diff options
Diffstat (limited to 'sysdeps/generic/pselect.c')
| -rw-r--r-- | sysdeps/generic/pselect.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/sysdeps/generic/pselect.c b/sysdeps/generic/pselect.c new file mode 100644 index 0000000000..43b371cce7 --- /dev/null +++ b/sysdeps/generic/pselect.c @@ -0,0 +1,88 @@ +/* Copyright (C) 1996,1997,1998,2001,2002,2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <signal.h> +#include <stddef.h> /* For NULL. */ +#include <sys/time.h> +#include <sys/select.h> +#include <sysdep-cancel.h> + +/* Check the first NFDS descriptors each in READFDS (if not NULL) for read + readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS + (if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out + after waiting the interval specified therein. Additionally set the sigmask + SIGMASK for this call. Returns the number of ready descriptors, or -1 for + errors. */ +static int +do_pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, + const struct timespec *timeout, const sigset_t *sigmask) +{ + struct timeval tval; + int retval; + sigset_t savemask; + + /* Change nanosecond number to microseconds. This might mean losing + precision and therefore the `pselect` should be available. But + for now it is hardly found. */ + if (timeout != NULL) + TIMESPEC_TO_TIMEVAL (&tval, timeout); + + /* The setting and restoring of the signal mask and the select call + should be an atomic operation. This can't be done without kernel + help. */ + if (sigmask != NULL) + __sigprocmask (SIG_SETMASK, sigmask, &savemask); + + /* Note the pselect() is a cancellation point. But since we call + select() which itself is a cancellation point we do not have + to do anything here. */ + retval = __select (nfds, readfds, writefds, exceptfds, + timeout != NULL ? &tval : NULL); + + if (sigmask != NULL) + __sigprocmask (SIG_SETMASK, &savemask, NULL); + + return retval; +} + + +int +__pselect (nfds, readfds, writefds, exceptfds, timeout, sigmask) + int nfds; + fd_set *readfds; + fd_set *writefds; + fd_set *exceptfds; + const struct timespec *timeout; + const sigset_t *sigmask; +{ + if (SINGLE_THREAD_P) + return do_pselect (nfds, readfds, writefds, exceptfds, timeout, sigmask); + + int oldtype = LIBC_CANCEL_ASYNC (); + + int result = do_pselect (nfds, readfds, writefds, exceptfds, timeout, + sigmask); + + LIBC_CANCEL_RESET (oldtype); + + return result; +} +weak_alias (__pselect, pselect) +strong_alias (__pselect, __libc_pselect) |