// Copyright (c) 2012 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 "ipc/ipc_channel.h"
#include <limits>
#include "base/atomic_sequence_num.h"
#include "base/rand_util.h"
#include "base/strings/stringprintf.h"
#if !defined(OS_NACL)
namespace {
// Global atomic used to guarantee channel IDs are unique.
base::StaticAtomicSequenceNumber g_last_id;
} // namespace
#endif
namespace IPC {
// static
std::string Channel::GenerateUniqueRandomChannelID() {
// Note: the string must start with the current process id, this is how
// some child processes determine the pid of the parent.
//
// This is composed of a unique incremental identifier, the process ID of
// the creator, an identifier for the child instance, and a strong random
// component. The strong random component prevents other processes from
// hijacking or squatting on predictable channel names.
int process_id = base::GetCurrentProcId();
return base::StringPrintf("%d.%u.%d",
process_id,
g_last_id.GetNext(),
base::RandInt(0, std::numeric_limits<int32>::max()));
}
} // namespace IPC