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Annotation of xinu/sys/sdelete.c, revision 1.1.1.1

1.1       root        1: /* sdelete.c - sdelete */
                      2: 
                      3: #include <conf.h>
                      4: #include <kernel.h>
                      5: #include <proc.h>
                      6: #include <q.h>
                      7: #include <sem.h>
                      8: 
                      9: /*------------------------------------------------------------------------
                     10:  * sdelete  --  delete a semaphore by releasing its table entry
                     11:  *------------------------------------------------------------------------
                     12:  */
                     13: SYSCALL sdelete(sem)
                     14:        int     sem;
                     15: {
                     16:        PStype  ps;
                     17:        int     pid;
                     18:        struct  sentry  *sptr;          /* address of sem to free       */
                     19: 
                     20:        disable(ps);
                     21:        if (isbadsem(sem) || semaph[sem].sstate==SFREE) {
                     22:                restore(ps);
                     23:                return(SYSERR);
                     24:        }
                     25:        sptr = &semaph[sem];
                     26:        sptr->sstate = SFREE;
                     27:        if (nonempty(sptr->sqhead)) {   /* free waiting processes       */
                     28:                while( (pid=getfirst(sptr->sqhead)) != EMPTY)
                     29:                        ready(pid,RESCHNO);
                     30:                resched();
                     31:        }
                     32:        restore(ps);
                     33:        return(OK);
                     34: }

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