code.vuplus.com Git - vuplus_transtreamproxy/blob - src/SharedMemory.h

   1 /*
   2  * SharedMemory.h
   3  *
   4  *  Created on: 2014. 6. 12.
   5  *      Author: oskwon
   6  */
   7
   8 #ifndef SHAREDMEMORY_H_
   9 #define SHAREDMEMORY_H_
  10
  11 #include <string>
  12
  13 #include <fcntl.h>
  14 #include <unistd.h>
  15 #include <semaphore.h>
  16 #include <sys/mman.h>
  17
  18 #include "Logger.h"
  19
  20 using namespace std;
  21 //-------------------------------------------------------------------------------
  22
  23 template <class T>
  24 class SharedMemory
  25 {
  26 protected:
  27         sem_t* mSemId;
  28         std::string mSemName;
  29
  30         int mShmFd;
  31         int mShmSize;
  32         std::string mShmName;
  33
  34         T* mShmData;
  35
  36 protected:
  37         void Close()
  38         {
  39                 if (mShmData > 0) {
  40                         munmap(mShmData, mShmSize);
  41                 }
  42                 mShmData = 0;
  43                 if (mShmFd > 0) {
  44                         close(mShmFd);
  45                         //shm_unlink(mShmName.c_str());
  46                 }
  47                 mShmFd = 0;
  48                 if (mSemId > 0) {
  49                         sem_close(mSemId);
  50                         sem_unlink(mSemName.c_str());
  51                 }
  52                 mSemId = 0;
  53         }
  54
  55         bool Open()
  56         {
  57                 mShmFd = shm_open(mShmName.c_str(), O_CREAT | O_RDWR, S_IRWXU | S_IRWXG);
  58                 if (mShmFd < 0) {
  59                         return false;
  60                 }
  61                 ftruncate(mShmFd, mShmSize);
  62
  63                 mShmData = (T*) mmap(NULL, mShmSize, PROT_READ | PROT_WRITE, MAP_SHARED, mShmFd, 0);
  64                 if (mShmData == 0) {
  65                         return false;
  66                 }
  67                 mSemId = sem_open(mSemName.c_str(), O_CREAT, S_IRUSR | S_IWUSR, 1);
  68                 return true;
  69         }
  70
  71         void Wait()
  72         {
  73                 DEBUG("WAIT-BEFORE");
  74                 sem_wait(mSemId);
  75                 DEBUG("WAIT-AFTER");
  76         }
  77         void Post()
  78         {
  79                 DEBUG("POST-BEFORE");
  80                 sem_post(mSemId);
  81                 DEBUG("POST-AFTER");
  82         }
  83
  84 public:
  85         ~SharedMemory()
  86         {
  87                 Close();
  88         }
  89 };
  90 //-------------------------------------------------------------------------------
  91
  92 #endif /* UPOSIXSHAREDMEMORY_H_ */