pipid32 pipcreate(void)
{
intmask mask; /* saved interrupt mask */
pipid32 pipid; /* ID of newly created pipe */
struct pipent *piptr; /* ptr to pipe's table entry */
mask = disable(); /* saved interrupt mask */
pipid = pipnewid();
if (isbadpipid(pipid) || (piptr->pistate != PIPE_FREE)) {
restore(mask);
return (pipid32)SYSERR;
}
piptr = &piptab[pipid];
piptr->pistate = PIPE_USED;
uint32 j; /* iterate through all buffer slots */
for (j = 0; j < PIPE_SIZ; j++) { /* initialize the buffer */
piptr->pipebuffer[j] = ' ';
}
//piptr->psem = semcreate(PIPE_SIZ); /* initialize producer sem */
//piptr->csem = semcreate(0); /* initialize consumer sem */
restore(mask);
return pipid;
}
syscall pipdelete(
pipid32 pip
)
{
struct pipent *pipptr;
intmask mask;
mask = disable();
if(isbadpipid(pip)){
restore(mask);
return (pipid32) (SYSERR);
}
pipptr = &piptab[pip];
if(pipptr->pipstate == PIPE_FREE){
restore(mask);
return (pipid32) (SYSERR);
}
if(pipptr->pipOwner != getpid()){
restore(mask);
return (pipid32) (SYSERR);
}
pipptr->pipstate = PIPE_FREE;
memset(pipptr->buf, '\0', PIPE_SIZE);
pipptr->pipOwner = -1;
pipptr->pipReader = -1;
pipptr->pipWriter = -1;
pipptr->bufCharCount = -1;
pipcount--;
semdelete(pipptr->fullSem);
semdelete(pipptr->emptySem);
restore(mask);
return OK;
}
syscall pipdisconnect(
pipid32 pipid /* ID of pipe to connect */
)
{
intmask mask; /* saved interrupt mask */
struct pipent *piptr; /* ptr to pipe's table entry */
mask = disable(); /* saved interrupt mask */
if (isbadpipid(pipid) || (piptr->pistate != PIPE_CONNECTED)) {
restore(mask);
return SYSERR;
}
piptr = &piptab[pipid];
piptr->pistate = PIPE_USED;
restore(mask);
return pipid;
}