diff options
Diffstat (limited to 'src/backend/port/qnx4/sem.c')
| -rw-r--r-- | src/backend/port/qnx4/sem.c | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/src/backend/port/qnx4/sem.c b/src/backend/port/qnx4/sem.c index f339e16973a..188a5f0616f 100644 --- a/src/backend/port/qnx4/sem.c +++ b/src/backend/port/qnx4/sem.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/port/qnx4/Attic/sem.c,v 1.4 2001/02/02 18:21:58 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/port/qnx4/Attic/sem.c,v 1.5 2001/05/24 15:53:33 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -23,14 +23,16 @@ #include "storage/ipc.h" #include "storage/proc.h" #include <sys/sem.h> +#include <sys/mman.h> +#include <sys/stat.h> -#define SETMAX ((MAXBACKENDS + PROC_NSEMS_PER_SET - 1) / PROC_NSEMS_PER_SET) +#define SETMAX ((MAXBACKENDS + PROC_NSEMS_PER_SET + 1) / PROC_NSEMS_PER_SET) #define SEMMAX (PROC_NSEMS_PER_SET+1) #define OPMAX 8 #define MODE 0700 -#define SHM_INFO_NAME "SysV_Sem_Info" +#define SHM_INFO_NAME "PgSysV_Sem_Info" struct pending_ops @@ -56,6 +58,17 @@ struct sem_info 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) @@ -132,6 +145,7 @@ semget(key_t key, int nsems, int semflg) semid, semnum /* , semnum1 */ ; int exist = 0; + struct stat statbuf; if (nsems < 0 || nsems > SEMMAX) { @@ -153,6 +167,26 @@ semget(key_t key, int nsems, int semflg) return fd; /* The size may only be set once. Ignore errors. */ ltrunc(fd, sizeof(struct sem_info), 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 != + ((( sizeof(struct sem_info) /__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", statbuf.st_size, + sizeof(struct sem_info), SHM_INFO_NAME); + errno = EACCES; + return -1; + } SemInfo = mmap(NULL, sizeof(struct sem_info), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (SemInfo == MAP_FAILED) @@ -167,6 +201,7 @@ semget(key_t key, int nsems, int semflg) for (semid = 0; semid < SETMAX; semid++) SemInfo->set[semid].key = -1; sem_post(&SemInfo->sem); + on_proc_exit( semclean, NULL ); } } |