org/aomedia/avif/android/AvifDecoder$Info");
- const jfieldID width = env->GetFieldID(info_class, "width", "I");
- const jfieldID height = env->GetFieldID(info_class, "height", "I");
- const jfieldID depth = env->GetFieldID(info_class, "depth", "I");
- const jfieldID alpha_present =
- env->GetFieldID(info_class, "alphaPresent", "Z");
+ FIND_CLASS(info_class, "org/aomedia/avif/android/AvifDecoder$Info", false);
+ GET_FIELD_ID(width, info_class, "width", "I", false);
+ GET_FIELD_ID(height, info_class, "height", "I", false);
+ GET_FIELD_ID(depth, info_class, "depth", "I", false);
+ GET_FIELD_ID(alpha_present, info_class, "alphaPresent", "Z", false);
env->SetIntField(info, width, decoder.decoder->image->width);
+ CHECK_EXCEPTION(false);
env->SetIntField(info, height, decoder.decoder->image->height);
+ CHECK_EXCEPTION(false);
env->SetIntField(info, depth, decoder.decoder->image->depth);
+ CHECK_EXCEPTION(false);
env->SetBooleanField(info, alpha_present, decoder.decoder->alphaPresent);
+ CHECK_EXCEPTION(false);
return true;
}
@@ -228,27 +258,30 @@
getThreadCount(threads))) {
return 0;
}
- const jclass avif_decoder_class =
- env->FindClass("org/aomedia/avif/android/AvifDecoder");
- const jfieldID width_id = env->GetFieldID(avif_decoder_class, "width", "I");
- const jfieldID height_id = env->GetFieldID(avif_decoder_class, "height", "I");
- const jfieldID depth_id = env->GetFieldID(avif_decoder_class, "depth", "I");
- const jfieldID alpha_present_id =
- env->GetFieldID(avif_decoder_class, "alphaPresent", "Z");
- const jfieldID frame_count_id =
- env->GetFieldID(avif_decoder_class, "frameCount", "I");
- const jfieldID repetition_count_id =
- env->GetFieldID(avif_decoder_class, "repetitionCount", "I");
- const jfieldID frame_durations_id =
- env->GetFieldID(avif_decoder_class, "frameDurations", "[D");
+ FIND_CLASS(avif_decoder_class, "org/aomedia/avif/android/AvifDecoder", 0);
+ GET_FIELD_ID(width_id, avif_decoder_class, "width", "I", 0);
+ GET_FIELD_ID(height_id, avif_decoder_class, "height", "I", 0);
+ GET_FIELD_ID(depth_id, avif_decoder_class, "depth", "I", 0);
+ GET_FIELD_ID(alpha_present_id, avif_decoder_class, "alphaPresent", "Z", 0);
+ GET_FIELD_ID(frame_count_id, avif_decoder_class, "frameCount", "I", 0);
+ GET_FIELD_ID(repetition_count_id, avif_decoder_class, "repetitionCount", "I",
+ 0);
+ GET_FIELD_ID(frame_durations_id, avif_decoder_class, "frameDurations", "[D",
+ 0);
env->SetIntField(thiz, width_id, decoder->decoder->image->width);
+ CHECK_EXCEPTION(0);
env->SetIntField(thiz, height_id, decoder->decoder->image->height);
+ CHECK_EXCEPTION(0);
env->SetIntField(thiz, depth_id, decoder->decoder->image->depth);
+ CHECK_EXCEPTION(0);
env->SetBooleanField(thiz, alpha_present_id, decoder->decoder->alphaPresent);
+ CHECK_EXCEPTION(0);
env->SetIntField(thiz, repetition_count_id,
decoder->decoder->repetitionCount);
+ CHECK_EXCEPTION(0);
const int frameCount = decoder->decoder->imageCount;
env->SetIntField(thiz, frame_count_id, frameCount);
+ CHECK_EXCEPTION(0);
// This native array is needed because setting one element at a time to a Java
// array from the JNI layer is inefficient.
std::unique_ptr<double[]> native_durations(
@@ -270,10 +303,16 @@
}
env->SetDoubleArrayRegion(durations, /*start=*/0, frameCount,
native_durations.get());
+ CHECK_EXCEPTION(0);
env->SetObjectField(thiz, frame_durations_id, durations);
+ CHECK_EXCEPTION(0);
return reinterpret_cast<jlong>(decoder.release());
}
+#undef GET_FIELD_ID
+#undef FIND_CLASS
+#undef CHECK_EXCEPTION
+
FUNC(jint, nextFrame, jlong jdecoder, jobject bitmap) {
AvifDecoderWrapper* const decoder =
reinterpret_cast<AvifDecoderWrapper*>(jdecoder);
