bsd/kern/sys_pipe.c

390  *  FREAD  | fd0 | -->[struct rpipe] --> |~~buffer~~| \
400 	struct pipe *rpipe, *wpipe;
407 	rpipe = wpipe = NULL;
408 	if (pipe_create(&rpipe) || pipe_create(&wpipe)) {
417 	error = pipespace(rpipe, choose_pipespace(rpipe->pipe_buffer.size, 0));
421 	TAILQ_INIT(&rpipe->pipe_evlist);
436 	rf->f_data = (caddr_t)rpipe;
449 	rpipe->pipe_peer = wpipe;
450 	wpipe->pipe_peer = rpipe;
452 	rpipe->pipe_mtxp = wpipe->pipe_mtxp = pmtx;
464 	mac_pipe_label_init(rpipe);
465 	mac_pipe_label_associate(kauth_cred_get(), rpipe);
466 	wpipe->pipe_label = rpipe->pipe_label;
479 	pipeclose(rpipe);
715 	struct pipe *rpipe = (struct pipe *)fp->f_data;
720 	PIPE_LOCK(rpipe);
721 	++rpipe->pipe_busy;
723 	error = pipeio_lock(rpipe, 1);
728 	error = mac_pipe_check_read(kauth_cred_get(), rpipe);
738 		if (rpipe->pipe_buffer.cnt > 0) {
744 			size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out;
745 			if (size > rpipe->pipe_buffer.cnt)
746 				size = rpipe->pipe_buffer.cnt;
751 			PIPE_UNLOCK(rpipe); /* we still hold io lock.*/
753 			    &rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
755 			PIPE_LOCK(rpipe);
759 			rpipe->pipe_buffer.out += size;
760 			if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size)
761 				rpipe->pipe_buffer.out = 0;
763 			rpipe->pipe_buffer.cnt -= size;
770 			if (rpipe->pipe_buffer.cnt == 0) {
771 				rpipe->pipe_buffer.in = 0;
772 				rpipe->pipe_buffer.out = 0;
780 			if (rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) {
787 			if (rpipe->pipe_state & PIPE_WANTW) {
788 				rpipe->pipe_state &= ~PIPE_WANTW;
789 				wakeup(rpipe);
803 			pipeio_unlock(rpipe);
812 				rpipe->pipe_state |= PIPE_WANTR;
813 				error = msleep(rpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, "piperd", 0);
815 				        error = pipeio_lock(rpipe, 1);
824 	pipeio_unlock(rpipe);
827 	--rpipe->pipe_busy;
832 	if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) {
833 		rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW);
834 		wakeup(rpipe);
835 	} else if (rpipe->pipe_buffer.cnt < rpipe->pipe_buffer.size) {
839 		if (rpipe->pipe_state & PIPE_WANTW) {
840 			rpipe->pipe_state &= ~PIPE_WANTW;
841 			wakeup(rpipe);
845 	if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) > 0)
846 		pipeselwakeup(rpipe, rpipe->pipe_peer);
849 	pipe_touch(rpipe, PIPE_ATIME);
851 	PIPE_UNLOCK(rpipe);
867 	struct pipe *wpipe, *rpipe;
872 	rpipe = (struct pipe *)fp->f_data;
874 	PIPE_LOCK(rpipe);
875 	wpipe = rpipe->pipe_peer;
881 		PIPE_UNLOCK(rpipe);
887 		PIPE_UNLOCK(rpipe);
936 			PIPE_UNLOCK(rpipe);
995 				PIPE_UNLOCK(rpipe);
998 				PIPE_LOCK(rpipe);
1011 					PIPE_UNLOCK(rpipe);
1015 					PIPE_LOCK(rpipe);
1106 	pipe_touch(rpipe, PIPE_MTIME | PIPE_CTIME);
1108 	PIPE_UNLOCK(rpipe);
1178 	struct pipe *rpipe = (struct pipe *)fp->f_data;
1182 	if (rpipe == NULL || rpipe == (struct pipe *)-1)
1185 	PIPE_LOCK(rpipe);
1187 	wpipe = rpipe->pipe_peer;
1196 	if (mac_pipe_check_select(vfs_context_ucred(ctx), rpipe, which)) {
1197 		PIPE_UNLOCK(rpipe);
1204 		if ((rpipe->pipe_state & PIPE_DIRECTW) ||
1205 		    (rpipe->pipe_buffer.cnt > 0) ||
1206 		    (rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
1210 		        rpipe->pipe_state |= PIPE_SEL;
1211 		        selrecord(vfs_context_proc(ctx), &rpipe->pipe_sel, wql);
1229 	        rpipe->pipe_state |= PIPE_SEL;
1230 		selrecord(vfs_context_proc(ctx), &rpipe->pipe_sel, wql);
1233 	PIPE_UNLOCK(rpipe);
1430 	struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
1441 	        PIPE_LOCK(rpipe);
1443 	wpipe = rpipe->pipe_peer;
1444 	kn->kn_data = rpipe->pipe_buffer.cnt;
1445 	if ((rpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) ||
1452 			if (rpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(rpipe))
1453 				lowwat = MAX_PIPESIZE(rpipe);
1461 	        PIPE_UNLOCK(rpipe);
1470 	struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
1480 	        PIPE_LOCK(rpipe);
1482 	wpipe = rpipe->pipe_peer;
1489 		        PIPE_UNLOCK(rpipe);
1503 	        PIPE_UNLOCK(rpipe);