Add multi_process_lock to chrome/common

chrome/common/multi_process_lock_win.cc

+// Copyright (c) 2010 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/multi_process_lock.h"
+
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "base/win/scoped_handle.h"
+
+class MultiProcessLockWin : public MultiProcessLock {
+ public:
+  explicit MultiProcessLockWin(const std::string& name) : name_(name) { }
+
+  virtual ~MultiProcessLockWin() {
+    if (event_.Get() != NULL) {
+      Unlock();
+    }
+  }
+
+  virtual bool TryLock() {
+    if (event_.Get() != NULL) {
+      DLOG(ERROR) << "MultiProcessLock is already locked - " << name_;
+      return true;
+    }
+
+    if (name_.length() > MULTI_PROCESS_LOCK_NAME_MAX_LEN) {
+      LOG(ERROR) << "Socket name too long - " << name_;
+      return false;
+    }
+
+    string16 wname = UTF8ToUTF16(name_);
+    event_.Set(CreateEvent(NULL, FALSE, FALSE, wname.c_str()));
+    if (event_.Get() && GetLastError() != ERROR_ALREADY_EXISTS) {
+      return true;
+    } else {
+      event_.Set(NULL);
+      return false;
+    }
+  }
+
+  virtual void Unlock() {
+    if (event_.Get() == NULL) {
+      DLOG(ERROR) << "Over-unlocked MultiProcessLock - " << name_;
+      return;
+    }
+    event_.Set(NULL);
+  }
+
+ private:
+  std::string name_;
+  base::win::ScopedHandle event_;
+  DISALLOW_COPY_AND_ASSIGN(MultiProcessLockWin);
+};
+
+MultiProcessLock* MultiProcessLock::Create(const std::string &name) {
+  return new MultiProcessLockWin(name);
+}