diff -r 000000000000 -r 6474c204b198 ipc/glue/SharedMemorySysV.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/glue/SharedMemorySysV.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,150 @@
+/* -*- 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_SharedMemorySysV_h
+#define mozilla_ipc_SharedMemorySysV_h
+
+#if (defined(OS_LINUX) && !defined(ANDROID)) || defined(OS_BSD)
+
+// SysV shared memory isn't available on Windows, but we define the
+// following macro so that #ifdefs are clearer (compared to #ifdef
+// OS_LINUX).
+#define MOZ_HAVE_SHAREDMEMORYSYSV
+
+#include "SharedMemory.h"
+
+#include "nsDebug.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+//
+// This is a low-level wrapper around platform shared memory.  Don't
+// use it directly; use Shmem allocated through IPDL interfaces.
+//
+
+namespace mozilla {
+namespace ipc {
+
+
+class SharedMemorySysV : public SharedMemory
+{
+public:
+  typedef int Handle;
+
+  SharedMemorySysV() :
+    mHandle(-1),
+    mData(nullptr)
+  {
+  }
+
+  SharedMemorySysV(Handle aHandle) :
+    mHandle(aHandle),
+    mData(nullptr)
+  {
+  }
+
+  virtual ~SharedMemorySysV()
+  {
+    shmdt(mData);
+    mHandle = -1;
+    mData = nullptr;
+  }
+
+  virtual bool Create(size_t aNbytes) MOZ_OVERRIDE
+  {
+    int id = shmget(IPC_PRIVATE, aNbytes, IPC_CREAT | 0600);
+    if (id == -1)
+      return false;
+
+    mHandle = id;
+    mAllocSize = aNbytes;
+    Created(aNbytes);
+
+    return Map(aNbytes);
+  }
+
+  virtual bool Map(size_t nBytes) MOZ_OVERRIDE
+  {
+    // already mapped
+    if (mData)
+      return true;
+
+    if (!IsHandleValid(mHandle))
+      return false;
+
+    void* mem = shmat(mHandle, nullptr, 0);
+    if (mem == (void*) -1) {
+      char warning[256];
+      ::snprintf(warning, sizeof(warning)-1,
+                 "shmat(): %s (%d)\n", strerror(errno), errno);
+
+      NS_WARNING(warning);
+
+      return false;
+    }
+
+    // Mark the handle as deleted so that, should this process go away, the
+    // segment is cleaned up.
+    shmctl(mHandle, IPC_RMID, 0);
+
+    mData = mem;
+
+#ifdef DEBUG
+    struct shmid_ds info;
+    if (shmctl(mHandle, IPC_STAT, &info) < 0)
+      return false;
+
+    NS_ABORT_IF_FALSE(nBytes <= info.shm_segsz,
+                      "Segment doesn't have enough space!");
+#endif
+
+    Mapped(nBytes);
+    return true;
+  }
+
+  virtual void* memory() const MOZ_OVERRIDE
+  {
+    return mData;
+  }
+
+  virtual SharedMemoryType Type() const MOZ_OVERRIDE
+  {
+    return TYPE_SYSV;
+  }
+
+  Handle GetHandle() const
+  {
+    NS_ABORT_IF_FALSE(IsHandleValid(mHandle), "invalid handle");
+    return mHandle;
+  }
+
+  static Handle NULLHandle()
+  {
+    return -1;
+  }
+
+  static bool IsHandleValid(Handle aHandle)
+  {
+    return aHandle != -1;
+  }
+
+private:
+  Handle mHandle;
+  void* mData;
+};
+
+} // namespace ipc
+} // namespace mozilla
+
+#endif // OS_LINUX
+
+#endif // ifndef mozilla_ipc_SharedMemorySysV_h