/*************************************************************************** * COPYRIGHT NOTICE * **************************************************************************** * ncurses is copyright (C) 1992-1995 * * Zeyd M. Ben-Halim * * zmbenhal@netcom.com * * Eric S. Raymond * * esr@snark.thyrsus.com * * * * Permission is hereby granted to reproduce and distribute ncurses * * by any means and for any fee, whether alone or as part of a * * larger distribution, in source or in binary form, PROVIDED * * this notice is included with any such distribution, and is not * * removed from any of its header files. Mention of ncurses in any * * applications linked with it is highly appreciated. * * * * ncurses comes AS IS with no warranty, implied or expressed. * * * ***************************************************************************/ /* ** lib_twait.c ** ** The routine _nc_timed_wait(). ** */ #include #if USE_FUNC_POLL #include #include #if HAVE_SYS_TIME_H #include #endif #elif HAVE_SELECT /* on SCO, conflicts with */ #if HAVE_SYS_TIME_H && ! SYSTEM_LOOKS_LIKE_SCO #include #endif #if HAVE_SYS_SELECT_H #include #endif #endif MODULE_ID("$Id: lib_twait.c,v 1.18 1997/02/15 18:27:51 tom Exp $") /* * We want to define GOOD_SELECT if the last argument of select(2) is * modified to indicate time left. The code will deal gracefully with * the other case, this is just an optimization to reduce the number * of system calls per input event. * * In general, expect System-V-like UNIXes to have this behavior and BSD-like * ones to not have it. Check your manual page. If it doesn't explicitly * say the last argument is modified, assume it's not. * * (We'd really like configure to autodetect this, but writing a proper test * turns out to be hard.) */ #if HAVE_GETTIMEOFDAY #if (defined(TRACE) && !HAVE_USLEEP) || ! GOOD_SELECT static void _nc_gettime(struct timeval *tp) { gettimeofday(tp, (struct timezone *)0); T(("time: %ld.%06ld", tp->tv_sec, tp->tv_usec)); } #endif #endif #if !HAVE_USLEEP int _nc_usleep(unsigned int usec) { int code; struct timeval tval; #if defined(TRACE) && HAVE_GETTIMEOFDAY _nc_gettime(&tval); #endif #if USE_FUNC_POLL { struct pollfd fds[1]; code = poll(fds, 0, usec / 1000); } #elif HAVE_SELECT tval.tv_sec = usec / 1000000; tval.tv_usec = usec % 1000000; code = select(0, NULL, NULL, NULL, &tval); #endif #if defined(TRACE) && HAVE_GETTIMEOFDAY _nc_gettime(&tval); #endif return code; } #endif /* !HAVE_USLEEP */ /* * Wait a specified number of milliseconds, returning true if the timer * didn't expire before there is activity on the specified file descriptors. * The file-descriptors are specified by the mode: * 0 - none (absolute time) * 1 - ncurses' normal input-descriptor * 2 - mouse descriptor, if any * 3 - either input or mouse. * * If the milliseconds given are -1, the wait blocks until activity on the * descriptors. */ int _nc_timed_wait(int mode, int milliseconds, int *timeleft) { int fd; int count = 0; long whole_secs = milliseconds / 1000; long micro_secs = (milliseconds % 1000) * 1000; int result = 0; struct timeval ntimeout; #if USE_FUNC_POLL struct pollfd fds[2]; #elif HAVE_SELECT static fd_set set; #endif #if !GOOD_SELECT && HAVE_GETTIMEOFDAY struct timeval starttime, returntime; long delta; _nc_gettime(&starttime); #endif if (milliseconds >= 0) { ntimeout.tv_sec = whole_secs; ntimeout.tv_usec = micro_secs; } else { ntimeout.tv_sec = 0; ntimeout.tv_usec = 0; } T(("start twait: %lu.%06lu secs", (long) ntimeout.tv_sec, (long) ntimeout.tv_usec)); /* * The do loop tries to make it look like we have restarting signals, * even if we don't. */ do { count = 0; #if USE_FUNC_POLL if (mode & 1) { fds[count].fd = SP->_ifd; fds[count].events = POLLIN; count++; } if ((mode & 2) && (fd = _nc_mouse_fd()) >= 0) { fds[count].fd = fd; fds[count].events = POLLIN; count++; } result = poll(fds, count, milliseconds); #elif HAVE_SELECT /* * Some systems modify the fd_set arguments; do this in the * loop. */ FD_ZERO(&set); if (mode & 1) { FD_SET(SP->_ifd, &set); count = SP->_ifd + 1; } if ((mode & 2) && (fd = _nc_mouse_fd()) >= 0) { FD_SET(fd, &set); count = max(fd, count) + 1; } errno = 0; result = select(count, &set, NULL, NULL, milliseconds >= 0 ? &ntimeout : 0); #endif #if !GOOD_SELECT && HAVE_GETTIMEOFDAY _nc_gettime(&returntime); /* The contents of ntimeout aren't guaranteed after return from * 'select()', so we disregard its contents. Also, note that * on some systems, tv_sec and tv_usec are unsigned. */ ntimeout.tv_sec = whole_secs; ntimeout.tv_usec = micro_secs; #define DELTA(f) (long)ntimeout.f - (long)returntime.f + (long)starttime.f delta = DELTA(tv_sec); if (delta < 0) delta = 0; ntimeout.tv_sec = delta; delta = DELTA(tv_usec); while (delta < 0 && ntimeout.tv_sec != 0) { ntimeout.tv_sec--; delta += 1000000; } ntimeout.tv_usec = delta; if (delta < 0) ntimeout.tv_sec = ntimeout.tv_usec = 0; /* * If the timeout hasn't expired, and we've gotten no data, * this is probably a system where 'select()' needs to be left * alone so that it can complete. Make this process sleep, * then come back for more. */ if (result == 0 && (ntimeout.tv_sec != 0 || ntimeout.tv_usec > 100000)) { napms(100); continue; } #endif } while (result == -1 && errno == EINTR); /* return approximate time left on the ntimeout, in milliseconds */ if (timeleft) *timeleft = (ntimeout.tv_sec * 1000) + (ntimeout.tv_usec / 1000); T(("end twait: returned %d, remaining time %lu.%06lu secs (%d msec)", result, (long) ntimeout.tv_sec, (long) ntimeout.tv_usec, timeleft ? *timeleft : -1)); /* * Both 'poll()' and 'select()' return the number of file descriptors * that are active. Translate this back to the mask that denotes which * file-descriptors, so that we don't need all of this system-specific * code everywhere. */ if (result != 0) { if (result > 0) { result = 0; #if USE_FUNC_POLL for (count = 0; count < 2; count++) { if ((mode & (1 << count)) && (fds[count].revents & POLLIN)) { result |= (1 << count); count++; } } #elif HAVE_SELECT if ((mode & 2) && (fd = _nc_mouse_fd()) >= 0 && FD_ISSET(fd, &set)) result |= 2; if ((mode & 1) && FD_ISSET(SP->_ifd, &set)) result |= 1; #endif } else result = 0; } return (result); }