xref: /minix3/minix/lib/libasyn/asyn_write.c (revision 433d6423c39e34ec4b79c950597bb2d236f886be)
1*433d6423SLionel Sambuc /*	asyn_write()					Author: Kees J. Bot
2*433d6423SLionel Sambuc  *								7 Jul 1997
3*433d6423SLionel Sambuc  */
4*433d6423SLionel Sambuc #include "asyn.h"
5*433d6423SLionel Sambuc #include <signal.h>
6*433d6423SLionel Sambuc 
asyn_write(asynchio_t * asyn,int fd,const void * buf,size_t len)7*433d6423SLionel Sambuc ssize_t asyn_write(asynchio_t *asyn, int fd, const void *buf, size_t len)
8*433d6423SLionel Sambuc /* Nonblocking write().  (See asyn_read()). */
9*433d6423SLionel Sambuc {
10*433d6423SLionel Sambuc 	asynfd_t *afd;
11*433d6423SLionel Sambuc 
12*433d6423SLionel Sambuc 	asyn->asyn_more++;
13*433d6423SLionel Sambuc 
14*433d6423SLionel Sambuc 	if ((unsigned) fd >= FD_SETSIZE) { errno= EBADF; return -1; }
15*433d6423SLionel Sambuc 	afd= &asyn->asyn_afd[fd];
16*433d6423SLionel Sambuc 
17*433d6423SLionel Sambuc 	if (!afd->afd_seen) {
18*433d6423SLionel Sambuc 		if ((afd->afd_flags= fcntl(fd, F_GETFL)) < 0) return -1;
19*433d6423SLionel Sambuc 		afd->afd_seen= 1;
20*433d6423SLionel Sambuc 	}
21*433d6423SLionel Sambuc 
22*433d6423SLionel Sambuc 	if (afd->afd_state[SEL_WRITE] == PENDING) {
23*433d6423SLionel Sambuc 		sigset_t mask;
24*433d6423SLionel Sambuc 		ssize_t result;
25*433d6423SLionel Sambuc 		int err;
26*433d6423SLionel Sambuc 
27*433d6423SLionel Sambuc 		sigemptyset(&mask);
28*433d6423SLionel Sambuc 		if (sigprocmask(SIG_SETMASK, &mask, &mask) < 0) return -1;
29*433d6423SLionel Sambuc 		(void) fcntl(fd, F_SETFL, afd->afd_flags | O_NONBLOCK);
30*433d6423SLionel Sambuc 
31*433d6423SLionel Sambuc 		result= write(fd, buf, len);
32*433d6423SLionel Sambuc 		err= errno;
33*433d6423SLionel Sambuc 
34*433d6423SLionel Sambuc 		(void) fcntl(fd, F_SETFL, afd->afd_flags);
35*433d6423SLionel Sambuc 		(void) sigprocmask(SIG_SETMASK, &mask, nil);
36*433d6423SLionel Sambuc 
37*433d6423SLionel Sambuc 		errno= err;
38*433d6423SLionel Sambuc 		if (result != -1 || errno != EAGAIN) {
39*433d6423SLionel Sambuc 			afd->afd_state[SEL_WRITE]= IDLE;
40*433d6423SLionel Sambuc 			return result;
41*433d6423SLionel Sambuc 		}
42*433d6423SLionel Sambuc 	}
43*433d6423SLionel Sambuc 
44*433d6423SLionel Sambuc 	afd->afd_state[SEL_WRITE]= WAITING;
45*433d6423SLionel Sambuc 	FD_SET(fd, &asyn->asyn_fdset[SEL_WRITE]);
46*433d6423SLionel Sambuc 	errno= EAGAIN;
47*433d6423SLionel Sambuc 	asyn->asyn_more--;
48*433d6423SLionel Sambuc 	return -1;
49*433d6423SLionel Sambuc }
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