1 /* asyn_write() Author: Kees J. Bot 2 * 7 Jul 1997 3 */ 4 #include "asyn.h" 5 #include <signal.h> 6 7 ssize_t asyn_write(asynchio_t *asyn, int fd, const void *buf, size_t len) 8 /* Nonblocking write(). (See asyn_read()). */ 9 { 10 asynfd_t *afd; 11 12 asyn->asyn_more++; 13 14 if ((unsigned) fd >= FD_SETSIZE) { errno= EBADF; return -1; } 15 afd= &asyn->asyn_afd[fd]; 16 17 if (!afd->afd_seen) { 18 if ((afd->afd_flags= fcntl(fd, F_GETFL)) < 0) return -1; 19 afd->afd_seen= 1; 20 } 21 22 if (afd->afd_state[SEL_WRITE] == PENDING) { 23 sigset_t mask; 24 ssize_t result; 25 int err; 26 27 sigemptyset(&mask); 28 if (sigprocmask(SIG_SETMASK, &mask, &mask) < 0) return -1; 29 (void) fcntl(fd, F_SETFL, afd->afd_flags | O_NONBLOCK); 30 31 result= write(fd, buf, len); 32 err= errno; 33 34 (void) fcntl(fd, F_SETFL, afd->afd_flags); 35 (void) sigprocmask(SIG_SETMASK, &mask, nil); 36 37 errno= err; 38 if (result != -1 || errno != EAGAIN) { 39 afd->afd_state[SEL_WRITE]= IDLE; 40 return result; 41 } 42 } 43 44 afd->afd_state[SEL_WRITE]= WAITING; 45 FD_SET(fd, &asyn->asyn_fdset[SEL_WRITE]); 46 errno= EAGAIN; 47 asyn->asyn_more--; 48 return -1; 49 } 50