sharedmem.h File Reference

Posix shared memory segment server/client management, shared memory ring buffer synchronized using posix semaphores. More...

#include "common.h"
#include <sys/shm.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <semaphore.h>
#include "framefilter.h"
#include "Python.h"

Include dependency graph for sharedmem.h:

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Classes
class	EventFd
	A file descriptor for running select and poll with shmem ring buffers. More...
class	SharedMemSegment
	Handles a shared memory segment with metadata (the segment size) More...
class	SimpleSharedMemSegment
	Shared mem segment with simple metadata : just the payload length. More...
struct	RGB24Meta
	A seriazable metadata object. More...
class	RGB24SharedMemSegment
	A Shmem segment describing an RGB24 frame. More...
class	SharedMemRingBufferBase
	Interprocess shared memory ring buffer synchronized with posix semaphores. More...
class	SharedMemRingBuffer
class	SharedMemRingBufferRGB
	SharedMemRingBuffer for AVRGBFrame. More...
class	ShmemFrameFilter
	This FrameFilter writes frames into a SharedMemRingBuffer. More...
class	RGBShmemFrameFilter
	Like ShmemFrameFilter. More...

Macros
#define	server_init(CLASSNAME, TYPENAME)
#define	client_init(CLASSNAME, TYPENAME)
#define	server_close(CLASSNAME, TYPENAME)
#define	client_close(CLASSNAME, TYPENAME)
#define	copy_meta_from(CLASSNAME, TYPENAME)
#define	copy_meta_to(CLASSNAME, TYPENAME)

Detailed Description

Posix shared memory segment server/client management, shared memory ring buffer synchronized using posix semaphores.

Author

Sampsa Riikonen

Date

2017

Version

1.6.1

Macro Definition Documentation

client_close

#define client_close	(		CLASSNAME,
			TYPENAME
	)

Value:

void CLASSNAME::clientClose() { \
if (munmap(ptr, n_bytes)!=0 or munmap(ptr_, sizeof(TYPENAME)!=0)) { \
    perror("valkka_core: sharedmem.cpp: CLASSNAME::clientClose: munmap failed"); \
    exit(2); \
  } \
} \

client_init

#define client_init	(		CLASSNAME,
			TYPENAME
	)

Value:

bool CLASSNAME::clientInit() { \
  int fd, fd_;\
  fd = shm_open(payload_name.c_str(), O_RDONLY, 0400);\
  fd_= shm_open(meta_name.c_str(), O_RDONLY, 0400);\
  if (fd == -1 or fd_==-1) {\
    /* perror("valkka_core: sharedmem.cpp: SharedMemSegment::clientInit: shm_open failed"); */\
    /* exit(2); */\
    return false;\
  }\
  /* std::cout << "got shmem" << std::endl; */\
  ptr  =mmap(0, n_bytes, PROT_READ, MAP_SHARED, fd,  0);\
  ptr_ =mmap(0, sizeof(TYPENAME), PROT_READ, MAP_SHARED, fd_, 0);\
  if (ptr == MAP_FAILED or ptr_ == MAP_FAILED) {\
    std::cout << "valkka_core: sharedmem.cpp: SharedMemSegment::clientInit: mmap failed" << std::endl;\
    /* perror("valkka_core: sharedmem.cpp: SharedMemSegment::clientInit: mmap failed"); */\
    /* exit(2);*/\
    return false;\
  }\
  payload = (uint8_t*) ptr;\
  meta    = (TYPENAME*) ptr_;\
  /*std::cout << "client meta reserved" << std::endl;*/\
  close(fd);\
  close(fd_);\
  /*std::cout << "Client reserved " << sizeof(TYPENAME) << "bytes" << std::endl;*/\
  return true;\
};\

copy_meta_from

#define copy_meta_from	(		CLASSNAME,
			TYPENAME
	)

Value:

void CLASSNAME::copyMetaFrom(void *meta_) { \
    *meta = *((TYPENAME*)(meta_)); \
}\

copy_meta_to

#define copy_meta_to	(		CLASSNAME,
			TYPENAME
	)

Value:

void CLASSNAME::copyMetaTo(void *meta_) { \
    *((TYPENAME*)(meta_)) = *meta; \
}\

server_close

#define server_close	(		CLASSNAME,
			TYPENAME
	)

Value:

void CLASSNAME::serverClose() { \
 if (munmap(ptr, n_bytes)!=0 or munmap(ptr_, sizeof(TYPENAME)!=0)) { \
    perror("valkka_core: sharedmem.cpp: CLASSNAME::serverClose: munmap failed"); \
    exit(2); \
  } \
  if (shm_unlink(payload_name.c_str())!=0 or shm_unlink(meta_name.c_str())!=0) { \
    perror("valkka_core: sharedmem.cpp: CLASSNAME::serverClose: shm_unlink failed"); \
    /*exit(2);*/ \
  } \
} \