[d8] Add no-wait-for-wasm flag

The flag lets d8 wait for async compilation of WebAssembly to finish
before d8 shuts down.

R=clemensh@chromium.org
CC=​kimanh@google.com

Change-Id: I4cf59a1f35cc5a0ecaf769d2745df5e2e14eb509
Reviewed-on: https://chromium-review.googlesource.com/966031
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51999}

src/d8.cc

@@ -2804,6 +2804,11 @@ bool Shell::SetOptions(int argc, char* argv[]) {
     } else if (strcmp(argv[i], "--omit-quit") == 0) {
       options.omit_quit = true;
       argv[i] = nullptr;
+    } else if (strcmp(argv[i], "--no-wait-for-wasm") == 0) {
+      // TODO(herhut) Remove this flag once wasm compilation is fully
+      // isolate-independent.
+      options.wait_for_wasm = false;
+      argv[i] = nullptr;
     } else if (strcmp(argv[i], "-f") == 0) {
       // Ignore any -f flags for compatibility with other stand-alone
       // JavaScript engines.
@@ -3018,7 +3023,8 @@ void Shell::CompleteMessageLoop(Isolate* isolate) {
     i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
     i::wasm::CompilationManager* wasm_compilation_manager =
         i_isolate->wasm_engine()->compilation_manager();
-    bool should_wait = wasm_compilation_manager->HasRunningCompileJob() ||
+    bool should_wait = (options.wait_for_wasm &&
+                        wasm_compilation_manager->HasRunningCompileJob()) ||
                        isolate_status_[isolate];
     return should_wait ? platform::MessageLoopBehavior::kWaitForWork
                        : platform::MessageLoopBehavior::kDoNotWait;

src/d8.h

@@ -292,6 +292,7 @@ class ShellOptions {
         send_idle_notification(false),
         invoke_weak_callbacks(false),
         omit_quit(false),
+        wait_for_wasm(true),
         stress_opt(false),
         stress_deopt(false),
         stress_runs(1),
@@ -327,6 +328,7 @@ class ShellOptions {
   bool send_idle_notification;
   bool invoke_weak_callbacks;
   bool omit_quit;
+  bool wait_for_wasm;
   bool stress_opt;
   bool stress_deopt;
   int stress_runs;

test/mjsunit/wasm/graceful_shutdown.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-wasm --wasm-async-compilation
+// Flags: --expose-wasm --wasm-async-compilation --no-wait-for-wasm
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");