1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/glue/SharedMemorySysV.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,150 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * vim: sw=2 ts=8 et :
1.6 + */
1.7 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.8 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.9 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.10 +
1.11 +#ifndef mozilla_ipc_SharedMemorySysV_h
1.12 +#define mozilla_ipc_SharedMemorySysV_h
1.13 +
1.14 +#if (defined(OS_LINUX) && !defined(ANDROID)) || defined(OS_BSD)
1.15 +
1.16 +// SysV shared memory isn't available on Windows, but we define the
1.17 +// following macro so that #ifdefs are clearer (compared to #ifdef
1.18 +// OS_LINUX).
1.19 +#define MOZ_HAVE_SHAREDMEMORYSYSV
1.20 +
1.21 +#include "SharedMemory.h"
1.22 +
1.23 +#include "nsDebug.h"
1.24 +
1.25 +#include <errno.h>
1.26 +#include <fcntl.h>
1.27 +#include <stdio.h>
1.28 +#include <string.h>
1.29 +#include <sys/ipc.h>
1.30 +#include <sys/shm.h>
1.31 +
1.32 +//
1.33 +// This is a low-level wrapper around platform shared memory. Don't
1.34 +// use it directly; use Shmem allocated through IPDL interfaces.
1.35 +//
1.36 +
1.37 +namespace mozilla {
1.38 +namespace ipc {
1.39 +
1.40 +
1.41 +class SharedMemorySysV : public SharedMemory
1.42 +{
1.43 +public:
1.44 + typedef int Handle;
1.45 +
1.46 + SharedMemorySysV() :
1.47 + mHandle(-1),
1.48 + mData(nullptr)
1.49 + {
1.50 + }
1.51 +
1.52 + SharedMemorySysV(Handle aHandle) :
1.53 + mHandle(aHandle),
1.54 + mData(nullptr)
1.55 + {
1.56 + }
1.57 +
1.58 + virtual ~SharedMemorySysV()
1.59 + {
1.60 + shmdt(mData);
1.61 + mHandle = -1;
1.62 + mData = nullptr;
1.63 + }
1.64 +
1.65 + virtual bool Create(size_t aNbytes) MOZ_OVERRIDE
1.66 + {
1.67 + int id = shmget(IPC_PRIVATE, aNbytes, IPC_CREAT | 0600);
1.68 + if (id == -1)
1.69 + return false;
1.70 +
1.71 + mHandle = id;
1.72 + mAllocSize = aNbytes;
1.73 + Created(aNbytes);
1.74 +
1.75 + return Map(aNbytes);
1.76 + }
1.77 +
1.78 + virtual bool Map(size_t nBytes) MOZ_OVERRIDE
1.79 + {
1.80 + // already mapped
1.81 + if (mData)
1.82 + return true;
1.83 +
1.84 + if (!IsHandleValid(mHandle))
1.85 + return false;
1.86 +
1.87 + void* mem = shmat(mHandle, nullptr, 0);
1.88 + if (mem == (void*) -1) {
1.89 + char warning[256];
1.90 + ::snprintf(warning, sizeof(warning)-1,
1.91 + "shmat(): %s (%d)\n", strerror(errno), errno);
1.92 +
1.93 + NS_WARNING(warning);
1.94 +
1.95 + return false;
1.96 + }
1.97 +
1.98 + // Mark the handle as deleted so that, should this process go away, the
1.99 + // segment is cleaned up.
1.100 + shmctl(mHandle, IPC_RMID, 0);
1.101 +
1.102 + mData = mem;
1.103 +
1.104 +#ifdef DEBUG
1.105 + struct shmid_ds info;
1.106 + if (shmctl(mHandle, IPC_STAT, &info) < 0)
1.107 + return false;
1.108 +
1.109 + NS_ABORT_IF_FALSE(nBytes <= info.shm_segsz,
1.110 + "Segment doesn't have enough space!");
1.111 +#endif
1.112 +
1.113 + Mapped(nBytes);
1.114 + return true;
1.115 + }
1.116 +
1.117 + virtual void* memory() const MOZ_OVERRIDE
1.118 + {
1.119 + return mData;
1.120 + }
1.121 +
1.122 + virtual SharedMemoryType Type() const MOZ_OVERRIDE
1.123 + {
1.124 + return TYPE_SYSV;
1.125 + }
1.126 +
1.127 + Handle GetHandle() const
1.128 + {
1.129 + NS_ABORT_IF_FALSE(IsHandleValid(mHandle), "invalid handle");
1.130 + return mHandle;
1.131 + }
1.132 +
1.133 + static Handle NULLHandle()
1.134 + {
1.135 + return -1;
1.136 + }
1.137 +
1.138 + static bool IsHandleValid(Handle aHandle)
1.139 + {
1.140 + return aHandle != -1;
1.141 + }
1.142 +
1.143 +private:
1.144 + Handle mHandle;
1.145 + void* mData;
1.146 +};
1.147 +
1.148 +} // namespace ipc
1.149 +} // namespace mozilla
1.150 +
1.151 +#endif // OS_LINUX
1.152 +
1.153 +#endif // ifndef mozilla_ipc_SharedMemorySysV_h
