From dc8fc722048bd9330e6f3bfdb9e6d0eaf87cec3b Mon Sep 17 00:00:00 2001
From: Johnny <hellojinqiang@gmail.com>
Date: Tue, 14 Sep 2021 11:28:17 +0800
Subject: [PATCH] Fix potential crash during SimulcastEncoderAdapter tear down.
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On the Android and iOS platforms, occasionally crash when using the SimulcastEncoderAdapter.

The Android platform reverted,
In function `SimulcastEncoderAdapter::EncoderContext::Release`,
After executing `encoder_->RegisterEncodeCompleteCallback(nullptr)`
before execute `encoder_->Release()`

If the encoder thread is executed here,
```
// out/xxx/xxx/gen/sdk/android/generated_video_jni/VideoEncoderWrapper_jni.h
JNI_GENERATOR_EXPORT void Java_org_webrtc_VideoEncoderWrapper_nativeOnEncodedFrame(
    JNIEnv* env,
    jclass jcaller,
    jlong nativeVideoEncoderWrapper,
    jobject frame) {
  VideoEncoderWrapper* native = reinterpret_cast<VideoEncoderWrapper*>(nativeVideoEncoderWrapper);
  CHECK_NATIVE_PTR(env, jcaller, native, "OnEncodedFrame");
  return native->OnEncodedFrame(env, base::android::JavaParamRef<jobject>(env, frame)); // HERE
}
```
it will cause `native` to nullptr.

iOS also.

Bug: webrtc:13156
Change-Id: Id5563b3fa2c11606ae7b35de56bbaa6adba59b14
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/231780
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#34989}
---
 AUTHORS                                   | 1 +
 media/engine/simulcast_encoder_adapter.cc | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/AUTHORS b/AUTHORS
index 2315b65c60..809628212d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -58,6 +58,7 @@ Jesús Leganés-Combarro <piranna@gmail.com>
 Jiawei Ou <jiawei.ou@gmail.com>
 Jie Mao <maojie0924@gmail.com>
 Jiwon Kim <jwkim0000@gmail.com>
+Johnny Wong <hellojinqiang@gmail.com>
 Jose Antonio Olivera Ortega <josea.olivera@gmail.com>
 Keiichi Enomoto <enm10k@gmail.com>
 Kiran Thind <kiran.thind@gmail.com>
diff --git a/media/engine/simulcast_encoder_adapter.cc b/media/engine/simulcast_encoder_adapter.cc
index 721ec88a24..a16f04d93e 100644
--- a/media/engine/simulcast_encoder_adapter.cc
+++ b/media/engine/simulcast_encoder_adapter.cc
@@ -159,8 +159,8 @@ SimulcastEncoderAdapter::EncoderContext::EncoderContext(
 
 void SimulcastEncoderAdapter::EncoderContext::Release() {
   if (encoder_) {
-    encoder_->RegisterEncodeCompleteCallback(nullptr);
     encoder_->Release();
+    encoder_->RegisterEncodeCompleteCallback(nullptr);
   }
 }