Profiler Take 2

runtime/vm/profiler_win.cc

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#include "platform/globals.h"
-#if defined(TARGET_OS_WINDOWS)
-
-#include "vm/isolate.h"
-#include "vm/profiler.h"
-
-namespace dart {
-
-#define kThreadError -1
-
-DECLARE_FLAG(bool, profile);
-DECLARE_FLAG(bool, trace_profiled_isolates);
-
-static void CollectSample(IsolateProfilerData* profiler_data,
-                          uintptr_t pc,
-                          uintptr_t fp,
-                          uintptr_t stack_lower,
-                          uintptr_t stack_upper) {
-  uintptr_t sp = stack_lower;
-  ASSERT(profiler_data != NULL);
-  SampleBuffer* sample_buffer = profiler_data->sample_buffer();
-  ASSERT(sample_buffer != NULL);
-  Sample* sample = sample_buffer->ReserveSample();
-  ASSERT(sample != NULL);
-  sample->timestamp = OS::GetCurrentTimeMicros();
-  // TODO(johnmccutchan): Make real use of vm_tags and runtime_tags.
-  // Issue # 14777
-  sample->vm_tags = Sample::kExecuting;
-  sample->runtime_tags = 0;
-  int64_t cpu_usage;
-  Thread::GetThreadCpuUsage(profiler_data->thread_id(), &cpu_usage);
-  sample->cpu_usage = profiler_data->ComputeDeltaAndSetCpuUsage(cpu_usage);
-  ProfilerSampleStackWalker stackWalker(sample, stack_lower, stack_upper,
-                                        pc, fp, sp);
-  stackWalker.walk();
-}
-
-
-static bool GrabRegisters(ThreadId thread, uintptr_t* pc, uintptr_t* fp,
-                          uintptr_t* sp) {
-  CONTEXT context;
-  memset(&context, 0, sizeof(context));
-  context.ContextFlags = CONTEXT_FULL;
-  if (GetThreadContext(thread, &context) != 0) {
-#if defined(TARGET_ARCH_IA32)
-    *pc = static_cast<uintptr_t>(context.Eip);
-    *fp = static_cast<uintptr_t>(context.Ebp);
-    *sp = static_cast<uintptr_t>(context.Esp);
-#elif defined(TARGET_ARCH_X64)
-    *pc = reinterpret_cast<uintptr_t>(context.Rip);
-    *fp = reinterpret_cast<uintptr_t>(context.Rbp);
-    *sp = reinterpret_cast<uintptr_t>(context.Rsp);
-#else
-    UNIMPLEMENTED();
-#endif
-    return true;
-  }
-  return false;
-}
-
-
-static void SuspendAndSample(Isolate* isolate,
-                             IsolateProfilerData* profiler_data) {
-  ASSERT(GetCurrentThread() != profiler_data->thread_id());
-  DWORD result = SuspendThread(profiler_data->thread_id());
-  if (result == kThreadError) {
-    return;
-  }
-  uintptr_t PC;
-  uintptr_t FP;
-  uintptr_t stack_lower;
-  uintptr_t stack_upper;
-  bool r = isolate->GetStackBounds(&stack_lower, &stack_upper);
-  if (r) {
-    r = GrabRegisters(profiler_data->thread_id(), &PC, &FP, &stack_lower);
-    if (r) {
-      int64_t sample_time = OS::GetCurrentTimeMicros();
-      profiler_data->SampledAt(sample_time);
-      CollectSample(profiler_data, PC, FP, stack_lower, stack_upper);
-    }
-  }
-
-  ResumeThread(profiler_data->thread_id());
-}
-
-
-static void Reschedule(IsolateProfilerData* profiler_data) {
-  profiler_data->Scheduled(OS::GetCurrentTimeMicros(),
-                           profiler_data->thread_id());
-}
-
-
-int64_t ProfilerManager::SampleAndRescheduleIsolates(int64_t current_time) {
-  if (isolates_size_ == 0) {
-    return 0;
-  }
-  static const int64_t max_time = 0x7fffffffffffffffLL;
-  int64_t lowest = max_time;
-  for (intptr_t i = 0; i < isolates_size_; i++) {
-    Isolate* isolate = isolates_[i];
-    ScopedMutex isolate_lock(isolate->profiler_data_mutex());
-    IsolateProfilerData* profiler_data = isolate->profiler_data();
-    if ((profiler_data == NULL) || !profiler_data->CanExpire() ||
-        (profiler_data->sample_buffer() == NULL)) {
-      // Descheduled.
-      continue;
-    }
-    if (profiler_data->ShouldSample(current_time)) {
-      SuspendAndSample(isolate, profiler_data);
-      Reschedule(profiler_data);
-    }
-    if (profiler_data->CanExpire()) {
-      int64_t isolate_time_left =
-          profiler_data->TimeUntilExpiration(current_time);
-      if (isolate_time_left < 0) {
-        continue;
-      }
-      if (isolate_time_left < lowest) {
-        lowest = isolate_time_left;
-      }
-    }
-  }
-  if (isolates_size_ == 0) {
-    return 0;
-  }
-  if (lowest == max_time) {
-    return 0;
-  }
-  ASSERT(lowest != max_time);
-  ASSERT(lowest > 0);
-  return lowest;
-}
-
-
-void ProfilerManager::ThreadMain(uword parameters) {
-  ASSERT(initialized_);
-  ASSERT(FLAG_profile);
-  if (FLAG_trace_profiled_isolates) {
-    OS::Print("ProfilerManager Windows ready.\n");
-  }
-  {
-    // Signal to main thread we are ready.
-    ScopedMonitor startup_lock(start_stop_monitor_);
-    thread_running_ = true;
-    startup_lock.Notify();
-  }
-  ScopedMonitor lock(monitor_);
-  while (!shutdown_) {
-    int64_t current_time = OS::GetCurrentTimeMicros();
-    int64_t next_sample = SampleAndRescheduleIsolates(current_time);
-    lock.WaitMicros(next_sample);
-  }
-  if (FLAG_trace_profiled_isolates) {
-    OS::Print("ProfilerManager Windows exiting.\n");
-  }
-  {
-    // Signal to main thread we are exiting.
-    ScopedMonitor shutdown_lock(start_stop_monitor_);
-    thread_running_ = false;
-    shutdown_lock.Notify();
-  }
-}
-
-}  // namespace dart
-
-#endif  // defined(TARGET_OS_WINDOWS)