Temporary commit to evaluate perf impact of prototype CPU profiler

base/profiler/cpu_profiler_win.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/profiler/cpu_profiler.h"
+
+#include <Tlhelp32.h>
+#include <dbghelp.h>
+#include <stddef.h>
+#include <windows.h>
+
+#include "base/debug/stack_trace.h"
+#include "base/threading/platform_thread.h"
+#include "base/threading/thread_id_name_manager.h"
+#include "base/time/time.h"
+
+namespace base {
+
+namespace {
+
+const DWORD kSuspendFailed = static_cast<DWORD>(-1);
+
+int StackTrace64(CONTEXT* context, int max_stack_size,
+                 StackTraceEntry* stack_trace,
+                 bool* last_frame_is_unknown_function) {
+#ifdef _WIN64
+  *last_frame_is_unknown_function = false;
+
+  IMAGEHLP_SYMBOL64 sym;
+  sym.SizeOfStruct  = sizeof(sym);
+  sym.MaxNameLength = 0;
+
+  for (int i = 0; i < max_stack_size; ++i, ++stack_trace) {
+    // Try to look up unwind metadata for the current function.
+    ULONG64 image_base;
+    PRUNTIME_FUNCTION runtime_function =
+        RtlLookupFunctionEntry(context->Rip, &image_base, nullptr);
+
+    stack_trace->rsp = context->Rsp;
+    stack_trace->rip = context->Rip;
+    stack_trace->module = nullptr;
+
+    if (runtime_function) {
+      KNONVOLATILE_CONTEXT_POINTERS nvcontext = {0};
+      void* handler_data;
+      ULONG64 establisher_frame;
+      RtlVirtualUnwind(0, image_base, context->Rip, runtime_function, context,
+          &handler_data, &establisher_frame, &nvcontext);
+    } else {
+      // If we don't have a RUNTIME_FUNCTION, then we've encountered
+      // a leaf function.  Adjust the stack appropriately.
+      context->Rip = *reinterpret_cast<PDWORD64>(context->Rsp);
+      context->Rsp += 8;
+      *last_frame_is_unknown_function = true;
+    }
+
+    if (!context->Rip)
+      return i;
+  }
+  return max_stack_size;
+#else
+  return 0;
+#endif
+}
+
+// Look up modules from instruction pointers.
+void FindModulesForIPs(StackTraceEntry* stack_trace, int stack_depth,
+                       bool last_frame_is_unknown_function) {
+  const int module_frames = last_frame_is_unknown_function ? stack_depth - 1 :
+      stack_depth;
+  for (int i = 0; i < module_frames; ++i) {
+    HMODULE module = NULL;
+    if (GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+                          GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                          reinterpret_cast<LPCTSTR>(stack_trace[i].rip),
+                          &module)) {
+      stack_trace->module = module;
+    }
+  }
+}
+
+int SampleThread(HANDLE thread_handle, int max_stack_size,
+                 StackTraceEntry* stack) {
+  if (::SuspendThread(thread_handle) == kSuspendFailed) {
+    LOG(ERROR) << "SuspendThread failed: " << GetLastError();
+    return 0;
+  }
+
+  CONTEXT thread_context = {0};
+  thread_context.ContextFlags = CONTEXT_ALL;
+  if (!::GetThreadContext(thread_handle, &thread_context)) {
+    LOG(ERROR) << "GetThreadContext failed: " << GetLastError();
+  }
+
+  bool last_frame_is_unknown_function = false;
+  int stack_depth = StackTrace64(&thread_context, max_stack_size, stack,
+                                 &last_frame_is_unknown_function);
+
+  if (::ResumeThread(thread_handle) == kSuspendFailed) {
+    LOG(ERROR) << "ResumeThread failed: " << GetLastError();
+  }
+
+  FindModulesForIPs(stack, stack_depth, last_frame_is_unknown_function);
+
+  return stack_depth;
+}
+
+void GetNames(StackTraceEntry* stack_trace, int stack_depth) {
+  HANDLE process = GetCurrentProcess();
+  DWORD64 displacement = 0;
+  DWORD line_displacement = 0;
+  char buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME * sizeof(wchar_t)];
+  SYMBOL_INFO* symbol_info = reinterpret_cast<SYMBOL_INFO*>(buffer);
+  symbol_info->SizeOfStruct = sizeof(SYMBOL_INFO);
+  symbol_info->MaxNameLen = MAX_SYM_NAME;
+  std::string file_name;
+
+  IMAGEHLP_LINE64 line;
+  line.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
+
+  for (int i = 0; i < stack_depth; ++i, ++stack_trace) {
+    DWORD64 address = stack_trace->rip;
+    if (!SymFromAddr(process, address, &displacement, symbol_info)) {
+      wcscpy_s(reinterpret_cast<wchar_t*>(symbol_info->Name),
+               symbol_info->MaxNameLen, L"failed");
+    }
+    if (!SymGetLineFromAddr64(process, address, &line_displacement, &line)) {
+      line.LineNumber = 0;
+      file_name.clear();
+    } else {
+      file_name.assign(line.FileName);
+    }
+  }
+}
+
+}
+
+CpuProfiler::CpuProfiler()
+    : main_thread_(0),
+      main_thread_stack_depth_(0) {
+#ifdef _WIN64
+  // Record the main thread's handle.
+  BOOL result = ::DuplicateHandle(::GetCurrentProcess(), ::GetCurrentThread(),
+                                  ::GetCurrentProcess(), &main_thread_, 0,
+                                  FALSE, DUPLICATE_SAME_ACCESS);
+  DCHECK(result) << "DuplicateHandle failed";
+
+  // Initialization
+  if (RtlVirtualUnwind == NULL && RtlLookupFunctionEntry == NULL) {
+    const HMODULE nt_dll_handle = ::GetModuleHandle(L"ntdll.dll");
+    reinterpret_cast<void*&>(RtlVirtualUnwind) =
+        ::GetProcAddress(nt_dll_handle, "RtlVirtualUnwind");
+    reinterpret_cast<void*&>(RtlLookupFunctionEntry) =
+        ::GetProcAddress(nt_dll_handle, "RtlLookupFunctionEntry");
+  }
+#endif
+}
+
+CpuProfiler::~CpuProfiler() {
+#ifdef _WIN64
+  CloseHandle(main_thread_);
+#endif
+}
+
+// static
+bool CpuProfiler::IsPlatformSupported() {
+#ifdef _WIN64
+  return true;
+#else
+  return false;
+#endif
+}
+
+void CpuProfiler::OnTimer() {
+  main_thread_stack_depth_ = SampleThread(
+      main_thread_, arraysize(main_thread_stack_), main_thread_stack_);
+  ProcessStack(main_thread_stack_, main_thread_stack_depth_);
+
+  modules_.clear();
+  main_thread_stack_depth_ = 0;
+}
+
+void CpuProfiler::ProcessStack(StackTraceEntry* stack, int stack_depth) {
+  for (int i = 0; i < stack_depth; ++i, ++stack) {
+    HMODULE module = stack->module;
+    if (!module || (modules_.find(module) != modules_.end()))
+      continue;
+
+    wchar_t module_name[MAX_PATH];
+    if (GetModuleFileName(module, module_name, arraysize(module_name))) {
+      modules_.insert(std::pair<HMODULE, base::string16>(module, module_name));
+    }
+  }
+}
+
+}  // namespace base