diff options
Diffstat (limited to 'src/backend/port/darwin/sem.c')
| -rw-r--r-- | src/backend/port/darwin/sem.c | 90 |
1 files changed, 51 insertions, 39 deletions
diff --git a/src/backend/port/darwin/sem.c b/src/backend/port/darwin/sem.c index 6130e6d72b2..83fc1bf118f 100644 --- a/src/backend/port/darwin/sem.c +++ b/src/backend/port/darwin/sem.c @@ -10,10 +10,11 @@ * - this required changing sem_info from containig an array of sem_t to an array of sem_t* * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/port/darwin/Attic/sem.c,v 1.3 2001/03/22 03:59:42 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/port/darwin/Attic/sem.c,v 1.4 2001/09/07 00:27:29 tgl Exp $ * *------------------------------------------------------------------------- */ +#include "postgres.h" #include <errno.h> #include <semaphore.h> @@ -22,13 +23,13 @@ #include <unistd.h> #include <fcntl.h> #include <sys/mman.h> -#include "postgres.h" + +#include "miscadmin.h" #include "storage/ipc.h" #include "storage/proc.h" #include "port/darwin/sem.h" #define SEMMAX IPC_NMAXSEM -#define SETMAX ((MAXBACKENDS + SEMMAX - 1) / SEMMAX) #define OPMAX 8 #define MODE 0700 @@ -41,19 +42,23 @@ struct pending_ops 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; - struct - { - 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 */ - } set[SETMAX]; + 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; @@ -66,7 +71,7 @@ semctl(int semid, int semnum, int cmd, /* ... */ union semun arg) sem_wait(SemInfo->sem); - if (semid < 0 || semid >= SETMAX || + if (semid < 0 || semid >= SemInfo->nsets || semnum < 0 || semnum >= SemInfo->set[semid].nsems) { sem_post(SemInfo->sem); @@ -132,8 +137,10 @@ semget(key_t key, int nsems, int semflg) { int fd, semid, - semnum /* , semnum1 */ ; + semnum, + nsets; int exist = 0; + Size sem_info_size; char semname[64]; if (nsems < 0 || nsems > SEMMAX) @@ -163,13 +170,20 @@ semget(key_t key, int nsems, int semflg) return fd; shm_unlink(SHM_INFO_NAME); /* The size may only be set once. Ignore errors. */ - ftruncate(fd, sizeof(struct sem_info)); - SemInfo = mmap(NULL, sizeof(struct sem_info), + nsets = PROC_SEM_MAP_ENTRIES(MaxBackends); + sem_info_size = sizeof(struct sem_info) + (nsets-1) * sizeof(struct sem_set_info); + ftruncate(fd, sem_info_size); + 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 */ sprintf(semname, "%s-map", SEM_NAME); #ifdef DEBUG_IPC @@ -177,30 +191,25 @@ semget(key_t key, int nsems, int semflg) #endif SemInfo->sem = sem_open(semname, O_CREAT, semflg & 0777, 1); sem_unlink(semname); - sem_wait(SemInfo->sem); - /* initilize shared memory */ - memset(SemInfo->set, 0, sizeof(SemInfo->set)); - for (semid = 0; semid < SETMAX; semid++) - SemInfo->set[semid].key = -1; - sem_post(SemInfo->sem); } } sem_wait(SemInfo->sem); + nsets = SemInfo->nsets; if (key != IPC_PRIVATE) { /* search existing element */ semid = 0; - while (semid < SETMAX && SemInfo->set[semid].key != key) + while (semid < nsets && SemInfo->set[semid].key != key) semid++; - if (!(semflg & IPC_CREAT) && semid >= SETMAX) + if (!(semflg & IPC_CREAT) && semid >= nsets) { sem_post(SemInfo->sem); errno = ENOENT; return -1; } - else if (semid < SETMAX) + else if (semid < nsets) { if (semflg & IPC_CREAT && semflg & IPC_EXCL) { @@ -228,12 +237,12 @@ semget(key_t key, int nsems, int semflg) /* search first free element */ semid = 0; - while (semid < SETMAX && SemInfo->set[semid].key != -1) + while (semid < nsets && SemInfo->set[semid].key != -1) semid++; - if (semid >= SETMAX) + if (semid >= nsets) { #ifdef DEBUG_IPC - fprintf(stderr, "darwin semget failed because all keys were -1 up to SETMAX\n"); + fprintf(stderr, "darwin semget failed because all keys were -1\n"); #endif sem_post(SemInfo->sem); errno = ENOSPC; @@ -249,15 +258,18 @@ semget(key_t key, int nsems, int semflg) SemInfo->set[semid].sem[semnum] = sem_open(semname, O_CREAT, semflg & 0777, 0); sem_unlink(semname); -/* Currently sem_init always returns -1. - if( sem_init( &SemInfo->set[semid].sem[semnum], 1, 0 ) == -1 ) { - for( semnum1 = 0; semnum1 < semnum; semnum1++ ) { - sem_close( SemInfo->set[semid].sem[semnum1] ); - } - sem_post( SemInfo->sem ); - return -1; - } -*/ + /* 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_close( SemInfo->set[semid].sem[semnum1] ); + } + sem_post( SemInfo->sem ); + return -1; + } +#endif } SemInfo->set[semid].key = key; @@ -279,7 +291,7 @@ semop(int semid, struct sembuf * sops, size_t nsops) sem_wait(SemInfo->sem); - if (semid < 0 || semid >= SETMAX) + if (semid < 0 || semid >= SemInfo->nsets) { sem_post(SemInfo->sem); errno = EINVAL; |