/* 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 #include #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; #ifdef __APPLE__ /* we need to align and pack data to 32bit so that x86_64 and arm64 work together */ typedef int32_t jack_shm_registry_index_t; #else typedef int16_t jack_shm_registry_index_t; #endif /** * A structure holding information about shared memory allocated by * JACK. this persists across invocations of JACK, and can be used by * multiple JACK servers. It contains no pointers and is valid across * address spaces. * * The registry consists of two parts: a header including an array of * server names, followed by an array of segment registry entries. */ 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) /** * a structure holding information about shared memory * allocated by JACK. this version is valid only * for a given address space. It contains a pointer * indicating where the shared memory has been * attached to the address space. */ 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 compiling 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__ */