Implemented GetSample.

test/cctest/test-sampler-api.cc

+// Copyright 2014 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 the sampling API in include/v8.h
+
+#include <string>
+#include "include/v8.h"
+#include "src/v8.h"
+#include "test/cctest/cctest.h"
+
+#if V8_OS_POSIX && !V8_OS_CYGWIN
+#include <ucontext.h>
+#elif V8_OS_WIN || V8_OS_CYGWIN
+#include "src/base/win32-headers.h"
+#endif
+
+using v8::Local;
+
+namespace {
+// The Sample which CollectSample fills up
+v8::Sample* sample;
+
+// The isolate used in the test
+v8::Isolate* isolate;
+
+// Forward declaration
+// (platform specific implementation at the bottom of this file)
+v8::RegisterState GetRegisterState();
+
+// The JavaScript calls this function when on full stack depth.
+void CollectSample(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  isolate->GetSample(GetRegisterState(), sample);
+}
+
+
+// A JavaScript function which takes stack depth
+// (minimum value 2) as an argument.
+// When at the bottom of the recursion,
+// the JavaScript code calls into C++ test code,
+// waiting for the sampler to take a sample.
+static const char* test_function =
+    "function func(depth) {"
+    "  if (depth == 2) CollectSample();"
+    "  else return func(depth - 1);"
+    "}";
+}

[alph, 2014/09/19 11:43:05]

nit:
}  // namespace

+
+
+#define SAMPLER_API_TESTS_BOOTSTRAP()                                       \
+  v8::Sample sample_;                                                       \
+  sample = &sample_;                                                        \
+  isolate = CcTest::isolate();                                              \
+  v8::HandleScope scope(isolate);                                           \
+  v8::Handle<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate); \
+  global->Set(v8::String::NewFromUtf8(isolate, "CollectSample"),            \
+              v8::FunctionTemplate::New(isolate, CollectSample));           \
+  LocalContext env(isolate, NULL, global)
+
+
+TEST(StackDepthIsConsistent) {
+  SAMPLER_API_TESTS_BOOTSTRAP();
+
+  std::string source(test_function);
+  source.append("func(8);");
+  v8::Script::Compile(v8::String::NewFromUtf8(isolate, source.c_str()))->Run();
+
+  CHECK_EQ(8, sample->size());
+}
+
+
+TEST(StackDepthDoesNotExceedMaxValue) {
+  SAMPLER_API_TESTS_BOOTSTRAP();
+
+  std::string source(test_function);
+  source.append("func(300);");
+  v8::Script::Compile(v8::String::NewFromUtf8(isolate, source.c_str()))->Run();
+
+  int MAX_SIZE = v8::Sample::kMaxSize;
+  CHECK_EQ(MAX_SIZE, sample->size());
+}
+
+
+namespace {
+std::vector<v8::JitCodeEvent> inner_funcs;
+std::vector<v8::JitCodeEvent> outer_funcs;
+
+void TestJitCodeEventHandler(const v8::JitCodeEvent* event) {
+  if (event->type != v8::JitCodeEvent::CODE_ADDED) return;
+  std::string name(event->name.str, event->name.len);
+  if (name.find("test_sampler_api_inner") != std::string::npos)
+    inner_funcs.push_back(*event);
+  if (name.find("test_sampler_api_outer") != std::string::npos)
+    outer_funcs.push_back(*event);
+}
+
+
+// Note: The arguments.callee stuff is there so that the
+//       functions are not optimized away.
+static const char* test_script =
+    "function test_sampler_api_inner() {"
+    "  CollectSample();"
+    "  return arguments.callee.toString();"
+    "}"
+    "function test_sampler_api_outer() {"
+    "  return test_sampler_api_inner() + arguments.callee.toString();"
+    "}"
+    "test_sampler_api_outer();";
+}

[alph, 2014/09/19 11:43:05]

ditto

+
+
+// The captured sample should have three pc values.
+// They should fall in the range where the compiled code
+// The expected stack is:
+// bottom of stack [{anon script}, outer, inner] top of stack
+//                              ^      ^       ^
+// sample.stack indices         2      1       0
+TEST(StackFramesConsistent) {
+  SAMPLER_API_TESTS_BOOTSTRAP();
+
+  v8::V8::SetJitCodeEventHandler(v8::kJitCodeEventDefault,
+                                 TestJitCodeEventHandler);
+  v8::Script::Compile(v8::String::NewFromUtf8(isolate, test_script))->Run();
+
+  CHECK_EQ(3, sample->size());
+
+  bool stack_top_is_inner = false;
+  bool below_inner_is_outer = false;
+
+  for (unsigned i = 0; i < inner_funcs.size(); i++) {
+    void* start_addr = inner_funcs[i].code_start;
+    void* end_addr = reinterpret_cast<void*>(
+        (int64_t)inner_funcs[i].code_start + inner_funcs[i].code_len);
+    if ((*sample->begin() >= start_addr) && (*sample->begin() < end_addr))
+      stack_top_is_inner = true;
+  }
+
+  for (unsigned i = 0; i < outer_funcs.size(); i++) {
+    void* start_addr = outer_funcs[i].code_start;
+    void* end_addr = reinterpret_cast<void*>(
+        (int64_t)outer_funcs[i].code_start + outer_funcs[i].code_len);
+    if ((*(sample->begin() + 1) >= start_addr) &&
+        (*(sample->begin() + 1) < end_addr))
+      below_inner_is_outer = true;
+  }
+
+  CHECK(stack_top_is_inner);
+  CHECK(below_inner_is_outer);
+}
+
+
+// Platform specific implementation of GetStackAndFramePointers
+namespace {
+v8::RegisterState GetRegisterState() {
+#if V8_OS_POSIX && !V8_OS_CYGWIN
+  ucontext_t context;
+  getcontext(&context);
+#elif V8_OS_WIN || V8_OS_CYGWIN
+  CONTEXT context;
+  memset(&context, 0, sizeof(context));
+  context.ContextFlags = CONTEXT_FULL;
+  GetThreadContext(OpenThread(THREAD_GET_CONTEXT | THREAD_SUSPEND_RESUME |
+                                  THREAD_QUERY_INFORMATION,
+                              false, GetCurrentThreadId()),
+                   &context);
+#endif  // V8_OS_POSIX && !V8_OS_CYGWIN / V8_OS_WIN || V8_OS_CYGWIN
+  return v8::RegisterState(context);
+}
+}

[alph, 2014/09/19 11:43:05]

ditto