Add pipe implementation for OOP memory logging

chrome/common/profiling/memlog_sender_pipe_win.cc

+// 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.
+
+#include "chrome/common/profiling/memlog_sender_pipe_win.h"
+
+#include "base/logging.h"
+#include "chrome/common/profiling/memlog_stream.h"
+
+namespace profiling {
+
+MemlogSenderPipe::MemlogSenderPipe(const base::string16& pipe_id)
+    : pipe_id_(pipe_id), handle_(INVALID_HANDLE_VALUE) {}
+
+MemlogSenderPipe::~MemlogSenderPipe() {
+  if (handle_ != INVALID_HANDLE_VALUE)
+    ::CloseHandle(handle_);
+}
+
+bool MemlogSenderPipe::Connect() {
+  DCHECK(handle_ == INVALID_HANDLE_VALUE);
+
+  base::string16 pipe_name = kWindowsPipePrefix;
+  pipe_name.append(pipe_id_);
+
+  const int kMaxWaitMS = 30000;
+  ULONGLONG begin_ticks = ::GetTickCount64();
+  do {
+    if (!::WaitNamedPipe(pipe_name.c_str(), kMaxWaitMS)) {
+      // Since it will wait "forever", the only time WaitNamedPipe should fail
+      // is if the pipe doesn't exist.
+      return false;
+    }
+    // This is a single-direction pipe so we don't specify GENERIC_READ, but
+    // MSDN says we need FILE_READ_ATTRIBUTES.
+    handle_ = ::CreateFile(pipe_name.c_str(),
+                           FILE_READ_ATTRIBUTES | GENERIC_WRITE, 0,
+                           NULL, OPEN_EXISTING, 0, NULL);
+    // Need to loop since there is a race condition waiting for a connection to
+    // be available and actually connecting to it.
+  } while (handle_ == INVALID_HANDLE_VALUE &&
+           ::GetTickCount64() < begin_ticks + kMaxWaitMS);

[Boris Vidolov, 2017/06/15 23:26:34]

Minor optimization: you can calculate the max time outside of the loop, instead
of doing it on each loop iteration

+
+  return handle_ != INVALID_HANDLE_VALUE;
+}
+
+bool MemlogSenderPipe::Send(const void* data, size_t sz) {
+  // The pipe uses a blocking wait mode (it doesn't specify PIPE_NOWAIT) so
+  // WriteFile should do only complete writes.
+  //
+  // Note: don't use logging here (CHECK, DCHECK) because they will allocate,
+  // and this function is called from within a malloc hook.
+  DWORD bytes_written = 0;
+  if (!::WriteFile(handle_, data, static_cast<DWORD>(sz), &bytes_written, NULL))
+    return false;
+  return true;
+}
+
+}  // namespace profiling