ExitCommandProcessingEarly after Shader::DoCompile

Shader::DoCompile is a source of frequent watchdog hangs (it involves
both ANGLE shader translation, as well as driver compilation steps).

Adding ExitCommandProcessingEarly after any calls to Shader::DoCompile.

Bug: 844780
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I58eae185384db7859f9ab451496e25da7c556c9c
Reviewed-on: https://chromium-review.googlesource.com/1144530Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577028}

gpu/command_buffer/service/gles2_cmd_decoder.cc

@@ -2360,6 +2360,9 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   void ReadBackBuffersIntoShadowCopies(
       base::flat_set<scoped_refptr<Buffer>> buffers_to_shadow_copy);
 
+  // Compiles the given shader and exits command processing early.
+  void CompileShaderAndExitCommandProcessingEarly(Shader* shader);
+
   // Generate a member function prototype for each command in an automated and
   // typesafe way.
 #define GLES2_CMD_OP(name) \
@@ -11030,7 +11033,7 @@ void GLES2DecoderImpl::DoGetShaderiv(GLuint shader_id,
     case GL_COMPILE_STATUS:
     case GL_INFO_LOG_LENGTH:
     case GL_TRANSLATED_SHADER_SOURCE_LENGTH_ANGLE:
-      shader->DoCompile();
+      CompileShaderAndExitCommandProcessingEarly(shader);
       break;
 
     default:
@@ -11096,7 +11099,7 @@ error::Error GLES2DecoderImpl::HandleGetTranslatedShaderSourceANGLE(
   }
 
   // Make sure translator has been utilized in compile.
-  shader->DoCompile();
+  CompileShaderAndExitCommandProcessingEarly(shader);
 
   bucket->SetFromString(shader->translated_source().c_str());
   return error::kNoError;
@@ -11135,7 +11138,7 @@ error::Error GLES2DecoderImpl::HandleGetShaderInfoLog(
   }
 
   // Shader must be compiled in order to get the info log.
-  shader->DoCompile();
+  CompileShaderAndExitCommandProcessingEarly(shader);
 
   bucket->SetFromString(shader->log_info().c_str());
   return error::kNoError;
@@ -20251,6 +20254,21 @@ void GLES2DecoderImpl::DoSetReadbackBufferShadowAllocationINTERNAL(
   writes_submitted_but_not_completed_.insert(buffer);
 }
 
+void GLES2DecoderImpl::CompileShaderAndExitCommandProcessingEarly(
+    Shader* shader) {
+  // No need to call DoCompile or exit command processing early if the call
+  // to DoCompile will be a no-op.
+  if (!shader->CanCompile())
+    return;
+
+  shader->DoCompile();
+
+  // Shader compilation can be very slow (see https://crbug.com/844780), Exit
+  // command processing to allow for context preemption and GPU watchdog
+  // checks.
+  ExitCommandProcessingEarly();
+}
+
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.

gpu/command_buffer/service/shader_manager.cc

@@ -75,9 +75,7 @@ void Shader::RequestCompile(scoped_refptr<ShaderTranslatorInterface> translator,
 }
 
 void Shader::DoCompile() {
-  // We require that RequestCompile() must be called before DoCompile(),
-  // so we can return early if the shader state is not what we expect.
-  if (shader_state_ != kShaderStateCompileRequested) {
+  if (!CanCompile()) {
     return;
   }
 

gpu/command_buffer/service/shader_manager.h

@@ -53,6 +53,9 @@ class GPU_GLES2_EXPORT Shader : public base::RefCounted<Shader> {
   void RequestCompile(scoped_refptr<ShaderTranslatorInterface> translator,
                       TranslatedShaderSourceType type);
 
+  // Returns true if we are ready to call DoCompile. If we have not yet called
+  // RequestCompile or if we've already compiled, returns false.
+  bool CanCompile() { return shader_state_ == kShaderStateCompileRequested; }
   void DoCompile();
   void RefreshTranslatedShaderSource();