Add pipe implementation for OOP memory logging

chrome/profiling/memlog_receiver_pipe_win.h

+// Copyright 2017 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.
+
+#ifndef CHROME_PROFILING_MEMLOG_RECEIVER_PIPE_WIN_H_
+#define CHROME_PROFILING_MEMLOG_RECEIVER_PIPE_WIN_H_
+
+#include <windows.h>
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/message_loop/message_pump_win.h"
+#include "base/strings/string16.h"
+#include "build/build_config.h"
+
+namespace base {
+class TaskRunner;
+}
+
+namespace profiling {
+
+class MemlogStreamReceiver;
+
+class MemlogReceiverPipe
+    : public base::RefCountedThreadSafe<MemlogReceiverPipe> {
+ public:
+  // RegisterIOHandler can't change the callback ID of a handle once it has
+  // been registered. This class allows switching the callbacks from the
+  // server to the pipe once the pipe is created while keeping the IOHandler
+  // attached to the handle the same.
+  class CompletionThunk : public base::MessagePumpForIO::IOHandler {
+   public:
+    using Callback = base::RepeatingCallback<void(size_t, DWORD)>;
+
+    // Takes ownership of HANDLE and closes it when the class goes out of scope.
+    CompletionThunk(HANDLE handle, Callback cb);
+    ~CompletionThunk();
+
+    void set_callback(Callback cb) { callback_ = cb; }
+
+    HANDLE handle() { return handle_; }
+    OVERLAPPED* overlapped() { return &context_.overlapped; }
+
+    void ZeroOverlapped();
+
+   private:
+    // IOHandler implementation.
+    void OnIOCompleted(base::MessagePumpForIO::IOContext* context,
+                       DWORD bytes_transfered,
+                       DWORD error) override;
+
+    base::MessagePumpForIO::IOContext context_;
+
+    HANDLE handle_;
+    Callback callback_;
+
+    DISALLOW_COPY_AND_ASSIGN(CompletionThunk);
+  };
+
+  explicit MemlogReceiverPipe(std::unique_ptr<CompletionThunk> thunk);
+  ~MemlogReceiverPipe();
+
+  void StartReadingOnIOThread();
+
+  int GetRemoteProcessID();
+  void SetReceiver(scoped_refptr<base::TaskRunner> task_runner,
+                   scoped_refptr<MemlogStreamReceiver> receiver);
+
+ private:
+  void OnIOCompleted(size_t bytes_transfered, DWORD error);
+
+  void ReadUntilBlocking();
+
+  std::unique_ptr<CompletionThunk> thunk_;
+
+  scoped_refptr<base::TaskRunner> receiver_task_runner_;
+  scoped_refptr<MemlogStreamReceiver> receiver_;
+
+  bool read_outstanding_ = false;
+
+  std::unique_ptr<char[]> read_buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemlogReceiverPipe);
+};
+
+}  // namespace profiling
+
+#endif  // CHROME_PROFILING_MEMLOG_RECEIVER_PIPE_WIN_H_