shm.h
/* This module provides a set of abstract shared memory interfaces
* with support using both System V and POSIX shared memory
* implementations. The code is divided into three sections:
*
* - common (interface-independent) code
* - POSIX implementation
* - System V implementation
* - Windows implementation
*
* The implementation used is determined by whether USE_POSIX_SHM was
* set in the ./configure step.
*/
/*
Copyright (C) 2001-2003 Paul Davis
Copyright (C) 2005-2012 Grame
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef __jack_shm_h__
#define __jack_shm_h__
#include <limits.h>
#include <sys/types.h>
#include "types.h"
#include "JackCompilerDeps.h"
#include "JackConstants.h"
#define TRUE 1
#define FALSE 0
#ifdef __cplusplus
extern "C"
{
#endif
#define MAX_SERVERS 8 /* maximum concurrent servers */
#define MAX_SHM_ID 256 /* generally about 16 per server */
#define JACK_SHM_MAGIC 0x4a41434b /* shm magic number: "JACK" */
#define JACK_SHM_NULL_INDEX -1 /* NULL SHM index */
#define JACK_SHM_REGISTRY_INDEX -2 /* pseudo SHM index for registry */
/* On Mac OS X, SHM_NAME_MAX is the maximum length of a shared memory
* segment name (instead of NAME_MAX or PATH_MAX as defined by the
* standard).
*/
#ifdef USE_POSIX_SHM
#ifndef NAME_MAX
#define NAME_MAX 255
#endif
#ifndef SHM_NAME_MAX
#define SHM_NAME_MAX NAME_MAX
#endif
typedef char shm_name_t[SHM_NAME_MAX];
typedef shm_name_t jack_shm_id_t;
#elif WIN32
#define NAME_MAX 255
#ifndef SHM_NAME_MAX
#define SHM_NAME_MAX NAME_MAX
#endif
typedef char shm_name_t[SHM_NAME_MAX];
typedef shm_name_t jack_shm_id_t;
#elif __ANDROID__
#ifndef NAME_MAX
#define NAME_MAX 255
#endif
#ifndef SHM_NAME_MAX
#define SHM_NAME_MAX NAME_MAX
#endif
typedef char shm_name_t[SHM_NAME_MAX];
typedef shm_name_t jack_shm_id_t;
typedef int jack_shm_fd_t;
#else
/* System V SHM */
typedef int jack_shm_id_t;
#endif /* SHM type */
/* shared memory type */
typedef enum {
shm_POSIX = 1, /* POSIX shared memory */
shm_SYSV = 2, /* System V shared memory */
shm_WIN32 = 3, /* Windows 32 shared memory */
shm_ANDROID = 4 /* Android shared memory */
} jack_shmtype_t;
typedef int16_t jack_shm_registry_index_t;
typedef struct _jack_shm_server {
#ifdef WIN32
int pid; /* process ID */
#else
pid_t pid; /* process ID */
#endif
char name[JACK_SERVER_NAME_SIZE+1];
}
jack_shm_server_t;
typedef struct _jack_shm_header {
uint32_t magic; /* magic number */
uint16_t protocol; /* JACK protocol version */
jack_shmtype_t type; /* shm type */
jack_shmsize_t size; /* total registry segment size */
jack_shmsize_t hdr_len; /* size of header */
jack_shmsize_t entry_len; /* size of registry entry */
jack_shm_server_t server[MAX_SERVERS]; /* current server array */
}
jack_shm_header_t;
typedef struct _jack_shm_registry {
jack_shm_registry_index_t index; /* offset into the registry */
#ifdef WIN32
int allocator; /* PID that created shm segment */
#else
pid_t allocator; /* PID that created shm segment */
#endif
jack_shmsize_t size; /* for POSIX unattach */
jack_shm_id_t id; /* API specific, see above */
#ifdef __ANDROID__
jack_shm_fd_t fd;
#endif
}
jack_shm_registry_t;
#define JACK_SHM_REGISTRY_SIZE (sizeof (jack_shm_header_t) \
+ sizeof (jack_shm_registry_t) * MAX_SHM_ID)
PRE_PACKED_STRUCTURE
struct _jack_shm_info {
jack_shm_registry_index_t index; /* offset into the registry */
uint32_t size;
#ifdef __ANDROID__
jack_shm_fd_t fd;
#endif
union {
void *attached_at; /* address where attached */
char ptr_size[8];
} ptr; /* a "pointer" that has the same 8 bytes size when compling in 32 or 64 bits */
} POST_PACKED_STRUCTURE;
typedef struct _jack_shm_info jack_shm_info_t;
/* utility functions used only within JACK */
void jack_shm_copy_from_registry (jack_shm_info_t*,
jack_shm_registry_index_t);
void jack_shm_copy_to_registry (jack_shm_info_t*,
jack_shm_registry_index_t*);
int jack_release_shm_info (jack_shm_registry_index_t);
char* jack_shm_addr (jack_shm_info_t* si);
// here begin the API
int jack_register_server (const char *server_name, int new_registry);
int jack_unregister_server (const char *server_name);
int jack_initialize_shm (const char *server_name);
int jack_initialize_shm_server (void);
int jack_initialize_shm_client (void);
int jack_cleanup_shm (void);
int jack_shmalloc (const char *shm_name, jack_shmsize_t size,
jack_shm_info_t* result);
void jack_release_shm (jack_shm_info_t*);
void jack_release_lib_shm (jack_shm_info_t*);
void jack_destroy_shm (jack_shm_info_t*);
int jack_attach_shm (jack_shm_info_t*);
int jack_attach_lib_shm (jack_shm_info_t*);
int jack_attach_shm_read (jack_shm_info_t*);
int jack_attach_lib_shm_read (jack_shm_info_t*);
int jack_resize_shm (jack_shm_info_t*, jack_shmsize_t size);
#ifdef __cplusplus
}
#endif
#endif /* __jack_shm_h__ */
_jack_shm_info
Definition: shm.h:170
_jack_shm_registry
Definition: shm.h:141
_jack_shm_header
Definition: shm.h:130
_jack_shm_server
Definition: shm.h:119