Checkin of unmodified version of Mach IPC utility class.

This is the same version of the class present in the Gears tree, modifications
are only the file & header guard names and the license.

Review URL: http://codereview.chromium.org/11278

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@5687 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 269 insertions, 0 deletions

diff --git a/chrome/common/mach_ipc_mac.mm b/chrome/common/mach_ipc_mac.mm
new file mode 100644
index 0000000..96786d0
--- /dev/null
+++ b/chrome/common/mach_ipc_mac.mm
@@ -0,0 +1,269 @@
+// Copyright (c) 2006-2008 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.
+
+#import <stdio.h>
+#import "chrome/common/mach_ipc_mac.h"
+
+//==============================================================================
+MachSendMessage::MachSendMessage(int32_t message_id) : MachMessage() {
+  head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, 0);
+
+  // head.msgh_remote_port = ...; // filled out in MachPortSender::SendMessage()
+  head.msgh_local_port = MACH_PORT_NULL;
+  head.msgh_reserved = 0;
+  head.msgh_id = 0;
+
+  SetDescriptorCount(0);  // start out with no descriptors
+
+  SetMessageID(message_id);
+  SetData(NULL, 0);       // client may add data later
+}
+
+//==============================================================================
+// returns true if successful
+bool MachMessage::SetData(void *data,
+                          int32_t data_length) {
+  // first check to make sure we have enough space
+  int size = CalculateSize();
+  int new_size = size + data_length;
+  
+  if ((unsigned)new_size > sizeof(MachMessage)) {
+    return false;  // not enough space
+  }
+
+  GetDataPacket()->data_length = EndianU32_NtoL(data_length);
+  if (data) memcpy(GetDataPacket()->data, data, data_length);
+
+  CalculateSize();
+
+  return true;
+}
+
+//==============================================================================
+// calculates and returns the total size of the message
+// Currently, the entire message MUST fit inside of the MachMessage
+//    messsage size <= sizeof(MachMessage)
+int MachMessage::CalculateSize() {
+  int size = sizeof(mach_msg_header_t) + sizeof(mach_msg_body_t);
+  
+  // add space for MessageDataPacket
+  int32_t alignedDataLength = (GetDataLength() + 3) & ~0x3;
+  size += 2*sizeof(int32_t) + alignedDataLength;
+  
+  // add space for descriptors
+  size += GetDescriptorCount() * sizeof(MachMsgPortDescriptor);
+  
+  head.msgh_size = size;
+  
+  return size;
+}
+
+//==============================================================================
+MachMessage::MessageDataPacket *MachMessage::GetDataPacket() {
+  int desc_size = sizeof(MachMsgPortDescriptor)*GetDescriptorCount();
+  MessageDataPacket *packet =
+    reinterpret_cast<MessageDataPacket*>(padding + desc_size);
+
+  return packet;
+}
+
+//==============================================================================
+void MachMessage::SetDescriptor(int n,
+                                const MachMsgPortDescriptor &desc) {
+  MachMsgPortDescriptor *desc_array =
+    reinterpret_cast<MachMsgPortDescriptor*>(padding);
+  desc_array[n] = desc;
+}
+
+//==============================================================================
+// returns true if successful otherwise there was not enough space
+bool MachMessage::AddDescriptor(const MachMsgPortDescriptor &desc) {
+  // first check to make sure we have enough space
+  int size = CalculateSize();
+  int new_size = size + sizeof(MachMsgPortDescriptor);
+  
+  if ((unsigned)new_size > sizeof(MachMessage)) {
+    return false;  // not enough space
+  }
+
+  // unfortunately, we need to move the data to allow space for the
+  // new descriptor
+  u_int8_t *p = reinterpret_cast<u_int8_t*>(GetDataPacket());
+  bcopy(p, p+sizeof(MachMsgPortDescriptor), GetDataLength()+2*sizeof(int32_t));
+  
+  SetDescriptor(GetDescriptorCount(), desc);
+  SetDescriptorCount(GetDescriptorCount() + 1);
+
+  CalculateSize();
+  
+  return true;
+}
+
+//==============================================================================
+void MachMessage::SetDescriptorCount(int n) {
+  body.msgh_descriptor_count = n;
+
+  if (n > 0) {
+    head.msgh_bits |= MACH_MSGH_BITS_COMPLEX;
+  } else {
+    head.msgh_bits &= ~MACH_MSGH_BITS_COMPLEX;
+  }
+}
+
+//==============================================================================
+MachMsgPortDescriptor *MachMessage::GetDescriptor(int n) {
+  if (n < GetDescriptorCount()) {
+    MachMsgPortDescriptor *desc =
+      reinterpret_cast<MachMsgPortDescriptor*>(padding);
+    return desc + n;
+  }
+  
+  return nil;
+}
+
+//==============================================================================
+mach_port_t MachMessage::GetTranslatedPort(int n) {
+  if (n < GetDescriptorCount()) {
+    return GetDescriptor(n)->GetMachPort();
+  }
+  return MACH_PORT_NULL;
+}
+
+#pragma mark -
+
+//==============================================================================
+// create a new mach port for receiving messages and register a name for it
+ReceivePort::ReceivePort(const char *receive_port_name) {
+  mach_port_t current_task = mach_task_self();
+
+  init_result_ = mach_port_allocate(current_task,
+                                    MACH_PORT_RIGHT_RECEIVE,
+                                    &port_);
+
+  if (init_result_ != KERN_SUCCESS)
+    return;
+    
+  init_result_ = mach_port_insert_right(current_task,
+                                        port_,
+                                        port_,
+                                        MACH_MSG_TYPE_MAKE_SEND);
+
+  if (init_result_ != KERN_SUCCESS)
+    return;
+
+  mach_port_t bootstrap_port = 0;
+  init_result_ = task_get_bootstrap_port(current_task, &bootstrap_port);
+
+  if (init_result_ != KERN_SUCCESS)
+    return;
+
+  init_result_ = bootstrap_register(bootstrap_port,
+                                    const_cast<char*>(receive_port_name),
+                                    port_);
+}
+
+//==============================================================================
+// create a new mach port for receiving messages
+ReceivePort::ReceivePort() {
+  mach_port_t current_task = mach_task_self();
+
+  init_result_ = mach_port_allocate(current_task,
+                                    MACH_PORT_RIGHT_RECEIVE,
+                                    &port_);
+
+  if (init_result_ != KERN_SUCCESS)
+    return;
+
+  init_result_ =   mach_port_insert_right(current_task,
+                                          port_,
+                                          port_,
+                                          MACH_MSG_TYPE_MAKE_SEND);
+}
+
+//==============================================================================
+// Given an already existing mach port, use it.  We take ownership of the
+// port and deallocate it in our destructor.
+ReceivePort::ReceivePort(mach_port_t receive_port)
+  : port_(receive_port),
+    init_result_(KERN_SUCCESS) {
+}
+
+//==============================================================================
+ReceivePort::~ReceivePort() {
+  if (init_result_ == KERN_SUCCESS)
+    mach_port_deallocate(mach_task_self(), port_);
+}
+
+//==============================================================================
+kern_return_t ReceivePort::WaitForMessage(MachReceiveMessage *out_message,
+                                          mach_msg_timeout_t timeout) {
+  if (!out_message) {
+    return KERN_INVALID_ARGUMENT;
+  }
+
+  // return any error condition encountered in constructor
+  if (init_result_ != KERN_SUCCESS)
+    return init_result_;
+  
+  out_message->head.msgh_bits = 0;
+  out_message->head.msgh_local_port = port_;
+  out_message->head.msgh_remote_port = MACH_PORT_NULL;
+  out_message->head.msgh_reserved = 0;
+  out_message->head.msgh_id = 0;
+
+  kern_return_t result = mach_msg(&out_message->head,
+                                  MACH_RCV_MSG | MACH_RCV_TIMEOUT,
+                                  0,
+                                  sizeof(MachMessage),
+                                  port_,
+                                  timeout,              // timeout in ms
+                                  MACH_PORT_NULL);
+
+  return result;
+}
+
+#pragma mark -
+
+//==============================================================================
+// get a port with send rights corresponding to a named registered service
+MachPortSender::MachPortSender(const char *receive_port_name) {
+  mach_port_t bootstrap_port = 0;
+  init_result_ = task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
+  
+  if (init_result_ != KERN_SUCCESS)
+    return;
+
+  init_result_ = bootstrap_look_up(bootstrap_port,
+                    const_cast<char*>(receive_port_name),
+                    &send_port_);
+}
+
+//==============================================================================
+MachPortSender::MachPortSender(mach_port_t send_port) 
+  : send_port_(send_port),
+    init_result_(KERN_SUCCESS) {
+}
+
+//==============================================================================
+kern_return_t MachPortSender::SendMessage(MachSendMessage &message,
+                                          mach_msg_timeout_t timeout) {
+  if (message.head.msgh_size == 0) {
+    return KERN_INVALID_VALUE;    // just for safety -- never should occur
+  };
+  
+  if (init_result_ != KERN_SUCCESS)
+    return init_result_;
+  
+  message.head.msgh_remote_port = send_port_;
+
+  kern_return_t result = mach_msg(&message.head,
+                                  MACH_SEND_MSG | MACH_SEND_TIMEOUT,
+                                  message.head.msgh_size,
+                                  0,
+                                  MACH_PORT_NULL,
+                                  timeout,              // timeout in ms
+                                  MACH_PORT_NULL);
+
+  return result;
+}