Add in-memory caching of network quality estimates across network changes.
[chromium-blink-merge.git] / ipc / ipc_channel.cc
blobac09c5ab1ef1d00b31c4f3a2e7b0a260673dbfbe
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "ipc/ipc_channel.h"
7 #include <limits>
9 #include "base/atomic_sequence_num.h"
10 #include "base/rand_util.h"
11 #include "base/strings/stringprintf.h"
13 namespace {
15 // Global atomic used to guarantee channel IDs are unique.
16 base::StaticAtomicSequenceNumber g_last_id;
18 } // namespace
20 namespace IPC {
22 // static
23 std::string Channel::GenerateUniqueRandomChannelID() {
24 // Note: the string must start with the current process id, this is how
25 // some child processes determine the pid of the parent.
27 // This is composed of a unique incremental identifier, the process ID of
28 // the creator, an identifier for the child instance, and a strong random
29 // component. The strong random component prevents other processes from
30 // hijacking or squatting on predictable channel names.
31 #if defined(OS_NACL_NONSFI)
32 // The seccomp sandbox disallows use of getpid(), so we provide a
33 // dummy PID.
34 int process_id = -1;
35 #else
36 int process_id = base::GetCurrentProcId();
37 #endif
38 return base::StringPrintf("%d.%u.%d",
39 process_id,
40 g_last_id.GetNext(),
41 base::RandInt(0, std::numeric_limits<int32>::max()));
44 } // namespace IPC