Com++: /home/fb/sf/compp/trunk/ComPP/ComPlusPlus/ShMem.cpp Source File

00001 // **************************************************************
00002 // Com ++ Framework by the C++ World
00003 // Please report defects: mailto:compp@cplusplusworld.com
00004 // Please visit: http://www.cplusplusworld.com/socketlibrary.html
00005 // **************************************************************
00006 
00007 
00008 #include <sys/types.h>
00009 #include <sys/ipc.h>
00010 
00011 #include <sys/shm.h>
00012 
00013 #include "ComPlusPlus/ShMem.h"
00014 #include "SysPlusPlus/ComException.h"
00015 #include "SysPlusPlus/syscall.h"
00016 
00017 
00018 compp::ShMem::ShMem( const int key, const int size, const int mode, bool exclusive  ) {
00019 
00020   Addr = NULL; 
00021   DestroyInDestructor = false;
00022   int locmodes = mode | IPC_CREAT;
00023   if ( exclusive ) {
00024     locmodes = locmodes | IPC_EXCL;
00025   }
00026   
00027   if ( -1 == ( ShMemId = syspp::Call::ShmGet( key, size, locmodes ) ) )
00028     throw syspp::ComException ( "Cannot create shared memory segment");
00029   
00030 }
00031 
00032 compp::ShMem::ShMem( const int key, const int size, const int mode ) {
00033   
00034   Addr = NULL;
00035   DestroyInDestructor = false;
00036   if ( -1 == ( ShMemId = syspp::Call::ShmGet( key, size, mode ) ) )
00037     throw syspp::ComException ( "Cannot create shared memory segment");
00038 
00039 }
00040 
00041 compp::ShMem::~ShMem() {
00042   
00043   Detach();
00044   if ( DestroyInDestructor )
00045     Destroy ();
00046 }
00047 
00048 int  compp::ShMem::getId() {
00049   return ShMemId;
00050 }
00051 
00052 void* compp::ShMem::getStartAddr ( ) {
00053 
00054   return Addr;
00055 }
00056 
00057 
00058 void compp::ShMem::Attach() {
00059 
00060   Addr = syspp::Call::ShmAt(ShMemId, NULL, 0 );
00061   if ( Addr == (void *) -1 ) {
00062     throw syspp::ComException ( "Cannot attache shared memory segment");
00063   }
00064 
00065 }
00066 
00067 void compp::ShMem::Detach() {
00068 
00069   if ( -1 == syspp::Call::ShmDt(Addr) ) {
00070     throw syspp::ComException ( "Cannot detach shared memory segment");
00071   }
00072    
00073   Addr = NULL;
00074 
00075 }
00076 
00077 void compp::ShMem::Destroy() {
00078   struct shmid_ds buffer;
00079 
00080   if ( -1 ==  shmctl(ShMemId, IPC_RMID, &buffer) ) {
00081     throw syspp::ComException ( "Cannot mark shared memory segment for deletion.");
00082   }
00083 
00084 }
00085 
00086 
00087 
00088 void compp::ShMem::AutoDestroy( const bool on ) {
00089 
00090   if ( on ) 
00091     DestroyInDestructor = true;
00092   else
00093     DestroyInDestructor = false;
00094 }