717bb04cb7
Refer to issue #8867 for details and rational. Convert sigset_t to an array type so that more than 32 signals can be supported. Why not use a uin64_t? - Using a uin32_t is more flexible if we decide to increase the number of signals beyound 64. - 64-bit accesses are not atomic, at least not on 32-bit ARMv7-M and similar - Keeping the base type as uint32_t does not introduce additional overhead due to padding to achieve 64-bit alignment of uin64_t - Some architectures still supported by NuttX do not support uin64_t types, Increased the number of signals to 64. This matches Linux. This will support all xsignals defined by Linux and also 32 real time signals (also like Linux). This is is a work in progress; a draft PR that you are encouraged to comment on.
96 lines
3.9 KiB
C
96 lines
3.9 KiB
C
/****************************************************************************
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* libs/libc/signal/sig_wait.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <signal.h>
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#include <assert.h>
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#include <errno.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: sigwait
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*
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* Description:
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* The sigwait() function selects a pending signal from set, atomically
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* clears it from the system's set of pending signals, and returns that
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* signal number in the location referenced by sig. If prior to the call
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* to sigwait() there are multiple pending instances of a single signal
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* number, it is implementation-dependent whether upon successful return
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* there are any remaining pending signals for that signal number. If the
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* implementation supports queued signals and there are multiple signals
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* queued for the signal number selected, the first such queued signal
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* causes a return from sigwait() and the remainder remain queued. If no
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* signal in set is pending at the time of the call, the thread is
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* suspended until one or more becomes pending. The signals defined by set
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* will been blocked at the time of the call to sigwait(); otherwise the
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* behavior is undefined. The effect of sigwait() on the signal actions
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* for the signals in set is unspecified.
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*
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* If more than one thread is using sigwait() to wait for the same
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* signal, no more than one of these threads will return from sigwait()
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* with the signal number. Which thread returns from sigwait() if more
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* than a single thread is waiting is unspecified.
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*
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* Should any of the multiple pending signals in the range SIGRTMIN to
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* SIGRTMAX be selected, it shall be the lowest numbered one. The selection
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* order between realtime and non-realtime signals, or between multiple
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* pending non-realtime signals, is unspecified.
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*
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* Input Parameters:
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* set - The set of pending signals to wait for
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* sig - The location in which to store the pending signal number.
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*
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* Returned Value:
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* Upon successful completion, sigwait() stores the signal number of the
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* received signal at the location referenced by sig and returns zero.
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* Otherwise, an error number is returned to indicate the error.
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*
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****************************************************************************/
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int sigwait(FAR const sigset_t *set, FAR int *sig)
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{
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int signo;
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DEBUGASSERT(set != NULL && sig != NULL);
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/* The standard sigwait() function behaves that same as sigwaitinfo() with
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* the info argument set to NULL.
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*/
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signo = sigwaitinfo(set, NULL);
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if (signo < 0)
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{
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/* If sigwaitinfo() fails, return the error number */
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return get_errno();
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}
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/* Return the signal number in the user provided location */
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*sig = signo;
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return OK;
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}
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