memshm.h Source File

00001 //
00002 // memshm.h
00003 //
00004 // Copyright (C) 1996 Limit Point Systems, Inc.
00005 //
00006 // Author: Curtis Janssen <cljanss@limitpt.com>
00007 // Maintainer: LPS
00008 //
00009 // This file is part of the SC Toolkit.
00010 //
00011 // The SC Toolkit is free software; you can redistribute it and/or modify
00012 // it under the terms of the GNU Library General Public License as published by
00013 // the Free Software Foundation; either version 2, or (at your option)
00014 // any later version.
00015 //
00016 // The SC Toolkit is distributed in the hope that it will be useful,
00017 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00018 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019 // GNU Library General Public License for more details.
00020 //
00021 // You should have received a copy of the GNU Library General Public License
00022 // along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
00023 // the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
00024 //
00025 // The U.S. Government is granted a limited license as per AL 91-7.
00026 //
00027 
00028 #ifdef __GNUC__
00029 #pragma interface
00030 #endif
00031 
00032 #ifndef _util_group_memshm_h
00033 #define _util_group_memshm_h
00034 
00035 #include <sys/types.h>
00036 #include <sys/ipc.h>
00037 #include <sys/shm.h>
00038 #include <iostream>
00039 
00040 #include <util/group/globcnt.h>
00041 #include <util/group/memmsg.h>
00042 
00043 #include <util/group/rnglock.h>
00044 
00045 namespace sc {
00046 
00050 class ShmMemoryGrp: public MsgMemoryGrp {
00051   private:
00052     int nregion_;
00053     int *shmid_;
00054     void **attach_address_;
00055     GlobalCounter lock_;
00056     GlobalCounter *update_;
00057     void *data_;
00058     void *memory_;
00059     Pool *pool_;
00060     RangeLock *rangelock_; // the locks_ member of the base class is ignored
00061 
00062     void clear_release_count();
00063     void wait_for_release();
00064     void note_release();
00065     void obtain_lock();
00066     void release_lock();
00067 
00068     void cleanup();
00069     int attach_memory(void *ataddress, int size);
00070     void detach_memory();
00071   public:
00072     ShmMemoryGrp(const Ref<MessageGrp>& msg);
00073     ShmMemoryGrp(const Ref<KeyVal>&);
00074     ~ShmMemoryGrp();
00075 
00076     void set_localsize(size_t);
00077     void *localdata();
00078 
00079     void *obtain_readwrite(distsize_t offset, int size);
00080     void *obtain_readonly(distsize_t offset, int size);
00081     void *obtain_writeonly(distsize_t offset, int size);
00082     void release_readonly(void *data, distsize_t offset, int size);
00083     void release_writeonly(void *data, distsize_t offset, int size);
00084     void release_readwrite(void *data, distsize_t offset, int size);
00085 
00086     void print(std::ostream &o = ExEnv::out0()) const;
00087 };
00088 
00089 }
00090 
00091 #endif
00092 
00093 // Local Variables:
00094 // mode: c++
00095 // c-file-style: "CLJ"
00096 // End: