blob: 82b136ac2055a5f7b2f588ce617934dbf3e33ab1 [file] [log] [blame]
// 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_message.h"
#include "base/atomic_sequence_num.h"
#include "base/logging.h"
#include "build/build_config.h"
#if defined(OS_POSIX)
#include "base/file_descriptor_posix.h"
#include "ipc/file_descriptor_set_posix.h"
#endif
namespace {
base::StaticAtomicSequenceNumber g_ref_num;
// Create a reference number for identifying IPC messages in traces. The return
// values has the reference number stored in the upper 24 bits, leaving the low
// 8 bits set to 0 for use as flags.
inline uint32 GetRefNumUpper24() {
base::debug::TraceLog* trace_log = base::debug::TraceLog::GetInstance();
uint32 pid = trace_log ? trace_log->process_id() : 0;
uint32 count = g_ref_num.GetNext();
// The 24 bit hash is composed of 14 bits of the count and 10 bits of the
// Process ID. With the current trace event buffer cap, the 14-bit count did
// not appear to wrap during a trace. Note that it is not a big deal if
// collisions occur, as this is only used for debugging and trace analysis.
return ((pid << 14) | (count & 0x3fff)) << 8;
}
} // namespace
namespace IPC {
//------------------------------------------------------------------------------
Message::~Message() {
}
Message::Message()
: Pickle(sizeof(Header)) {
header()->routing = header()->type = 0;
header()->flags = GetRefNumUpper24();
#if defined(OS_POSIX)
header()->num_fds = 0;
header()->pad = 0;
#endif
Init();
}
Message::Message(int32 routing_id, uint32 type, PriorityValue priority)
: Pickle(sizeof(Header)) {
header()->routing = routing_id;
header()->type = type;
DCHECK((priority & 0xffffff00) == 0);
header()->flags = priority | GetRefNumUpper24();
#if defined(OS_POSIX)
header()->num_fds = 0;
header()->pad = 0;
#endif
Init();
}
Message::Message(const char* data, int data_len) : Pickle(data, data_len) {
Init();
}
Message::Message(const Message& other) : Pickle(other) {
Init();
#if defined(OS_POSIX)
file_descriptor_set_ = other.file_descriptor_set_;
#endif
}
void Message::Init() {
dispatch_error_ = false;
#ifdef IPC_MESSAGE_LOG_ENABLED
received_time_ = 0;
dont_log_ = false;
log_data_ = NULL;
#endif
}
Message& Message::operator=(const Message& other) {
*static_cast<Pickle*>(this) = other;
#if defined(OS_POSIX)
file_descriptor_set_ = other.file_descriptor_set_;
#endif
return *this;
}
void Message::SetHeaderValues(int32 routing, uint32 type, uint32 flags) {
// This should only be called when the message is already empty.
DCHECK(payload_size() == 0);
header()->routing = routing;
header()->type = type;
header()->flags = flags;
}
#ifdef IPC_MESSAGE_LOG_ENABLED
void Message::set_sent_time(int64 time) {
DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0);
header()->flags |= HAS_SENT_TIME_BIT;
WriteInt64(time);
}
int64 Message::sent_time() const {
if ((header()->flags & HAS_SENT_TIME_BIT) == 0)
return 0;
const char* data = end_of_payload();
data -= sizeof(int64);
return *(reinterpret_cast<const int64*>(data));
}
void Message::set_received_time(int64 time) const {
received_time_ = time;
}
#endif
#if defined(OS_POSIX)
bool Message::WriteFile(base::ScopedFD descriptor) {
// We write the index of the descriptor so that we don't have to
// keep the current descriptor as extra decoding state when deserialising.
WriteInt(file_descriptor_set()->size());
return file_descriptor_set()->AddToOwn(descriptor.Pass());
}
bool Message::WriteBorrowingFile(const base::PlatformFile& descriptor) {
// We write the index of the descriptor so that we don't have to
// keep the current descriptor as extra decoding state when deserialising.
WriteInt(file_descriptor_set()->size());
return file_descriptor_set()->AddToBorrow(descriptor);
}
bool Message::ReadFile(PickleIterator* iter, base::ScopedFD* descriptor) const {
int descriptor_index;
if (!ReadInt(iter, &descriptor_index))
return false;
FileDescriptorSet* file_descriptor_set = file_descriptor_set_.get();
if (!file_descriptor_set)
return false;
base::PlatformFile file =
file_descriptor_set->TakeDescriptorAt(descriptor_index);
if (file < 0)
return false;
descriptor->reset(file);
return true;
}
bool Message::HasFileDescriptors() const {
return file_descriptor_set_.get() && !file_descriptor_set_->empty();
}
void Message::EnsureFileDescriptorSet() {
if (file_descriptor_set_.get() == NULL)
file_descriptor_set_ = new FileDescriptorSet;
}
#endif
} // namespace IPC