bsd/kern/sys_pipe.c

392  *  FWRITE | fd1 | -->[struct wpipe] --X              /
400 	struct pipe *rpipe, *wpipe;
407 	rpipe = wpipe = NULL;
408 	if (pipe_create(&rpipe) || pipe_create(&wpipe)) {
422 	TAILQ_INIT(&wpipe->pipe_evlist);
446 	wf->f_data = (caddr_t)wpipe;
449 	rpipe->pipe_peer = wpipe;
450 	wpipe->pipe_peer = rpipe;
452 	rpipe->pipe_mtxp = wpipe->pipe_mtxp = pmtx;
466 	wpipe->pipe_label = rpipe->pipe_label;
480 	pipeclose(wpipe);
867 	struct pipe *wpipe, *rpipe;
875 	wpipe = rpipe->pipe_peer;
880 	if (wpipe == NULL || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
885 	error = mac_pipe_check_write(kauth_cred_get(), wpipe);
891 	++wpipe->pipe_busy;
902 	if ( wpipe->pipe_buffer.buffer == 0 || (
903 		(unsigned)orig_resid > wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt &&
906 	        pipe_size = choose_pipespace(wpipe->pipe_buffer.size, wpipe->pipe_buffer.cnt + orig_resid);
913 		if ((error = pipeio_lock(wpipe, 1)) == 0) {
914 			if (wpipe->pipe_buffer.cnt == 0)
915 				error = pipespace(wpipe, pipe_size);
917 				error = expand_pipespace(wpipe, pipe_size);
919 			pipeio_unlock(wpipe);
922 			if (wpipe->pipe_buffer.buffer == 0)
930 		        --wpipe->pipe_busy;
931 			if ((wpipe->pipe_busy == 0) &&
932 			    (wpipe->pipe_state & PIPE_WANT)) {
933 			        wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR);
934 				wakeup(wpipe);
944 		space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
952 			if ((error = pipeio_lock(wpipe,1)) == 0) {
956 				if (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) {
957 					pipeio_unlock(wpipe);
966 				if (space > (int)(wpipe->pipe_buffer.size -
967 				    wpipe->pipe_buffer.cnt)) {
968 					pipeio_unlock(wpipe);
988 				segsize = wpipe->pipe_buffer.size -
989 					wpipe->pipe_buffer.in;
996 				error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
1006 					if (wpipe->pipe_buffer.in + segsize !=
1007 					    wpipe->pipe_buffer.size)
1013 					    &wpipe->pipe_buffer.buffer[0],
1021 					wpipe->pipe_buffer.in += size;
1022 					if (wpipe->pipe_buffer.in >
1023 					    wpipe->pipe_buffer.size) {
1024 						if (wpipe->pipe_buffer.in !=
1026 						    wpipe->pipe_buffer.size)
1029 						wpipe->pipe_buffer.in = size -
1033 					wpipe->pipe_buffer.cnt += size;
1034 					if (wpipe->pipe_buffer.cnt >
1035 					    wpipe->pipe_buffer.size)
1039 				pipeio_unlock(wpipe);
1048 			if (wpipe->pipe_state & PIPE_WANTR) {
1049 				wpipe->pipe_state &= ~PIPE_WANTR;
1050 				wakeup(wpipe);
1065 			if (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) {
1074 			pipeselwakeup(wpipe, wpipe);
1076 			wpipe->pipe_state |= PIPE_WANTW;
1078 			error = msleep(wpipe, PIPE_MTX(wpipe), PRIBIO | PCATCH, "pipewr", 0);
1084 	--wpipe->pipe_busy;
1086 	if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) {
1087 		wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR);
1088 		wakeup(wpipe);
1090 	if (wpipe->pipe_buffer.cnt > 0) {
1095 		if (wpipe->pipe_state & PIPE_WANTR) {
1096 			wpipe->pipe_state &= ~PIPE_WANTR;
1097 			wakeup(wpipe);
1102 		pipeselwakeup(wpipe, wpipe);
1107 	pipe_touch(wpipe, PIPE_MTIME | PIPE_CTIME);
1179 	struct pipe *wpipe;
1187 	wpipe = rpipe->pipe_peer;
1216 		if (wpipe)
1217 			wpipe->pipe_state |= PIPE_WSELECT;
1218 		if (wpipe == NULL || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF)) ||
1219 		    (((wpipe->pipe_state & PIPE_DIRECTW) == 0) &&
1220 		     (MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt) > 0)) {
1224 		        wpipe->pipe_state |= PIPE_SEL;
1225 			selrecord(vfs_context_proc(ctx), &wpipe->pipe_sel, wql);
1431 	struct pipe *wpipe;
1443 	wpipe = rpipe->pipe_peer;
1446 	    (wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
1471 	struct pipe *wpipe;
1482 	wpipe = rpipe->pipe_peer;
1484 	if ((wpipe == NULL) || (wpipe->pipe_state & (PIPE_DRAIN | PIPE_EOF))) {
1492 	kn->kn_data = MAX_PIPESIZE(wpipe) - wpipe->pipe_buffer.cnt;
1496 		if (wpipe->pipe_buffer.size && kn->kn_sdata > MAX_PIPESIZE(wpipe))
1497 			lowwat = MAX_PIPESIZE(wpipe);