bionic/libc/unistd/sigwait.c
2009-03-03 19:28:35 -08:00

75 lines
2.7 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.h>
int __rt_sigtimedwait(const sigset_t *uthese, siginfo_t *uinfo, const struct timespec *uts, size_t sigsetsize);
/* ok, this is really subtle: <asm/signal.h> defines sigset_t differently
* when you're in the kernel or in the C library.
*
* in the kernel, this is an array of 2 32-bit unsigned longs
* in the C library, this is a single 32-bit unsigned long
*
* moreover, the kernel implementation of rt_sigtimedwait doesn't
* accept anything except kernel-sized signal sets (probably a bug !)
*
* we thus need to create a fake kernel sigset !!
*/
int sigwait(const sigset_t *set, int *sig)
{
int ret;
/* use a union to get rid of aliasing warnings */
union {
unsigned long kernel_sigset[2];
sigset_t dummy_sigset;
} u;
u.kernel_sigset[0] = *set;
u.kernel_sigset[1] = 0; /* no real-time signals supported ? */
for (;;)
{
/* __rt_sigtimedwait can return EAGAIN or EINTR, we need to loop
* around them since sigwait is only allowed to return EINVAL
*/
ret = __rt_sigtimedwait ( &u.dummy_sigset, NULL, NULL, sizeof(u.kernel_sigset));
if (ret >= 0)
break;
if (errno != EAGAIN && errno != EINTR)
return errno;
}
*sig = ret;
return 0;
}