Create libsampler as V8 sampler library.

test/cctest/libsampler/test-sampler.cc

Index: test/cctest/libsampler/test-sampler.cc
diff --git a/test/cctest/libsampler/test-sampler.cc b/test/cctest/libsampler/test-sampler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..95db6373902c2eba9dbc14511fc91527502c2e13
--- /dev/null
+++ b/test/cctest/libsampler/test-sampler.cc
@@ -0,0 +1,168 @@
+// Copyright 2016 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.
+// Tests of sampler functionalities.
+
+#include "src/libsampler/v8-sampler.h"
+
+#include "src/base/platform/platform.h"
+#include "test/cctest/cctest.h"
+
+
+namespace v8 {
+namespace sampler {
+
+namespace {
+
+class TestSamplingThread : public base::Thread {
+ public:
+  static const int kSamplerThreadStackSize = 64 * 1024;
+
+  explicit TestSamplingThread(Sampler* sampler)
+      : Thread(base::Thread::Options("TestSamplingThread",
+                                     kSamplerThreadStackSize)),
+        sampler_(sampler) {}
+
+  // Implement Thread::Run().
+  virtual void Run() {
+    while (true) {

[alph, 2016/05/23 23:37:27]

while (sampler_->IsProfiling()) {

[lpy, 2016/05/24 17:07:57]

Done.

+      if (!sampler_->IsProfiling()) break;
+      sampler_->DoSample();
+      base::OS::Sleep(base::TimeDelta::FromMilliseconds(10));
+    }
+  }
+
+ private:
+  Sampler* sampler_;
+};
+
+
+class TestSampler : public Sampler {
+ public:
+  explicit TestSampler(Isolate* isolate) : Sampler(isolate) {}
+
+  void SampleStack(const v8::RegisterState& regs) override {
+    void* frames[Sampler::kMaxFramesCount];
+    SampleInfo sample_info;
+    isolate()->GetStackSample(regs, reinterpret_cast<void**>(frames),
+                              Sampler::kMaxFramesCount, &sample_info);
+    if (is_counting_samples_) {
+      if (sample_info.vm_state == JS) ++js_sample_count_;
+      if (sample_info.vm_state == EXTERNAL) ++external_sample_count_;
+    }
+  }
+};
+
+
+class TestApiCallbacks {
+ public:
+  explicit TestApiCallbacks(int min_duration_ms)
+      : min_duration_ms_(min_duration_ms) {}
+
+  static void Getter(v8::Local<v8::String> name,
+                     const v8::PropertyCallbackInfo<v8::Value>& info) {
+    TestApiCallbacks* data = FromInfo(info);
+    data->Wait();
+  }
+
+  static void Setter(v8::Local<v8::String> name,
+                     v8::Local<v8::Value> value,
+                     const v8::PropertyCallbackInfo<void>& info) {
+    TestApiCallbacks* data = FromInfo(info);
+    data->Wait();
+  }
+
+  static void Callback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+    TestApiCallbacks* data = FromInfo(info);
+    data->Wait();
+  }
+
+ private:
+  void Wait() {

[alph, 2016/05/23 23:37:27]

Do you really need to wait. Just empty callbacks should be enough

[lpy, 2016/05/24 17:07:57]

Done.

+    double start = v8::base::OS::TimeCurrentMillis();
+    double duration = 0;
+    while (duration < min_duration_ms_) {
+      v8::base::OS::Sleep(v8::base::TimeDelta::FromMilliseconds(1));
+      duration = v8::base::OS::TimeCurrentMillis() - start;
+    }
+  }
+
+  template <typename T>
+  static TestApiCallbacks* FromInfo(const T& info) {
+    void* data = v8::External::Cast(*info.Data())->Value();
+    return reinterpret_cast<TestApiCallbacks*>(data);
+  }
+
+  int min_duration_ms_;
+};
+
+
+static void RunSampler(v8::Local<v8::Context> env,
+                       v8::Local<v8::Function> function,
+                       v8::Local<v8::Value> argv[], int argc,
+                       unsigned min_js_samples = 0,
+                       unsigned min_external_samples = 0) {
+  Sampler::SetUp();
+  TestSampler* sampler = new TestSampler(env->GetIsolate());
+  TestSamplingThread* thread = new TestSamplingThread(sampler);
+  sampler->IncreaseProfilingDepth();
+  sampler->Start();
+  sampler->StartCountingSamples();
+  thread->StartSynchronously();
+  do {
+    function->Call(env, env->Global(), argc, argv).ToLocalChecked();
+  } while (sampler->js_sample_count() < min_js_samples ||
+           sampler->external_sample_count() < min_external_samples);
+  sampler->Stop();
+  sampler->DecreaseProfilingDepth();
+  thread->Join();
+  Sampler::TearDown();
+}
+
+}  // namespace
+
+static const char* sampler_test_source = "function start(count) {\n"
+"  for (var i = 0; i < count; i++) {\n"
+"    var o = instance.foo;\n"
+"    instance.foo = o + 1;\n"
+"  }\n"
+"}\n";
+
+static v8::Local<v8::Function> GetFunction(v8::Local<v8::Context> env,
+                                           const char* name) {
+  return v8::Local<v8::Function>::Cast(
+      env->Global()->Get(env, v8_str(name)).ToLocalChecked());
+}
+
+
+TEST(LibSamplerCollectSample) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope scope(isolate);
+
+  v8::Local<v8::FunctionTemplate> func_template =
+      v8::FunctionTemplate::New(isolate);
+  v8::Local<v8::ObjectTemplate> instance_template =
+      func_template->InstanceTemplate();
+
+  TestApiCallbacks accessors(1);
+  v8::Local<v8::External> data =
+      v8::External::New(isolate, &accessors);
+  instance_template->SetAccessor(v8_str("foo"), &TestApiCallbacks::Getter,
+                                 &TestApiCallbacks::Setter, data);
+  v8::Local<v8::Function> func =
+      func_template->GetFunction(env.local()).ToLocalChecked();
+  v8::Local<v8::Object> instance =
+      func->NewInstance(env.local()).ToLocalChecked();
+  env->Global()->Set(env.local(), v8_str("instance"), instance).FromJust();
+
+  CompileRun(sampler_test_source);
+  v8::Local<v8::Function> function = GetFunction(env.local(), "start");
+
+  int32_t repeat_count = 100;
+  v8::Local<v8::Value> args[] = {v8::Integer::New(isolate, repeat_count)};
+  RunSampler(env.local(), function, args, arraysize(args), 100, 100);

[alph, 2016/05/23 23:37:27]

(100 + 100) * 10ms = 2000ms, which is quite long for a test. Change the interval
to at most 1ms.

[lpy, 2016/05/24 17:07:57]

Done.

+}
+
+}  // namespace sampler
+}  // namespace v8