[wasm] Introduce a compilation manager for WebAssembly

This CL is the first step in introducing a compilation manager for
asynchronous compile jobs in WebAssembly.

The compilation manager holds a list of currently active
AsyncCompileJobs. With the compilation manager these compile jobs get
deallocated when the isolate shuts down. Note that this CL is not enough
to provide a graceful isolate shutdown. For this we have to wait for all
compilation tasks to finish before we shut down, and we have to make the
tasks stateless. I plan to do these changes in separate CLs.

R=clemensh@chromium.org, mtrofin@chromium.org

BUG=v8:6436

Change-Id: I9a6e165dd2ef6d33944ca303fed49f7940eea7a2
Reviewed-on: https://chromium-review.googlesource.com/528079
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45858}

BUILD.gn

@@ -2013,6 +2013,8 @@ v8_source_set("v8_base") {
     "src/visitors.h",
     "src/vm-state-inl.h",
     "src/vm-state.h",
+    "src/wasm/compilation-manager.cc",
+    "src/wasm/compilation-manager.h",
     "src/wasm/decoder.h",
     "src/wasm/function-body-decoder-impl.h",
     "src/wasm/function-body-decoder.cc",

src/isolate.cc

@@ -52,6 +52,7 @@
 #include "src/version.h"
 #include "src/visitors.h"
 #include "src/vm-state-inl.h"
+#include "src/wasm/compilation-manager.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects.h"
 #include "src/zone/accounting-allocator.h"
@@ -2341,6 +2342,7 @@ Isolate::Isolate(bool enable_serializer)
       use_counter_callback_(NULL),
       basic_block_profiler_(NULL),
       cancelable_task_manager_(new CancelableTaskManager()),
+      wasm_compilation_manager_(new wasm::CompilationManager()),
       abort_on_uncaught_exception_callback_(NULL),
       total_regexp_code_generated_(0) {
   {
@@ -2431,17 +2433,14 @@ void Isolate::Deinit() {
 
   debug()->Unload();
 
-  FreeThreadResources();
-  // Release managed objects before shutting down the heap. The finalizer might
-  // need to access heap objects.
-  ReleaseManagedObjects();
-
   if (concurrent_recompilation_enabled()) {
     optimizing_compile_dispatcher_->Stop();
     delete optimizing_compile_dispatcher_;
     optimizing_compile_dispatcher_ = NULL;
   }
 
+  wasm_compilation_manager_->TearDown();
+
   heap_.mark_compact_collector()->EnsureSweepingCompleted();
 
   DumpAndResetStats();
@@ -2458,6 +2457,11 @@ void Isolate::Deinit() {
   sampler::Sampler* sampler = logger_->sampler();
   if (sampler && sampler->IsActive()) sampler->Stop();
 
+  FreeThreadResources();
+  // Release managed objects before shutting down the heap. The finalizer might
+  // need to access heap objects.
+  ReleaseManagedObjects();
+
   delete deoptimizer_data_;
   deoptimizer_data_ = NULL;
   builtins_.TearDown();

src/isolate.h

@@ -107,6 +107,10 @@ namespace interpreter {
 class Interpreter;
 }
 
+namespace wasm {
+class CompilationManager;
+}
+
 #define RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate)    \
   do {                                                    \
     Isolate* __isolate__ = (isolate);                     \
@@ -1212,6 +1216,10 @@ class Isolate {
     return cancelable_task_manager_;
   }
 
+  wasm::CompilationManager* wasm_compilation_manager() {
+    return wasm_compilation_manager_.get();
+  }
+
   const AstStringConstants* ast_string_constants() const {
     return ast_string_constants_;
   }
@@ -1569,6 +1577,8 @@ class Isolate {
 
   CancelableTaskManager* cancelable_task_manager_;
 
+  std::unique_ptr<wasm::CompilationManager> wasm_compilation_manager_;
+
   debug::ConsoleDelegate* console_delegate_ = nullptr;
 
   v8::Isolate::AbortOnUncaughtExceptionCallback

src/v8.gyp

@@ -1473,6 +1473,8 @@
         'visitors.h',
         'vm-state-inl.h',
         'vm-state.h',
+        'wasm/compilation-manager.cc',
+        'wasm/compilation-manager.h',
         'wasm/decoder.h',
         'wasm/function-body-decoder.cc',
         'wasm/function-body-decoder.h',

src/wasm/compilation-manager.cc

@@ -0,0 +1,32 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/wasm/compilation-manager.h"
+
+#include "src/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+void CompilationManager::StartAsyncCompileJob(
+    Isolate* isolate, std::unique_ptr<byte[]> bytes_copy, size_t length,
+    Handle<Context> context, Handle<JSPromise> promise) {
+  std::shared_ptr<AsyncCompileJob> job(new AsyncCompileJob(
+      isolate, std::move(bytes_copy), length, context, promise));
+  jobs_.insert({job.get(), job});
+  job->Start();
+}
+
+void CompilationManager::RemoveJob(AsyncCompileJob* job) {
+  size_t num_removed = jobs_.erase(job);
+  USE(num_removed);
+  DCHECK_EQ(1, num_removed);
+}
+
+void CompilationManager::TearDown() { jobs_.clear(); }
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8

src/wasm/compilation-manager.h

@@ -0,0 +1,44 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_WASM_COMPILATION_MANAGER_H_
+#define V8_WASM_COMPILATION_MANAGER_H_
+
+#include <vector>
+
+#include "src/handles.h"
+#include "src/isolate.h"
+#include "src/wasm/module-compiler.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+// The CompilationManager manages a list of active WebAssembly compile jobs. The
+// manager owns the memory of the compile jobs and can trigger the abortion of
+// compile jobs. If the isolate tears down, the CompilationManager makes sure
+// that all compile jobs finish executing before the isolate becomes
+// unavailable.
+class CompilationManager {
+ public:
+  void StartAsyncCompileJob(Isolate* isolate,
+                            std::unique_ptr<byte[]> bytes_copy, size_t length,
+                            Handle<Context> context, Handle<JSPromise> promise);
+
+  // Removes {job} from the list of active compile jobs. This will delete {job}.
+  void RemoveJob(AsyncCompileJob* job);
+
+  void TearDown();
+
+ private:
+  // We use an AsyncCompileJob as the key for itself so that we can delete the
+  // job from the map when it is finished.
+  std::unordered_map<AsyncCompileJob*, std::shared_ptr<AsyncCompileJob>> jobs_;
+};
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_COMPILATION_MANAGER_H_

src/wasm/module-compiler.cc

@@ -8,6 +8,7 @@
 #include "src/asmjs/asm-js.h"
 #include "src/assembler-inl.h"
 #include "src/property-descriptor.h"
+#include "src/wasm/compilation-manager.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-module.h"
@@ -1880,16 +1881,12 @@ void AsyncCompileJob::ReopenHandlesInDeferredScope() {
 
 void AsyncCompileJob::AsyncCompileFailed(ErrorThrower& thrower) {
   RejectPromise(isolate_, context_, thrower, module_promise_);
-  // The AsyncCompileJob is finished, we resolved the promise, we do not need
+  isolate_->wasm_compilation_manager()->RemoveJob(this);
-  // the data anymore. We can delete the AsyncCompileJob object.
-  delete this;
 }
 
 void AsyncCompileJob::AsyncCompileSucceeded(Handle<Object> result) {
   ResolvePromise(isolate_, context_, module_promise_, result);
-  // The AsyncCompileJob is finished, we resolved the promise, we do not need
+  isolate_->wasm_compilation_manager()->RemoveJob(this);
-  // the data anymore. We can delete the AsyncCompileJob object.
-  delete this;
 }
 
 // A closure to run a compilation step (either as foreground or background

src/wasm/wasm-module.cc

@@ -14,6 +14,7 @@
 #include "src/snapshot/snapshot.h"
 #include "src/v8.h"
 
+#include "src/wasm/compilation-manager.h"
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-code-specialization.h"
@@ -873,9 +874,9 @@ void wasm::AsyncCompile(Isolate* isolate, Handle<JSPromise> promise,
   // during asynchronous compilation.
   std::unique_ptr<byte[]> copy(new byte[bytes.length()]);
   memcpy(copy.get(), bytes.start(), bytes.length());
-  auto job = new AsyncCompileJob(isolate, std::move(copy), bytes.length(),
+  isolate->wasm_compilation_manager()->StartAsyncCompileJob(
-                                 handle(isolate->context()), promise);
+      isolate, std::move(copy), bytes.length(), handle(isolate->context()),
-  job->Start();
+      promise);
 }
 
 Handle<Code> wasm::CompileLazy(Isolate* isolate) {