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/*
* (c) The GRASP/AQUA Project, Glasgow University, 1994-2002
*
* hWaitForInput Runtime Support
*/
/* select and supporting types is not Posix */
/* #include "PosixSource.h" */
#include "HsBase.h"
/*
* inputReady(fd) checks to see whether input is available on the file
* descriptor 'fd'. Input meaning 'can I safely read at least a
* *character* from this file object without blocking?'
*/
int
inputReady(int fd, int msecs, int isSock)
{
if
#ifndef mingw32_TARGET_OS
( 1 ) {
#else
( isSock ) {
#endif
int maxfd, ready;
fd_set rfd;
struct timeval tv;
FD_ZERO(&rfd);
FD_SET(fd, &rfd);
/* select() will consider the descriptor set in the range of 0 to
* (maxfd-1)
*/
maxfd = fd + 1;
tv.tv_sec = msecs / 1000;
tv.tv_usec = (msecs % 1000) * 1000;
while ((ready = select(maxfd, &rfd, NULL, NULL, &tv)) < 0 ) {
if (errno != EINTR ) {
return -1;
}
}
/* 1 => Input ready, 0 => not ready, -1 => error */
return (ready);
}
#ifdef mingw32_TARGET_OS
else {
DWORD rc;
HANDLE hFile = (HANDLE)_get_osfhandle(fd);
rc = WaitForMultipleObjects( 1,
&hFile,
TRUE, /* wait all */
msecs); /*millisecs*/
/* 1 => Input ready, 0 => not ready, -1 => error */
switch (rc) {
case WAIT_TIMEOUT: return 0;
case WAIT_OBJECT_0: return 1;
default: return -1;
}
}
#endif
}
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