/* 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 /* this is necessary for Solaris/Linux */ #include #include #ifdef _AIX #include #else #include #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 shared_getaddr(int id, char **address); /* get starting address of FITS file in segment */ 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, LONGLONG *size); int smem_flush(int driverhandle); int smem_seek(int driverhandle, LONGLONG offset); int smem_read(int driverhandle, void *buffer, long nbytes); int smem_write(int driverhandle, void *buffer, long nbytes); #ifdef __cplusplus } #endif