Jack2  1.9.8
shm.h
1 #ifndef __jack_shm_h__
2 #define __jack_shm_h__
3 
4 #include <limits.h>
5 #include <sys/types.h>
6 #include "types.h"
7 #include "JackCompilerDeps.h"
8 
9 #define TRUE 1
10 #define FALSE 0
11 
12 #ifdef __cplusplus
13 extern "C"
14 {
15 #endif
16 
17 #define MAX_SERVERS 8 /* maximum concurrent servers */
18 #define MAX_SHM_ID 256 /* generally about 16 per server */
19 #define JACK_SERVER_NAME_SIZE 256 /* maximum length of server name */
20 #define JACK_SHM_MAGIC 0x4a41434b /* shm magic number: "JACK" */
21 #define JACK_SHM_NULL_INDEX -1 /* NULL SHM index */
22 #define JACK_SHM_REGISTRY_INDEX -2 /* pseudo SHM index for registry */
23 
24 
25  /* On Mac OS X, SHM_NAME_MAX is the maximum length of a shared memory
26  * segment name (instead of NAME_MAX or PATH_MAX as defined by the
27  * standard).
28  */
29 #ifdef USE_POSIX_SHM
30 
31 #ifndef NAME_MAX
32 #define NAME_MAX 255
33 #endif
34 
35 #ifndef SHM_NAME_MAX
36 #define SHM_NAME_MAX NAME_MAX
37 #endif
38  typedef char shm_name_t[SHM_NAME_MAX];
39  typedef shm_name_t jack_shm_id_t;
40 
41 #elif WIN32 // TO CHECK
42 #define NAME_MAX 255
43 #ifndef SHM_NAME_MAX
44 #define SHM_NAME_MAX NAME_MAX
45 #endif
46  typedef char shm_name_t[SHM_NAME_MAX];
47  typedef shm_name_t jack_shm_id_t;
48 
49 #else
50  /* System V SHM */
51  typedef int jack_shm_id_t;
52 #endif /* SHM type */
53 
54  /* shared memory type */
55  typedef enum {
56  shm_POSIX = 1, /* POSIX shared memory */
57  shm_SYSV = 2, /* System V shared memory */
58  shm_WIN32 = 3 /* Windows 32 shared memory */
59  } jack_shmtype_t;
60 
61  typedef int16_t jack_shm_registry_index_t;
62 
72  typedef struct _jack_shm_server {
73 #ifdef WIN32
74  int pid; /* process ID */
75 #else
76  pid_t pid; /* process ID */
77 #endif
78 
79  char name[JACK_SERVER_NAME_SIZE];
80  }
82 
83  typedef struct _jack_shm_header {
84  uint32_t magic; /* magic number */
85  uint16_t protocol; /* JACK protocol version */
86  jack_shmtype_t type; /* shm type */
87  jack_shmsize_t size; /* total registry segment size */
88  jack_shmsize_t hdr_len; /* size of header */
89  jack_shmsize_t entry_len; /* size of registry entry */
90  jack_shm_server_t server[MAX_SERVERS]; /* current server array */
91  }
93 
94  typedef struct _jack_shm_registry {
95  jack_shm_registry_index_t index; /* offset into the registry */
96 
97 #ifdef WIN32
98  int allocator; /* PID that created shm segment */
99 #else
100  pid_t allocator; /* PID that created shm segment */
101 #endif
102 
103  jack_shmsize_t size; /* for POSIX unattach */
104  jack_shm_id_t id; /* API specific, see above */
105  }
107 
108 #define JACK_SHM_REGISTRY_SIZE (sizeof (jack_shm_header_t) \
109  + sizeof (jack_shm_registry_t) * MAX_SHM_ID)
110 
119  PRE_PACKED_STRUCTURE
120  typedef struct _jack_shm_info {
121  jack_shm_registry_index_t index; /* offset into the registry */
122  uint32_t size;
123  union {
124  void *attached_at; /* address where attached */
125  char ptr_size[8];
126  } ptr; /* a "pointer" that has the same 8 bytes size when compling in 32 or 64 bits */
127  }
128 #ifdef _MSC_VER
129  jack_shm_info_t; POST_PACKED_STRUCTURE
130 #else
131  POST_PACKED_STRUCTURE jack_shm_info_t;
132 #endif
133 
134  /* utility functions used only within JACK */
135 
136  void jack_shm_copy_from_registry (jack_shm_info_t*,
137  jack_shm_registry_index_t);
138  void jack_shm_copy_to_registry (jack_shm_info_t*,
139  jack_shm_registry_index_t*);
140  int jack_release_shm_info (jack_shm_registry_index_t);
141  char* jack_shm_addr (jack_shm_info_t* si);
142 
143  // here begin the API
144  int jack_register_server (const char *server_name, int new_registry);
145  int jack_unregister_server (const char *server_name);
146 
147  int jack_initialize_shm (const char *server_name);
148  int jack_initialize_shm_server (void);
149  int jack_initialize_shm_client (void);
150  int jack_cleanup_shm (void);
151 
152  int jack_shmalloc (const char *shm_name, jack_shmsize_t size,
153  jack_shm_info_t* result);
154  void jack_release_shm (jack_shm_info_t*);
155  void jack_release_lib_shm (jack_shm_info_t*);
156  void jack_destroy_shm (jack_shm_info_t*);
157  int jack_attach_shm (jack_shm_info_t*);
158  int jack_attach_lib_shm (jack_shm_info_t*);
159  int jack_attach_shm_read (jack_shm_info_t*);
160  int jack_attach_lib_shm_read (jack_shm_info_t*);
161  int jack_resize_shm (jack_shm_info_t*, jack_shmsize_t size);
162 
163 #ifdef __cplusplus
164 }
165 #endif
166 
167 #endif /* __jack_shm_h__ */