diff options
author | Geoff Norton <grompf@sublimeintervention.com> | 2010-06-14 23:31:02 +0400 |
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committer | Geoff Norton <grompf@sublimeintervention.com> | 2010-06-14 23:31:02 +0400 |
commit | f90c1d24800dccbf2354d211036253db53681d06 (patch) | |
tree | bd0bce104cd158665141daa09b87c32300714f8e /support | |
parent | 759b2ca4ce06201add69c12b277de32215960455 (diff) |
oops
svn path=/trunk/mono/; revision=158898
Diffstat (limited to 'support')
-rw-r--r-- | support/fakepoll.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/support/fakepoll.h b/support/fakepoll.h new file mode 100644 index 00000000000..b5805ee9f10 --- /dev/null +++ b/support/fakepoll.h @@ -0,0 +1,162 @@ +// fakepoll.h +// poll using select +// Warning: a call to this poll() takes about 4K of stack space. + +// Greg Parker gparker-web@sealiesoftware.com December 2000 +// This code is in the public domain and may be copied or modified without +// permission. + +// Updated May 2002: +// * fix crash when an fd is less than 0 +// * set errno=EINVAL if an fd is greater or equal to FD_SETSIZE +// * don't set POLLIN or POLLOUT in revents if it wasn't requested +// in events (only happens when an fd is in the poll set twice) + +#ifndef _FAKE_POLL_H +#define _FAKE_POLL_H + +#include <limits.h> +#define FD_SETSIZE OPEN_MAX +#include <sys/types.h> +#include <sys/time.h> +#include <unistd.h> +#include <stdlib.h> + +typedef struct pollfd { + int fd; /* file desc to poll */ + short events; /* events of interest on fd */ + short revents; /* events that occurred on fd */ +} pollfd_t; + + +// poll flags +#define POLLIN 0x0001 +#define POLLOUT 0x0004 +#define POLLERR 0x0008 + +// synonyms +#define POLLNORM POLLIN +#define POLLPRI POLLIN +#define POLLRDNORM POLLIN +#define POLLRDBAND POLLIN +#define POLLWRNORM POLLOUT +#define POLLWRBAND POLLOUT + +// ignored +#define POLLHUP 0x0010 +#define POLLNVAL 0x0020 + +static +inline int poll(struct pollfd *pollSet, int pollCount, int pollTimeout) +{ + struct timeval tv; + struct timeval *tvp; + fd_set readFDs, writeFDs, exceptFDs; + fd_set *readp, *writep, *exceptp; + struct pollfd *pollEnd, *p; + int selected; + int result; + int maxFD; + + if (!pollSet) { + pollEnd = NULL; + readp = NULL; + writep = NULL; + exceptp = NULL; + maxFD = 0; + } + else { + pollEnd = pollSet + pollCount; + readp = &readFDs; + writep = &writeFDs; + exceptp = &exceptFDs; + + FD_ZERO(readp); + FD_ZERO(writep); + FD_ZERO(exceptp); + + // Find the biggest fd in the poll set + maxFD = 0; + for (p = pollSet; p < pollEnd; p++) { + if (p->fd > maxFD) maxFD = p->fd; + } + + if (maxFD >= FD_SETSIZE) { + // At least one fd is too big + errno = EINVAL; + return -1; + } + + // Transcribe flags from the poll set to the fd sets + for (p = pollSet; p < pollEnd; p++) { + if (p->fd < 0) { + // Negative fd checks nothing and always reports zero + } else { + if (p->events & POLLIN) FD_SET(p->fd, readp); + if (p->events & POLLOUT) FD_SET(p->fd, writep); + if (p->events != 0) FD_SET(p->fd, exceptp); + // POLLERR is never set coming in; poll() always reports errors + // But don't report if we're not listening to anything at all. + } + } + } + + // poll timeout is in milliseconds. Convert to struct timeval. + // poll timeout == -1 : wait forever : select timeout of NULL + // poll timeout == 0 : return immediately : select timeout of zero + if (pollTimeout >= 0) { + tv.tv_sec = pollTimeout / 1000; + tv.tv_usec = (pollTimeout % 1000) * 1000; + tvp = &tv; + } else { + tvp = NULL; + } + + + selected = select(maxFD+1, readp, writep, exceptp, tvp); + + + if (selected < 0) { + // Error during select + result = -1; + } + else if (selected > 0) { + // Select found something + // Transcribe result from fd sets to poll set. + // Also count the number of selected fds. poll returns the + // number of ready fds; select returns the number of bits set. + int polled = 0; + for (p = pollSet; p < pollEnd; p++) { + p->revents = 0; + if (p->fd < 0) { + // Negative fd always reports zero + } else { + if ((p->events & POLLIN) && FD_ISSET(p->fd, readp)) { + p->revents |= POLLIN; + } + if ((p->events & POLLOUT) && FD_ISSET(p->fd, writep)) { + p->revents |= POLLOUT; + } + if ((p->events != 0) && FD_ISSET(p->fd, exceptp)) { + p->revents |= POLLERR; + } + + if (p->revents) polled++; + } + } + result = polled; + } + else { + // selected == 0, select timed out before anything happened + // Clear all result bits and return zero. + for (p = pollSet; p < pollEnd; p++) { + p->revents = 0; + } + result = 0; + } + + return result; +} + + +#endif |