bug 1161166 - Use mach shared memory for shared memory on OSX r=billm

ipc/chromium/src/chrome/common/mach_ipc_mac.h

@@ -274,6 +274,9 @@ class ReceivePort {
   kern_return_t WaitForMessage(MachReceiveMessage *out_message,
                                mach_msg_timeout_t timeout);
 
+  kern_return_t SendMessageToSelf(MachSendMessage& msg,
+                                  mach_msg_timeout_t timeout);
+
   // The underlying mach port that we wrap
   mach_port_t  GetPort() const { return port_; }
 

ipc/chromium/src/chrome/common/mach_ipc_mac.mm

@@ -266,7 +266,7 @@ kern_return_t ReceivePort::WaitForMessage(MachReceiveMessage *out_message,
   out_message->Head()->msgh_id = 0;
 
   kern_return_t result = mach_msg(out_message->Head(),
-                                  MACH_RCV_MSG | MACH_RCV_TIMEOUT,
+                                  MACH_RCV_MSG | (timeout == MACH_MSG_TIMEOUT_NONE ? 0 : MACH_RCV_TIMEOUT),
                                   0,
                                   out_message->MaxSize(),
                                   port_,
@@ -276,6 +276,34 @@ kern_return_t ReceivePort::WaitForMessage(MachReceiveMessage *out_message,
   return result;
 }
 
+//==============================================================================
+// send a message to this port
+kern_return_t ReceivePort::SendMessageToSelf(MachSendMessage& message, mach_msg_timeout_t timeout) {
+  if (message.Head()->msgh_size == 0) {
+    NOTREACHED();
+    return KERN_INVALID_VALUE;    // just for safety -- never should occur
+  };
+
+  if (init_result_ != KERN_SUCCESS)
+    return init_result_;
+
+  message.Head()->msgh_remote_port = port_;
+  message.Head()->msgh_bits
+        = MACH_MSGH_BITS (MACH_MSG_TYPE_MAKE_SEND,
+                          MACH_MSG_TYPE_MAKE_SEND_ONCE);
+  kern_return_t result = mach_msg(message.Head(),
+                                  MACH_SEND_MSG | (timeout == MACH_MSG_TIMEOUT_NONE ? 0 : MACH_SEND_TIMEOUT),
+                                  message.Head()->msgh_size,
+                                  0,
+                                  MACH_PORT_NULL,
+                                  timeout,              // timeout in ms
+                                  MACH_PORT_NULL);
+
+  return result;
+
+}
+
+
 #pragma mark -
 
 //==============================================================================
@@ -312,7 +340,7 @@ kern_return_t MachPortSender::SendMessage(MachSendMessage &message,
   message.Head()->msgh_remote_port = send_port_;
 
   kern_return_t result = mach_msg(message.Head(),
-                                  MACH_SEND_MSG | MACH_SEND_TIMEOUT,
+                                  MACH_SEND_MSG | (timeout == MACH_MSG_TIMEOUT_NONE ? 0 : MACH_SEND_TIMEOUT),
                                   message.Head()->msgh_size,
                                   0,
                                   MACH_PORT_NULL,

ipc/glue/GeckoChildProcessHost.cpp

@@ -14,6 +14,7 @@
 #include "chrome/common/mach_ipc_mac.h"
 #include "base/rand_util.h"
 #include "nsILocalFileMac.h"
+#include "SharedMemoryBasic.h"
 #endif
 
 #include "MainThreadUtils.h"
@@ -119,12 +120,16 @@ GeckoChildProcessHost::~GeckoChildProcessHost()
 
   MOZ_COUNT_DTOR(GeckoChildProcessHost);
 
-  if (mChildProcessHandle > 0)
+  if (mChildProcessHandle > 0) {
+#if defined(MOZ_WIDGET_COCOA)
+    SharedMemoryBasic::CleanupForPid(mChildProcessHandle);
+#endif
     ProcessWatcher::EnsureProcessTerminated(mChildProcessHandle
 #if defined(NS_BUILD_REFCNT_LOGGING)
                                             , false // don't "force"
 #endif
     );
+  }
 
 #if defined(MOZ_WIDGET_COCOA)
   if (mChildTask != MACH_PORT_NULL)
@@ -783,18 +788,44 @@ GeckoChildProcessHost::PerformAsyncLaunchInternal(std::vector<std::string>& aExt
   }
   MachPortSender parent_sender(child_message.GetTranslatedPort(1));
 
+  if (child_message.GetTranslatedPort(2) == MACH_PORT_NULL) {
+    CHROMIUM_LOG(ERROR) << "parent GetTranslatedPort(2) failed.";
+  }
+  MachPortSender* parent_recv_port_memory_ack = new MachPortSender(child_message.GetTranslatedPort(2));
+
+  if (child_message.GetTranslatedPort(3) == MACH_PORT_NULL) {
+    CHROMIUM_LOG(ERROR) << "parent GetTranslatedPort(3) failed.";
+  }
+  MachPortSender* parent_send_port_memory = new MachPortSender(child_message.GetTranslatedPort(3));
+
   MachSendMessage parent_message(/* id= */0);
   if (!parent_message.AddDescriptor(MachMsgPortDescriptor(bootstrap_port))) {
     CHROMIUM_LOG(ERROR) << "parent AddDescriptor(" << bootstrap_port << ") failed.";
     return false;
   }
 
+  ReceivePort* parent_recv_port_memory = new ReceivePort();
+  if (!parent_message.AddDescriptor(MachMsgPortDescriptor(parent_recv_port_memory->GetPort()))) {
+    CHROMIUM_LOG(ERROR) << "parent AddDescriptor(" << parent_recv_port_memory->GetPort() << ") failed.";
+    return false;
+  }
+
+  ReceivePort* parent_send_port_memory_ack = new ReceivePort();
+  if (!parent_message.AddDescriptor(MachMsgPortDescriptor(parent_send_port_memory_ack->GetPort()))) {
+    CHROMIUM_LOG(ERROR) << "parent AddDescriptor(" << parent_send_port_memory_ack->GetPort() << ") failed.";
+    return false;
+  }
+
   err = parent_sender.SendMessage(parent_message, kTimeoutMs);
   if (err != KERN_SUCCESS) {
     std::string errString = StringPrintf("0x%x %s", err, mach_error_string(err));
     CHROMIUM_LOG(ERROR) << "parent SendMessage() failed: " << errString;
     return false;
   }
+
+  SharedMemoryBasic::SetupMachMemory(process, parent_recv_port_memory, parent_recv_port_memory_ack,
+                                     parent_send_port_memory, parent_send_port_memory_ack, false);
+
 #endif
 
 //--------------------------------------------------

ipc/glue/SharedMemoryBasic.h

@@ -10,6 +10,8 @@
 
 #ifdef ANDROID
 #  include "mozilla/ipc/SharedMemoryBasic_android.h"
+#elif defined(XP_MACOSX)
+#  include "mozilla/ipc/SharedMemoryBasic_mach.h"
 #else
 #  include "mozilla/ipc/SharedMemoryBasic_chromium.h"
 #endif

ipc/glue/SharedMemoryBasic_mach.cpp

@@ -0,0 +1,623 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <map>
+
+#include <mach/vm_map.h>
+#include <mach/mach_port.h>
+#include <mach/mach_vm.h>
+#include "SharedMemoryBasic.h"
+#include "chrome/common/mach_ipc_mac.h"
+
+#include "mozilla/StaticMutex.h"
+
+#ifdef DEBUG
+#define LOG_ERROR(str, args...)                 \
+  PR_BEGIN_MACRO                                \
+  char *msg = PR_smprintf(str, ## args);        \
+  NS_WARNING(msg);                              \
+  PR_smprintf_free(msg);                        \
+  PR_END_MACRO
+#else
+#define LOG_ERROR(str, args...) do { /* nothing */ } while(0)
+#endif
+
+#define CHECK_MACH_ERROR(kr, msg)                               \
+  PR_BEGIN_MACRO                                                \
+  if (kr != KERN_SUCCESS) {                                     \
+    LOG_ERROR("%s %s (%x)\n", msg, mach_error_string(kr), kr);  \
+    return false;                                               \
+  }                                                             \
+  PR_END_MACRO
+
+/*
+ * This code is responsible for sharing memory between processes. Memory can be
+ * shared between parent and child or between two children. Each memory region is
+ * referenced via a Mach port. Mach ports are also used for messaging when
+ * sharing a memory region.
+ *
+ * When the parent starts a child, it starts a thread whose only purpose is to
+ * communicate with the child about shared memory. Once the child has started,
+ * it starts a similar thread for communicating with the parent. Each side can
+ * communicate with the thread on the other side via Mach ports. When either
+ * side wants to share memory with the other, it sends a Mach message to the
+ * other side. Attached to the message is the port that references the shared
+ * memory region. When the other side receives the message, it automatically
+ * gets access to the region. It sends a reply (also via a Mach port) so that
+ * the originating side can continue.
+ *
+ * The two sides communicate using four ports. Two ports are used when the
+ * parent shares memory with the child. The other two are used when the child
+ * shares memory with the parent. One of these two ports is used for sending the
+ * "share" message and the other is used for the reply.
+ *
+ * If a child wants to share memory with another child, it sends a "GetPorts"
+ * message to the parent. The parent forwards this GetPorts message to the
+ * target child. The message includes some ports so that the children can talk
+ * directly. Both children start up a thread to communicate with the other child,
+ * similar to the way parent and child communicate. In the future, when these
+ * two children want to communicate, they re-use the channels that were created.
+ *
+ * When a child shuts down, the parent notifies all other children. Those
+ * children then have the opportunity to shut down any threads they might have
+ * been using to communicate directly with that child.
+ */
+
+namespace mozilla {
+namespace ipc {
+
+struct MemoryPorts {
+  MachPortSender* mSender;
+  ReceivePort* mReceiver;
+
+  MemoryPorts() {}
+  MemoryPorts(MachPortSender* sender, ReceivePort* receiver)
+   : mSender(sender), mReceiver(receiver) {}
+};
+
+// Protects gMemoryCommPorts and gThreads.
+static StaticMutex gMutex;
+
+static std::map<pid_t, MemoryPorts> gMemoryCommPorts;
+
+enum {
+  kGetPortsMsg = 1,
+  kSharePortsMsg,
+  kReturnIdMsg,
+  kReturnPortsMsg,
+  kShutdownMsg,
+  kCleanupMsg,
+};
+
+const int kTimeout = 1000;
+
+pid_t gParentPid = 0;
+
+struct PIDPair {
+  pid_t mRequester;
+  pid_t mRequested;
+
+  PIDPair(pid_t requester, pid_t requested)
+   : mRequester(requester), mRequested(requested) {}
+};
+
+struct ListeningThread {
+  pthread_t mThread;
+  MemoryPorts* mPorts;
+
+  ListeningThread() {}
+  ListeningThread(pthread_t thread, MemoryPorts* ports)
+   : mThread(thread), mPorts(ports) {}
+};
+
+std::map<pid_t, ListeningThread> gThreads;
+
+static void *
+PortServerThread(void *argument);
+
+
+static void
+SetupMachMemory(pid_t pid,
+                ReceivePort* listen_port,
+                MachPortSender* listen_port_ack,
+                MachPortSender* send_port,
+                ReceivePort* send_port_ack,
+                bool pidIsParent)
+{
+  if (pidIsParent) {
+    gParentPid = pid;
+  }
+  MemoryPorts* listen_ports = new MemoryPorts(listen_port_ack, listen_port);
+  pthread_t thread;
+  int err = pthread_create(&thread, nullptr, PortServerThread, listen_ports);
+  if (err) {
+    LOG_ERROR("pthread_create failed with %x\n", err);
+    return;
+  }
+
+  gMutex.AssertCurrentThreadOwns();
+  gThreads[pid] = ListeningThread(thread, listen_ports);
+  gMemoryCommPorts[pid] = MemoryPorts(send_port, send_port_ack);
+}
+
+// Send two communication ports to another process along with the pid of the process that is
+// listening on them.
+bool
+SendPortsMessage(MachPortSender* sender,
+                 mach_port_t ports_in_receiver,
+                 mach_port_t ports_out_receiver,
+                 PIDPair pid_pair)
+{
+  MachSendMessage getPortsMsg(kGetPortsMsg);
+  if (!getPortsMsg.AddDescriptor(MachMsgPortDescriptor(ports_in_receiver))) {
+    LOG_ERROR("Adding descriptor to message failed");
+    return false;
+  }
+  if (!getPortsMsg.AddDescriptor(MachMsgPortDescriptor(ports_out_receiver))) {
+    LOG_ERROR("Adding descriptor to message failed");
+    return false;
+  }
+
+  getPortsMsg.SetData(&pid_pair, sizeof(PIDPair));
+  kern_return_t err = sender->SendMessage(getPortsMsg, kTimeout);
+  if (KERN_SUCCESS != err) {
+    LOG_ERROR("Error sending get ports message %s (%x)\n",  mach_error_string(err), err);
+    return false;
+  }
+  return true;
+}
+
+// Receive two communication ports from another process
+bool
+RecvPortsMessage(ReceivePort* receiver, mach_port_t* ports_in_sender, mach_port_t* ports_out_sender)
+{
+  MachReceiveMessage rcvPortsMsg;
+  kern_return_t err = receiver->WaitForMessage(&rcvPortsMsg, kTimeout);
+  if (KERN_SUCCESS != err) {
+    LOG_ERROR("Error receiving get ports message %s (%x)\n",  mach_error_string(err), err);
+  }
+  if (rcvPortsMsg.GetTranslatedPort(0) == MACH_PORT_NULL) {
+    LOG_ERROR("GetTranslatedPort(0) failed");
+    return false;
+  }
+  *ports_in_sender = rcvPortsMsg.GetTranslatedPort(0);
+
+  if (rcvPortsMsg.GetTranslatedPort(1) == MACH_PORT_NULL) {
+    LOG_ERROR("GetTranslatedPort(1) failed");
+    return false;
+  }
+  *ports_out_sender = rcvPortsMsg.GetTranslatedPort(1);
+  return true;
+}
+
+// Send two communication ports to another process and receive two back
+bool
+RequestPorts(const MemoryPorts& request_ports,
+             mach_port_t  ports_in_receiver,
+             mach_port_t* ports_in_sender,
+             mach_port_t* ports_out_sender,
+             mach_port_t ports_out_receiver,
+             PIDPair pid_pair)
+{
+  if (!SendPortsMessage(request_ports.mSender, ports_in_receiver, ports_out_receiver, pid_pair)) {
+    return false;
+  }
+  return RecvPortsMessage(request_ports.mReceiver, ports_in_sender, ports_out_sender);
+}
+
+MemoryPorts*
+GetMemoryPortsForPid(pid_t pid)
+{
+  gMutex.AssertCurrentThreadOwns();
+
+  if (gMemoryCommPorts.find(pid) == gMemoryCommPorts.end()) {
+    // We don't have the ports open to communicate with that pid, so we're going to
+    // ask our parent process over IPC to set them up for us.
+    if (gParentPid == 0) {
+      // If we're the top level parent process, we have no parent to ask.
+      LOG_ERROR("request for ports for pid %d, but we're the chrome process\n", pid);
+      return nullptr;
+    }
+    const MemoryPorts& parent = gMemoryCommPorts[gParentPid];
+
+    // Create two receiving ports in this process to send to the parent. One will be used for
+    // for listening for incoming memory to be shared, the other for getting the Handle of
+    // memory we share to the other process.
+    ReceivePort* ports_in_receiver = new ReceivePort();
+    ReceivePort* ports_out_receiver = new ReceivePort();
+    mach_port_t raw_ports_in_sender, raw_ports_out_sender;
+    if (!RequestPorts(parent,
+                      ports_in_receiver->GetPort(),
+                      &raw_ports_in_sender,
+                      &raw_ports_out_sender,
+                      ports_out_receiver->GetPort(),
+                      PIDPair(getpid(), pid))) {
+      LOG_ERROR("failed to request ports\n");
+      return nullptr;
+    }
+    // Our parent process sent us two ports, one is for sending new memory to, the other
+    // is for replying with the Handle when we receive new memory.
+    MachPortSender* ports_in_sender = new MachPortSender(raw_ports_in_sender);
+    MachPortSender* ports_out_sender = new MachPortSender(raw_ports_out_sender);
+    SetupMachMemory(pid,
+                    ports_in_receiver,
+                    ports_in_sender,
+                    ports_out_sender,
+                    ports_out_receiver,
+                    false);
+    MOZ_ASSERT(gMemoryCommPorts.find(pid) != gMemoryCommPorts.end());
+  }
+  return &gMemoryCommPorts.at(pid);
+}
+
+// We just received a port representing a region of shared memory, reply to
+// the process that set it with the mach_port_t that represents it in this process.
+// That will be the Handle to be shared over normal IPC
+void
+HandleSharePortsMessage(MachReceiveMessage* rmsg, MemoryPorts* ports)
+{
+  mach_port_t port = rmsg->GetTranslatedPort(0);
+  MachSendMessage msg(kReturnIdMsg);
+  msg.SetData(&port, sizeof(port));
+  kern_return_t err = ports->mSender->SendMessage(msg, kTimeout);
+  if (KERN_SUCCESS != err) {
+    LOG_ERROR("SendMessage failed 0x%x %s\n", err, mach_error_string(err));
+  }
+}
+
+// We were asked by another process to get communications ports to some process. Return
+// those ports via an IPC message.
+bool
+SendReturnPortsMsg(MachPortSender* sender,
+                   mach_port_t raw_ports_in_sender,
+                   mach_port_t raw_ports_out_sender)
+{
+  MachSendMessage getPortsMsg(kReturnPortsMsg);
+  if (!getPortsMsg.AddDescriptor(MachMsgPortDescriptor(raw_ports_in_sender))) {
+    LOG_ERROR("Adding descriptor to message failed");
+    return false;
+  }
+
+  if (!getPortsMsg.AddDescriptor(MachMsgPortDescriptor(raw_ports_out_sender))) {
+    LOG_ERROR("Adding descriptor to message failed");
+    return false;
+  }
+  kern_return_t err = sender->SendMessage(getPortsMsg, kTimeout);
+  if (KERN_SUCCESS != err) {
+    LOG_ERROR("Error sending get ports message %s (%x)\n",  mach_error_string(err), err);
+    return false;
+  }
+  return true;
+}
+
+// We were asked for communcations ports to a process that isn't us. Assuming that process
+// is one of our children, forward that request on.
+void
+ForwardGetPortsMessage(MachReceiveMessage* rmsg, MemoryPorts* ports, PIDPair* pid_pair)
+{
+  if (rmsg->GetTranslatedPort(0) == MACH_PORT_NULL) {
+    LOG_ERROR("GetTranslatedPort(0) failed");
+    return;
+  }
+  if (rmsg->GetTranslatedPort(1) == MACH_PORT_NULL) {
+    LOG_ERROR("GetTranslatedPort(1) failed");
+    return;
+  }
+  mach_port_t raw_ports_in_sender, raw_ports_out_sender;
+  MemoryPorts* requestedPorts = GetMemoryPortsForPid(pid_pair->mRequested);
+  if (!requestedPorts) {
+    LOG_ERROR("failed to find port for process\n");
+    return;
+  }
+  if (!RequestPorts(*requestedPorts, rmsg->GetTranslatedPort(0), &raw_ports_in_sender,
+                    &raw_ports_out_sender, rmsg->GetTranslatedPort(1), *pid_pair)) {
+    LOG_ERROR("failed to request ports\n");
+    return;
+  }
+  SendReturnPortsMsg(ports->mSender, raw_ports_in_sender, raw_ports_out_sender);
+}
+
+// We receieved a message asking us to get communications ports for another process
+void
+HandleGetPortsMessage(MachReceiveMessage* rmsg, MemoryPorts* ports)
+{
+  PIDPair* pid_pair;
+  if (rmsg->GetDataLength() != sizeof(PIDPair)) {
+    LOG_ERROR("Improperly formatted message\n");
+    return;
+  }
+  pid_pair = reinterpret_cast<PIDPair*>(rmsg->GetData());
+  if (pid_pair->mRequested != getpid()) {
+    // This request is for ports to a process that isn't us, forward it to that process
+    ForwardGetPortsMessage(rmsg, ports, pid_pair);
+  } else {
+    if (rmsg->GetTranslatedPort(0) == MACH_PORT_NULL) {
+      LOG_ERROR("GetTranslatedPort(0) failed");
+      return;
+    }
+
+    if (rmsg->GetTranslatedPort(1) == MACH_PORT_NULL) {
+      LOG_ERROR("GetTranslatedPort(1) failed");
+      return;
+    }
+
+    MachPortSender* ports_in_sender = new MachPortSender(rmsg->GetTranslatedPort(0));
+    MachPortSender* ports_out_sender = new MachPortSender(rmsg->GetTranslatedPort(1));
+
+    ReceivePort* ports_in_receiver = new ReceivePort();
+    ReceivePort* ports_out_receiver = new ReceivePort();
+    if (SendReturnPortsMsg(ports->mSender, ports_in_receiver->GetPort(), ports_out_receiver->GetPort())) {
+      SetupMachMemory(pid_pair->mRequester,
+                      ports_out_receiver,
+                      ports_out_sender,
+                      ports_in_sender,
+                      ports_in_receiver,
+                      false);
+    }
+  }
+}
+
+static void *
+PortServerThread(void *argument)
+{
+  MemoryPorts* ports = static_cast<MemoryPorts*>(argument);
+  MachReceiveMessage child_message;
+  while (true) {
+    MachReceiveMessage rmsg;
+    kern_return_t err = ports->mReceiver->WaitForMessage(&rmsg, MACH_MSG_TIMEOUT_NONE);
+    if (err != KERN_SUCCESS) {
+      LOG_ERROR("Wait for message failed 0x%x %s\n", err, mach_error_string(err));
+      continue;
+    }
+    if (rmsg.GetMessageID() == kShutdownMsg) {
+      delete ports->mSender;
+      delete ports->mReceiver;
+      delete ports;
+      return nullptr;
+    }
+    StaticMutexAutoLock smal(gMutex);
+    switch (rmsg.GetMessageID()) {
+    case kSharePortsMsg:
+      HandleSharePortsMessage(&rmsg, ports);
+      break;
+    case kGetPortsMsg:
+      HandleGetPortsMessage(&rmsg, ports);
+      break;
+    case kCleanupMsg:
+     if (gParentPid == 0) {
+       LOG_ERROR("Cleanup message not valid for parent process");
+       continue;
+     }
+
+      pid_t* pid;
+      if (rmsg.GetDataLength() != sizeof(pid_t)) {
+        LOG_ERROR("Improperly formatted message\n");
+        continue;
+      }
+      pid = reinterpret_cast<pid_t*>(rmsg.GetData());
+      SharedMemoryBasic::CleanupForPid(*pid);
+      break;
+    default:
+      LOG_ERROR("Unknown message\n");
+    }
+  }
+}
+
+void
+SharedMemoryBasic::SetupMachMemory(pid_t pid,
+                                   ReceivePort* listen_port,
+                                   MachPortSender* listen_port_ack,
+                                   MachPortSender* send_port,
+                                   ReceivePort* send_port_ack,
+                                   bool pidIsParent)
+{
+  StaticMutexAutoLock smal(gMutex);
+  mozilla::ipc::SetupMachMemory(pid, listen_port, listen_port_ack, send_port, send_port_ack, pidIsParent);
+}
+
+void
+SharedMemoryBasic::Shutdown()
+{
+  StaticMutexAutoLock smal(gMutex);
+
+  for (auto it = gThreads.begin(); it != gThreads.end(); ++it) {
+    MachSendMessage shutdownMsg(kShutdownMsg);
+    it->second.mPorts->mReceiver->SendMessageToSelf(shutdownMsg, kTimeout);
+    pthread_join(it->second.mThread, nullptr);
+  }
+  gThreads.clear();
+
+  for (auto it = gMemoryCommPorts.begin(); it != gMemoryCommPorts.end(); ++it) {
+    delete it->second.mSender;
+    delete it->second.mReceiver;
+  }
+  gMemoryCommPorts.clear();
+}
+
+void
+SharedMemoryBasic::CleanupForPid(pid_t pid)
+{
+  if (gThreads.find(pid) == gThreads.end()) {
+    return;
+  }
+  const ListeningThread& listeningThread = gThreads[pid];
+  MachSendMessage shutdownMsg(kShutdownMsg);
+  kern_return_t ret = listeningThread.mPorts->mReceiver->SendMessageToSelf(shutdownMsg, kTimeout);
+  if (ret != KERN_SUCCESS) {
+    LOG_ERROR("sending shutdown msg failed %s %x\n", mach_error_string(ret), ret);
+  }
+  gThreads.erase(pid);
+
+  if (gParentPid == 0) {
+    // We're the parent. Broadcast the cleanup message to everyone else.
+    for (auto it = gMemoryCommPorts.begin(); it != gMemoryCommPorts.end(); ++it) {
+      MachSendMessage msg(kCleanupMsg);
+      msg.SetData(&pid, sizeof(pid));
+      // We don't really care if this fails, we could be trying to send to an already shut down proc
+      it->second.mSender->SendMessage(msg, kTimeout);
+    }
+  }
+
+  MemoryPorts& ports = gMemoryCommPorts[pid];
+  delete ports.mSender;
+  delete ports.mReceiver;
+  gMemoryCommPorts.erase(pid);
+}
+
+SharedMemoryBasic::SharedMemoryBasic()
+  : mPort(MACH_PORT_NULL)
+  , mMemory(nullptr)
+{
+}
+
+SharedMemoryBasic::SharedMemoryBasic(Handle aHandle)
+  : mPort(MACH_PORT_NULL)
+  , mMemory(nullptr)
+{
+  mPort = aHandle;
+}
+
+SharedMemoryBasic::~SharedMemoryBasic()
+{
+  Unmap();
+  Destroy();
+}
+
+static inline void*
+toPointer(mach_vm_address_t address)
+{
+  return reinterpret_cast<void*>(static_cast<uintptr_t>(address));
+}
+
+static inline mach_vm_address_t
+toVMAddress(void* pointer)
+{
+  return static_cast<mach_vm_address_t>(reinterpret_cast<uintptr_t>(pointer));
+}
+
+bool
+SharedMemoryBasic::Create(size_t size)
+{
+  mach_vm_address_t address;
+
+  kern_return_t kr = mach_vm_allocate(mach_task_self(), &address, round_page(size), VM_FLAGS_ANYWHERE);
+  if (kr != KERN_SUCCESS) {
+    LOG_ERROR("Failed to allocate mach_vm_allocate shared memory (%zu bytes). %s (%x)\n",
+              size, mach_error_string(kr), kr);
+    return false;
+  }
+
+  memory_object_size_t memoryObjectSize = round_page(size);
+
+  kr = mach_make_memory_entry_64(mach_task_self(),
+                                 &memoryObjectSize,
+                                 address,
+                                 VM_PROT_DEFAULT,
+                                 &mPort,
+                                 MACH_PORT_NULL);
+  if (kr != KERN_SUCCESS) {
+    LOG_ERROR("Failed to make memory entry (%zu bytes). %s (%x)\n",
+              size, mach_error_string(kr), kr);
+    return false;
+  }
+
+  mMemory = toPointer(address);
+  Mapped(size);
+  return true;
+}
+
+bool
+SharedMemoryBasic::Map(size_t size)
+{
+  if (mMemory) {
+    return true;
+  }
+
+  if (MACH_PORT_NULL == mPort) {
+    return false;
+  }
+
+  kern_return_t kr;
+  mach_vm_address_t address = 0;
+
+  vm_prot_t vmProtection = VM_PROT_READ | VM_PROT_WRITE;
+
+  kr = mach_vm_map(mach_task_self(), &address, round_page(size), 0, VM_FLAGS_ANYWHERE,
+                   mPort, 0, false, vmProtection, vmProtection, VM_INHERIT_NONE);
+  if (kr != KERN_SUCCESS) {
+    LOG_ERROR("Failed to map shared memory (%zu bytes) into %x, port %x. %s (%x)\n",
+              size, mach_task_self(), mPort, mach_error_string(kr), kr);
+    return false;
+  }
+
+  mMemory = toPointer(address);
+  Mapped(size);
+  return true;
+}
+
+bool
+SharedMemoryBasic::ShareToProcess(base::ProcessId pid,
+                                  Handle* aNewHandle)
+{
+  StaticMutexAutoLock smal(gMutex);
+
+  MemoryPorts* ports = GetMemoryPortsForPid(pid);
+  if (!ports) {
+    LOG_ERROR("Unable to get ports for process.\n");
+    return false;
+  }
+  MachSendMessage smsg(kSharePortsMsg);
+  smsg.AddDescriptor(MachMsgPortDescriptor(mPort, MACH_MSG_TYPE_COPY_SEND));
+  kern_return_t err = ports->mSender->SendMessage(smsg, kTimeout);
+  if (err != KERN_SUCCESS) {
+    LOG_ERROR("sending port failed %s %x\n", mach_error_string(err), err);
+    return false;
+  }
+  MachReceiveMessage msg;
+  err = ports->mReceiver->WaitForMessage(&msg, kTimeout);
+  if (err != KERN_SUCCESS) {
+    LOG_ERROR("didn't get an id %s %x\n", mach_error_string(err), err);
+    return false;
+  }
+  if (msg.GetDataLength() != sizeof(mach_port_t)) {
+    LOG_ERROR("Improperly formatted reply\n");
+    return false;
+  }
+  mach_port_t *id = reinterpret_cast<mach_port_t*>(msg.GetData());
+  *aNewHandle = *id;
+  return true;
+}
+
+void
+SharedMemoryBasic::Unmap()
+{
+  if (!mMemory) {
+    return;
+  }
+  vm_address_t address = toVMAddress(mMemory);
+  kern_return_t kr = vm_deallocate(mach_task_self(), address, vm_page_size);
+  if (kr != KERN_SUCCESS) {
+    LOG_ERROR("Failed to deallocate shared memory. %s (%x)\n",  mach_error_string(kr), kr);
+    return;
+  }
+  mMemory = nullptr;
+}
+
+void
+SharedMemoryBasic::Destroy()
+{
+  mach_port_deallocate(mach_task_self(), mPort);
+}
+
+bool
+SharedMemoryBasic::IsHandleValid(const Handle& aHandle)
+{
+  return aHandle > 0;
+}
+
+} // namespace ipc
+} // namespace mozilla

ipc/glue/SharedMemoryBasic_mach.h

@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ipc_SharedMemoryBasic_mach_h
+#define mozilla_ipc_SharedMemoryBasic_mach_h
+
+#include "base/file_descriptor_posix.h"
+#include "base/process.h"
+
+#include "SharedMemory.h"
+#include <mach/port.h>
+
+//
+// This is a low-level wrapper around platform shared memory.  Don't
+// use it directly; use Shmem allocated through IPDL interfaces.
+//
+
+class MachPortSender;
+class ReceivePort;
+
+namespace mozilla {
+namespace ipc {
+
+class SharedMemoryBasic final : public SharedMemory
+{
+public:
+  typedef mach_port_t Handle;
+
+  static void SetupMachMemory(pid_t pid,
+                              ReceivePort* listen_port,
+                              MachPortSender* listen_port_ack,
+                              MachPortSender* send_port,
+                              ReceivePort* send_port_ack,
+                              bool pidIsParent);
+
+  static void CleanupForPid(pid_t pid);
+
+  static void Shutdown();
+
+  SharedMemoryBasic();
+
+  explicit SharedMemoryBasic(Handle aHandle);
+
+  virtual bool Create(size_t aNbytes) override;
+
+  virtual bool Map(size_t nBytes) override;
+
+  virtual void* memory() const override
+  {
+    return mMemory;
+  }
+
+  virtual SharedMemoryType Type() const override
+  {
+    return TYPE_BASIC;
+  }
+
+  static Handle NULLHandle()
+  {
+    return Handle();
+  }
+
+
+  static bool IsHandleValid(const Handle &aHandle);
+
+  bool ShareToProcess(base::ProcessId aProcessId,
+                      Handle* aNewHandle);
+
+private:
+  ~SharedMemoryBasic();
+
+  void Unmap();
+  void Destroy();
+  mach_port_t mPort;
+  // Pointer to mapped region, null if unmapped.
+  void *mMemory;
+};
+
+} // namespace ipc
+} // namespace mozilla
+
+#endif // ifndef mozilla_ipc_SharedMemoryBasic_mach_h

ipc/glue/moz.build

@@ -76,6 +76,11 @@ if CONFIG['OS_TARGET'] == 'Android':
     UNIFIED_SOURCES += [
         'SharedMemoryBasic_android.cpp',
     ]
+elif CONFIG['OS_ARCH'] == 'Darwin':
+    EXPORTS.mozilla.ipc += ['SharedMemoryBasic_mach.h']
+    SOURCES += [
+        'SharedMemoryBasic_mach.cpp',
+    ]
 else:
     EXPORTS.mozilla.ipc += ['SharedMemoryBasic_chromium.h']
 

toolkit/xre/nsEmbedFunctions.cpp

@@ -378,6 +378,18 @@ XRE_InitChildProcess(int aArgc,
     return NS_ERROR_FAILURE;
   }
 
+  ReceivePort* ports_out_receiver = new ReceivePort();
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(ports_out_receiver->GetPort()))) {
+    NS_WARNING("Adding descriptor to message failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  ReceivePort* ports_in_receiver = new ReceivePort();
+  if (!child_message.AddDescriptor(MachMsgPortDescriptor(ports_in_receiver->GetPort()))) {
+    NS_WARNING("Adding descriptor to message failed");
+    return NS_ERROR_FAILURE;
+  }
+
   MachPortSender child_sender(mach_port_name);
   kern_return_t err = child_sender.SendMessage(child_message, kTimeoutMs);
   if (err != KERN_SUCCESS) {
@@ -396,12 +408,27 @@ XRE_InitChildProcess(int aArgc,
     NS_WARNING("child GetTranslatedPort(0) failed");
     return NS_ERROR_FAILURE;
   }
+
   err = task_set_bootstrap_port(mach_task_self(),
                                 parent_message.GetTranslatedPort(0));
+
+  if (parent_message.GetTranslatedPort(1) == MACH_PORT_NULL) {
+    NS_WARNING("child GetTranslatedPort(1) failed");
+    return NS_ERROR_FAILURE;
+  }
+  MachPortSender* ports_out_sender = new MachPortSender(parent_message.GetTranslatedPort(1));
+
+  if (parent_message.GetTranslatedPort(2) == MACH_PORT_NULL) {
+    NS_WARNING("child GetTranslatedPort(2) failed");
+    return NS_ERROR_FAILURE;
+  }
+  MachPortSender* ports_in_sender = new MachPortSender(parent_message.GetTranslatedPort(2));
+
   if (err != KERN_SUCCESS) {
     NS_WARNING("child task_set_bootstrap_port() failed");
     return NS_ERROR_FAILURE;
   }
+
 #endif
 
   SetupErrorHandling(aArgv[0]);  
@@ -470,6 +497,11 @@ XRE_InitChildProcess(int aArgc,
   base::ProcessId parentPID = strtol(parentPIDString, &end, 10);
   MOZ_ASSERT(!*end, "invalid parent PID");
 
+#ifdef XP_MACOSX
+  mozilla::ipc::SharedMemoryBasic::SetupMachMemory(parentPID, ports_in_receiver, ports_in_sender,
+                                                   ports_out_sender, ports_out_receiver, true);
+#endif
+
 #if defined(XP_WIN)
   // On Win7+, register the application user model id passed in by
   // parent. This insures windows created by the container properly
@@ -757,6 +789,9 @@ void
 XRE_ShutdownChildProcess()
 {
   MOZ_ASSERT(NS_IsMainThread(), "Wrong thread!");
+#if defined(XP_MACOSX)
+  mozilla::ipc::SharedMemoryBasic::Shutdown();
+#endif
 
   mozilla::DebugOnly<MessageLoop*> ioLoop = XRE_GetIOMessageLoop();
   MOZ_ASSERT(!!ioLoop, "Bad shutdown order");