[VM] Make it so that --profile-microtasks is processed by the code in both runtime/bin/main_options.h and runtime/vm/flags.h

TEST=pkg/vm_service/test/timeline_events_for_completed_microtasks_test

Change-Id: Ia544cabc7bfe6e322955d16d3078cab461b803ae
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/425100
Reviewed-by: Ben Konyi <[email protected]>

Author: derekxu16

pkg/dartdev/lib/src/commands/run.dart

@@ -178,6 +178,14 @@ class RunCommand extends DartdevCommand {
               'Defaults to ring.',
           valueHelp: 'recorder',
           hide: !verbose,
+        )
+        ..addFlag(
+          'profile-microtasks',
+          hide: !verbose,
+          negatable: false,
+          help: 'Record information about each microtask. Information about '
+              'completed microtasks will be written to the "Microtask" '
+              'timeline stream.',
         );
     } else {
       argParser.addOption('timeline-recorder',

runtime/bin/main_options.cc

@@ -471,6 +471,24 @@ bool Options::ProcessObserveOption(const char* arg,
 #endif  // !defined(PRODUCT)
 }
 
+bool Options::ProcessProfileMicrotasksOption(const char* arg,
+                                             CommandLineOptions* vm_options) {
+#if !defined(PRODUCT)
+  constexpr const char* kProfileMicrotasksFlagAsCstr = "--profile-microtasks";
+  constexpr const char* kAlternativeProfileMicrotasksFlagAsCstr =
+      "--profile_microtasks";
+  if (strncmp(kProfileMicrotasksFlagAsCstr, arg,
+              strlen(kProfileMicrotasksFlagAsCstr)) == 0 ||
+      strncmp(kAlternativeProfileMicrotasksFlagAsCstr, arg,
+              strlen(kAlternativeProfileMicrotasksFlagAsCstr)) == 0) {
+    profile_microtasks_ = true;
+    vm_options->AddArgument(kProfileMicrotasksFlagAsCstr);
+    return true;
+  }
+#endif  // !defined(PRODUCT)
+  return false;
+}
+
 // Explicitly handle VM flags that can be parsed by DartDev's run command.
 bool Options::ProcessVMDebuggingOptions(const char* arg,
                                         CommandLineOptions* vm_options) {

runtime/bin/main_options.h

@@ -85,6 +85,7 @@ namespace bin {
   V(ProcessEnvironmentOption)                                                  \
   V(ProcessEnableVmServiceOption)                                              \
   V(ProcessObserveOption)                                                      \
+  V(ProcessProfileMicrotasksOption)                                            \
   V(ProcessVMDebuggingOptions)
 
 // This enum must match the strings in kSnapshotKindNames in main_options.cc.

runtime/lib/async.cc

@@ -15,6 +15,9 @@
 
 namespace dart {
 
+// This flag is defined in "vm/microtask_mirror_queues.cc".
+DECLARE_FLAG(bool, profile_microtasks);
+
 DEFINE_NATIVE_ENTRY(AsyncStarMoveNext_debuggerStepCheck, 0, 1) {
 #if !defined(PRODUCT)
   GET_NON_NULL_NATIVE_ARGUMENT(Closure, generator, arguments->NativeArgAt(0));
@@ -65,6 +68,7 @@ DEFINE_NATIVE_ENTRY(MicrotaskMirrorQueue_onScheduleAsyncCallback, 0, 0) {
   // this function can only ever be called when the `--profile-microtasks` CLI
   // flag is set in non-PRODUCT modes.
 #if !defined(PRODUCT)
+  ASSERT(FLAG_profile_microtasks);
   const StackTrace& stack_trace = GetCurrentStackTrace(
       // We pass a `skip_frames` argument of 1 to skip the
       // `_MicrotaskMirrorQueue._onScheduleAsyncCallback` frame.
@@ -84,6 +88,7 @@ DEFINE_NATIVE_ENTRY(MicrotaskMirrorQueue_onSchedulePriorityAsyncCallback,
   // this function can only ever be called when the `--profile-microtasks` CLI
   // flag is set in non-PRODUCT modes.
 #if !defined(PRODUCT)
+  ASSERT(FLAG_profile_microtasks);
   MicrotaskMirrorQueues::GetQueue(static_cast<int64_t>(isolate->main_port()))
       ->OnSchedulePriorityAsyncCallback();
   return Object::null();
@@ -97,6 +102,7 @@ DEFINE_NATIVE_ENTRY(MicrotaskMirrorQueue_onAsyncCallbackComplete, 0, 2) {
   // this function can only ever be called when the `--profile-microtasks` CLI
   // flag is set in non-PRODUCT modes.
 #if !defined(PRODUCT)
+  ASSERT(FLAG_profile_microtasks);
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, start_time, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, end_time, arguments->NativeArgAt(1));
   MicrotaskMirrorQueues::GetQueue(static_cast<int64_t>(isolate->main_port()))

runtime/vm/microtask_mirror_queues.cc

@@ -15,6 +15,13 @@
 
 namespace dart {
 
+DEFINE_FLAG(
+    bool,
+    profile_microtasks,
+    false,
+    "Record information about each microtask. Information about completed "
+    "microtasks will be written to the \"Microtask\" timeline stream.");
+
 MicrotaskMirrorQueue* MicrotaskMirrorQueues::GetQueue(int64_t isolate_id) {
   void* key = reinterpret_cast<void*>(isolate_id);
   const intptr_t hash = Utils::WordHash(isolate_id);