[wasm] Add counter for time spent executing Wasm

Bug: v8:6514
Change-Id: Ifda1b80a80fc0b077e982005d9493e0fe7ced471
Reviewed-on: https://chromium-review.googlesource.com/599021Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Commit-Queue: Eric Holk <eholk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47176}

src/compiler/wasm-compiler.cc

@@ -2989,6 +2989,10 @@ void WasmGraphBuilder::EnsureFunctionTableNodes() {
 Node* WasmGraphBuilder::BuildModifyThreadInWasmFlag(bool new_value) {
   // TODO(eholk): generate code to modify the thread-local storage directly,
   // rather than calling the runtime.
+  //
+  // Note that the runtime functions also toggle the wasm_execution_time
+  // counters. Make sure this behavior is preserved if we avoid the runtime
+  // call.
   if (!trap_handler::UseTrapHandler()) {
     return *control_;
   }

src/counters.h

@@ -1062,6 +1062,8 @@ class RuntimeCallTimerScope {
   HT(asm_wasm_translation_time, V8.AsmWasmTranslationMicroSeconds, 1000000,    \
      MICROSECOND)                                                              \
   HT(wasm_lazy_compilation_time, V8.WasmLazyCompilationMicroSeconds, 1000000,  \
+     MICROSECOND)                                                              \
+  HT(wasm_execution_time, V8.WasmExecutionTimeMicroSeconds, 10000000,          \
      MICROSECOND)
 
 #define TIMED_HISTOGRAM_LIST(HT)                                               \

src/isolate.cc

@@ -1224,8 +1224,10 @@ Object* Isolate::UnwindAndFindHandler() {
           trap_handler::ClearThreadInWasm();
         }
 
-        if (!FLAG_experimental_wasm_eh || !is_catchable_by_wasm(exception))
+        if (!FLAG_experimental_wasm_eh || !is_catchable_by_wasm(exception)) {
+          counters()->wasm_execution_time()->Stop();
           break;
+        }
         int stack_slots = 0;  // Will contain stack slot count of frame.
         WasmCompiledFrame* wasm_frame = static_cast<WasmCompiledFrame*>(frame);
         int offset = wasm_frame->LookupExceptionHandlerInTable(&stack_slots);

src/runtime/runtime-wasm.cc

@@ -180,11 +180,17 @@ RUNTIME_FUNCTION(Runtime_WasmSetCaughtExceptionValue) {
 
 RUNTIME_FUNCTION(Runtime_SetThreadInWasm) {
   trap_handler::SetThreadInWasm();
+  if (!isolate->counters()->wasm_execution_time()->Running()) {
+    isolate->counters()->wasm_execution_time()->Start();
+  }
   return isolate->heap()->undefined_value();
 }
 
 RUNTIME_FUNCTION(Runtime_ClearThreadInWasm) {
   trap_handler::ClearThreadInWasm();
+  if (isolate->counters()->wasm_execution_time()->Running()) {
+    isolate->counters()->wasm_execution_time()->Stop();
+  }
   return isolate->heap()->undefined_value();
 }