raedle commented 1 year ago

Summary: The Hermes GC will eventually clean up orphan host objects. This is also the case for ImageHostObject, which itself has a reference to Image that needs to be cleaned up, hence the call to the Image::~Image destructor. On Android, it will try to release the global_ref<JImage> resource, which at the time, may not run in the JVM thread scope causing an app carsh with an error like:

Abort message: 'terminating with uncaught exception of type std::runtime_error: Unable to retrieve jni environment. Is the thread attached?'

/data/app/~~tGo_W1LgnykvwiT9t7jBtQ==/dev.playtorch-NUv9YPDoqWoQiv-dKR2ylA==/lib/arm64/libtorchlive.so (__clang_call_terminate+8) (BuildId: 0a803d5f698a12e07d4c31b32095ee75a8eefd87)
12-10 18:51:24.290 20638 20638 F DEBUG : #6 pc 0000000000088f00 /data/app/~~tGo_W1LgnykvwiT9t7jBtQ==/dev.playtorch-NUv9YPDoqWoQiv-dKR2ylA==/lib/arm64/libtorchlive.so (torchlive::media::Image::~Image()+92) (BuildId: 0a803d5f698a12e07d4c31b32095ee75a8eefd87)
12-10 18:51:24.290 20638 20638 F DEBUG : #7 pc 0000000000043874 /data/app/~~tGo_W1LgnykvwiT9t7jBtQ==/dev.playtorch-NUv9YPDoqWoQiv-dKR2ylA==/lib/arm64/libtorchlive.so (torchlive::media::ImageHostObject::~ImageHostObject()+76) (BuildId: 0a803d5f698a12e07d4c31b32095ee75a8eefd87)
12-10 18:51:24.290 20638 20638 F DEBUG : #8 pc 000000000001cc20 /data/app/~~tGo_W1LgnykvwiT9t7jBtQ==/dev.playtorch-NUv9YPDoqWoQiv-dKR2ylA==/lib/arm64/libhermes-executor-release.so (facebook::jsi::DecoratedHostObject::~DecoratedHostObject()+76) (BuildId: f9ec095fd26bd03ab3b56d56ec655670c546c472)
12-10 18:51:24.290 20638 20638 F DEBUG : #9 pc 000000000007033c /data/app/~~tGo_W1LgnykvwiT9t7jBtQ==/dev.playtorch-NUv9YPDoqWoQiv-dKR2ylA==/lib/arm64/libhermes.so (BuildId: 957ec0f39e08feadc6d0ec99bbe00fa14a3687b3)

Reported here: https://github.com/facebookresearch/playtorch/issues/175

This change ensures that the image instance release happens within the JVM environment.

More details: https://github.com/facebookincubator/fbjni/blob/5eacdd11c5d9c46f5a752faad3457f3b07fe40cb/cxx/fbjni/detail/Environment.h#L114