Profiler Take 2

runtime/vm/thread_interrupter_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/thread_interrupter.h"
+
+namespace dart {
+
+DECLARE_FLAG(bool, thread_interrupter);
+DECLARE_FLAG(bool, trace_thread_interrupter);
+
+#define kThreadError -1
+
+class ThreadInterrupterWin : public AllStatic {
+ public:
+  static bool GrabRegisters(ThreadId thread, InterruptedThreadState* state) {
+    CONTEXT context;
+    memset(&context, 0, sizeof(context));
+    context.ContextFlags = CONTEXT_FULL;
+    if (GetThreadContext(thread, &context) != 0) {
+#if defined(TARGET_ARCH_IA32)
+      state->pc = static_cast<uintptr_t>(context.Eip);
+      state->fp = static_cast<uintptr_t>(context.Ebp);
+      state->sp = static_cast<uintptr_t>(context.Esp);
+#elif defined(TARGET_ARCH_X64)
+      state->pc = reinterpret_cast<uintptr_t>(context.Rip);
+      state->fp = reinterpret_cast<uintptr_t>(context.Rbp);
+      state->sp = reinterpret_cast<uintptr_t>(context.Rsp);
+#else
+      UNIMPLEMENTED();
+#endif
+      return true;
+    }
+    return false;
+  }
+
+  static void Interrupt(ThreadInterrupter::ThreadState* state) {
+    ASSERT(GetCurrentThread() != state->id);
+    DWORD result = SuspendThread(state->id);
+    if (result == kThreadError) {
+      if (FLAG_trace_thread_interrupter) {
+        OS::Print("ThreadInterrupted failed to suspend thread %p\n",
+                  reinterpret_cast<void*>(state->id));
+      }
+      return;
+    }
+    InterruptedThreadState its;
+    its.tid = state->id;
+    if (!GrabRegisters(state->id, &its)) {
+      // Failed to get thread registers.
+      ResumeThread(state->id);
+      if (FLAG_trace_thread_interrupter) {
+        OS::Print("ThreadInterrupted failed to get registers for %p\n",
+                  reinterpret_cast<void*>(state->id));
+      }
+      return;
+    }
+    if (state->callback == NULL) {
+      // No callback registered.
+      ResumeThread(state->id);
+      return;
+    }
+    state->callback(its, state->data);
+    ResumeThread(state->id);
+  }
+};
+
+
+void ThreadInterrupter::InterruptThreads(int64_t current_time) {
+  for (intptr_t i = 0; i < threads_size_; i++) {
+    ThreadState* state = threads_[i];
+    ASSERT(state->id != Thread::kInvalidThreadId);
+    if (FLAG_trace_thread_interrupter) {
+      OS::Print("ThreadInterrupter suspending %p\n",
+                reinterpret_cast<void*>(state->id));
+    }
+    ThreadInterrupterWin::Interrupt(state);
+    if (FLAG_trace_thread_interrupter) {
+      OS::Print("ThreadInterrupter resuming %p\n",
+                reinterpret_cast<void*>(state->id));
+    }
+  }
+}
+
+
+void ThreadInterrupter::ThreadMain(uword parameters) {
+  ASSERT(FLAG_thread_interrupter);
+  ASSERT(initialized_);
+  if (FLAG_trace_thread_interrupter) {
+    OS::Print("ThreadInterrupter Windows ready.\n");
+  }
+  {
+    // Signal to main thread we are ready.
+    MonitorLocker startup_ml(start_stop_monitor_);
+    thread_running_ = true;
+    interrupter_thread_id_ = Thread::GetCurrentThreadId();
+    startup_ml.Notify();
+  }
+  monitor_->Enter();
+  while (!shutdown_) {
+    int64_t current_time = OS::GetCurrentTimeMicros();
+    InterruptThreads(current_time);
+    monitor_->Exit();
+    OS::SleepMicros(interrupt_period_);
+    monitor_->Enter();
+  }

[siva, 2013/12/11 02:52:21]

Why is the pattern different here?
We have a MutexLocker for Windows too.

+  if (FLAG_trace_thread_interrupter) {
+    OS::Print("ThreadInterrupter Windows exiting.\n");
+  }
+  {
+    // Signal to main thread we are exiting.
+    MonitorLocker shutdown_ml(start_stop_monitor_);
+    thread_running_ = false;
+    shutdown_ml.Notify();
+  }
+}
+
+
+}  // namespace dart
+
+#endif  // defined(TARGET_OS_WINDOWS)
+