diff options
Diffstat (limited to 'src/backend/port/qnx4/sem.c')
| -rw-r--r-- | src/backend/port/qnx4/sem.c | 396 |
1 files changed, 0 insertions, 396 deletions
diff --git a/src/backend/port/qnx4/sem.c b/src/backend/port/qnx4/sem.c deleted file mode 100644 index 4a8d6a348fa..00000000000 --- a/src/backend/port/qnx4/sem.c +++ /dev/null @@ -1,396 +0,0 @@ -/*------------------------------------------------------------------------- - * - * sem.c - * System V Semaphore Emulation - * - * Copyright (c) 1999, repas AEG Automation GmbH - * - * - * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/port/qnx4/sem.c,v 1.13 2005/10/15 02:49:23 momjian Exp $ - * - *------------------------------------------------------------------------- - */ - -#include "postgres.h" - -#include <errno.h> -#include <semaphore.h> -#include <unistd.h> -#include <fcntl.h> -#include <sys/mman.h> -#include <sys/sem.h> -#include <sys/mman.h> -#include <sys/stat.h> - -#include "miscadmin.h" -#include "storage/ipc.h" -#include "storage/proc.h" - - -#define SEMMAX (PROC_NSEMS_PER_SET+1) -#define OPMAX 8 - -#define MODE 0700 -#define SHM_INFO_NAME "PgSysV_Sem_Info" - - -struct pending_ops -{ - int op[OPMAX]; /* array of pending operations */ - int idx; /* index of first free array member */ -}; - -struct sem_set_info -{ - key_t key; - int nsems; - sem_t sem[SEMMAX]; /* array of POSIX semaphores */ - struct sem semV[SEMMAX]; /* array of System V semaphore structures */ - struct pending_ops pendingOps[SEMMAX]; /* array of pending operations */ -}; - -struct sem_info -{ - sem_t sem; - int nsets; - /* there are actually nsets of these: */ - struct sem_set_info set[1]; /* VARIABLE LENGTH ARRAY */ -}; - -static struct sem_info *SemInfo = (struct sem_info *) - 1; - -/* ---------------------------------------------------------------- - * semclean - remove the shared memory file on exit - * only called by the process which created the shm file - * ---------------------------------------------------------------- - */ - -static void -semclean(void) -{ - remove("/dev/shmem/" SHM_INFO_NAME); -} - -int -semctl(int semid, int semnum, int cmd, /* ... */ union semun arg) -{ - int r = 0; - - sem_wait(&SemInfo->sem); - - if (semid < 0 || semid >= SemInfo->nsets || - semnum < 0 || semnum >= SemInfo->set[semid].nsems) - { - sem_post(&SemInfo->sem); - errno = EINVAL; - return -1; - } - - switch (cmd) - { - case GETNCNT: - r = SemInfo->set[semid].semV[semnum].semncnt; - break; - - case GETPID: - r = SemInfo->set[semid].semV[semnum].sempid; - break; - - case GETVAL: - r = SemInfo->set[semid].semV[semnum].semval; - break; - - case GETALL: - for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++) - arg.array[semnum] = SemInfo->set[semid].semV[semnum].semval; - break; - - case SETVAL: - SemInfo->set[semid].semV[semnum].semval = arg.val; - break; - - case SETALL: - for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++) - SemInfo->set[semid].semV[semnum].semval = arg.array[semnum]; - break; - - case GETZCNT: - r = SemInfo->set[semid].semV[semnum].semzcnt; - break; - - case IPC_RMID: - for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++) - { - if (sem_destroy(&SemInfo->set[semid].sem[semnum]) == -1) - r = -1; - } - SemInfo->set[semid].key = -1; - SemInfo->set[semid].nsems = 0; - break; - - default: - sem_post(&SemInfo->sem); - errno = EINVAL; - return -1; - } - - sem_post(&SemInfo->sem); - - return r; -} - -int -semget(key_t key, int nsems, int semflg) -{ - int fd, - semid, - semnum, - nsets; - int exist = 0; - Size sem_info_size; - struct stat statbuf; - - if (nsems < 0 || nsems > SEMMAX) - { - errno = EINVAL; - return -1; - } - - /* open and map shared memory */ - if (SemInfo == (struct sem_info *) - 1) - { - /* test if the shared memory already exists */ - fd = shm_open(SHM_INFO_NAME, O_RDWR | O_CREAT | O_EXCL, MODE); - if (fd == -1 && errno == EEXIST) - { - exist = 1; - fd = shm_open(SHM_INFO_NAME, O_RDWR | O_CREAT, MODE); - } - if (fd == -1) - return fd; - /* The size may only be set once. Ignore errors. */ - nsets = PROC_SEM_MAP_ENTRIES(MaxBackends); - sem_info_size = sizeof(struct sem_info) + (nsets - 1) * sizeof(struct sem_set_info); - ltrunc(fd, sem_info_size, SEEK_SET); - if (fstat(fd, &statbuf)) /* would be strange : the only doc'ed */ - { /* error is EBADF */ - close(fd); - return -1; - } - - /* - * size is rounded by proc to the next __PAGESIZE - */ - if (statbuf.st_size != - (((sem_info_size / __PAGESIZE) + 1) * __PAGESIZE)) - { - fprintf(stderr, - "Found a pre-existing shared memory block for the semaphore memory\n" - "of a different size (%ld instead %ld). Make sure that all executables\n" - "are from the same release or remove the file \"/dev/shmem/%s\"\n" - "left by a previous version.\n", - (long) statbuf.st_size, - (long) sem_info_size, - SHM_INFO_NAME); - errno = EACCES; - return -1; - } - SemInfo = mmap(NULL, sem_info_size, - PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); - if (SemInfo == MAP_FAILED) - return -1; - if (!exist) - { - /* initialize shared memory */ - memset(SemInfo, 0, sem_info_size); - SemInfo->nsets = nsets; - for (semid = 0; semid < nsets; semid++) - SemInfo->set[semid].key = -1; - /* create semaphore for locking */ - sem_init(&SemInfo->sem, 1, 1); - on_proc_exit(semclean, 0); - } - } - - sem_wait(&SemInfo->sem); - nsets = SemInfo->nsets; - - if (key != IPC_PRIVATE) - { - /* search existing element */ - semid = 0; - while (semid < nsets && SemInfo->set[semid].key != key) - semid++; - if (!(semflg & IPC_CREAT) && semid >= nsets) - { - sem_post(&SemInfo->sem); - errno = ENOENT; - return -1; - } - else if (semid < nsets) - { - if (semflg & IPC_CREAT && semflg & IPC_EXCL) - { - sem_post(&SemInfo->sem); - errno = EEXIST; - return -1; - } - else - { - if (nsems != 0 && SemInfo->set[semid].nsems < nsems) - { - sem_post(&SemInfo->sem); - errno = EINVAL; - return -1; - } - sem_post(&SemInfo->sem); - return semid; - } - } - } - - /* search first free element */ - semid = 0; - while (semid < nsets && SemInfo->set[semid].key != -1) - semid++; - if (semid >= nsets) - { - sem_post(&SemInfo->sem); - errno = ENOSPC; - return -1; - } - - for (semnum = 0; semnum < nsems; semnum++) - { - sem_init(&SemInfo->set[semid].sem[semnum], 1, 0); -/* Currently sem_init always returns -1. */ -#ifdef NOT_USED - if (sem_init(&SemInfo->set[semid].sem[semnum], 1, 0) == -1) - { - int semnum1; - - for (semnum1 = 0; semnum1 < semnum; semnum1++) - sem_destroy(&SemInfo->set[semid].sem[semnum1]); - sem_post(&SemInfo->sem); - return -1; - } -#endif - } - - SemInfo->set[semid].key = key; - SemInfo->set[semid].nsems = nsems; - - sem_post(&SemInfo->sem); - - return semid; -} - -int -semop(int semid, struct sembuf * sops, size_t nsops) -{ - int i, - r = 0, - r1, - errno1 = 0, - op; - - sem_wait(&SemInfo->sem); - - if (semid < 0 || semid >= SemInfo->nsets) - { - sem_post(&SemInfo->sem); - errno = EINVAL; - return -1; - } - for (i = 0; i < nsops; i++) - { - if ( /* sops[i].sem_num < 0 || */ sops[i].sem_num >= SemInfo->set[semid].nsems) - { - sem_post(&SemInfo->sem); - errno = EFBIG; - return -1; - } - } - - for (i = 0; i < nsops; i++) - { - if (sops[i].sem_op < 0) - { - if (SemInfo->set[semid].semV[sops[i].sem_num].semval < -sops[i].sem_op) - { - if (sops[i].sem_flg & IPC_NOWAIT) - { - sem_post(&SemInfo->sem); - errno = EAGAIN; - return -1; - } - SemInfo->set[semid].semV[sops[i].sem_num].semncnt++; - if (SemInfo->set[semid].pendingOps[sops[i].sem_num].idx >= OPMAX) - { - /* pending operations array overflow */ - sem_post(&SemInfo->sem); - errno = ERANGE; - return -1; - } - SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx++] = sops[i].sem_op; - /* suspend */ - sem_post(&SemInfo->sem); /* avoid deadlock */ - r1 = sem_wait(&SemInfo->set[semid].sem[sops[i].sem_num]); - sem_wait(&SemInfo->sem); - if (r1) - { - errno1 = errno; - r = r1; - /* remove pending operation */ - SemInfo->set[semid].pendingOps[sops[i].sem_num].op[--SemInfo->set[semid].pendingOps[sops[i].sem_num].idx] = 0; - } - else - SemInfo->set[semid].semV[sops[i].sem_num].semval -= -sops[i].sem_op; - SemInfo->set[semid].semV[sops[i].sem_num].semncnt--; - } - else - SemInfo->set[semid].semV[sops[i].sem_num].semval -= -sops[i].sem_op; - } - else if (sops[i].sem_op > 0) - { - SemInfo->set[semid].semV[sops[i].sem_num].semval += sops[i].sem_op; - op = sops[i].sem_op; - while (op > 0 && SemInfo->set[semid].pendingOps[sops[i].sem_num].idx > 0) - { /* operations pending */ - if (SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx - 1] + op >= 0) - { - /* unsuspend processes */ - if (sem_post(&SemInfo->set[semid].sem[sops[i].sem_num])) - { - errno1 = errno; - r = -1; - } - /* adjust pending operations */ - op += SemInfo->set[semid].pendingOps[sops[i].sem_num].op[--SemInfo->set[semid].pendingOps[sops[i].sem_num].idx]; - SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx] = 0; - } - else - { - /* adjust pending operations */ - SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx - 1] += op; - op = 0; - } - } - } - else - /* sops[i].sem_op == 0 */ - { - /* not supported */ - sem_post(&SemInfo->sem); - errno = ENOSYS; - return -1; - } - SemInfo->set[semid].semV[sops[i].sem_num].sempid = getpid(); - } - - sem_post(&SemInfo->sem); - - errno = errno1; - return r; -} |