/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
*------------------------------------------------------------------------
* File: uxwrap.c
*
* Our wrapped versions of the Unix select() and poll() system calls.
*
*------------------------------------------------------------------------
*/
#include "primpl.h"
#if defined(_PR_PTHREADS) ||
defined(_PR_GLOBAL_THREADS_ONLY) ||
defined(QNX)
/* Do not wrap select() and poll(). */
#else /* defined(_PR_PTHREADS) || defined(_PR_GLOBAL_THREADS_ONLY) */
/* The include files for select() */
# include <string.h>
# include <sys/types.h>
# include <sys/time.h>
# define ZAP_SET(_to, _width) \
PR_BEGIN_MACRO \
memset( \
_to, 0, \
((_width + 8 *
sizeof(
int) - 1) / (8 *
sizeof(
int))) *
sizeof(
int)); \
PR_END_MACRO
/* see comments in ns/cmd/xfe/mozilla.c (look for "PR_XGetXtHackFD") */
static int _pr_xt_hack_fd = -1;
int PR_XGetXtHackFD(
void) {
int fds[2];
if (_pr_xt_hack_fd == -1) {
if (!pipe(fds)) {
_pr_xt_hack_fd = fds[0];
}
}
return _pr_xt_hack_fd;
}
static int (*_pr_xt_hack_okayToReleaseXLock)(
void) = 0;
void PR_SetXtHackOkayToReleaseXLockFn(
int (*fn)(
void)) {
_pr_xt_hack_okayToReleaseXLock = fn;
}
/*
*-----------------------------------------------------------------------
* select() --
*
* Wrap up the select system call so that we can deschedule
* a thread that tries to wait for i/o.
*
*-----------------------------------------------------------------------
*/
# if defined(AIX_RENAME_SELECT)
int wrap_select(
unsigned long width,
void* rl,
void* wl,
void* el,
struct timeval* tv)
# elif
defined(_PR_SELECT_CONST_TIMEVAL)
int select(
int width, fd_set* rd, fd_set* wr, fd_set* ex,
const struct timeval* tv)
# else
int select(
int width, fd_set* rd, fd_set* wr, fd_set* ex,
struct timeval* tv)
# endif
{
int osfd;
_PRUnixPollDesc *unixpds, *unixpd, *eunixpd;
PRInt32 pdcnt;
PRIntervalTime timeout;
int retVal;
# if defined(AIX_RENAME_SELECT)
fd_set* rd = (fd_set*)rl;
fd_set* wr = (fd_set*)wl;
fd_set* ex = (fd_set*)el;
# endif
# if 0
/*
* Easy special case: zero timeout. Simply call the native
* select() with no fear of blocking.
*/
if (tv != NULL && tv->tv_sec == 0 && tv->tv_usec == 0) {
# if defined(AIX_RENAME_SELECT)
return _MD_SELECT(width, rl, wl, el, tv);
# else
return _MD_SELECT(width, rd, wr, ex, tv);
# endif
}
# endif
if (!_pr_initialized) {
_PR_ImplicitInitialization();
}
# ifndef _PR_LOCAL_THREADS_ONLY
if (_PR_IS_NATIVE_THREAD(_PR_MD_CURRENT_THREAD())) {
return _MD_SELECT(width, rd, wr, ex, tv);
}
# endif
if (width < 0 || width > FD_SETSIZE) {
errno = EINVAL;
return -1;
}
/* Compute timeout */
if (tv) {
/*
* These acceptable ranges for t_sec and t_usec are taken
* from the select() man pages.
*/
if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || tv->tv_usec < 0 ||
tv->tv_usec >= 1000000) {
errno = EINVAL;
return -1;
}
/* Convert microseconds to ticks */
timeout = PR_MicrosecondsToInterval(1000000 * tv->tv_sec + tv->tv_usec);
}
else {
/* tv being a NULL pointer means blocking indefinitely */
timeout = PR_INTERVAL_NO_TIMEOUT;
}
/* Check for no descriptors case (just doing a timeout) */
if ((!rd && !wr && !ex) || !width) {
PR_Sleep(timeout);
return 0;
}
/*
* Set up for PR_Poll(). The PRPollDesc array is allocated
* dynamically. If this turns out to have high performance
* penalty, one can change to use a large PRPollDesc array
* on the stack, and allocate dynamically only when it turns
* out to be not large enough.
*
* I allocate an array of size 'width', which is the maximum
* number of fds we may need to poll.
*/
unixpds = (_PRUnixPollDesc*)PR_CALLOC(width *
sizeof(_PRUnixPollDesc));
if (!unixpds) {
errno = ENOMEM;
return -1;
}
pdcnt = 0;
unixpd = unixpds;
for (osfd = 0; osfd < width; osfd++) {
int in_flags = 0;
if (rd && FD_ISSET(osfd, rd)) {
in_flags |= _PR_UNIX_POLL_READ;
}
if (wr && FD_ISSET(osfd, wr)) {
in_flags |= _PR_UNIX_POLL_WRITE;
}
if (ex && FD_ISSET(osfd, ex)) {
in_flags |= _PR_UNIX_POLL_EXCEPT;
}
if (in_flags) {
unixpd->osfd = osfd;
unixpd->in_flags = in_flags;
unixpd->out_flags = 0;
unixpd++;
pdcnt++;
}
}
/*
* see comments in mozilla/cmd/xfe/mozilla.c (look for
* "PR_XGetXtHackFD")
*/
{
int needToLockXAgain;
needToLockXAgain = 0;
if (rd && (_pr_xt_hack_fd != -1) && FD_ISSET(_pr_xt_hack_fd, rd) &&
_PR_XIsLocked() &&
(!_pr_xt_hack_okayToReleaseXLock || _pr_xt_hack_okayToReleaseXLock())) {
_PR_XUnlock();
needToLockXAgain = 1;
}
/* This is the potentially blocking step */
retVal = _PR_WaitForMultipleFDs(unixpds, pdcnt, timeout);
if (needToLockXAgain) {
_PR_XLock();
}
}
if (retVal > 0) {
/* Compute select results */
if (rd) {
ZAP_SET(rd, width);
}
if (wr) {
ZAP_SET(wr, width);
}
if (ex) {
ZAP_SET(ex, width);
}
/*
* The return value can be either the number of ready file
* descriptors or the number of set bits in the three fd_set's.
*/
retVal = 0;
/* we're going to recompute */
eunixpd = unixpds + pdcnt;
for (unixpd = unixpds; unixpd < eunixpd; unixpd++) {
if (unixpd->out_flags) {
int nbits = 0;
/* The number of set bits on for this fd */
if (unixpd->out_flags & _PR_UNIX_POLL_NVAL) {
errno = EBADF;
PR_LOG(_pr_io_lm, PR_LOG_ERROR,
(
"select returns EBADF for %d", unixpd->osfd));
retVal = -1;
break;
}
/*
* If a socket has a pending error, it is considered
* both readable and writable. (See W. Richard Stevens,
* Unix Network Programming, Vol. 1, 2nd Ed., Section 6.3,
* pp. 153-154.) We also consider a socket readable if
* it has a hangup condition.
*/
if (rd && (unixpd->in_flags & _PR_UNIX_POLL_READ) &&
(unixpd->out_flags &
(_PR_UNIX_POLL_READ | _PR_UNIX_POLL_ERR | _PR_UNIX_POLL_HUP))) {
FD_SET(unixpd->osfd, rd);
nbits++;
}
if (wr && (unixpd->in_flags & _PR_UNIX_POLL_WRITE) &&
(unixpd->out_flags & (_PR_UNIX_POLL_WRITE | _PR_UNIX_POLL_ERR))) {
FD_SET(unixpd->osfd, wr);
nbits++;
}
if (ex && (unixpd->in_flags & _PR_UNIX_POLL_WRITE) &&
(unixpd->out_flags & PR_POLL_EXCEPT)) {
FD_SET(unixpd->osfd, ex);
nbits++;
}
PR_ASSERT(nbits > 0);
# if defined(HPUX) ||
defined(SOLARIS) ||
defined(AIX)
retVal += nbits;
# endif
}
}
}
PR_ASSERT(tv || retVal != 0);
PR_LOG(_pr_io_lm, PR_LOG_MIN, (
"select returns %d", retVal));
PR_DELETE(unixpds);
return retVal;
}
/*
* Redefine poll, when supported on platforms, for local threads
*/
/*
* I am commenting out the poll() wrapper for Linux for now
* because it is difficult to define _MD_POLL that works on all
* Linux varieties. People reported that glibc 2.0.7 on Debian
* 2.0 Linux machines doesn't have the __syscall_poll symbol
* defined. (WTC 30 Nov. 1998)
*/
# if defined(_PR_POLL_AVAILABLE) && !
defined(LINUX)
/*
*-----------------------------------------------------------------------
* poll() --
*
* RETURN VALUES:
* -1: fails, errno indicates the error.
* 0: timed out, the revents bitmasks are not set.
* positive value: the number of file descriptors for which poll()
* has set the revents bitmask.
*
*-----------------------------------------------------------------------
*/
# include <poll.h>
# if defined(AIX_RENAME_SELECT)
int wrap_poll(
void* listptr,
unsigned long nfds,
long timeout)
# elif (
defined(AIX) && !
defined(AIX_RENAME_SELECT))
int poll(
void* listptr,
unsigned long nfds,
long timeout)
# elif
defined(HPUX)
int poll(
struct pollfd filedes[],
unsigned int nfds,
int timeout)
# elif
defined(NETBSD)
int poll(
struct pollfd* filedes, nfds_t nfds,
int timeout)
# elif
defined(OPENBSD)
int poll(
struct pollfd filedes[], nfds_t nfds,
int timeout)
# elif
defined(FREEBSD)
int poll(
struct pollfd* filedes,
unsigned nfds,
int timeout)
# else
int poll(
struct pollfd* filedes,
unsigned long nfds,
int timeout)
# endif
{
# ifdef AIX
struct pollfd* filedes = (
struct pollfd*)listptr;
# endif
struct pollfd *pfd, *epfd;
_PRUnixPollDesc *unixpds, *unixpd, *eunixpd;
PRIntervalTime ticks;
PRInt32 pdcnt;
int ready;
/*
* Easy special case: zero timeout. Simply call the native
* poll() with no fear of blocking.
*/
if (timeout == 0) {
# if defined(AIX)
return _MD_POLL(listptr, nfds, timeout);
# else
return _MD_POLL(filedes, nfds, timeout);
# endif
}
if (!_pr_initialized) {
_PR_ImplicitInitialization();
}
# ifndef _PR_LOCAL_THREADS_ONLY
if (_PR_IS_NATIVE_THREAD(_PR_MD_CURRENT_THREAD())) {
return _MD_POLL(filedes, nfds, timeout);
}
# endif
/* We do not support the pollmsg structures on AIX */
# ifdef AIX
PR_ASSERT((nfds & 0xff00) == 0);
# endif
if (timeout < 0 && timeout != -1) {
errno = EINVAL;
return -1;
}
/* Convert timeout from miliseconds to ticks */
if (timeout == -1) {
ticks = PR_INTERVAL_NO_TIMEOUT;
}
else {
ticks = PR_MillisecondsToInterval(timeout);
}
/* Check for no descriptor case (just do a timeout) */
if (nfds == 0) {
PR_Sleep(ticks);
return 0;
}
unixpds = (_PRUnixPollDesc*)PR_MALLOC(nfds *
sizeof(_PRUnixPollDesc));
if (NULL == unixpds) {
errno = EAGAIN;
return -1;
}
pdcnt = 0;
epfd = filedes + nfds;
unixpd = unixpds;
for (pfd = filedes; pfd < epfd; pfd++) {
/*
* poll() ignores negative fd's.
*/
if (pfd->fd >= 0) {
unixpd->osfd = pfd->fd;
# ifdef _PR_USE_POLL
unixpd->in_flags = pfd->events;
# else
/*
* Map the poll events to one of the three that can be
* represented by the select fd_sets:
* POLLIN, POLLRDNORM ===> readable
* POLLOUT, POLLWRNORM ===> writable
* POLLPRI, POLLRDBAND ===> exception
* POLLNORM, POLLWRBAND (and POLLMSG on some platforms)
* are ignored.
*
* The output events POLLERR and POLLHUP are never turned on.
* POLLNVAL may be turned on.
*/
unixpd->in_flags = 0;
if (pfd->events & (POLLIN
# ifdef POLLRDNORM
| POLLRDNORM
# endif
)) {
unixpd->in_flags |= _PR_UNIX_POLL_READ;
}
if (pfd->events & (POLLOUT
# ifdef POLLWRNORM
| POLLWRNORM
# endif
)) {
unixpd->in_flags |= _PR_UNIX_POLL_WRITE;
}
if (pfd->events & (POLLPRI
# ifdef POLLRDBAND
| POLLRDBAND
# endif
)) {
unixpd->in_flags |= PR_POLL_EXCEPT;
}
# endif
/* _PR_USE_POLL */
unixpd->out_flags = 0;
unixpd++;
pdcnt++;
}
}
ready = _PR_WaitForMultipleFDs(unixpds, pdcnt, ticks);
if (-1 == ready) {
if (PR_GetError() == PR_PENDING_INTERRUPT_ERROR) {
errno = EINTR;
/* XXX we aren't interrupted by a signal, but... */
}
else {
errno = PR_GetOSError();
}
}
if (ready <= 0) {
goto done;
}
/*
* Copy the out_flags from the _PRUnixPollDesc structures to the
* user's pollfd structures and free the allocated memory
*/
unixpd = unixpds;
for (pfd = filedes; pfd < epfd; pfd++) {
pfd->revents = 0;
if (pfd->fd >= 0) {
# ifdef _PR_USE_POLL
pfd->revents = unixpd->out_flags;
# else
if (0 != unixpd->out_flags) {
if (unixpd->out_flags & _PR_UNIX_POLL_READ) {
if (pfd->events & POLLIN) {
pfd->revents |= POLLIN;
}
# ifdef POLLRDNORM
if (pfd->events & POLLRDNORM) {
pfd->revents |= POLLRDNORM;
}
# endif
}
if (unixpd->out_flags & _PR_UNIX_POLL_WRITE) {
if (pfd->events & POLLOUT) {
pfd->revents |= POLLOUT;
}
# ifdef POLLWRNORM
if (pfd->events & POLLWRNORM) {
pfd->revents |= POLLWRNORM;
}
# endif
}
if (unixpd->out_flags & _PR_UNIX_POLL_EXCEPT) {
if (pfd->events & POLLPRI) {
pfd->revents |= POLLPRI;
}
# ifdef POLLRDBAND
if (pfd->events & POLLRDBAND) {
pfd->revents |= POLLRDBAND;
}
# endif
}
if (unixpd->out_flags & _PR_UNIX_POLL_ERR) {
pfd->revents |= POLLERR;
}
if (unixpd->out_flags & _PR_UNIX_POLL_NVAL) {
pfd->revents |= POLLNVAL;
}
if (unixpd->out_flags & _PR_UNIX_POLL_HUP) {
pfd->revents |= POLLHUP;
}
}
# endif
/* _PR_USE_POLL */
unixpd++;
}
}
done:
PR_DELETE(unixpds);
return ready;
}
# endif
/* !defined(LINUX) */
#endif /* defined(_PR_PTHREADS) || defined(_PR_GLOBAL_THREADS_ONLY) */
/* uxwrap.c */
