vasp5源代码

/* * Some functions, callable from fortran to use shared memory * wv 2011 * shmem stuff from Willem Vermin, SARA */ #include <stdio.h> #include <sys/ipc.h> #include <sys/shm.h> #include <stdlib.h> #include <errno.h> #include <sys/sem.h> /* * get a shared memory segment * input: size (fortran integer*8) * output: shmem id */ void getshmem_(size_t *size, int*id) { key_t key; int shmflg; int shmid; key = IPC_PRIVATE; shmflg = IPC_CREAT | IPC_EXCL | 0600 | SHM_NORESERVE ; shmid = shmget(key, *size, shmflg); if (shmid == -1) { fprintf(stderr,"%s in %s: cannot create shared segment %ld \n",__FUNCTION__,__FILE__,*size); perror(0); exit(1); } *id = shmid; } void getshmem_error_(size_t *size, int*id) { key_t key; int shmflg; int shmid; key = IPC_PRIVATE; shmflg = IPC_CREAT | IPC_EXCL | 0600 | SHM_NORESERVE ; shmid = shmget(key, *size, shmflg); *id = shmid; } /* * attach shared memory to a pointer * input: shhmid: shared memory id * output: address (fortran integer*8) */ void attachshmem_(int *shmid, void **address) { void *shmaddr,*r; int shmflg; shmflg = 0; shmaddr = 0; r = shmat(*shmid, shmaddr, shmflg); if (r == (void*) -1) { fprintf(stderr,"%s in %s: cannot get address of shared segment\n",__FUNCTION__,__FILE__); perror(0); exit(1); } *address = r; } /* * detach shared memory from pointer * input: address (fortran integer*8) */ void detachshmem_(void **address) { int r; r = shmdt(*address); if (r == -1) { fprintf(stderr,"%s in %s:%d: cannot detach shared segment\n",__FUNCTION__,__FILE__,__LINE__); perror(0); exit(1); } } /* * destroy shared memory * input: shmid: shared memory id */ void destroyshmem_(int *shmid) { struct shmid_ds buf; int r = shmctl(*shmid,IPC_RMID,&buf); if (r == -1) { fprintf(stderr,"%s in %s:%d: cannot destroy shared segment\n",__FUNCTION__,__FILE__,__LINE__); perror(0); exit(1); } } /* * get a set of semaphores * input: size * output: semaphores id */ void getsem_(int *size, int*id) { key_t key; int semflg; int semid; int mysize; int i, rc; short sarray[(*size)+1]; key = IPC_PRIVATE; semflg = IPC_CREAT | IPC_EXCL | 0600; semflg = IPC_CREAT | 0600; mysize=(*size)+1 ; /* here I have an odd problem: using *size+1 instead of mysize sometimes failed very odd, some cross C-Fortran problem, no idea */ semid = semget(key, mysize, semflg); if (semid == -1) { perror(0); fprintf(stderr,"%s in %s: cannot create semaphores \n",__FUNCTION__,__FILE__); fprintf(stderr,"requested size was %d\n", mysize); exit(1); } /* '1' -- The shared memory segment is being used. */ /* '0' -- The shared memory segment is freed. */ /* the very first sempaphore can be used to loc all others currently this is not entirely thread save and might fail if no barrier is used before this lock, since we do not lock the slots individually */ for (i=0; i< mysize ; i++ ) sarray[i]=0 ; rc = semctl( semid, 1, SETALL, sarray); if(rc == -1) { fprintf(stderr,"%s in %s: cannot initialize semaphores \n",__FUNCTION__,__FILE__); perror(0); exit(1); } *id = semid; } /* * loc a specific semaphores in the set * we only support two states * '1' -- The semaphore/shared memory segment is being used. * '0' -- The semaphore/shared memory segment is freed. */ void locksem_(int *semid, int* id) { struct sembuf operations[2]; #ifdef debug fprintf(stderr,"%d: semaphores lock\n",*id) ; #endif operations[0].sem_num = *id; /* Operate on the sem id */ operations[0].sem_op = 0; /* Wait for the value 0 */ operations[0].sem_flg = 0; /* Allow a wait to occur */ operations[1].sem_num = *id; /* Operate on the sem is */ operations[1].sem_op = 1; /* Increment the semval by 1 */ operations[1].sem_flg = 0; /* Allow a wait to occur */ int rc = semop( *semid, operations, 2 ); if (rc == -1) { fprintf(stderr,"%s in %s:%d: cannot lock semaphores \n",__FUNCTION__,__FILE__,__LINE__); perror(0); exit(1); } #ifdef debug fprintf(stderr,"%d: semaphores done \n",*id) ; #endif } /* * unloc a specific semaphores in the set * this will only succeed if the semaphores was previously locked * should be called only by the locing process */ void unlocksem_(int *semid, int* id) { struct sembuf operations[2]; operations[0].sem_num = *id; /* Operate on the sem id */ operations[0].sem_op = -1; /* decrease to value 0 */ operations[0].sem_flg = IPC_NOWAIT; /* Allow no wait to occur */ #ifdef debug fprintf(stderr,"%d: semaphores unlock \n",*semid) ; #endif int rc = semop( *semid, operations, 1 ); if (rc == -1) { fprintf(stderr,"%s in %s:%d: cannot unlock semaphores \n",__FUNCTION__,__FILE__,__LINE__); perror(0); exit(1); } #ifdef debug fprintf(stderr,"%d: semaphores clear done \n",*id) ; #endif } /* * destroy semaphores * input: semid: semaphores id */ void destroysem_(int *semid) { int rc = semctl(*semid,1, IPC_RMID); if (rc == -1) { fprintf(stderr,"%s in %s:%d: cannot destroy semaphores \n",__FUNCTION__,__FILE__,__LINE__); perror(0); exit(1); } }