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Diffstat (limited to 'src/include/drvrsmem.h')
| -rw-r--r-- | src/include/drvrsmem.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/include/drvrsmem.h b/src/include/drvrsmem.h new file mode 100644 index 0000000..cd63810 --- /dev/null +++ b/src/include/drvrsmem.h @@ -0,0 +1,178 @@ +/* S H A R E D M E M O R Y D R I V E R + ======================================= + + by Jerzy.Borkowski@obs.unige.ch + +09-Mar-98 : initial version 1.0 released +23-Mar-98 : shared_malloc now accepts new handle as an argument +*/ + + +#include <sys/ipc.h> /* this is necessary for Solaris/Linux */ +#include <sys/shm.h> +#include <sys/sem.h> + +#ifdef _AIX +#include <fcntl.h> +#else +#include <sys/fcntl.h> +#endif + + /* configuration parameters */ + +#define SHARED_MAXSEG (16) /* maximum number of shared memory blocks */ + +#define SHARED_KEYBASE (14011963) /* base for shared memory keys, may be overriden by getenv */ +#define SHARED_FDNAME ("/tmp/.shmem-lockfile") /* template for lock file name */ + +#define SHARED_ENV_KEYBASE ("SHMEM_LIB_KEYBASE") /* name of environment variable */ +#define SHARED_ENV_MAXSEG ("SHMEM_LIB_MAXSEG") /* name of environment variable */ + + /* useful constants */ + +#define SHARED_RDONLY (0) /* flag for shared_(un)lock, lock for read */ +#define SHARED_RDWRITE (1) /* flag for shared_(un)lock, lock for write */ +#define SHARED_WAIT (0) /* flag for shared_lock, block if cannot lock immediate */ +#define SHARED_NOWAIT (2) /* flag for shared_lock, fail if cannot lock immediate */ +#define SHARED_NOLOCK (0x100) /* flag for shared_validate function */ + +#define SHARED_RESIZE (4) /* flag for shared_malloc, object is resizeable */ +#define SHARED_PERSIST (8) /* flag for shared_malloc, object is not deleted after last proc detaches */ + +#define SHARED_INVALID (-1) /* invalid handle for semaphore/shared memory */ + +#define SHARED_EMPTY (0) /* entries for shared_used table */ +#define SHARED_USED (1) + +#define SHARED_GRANUL (16384) /* granularity of shared_malloc allocation = phys page size, system dependent */ + + + + /* checkpoints in shared memory segments - might be omitted */ + +#define SHARED_ID_0 ('J') /* first byte of identifier in BLKHEAD */ +#define SHARED_ID_1 ('B') /* second byte of identifier in BLKHEAD */ + +#define BLOCK_REG (0) /* value for tflag member of BLKHEAD */ +#define BLOCK_SHARED (1) /* value for tflag member of BLKHEAD */ + + /* generic error codes */ + +#define SHARED_OK (0) + +#define SHARED_ERR_MIN_IDX SHARED_BADARG +#define SHARED_ERR_MAX_IDX SHARED_NORESIZE + + +#define DAL_SHM_FREE (0) +#define DAL_SHM_USED (1) + +#define DAL_SHM_ID0 ('D') +#define DAL_SHM_ID1 ('S') +#define DAL_SHM_ID2 ('M') + +#define DAL_SHM_SEGHEAD_ID (0x19630114) + + + + /* data types */ + +/* BLKHEAD object is placed at the beginning of every memory segment (both + shared and regular) to allow automatic recognition of segments type */ + +typedef union + { struct BLKHEADstruct + { char ID[2]; /* ID = 'JB', just as a checkpoint */ + char tflag; /* is it shared memory or regular one ? */ + int handle; /* this is not necessary, used only for non-resizeable objects via ptr */ + } s; + double d; /* for proper alignment on every machine */ + } BLKHEAD; + +typedef void *SHARED_P; /* generic type of shared memory pointer */ + +typedef struct SHARED_GTABstruct /* data type used in global table */ + { int sem; /* access semaphore (1 field): process count */ + int semkey; /* key value used to generate semaphore handle */ + int key; /* key value used to generate shared memory handle (realloc changes it) */ + int handle; /* handle of shared memory segment */ + int size; /* size of shared memory segment */ + int nprocdebug; /* attached proc counter, helps remove zombie segments */ + char attr; /* attributes of shared memory object */ + } SHARED_GTAB; + +typedef struct SHARED_LTABstruct /* data type used in local table */ + { BLKHEAD *p; /* pointer to segment (may be null) */ + int tcnt; /* number of threads in this process attached to segment */ + int lkcnt; /* >=0 <- number of read locks, -1 - write lock */ + long seekpos; /* current pointer position, read/write/seek operations change it */ + } SHARED_LTAB; + + + /* system dependent definitions */ + +#ifndef HAVE_FLOCK_T +typedef struct flock flock_t; +#define HAVE_FLOCK_T +#endif + +#ifndef HAVE_UNION_SEMUN +union semun + { int val; + struct semid_ds *buf; + unsigned short *array; + }; +#define HAVE_UNION_SEMUN +#endif + + +typedef struct DAL_SHM_SEGHEAD_STRUCT DAL_SHM_SEGHEAD; + +struct DAL_SHM_SEGHEAD_STRUCT + { int ID; /* ID for debugging */ + int h; /* handle of sh. mem */ + int size; /* size of data area */ + int nodeidx; /* offset of root object (node struct typically) */ + }; + + /* API routines */ + +#ifdef __cplusplus +extern "C" { +#endif + +void shared_cleanup(void); /* must be called at exit/abort */ +int shared_init(int debug_msgs); /* must be called before any other shared memory routine */ +int shared_recover(int id); /* try to recover dormant segment(s) after applic crash */ +int shared_malloc(long size, int mode, int newhandle); /* allocate n-bytes of shared memory */ +int shared_attach(int idx); /* attach to segment given index to table */ +int shared_free(int idx); /* release shared memory */ +SHARED_P shared_lock(int idx, int mode); /* lock segment for reading */ +SHARED_P shared_realloc(int idx, long newsize); /* reallocate n-bytes of shared memory (ON LOCKED SEGMENT ONLY) */ +int shared_size(int idx); /* get size of attached shared memory segment (ON LOCKED SEGMENT ONLY) */ +int shared_attr(int idx); /* get attributes of attached shared memory segment (ON LOCKED SEGMENT ONLY) */ +int shared_set_attr(int idx, int newattr); /* set attributes of attached shared memory segment (ON LOCKED SEGMENT ONLY) */ +int shared_unlock(int idx); /* unlock segment (ON LOCKED SEGMENT ONLY) */ +int shared_set_debug(int debug_msgs); /* set/reset debug mode */ +int shared_set_createmode(int mode); /* set/reset debug mode */ +int shared_list(int id); /* list segment(s) */ +int shared_uncond_delete(int id); /* uncondintionally delete (NOWAIT operation) segment(s) */ + +int smem_init(void); +int smem_shutdown(void); +int smem_setoptions(int options); +int smem_getoptions(int *options); +int smem_getversion(int *version); +int smem_open(char *filename, int rwmode, int *driverhandle); +int smem_create(char *filename, int *driverhandle); +int smem_close(int driverhandle); +int smem_remove(char *filename); +int smem_size(int driverhandle, long *size); +int smem_flush(int driverhandle); +int smem_seek(int driverhandle, long offset); +int smem_read(int driverhandle, void *buffer, long nbytes); +int smem_write(int driverhandle, void *buffer, long nbytes); + +#ifdef __cplusplus +} +#endif |