Implement pause()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5376 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2012-11-21 00:39:30 +00:00
parent 167d95b3a2
commit 9b37a2c4fc
5 changed files with 152 additions and 3 deletions

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@ -3651,4 +3651,6 @@
* arch/several: Change UARTs are enabled for i.MX, LM3S, ez80, and M16C to
match how they are enabled for other architectures.
* configs/ez80f910200kitg: Convert to use mconf configuration.
* sched/pause.c: Implements the POSIX pause() function.

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@ -13,7 +13,7 @@
<h1><big><font color="#3c34ec"><i>NuttX Operating System<p>User's Manual</i></font></big></h1>
<p><small>by</small></p>
<p>Gregory Nutt<p>
<p>Last Updated: August 1, 2012</p>
<p>Last Updated: November 20, 2012</p>
</td>
</tr>
</table>
@ -3419,6 +3419,7 @@ interface of the same name.
<li><a href="#sigtimedwait">2.8.11 sigtimedwait</a></li>
<li><a href="#sigqueue">2.8.12 sigqueue</a></li>
<li><a href="#kill">2.8.13 kill</a></li>
<li><a href="#pause">2.8.14 pause</a></li>
</ul>
<H3><a name="sigemptyset">2.8.1 sigemptyset</a></H3>
@ -3946,7 +3947,7 @@ be sent.
<b>Function Prototype:</b>
<pre>
#include &lt;sys/types.h&gt;
#include &ltsignal.h&gt;
#include &lt;signal.h&gt;
int kill(pid_t pid, int sig);
</pre>
@ -3996,6 +3997,39 @@ be sent.
<li>Sending of signals to 'process groups' is not supported in NuttX.</li>
</ul>
<H3><a name="pause">2.8.14 pause</a></H3>
<p>
<b>Function Prototype:</b>
<pre>
#include &lt;unistd.h&gt;
int pause(void);
</pre>
<p>
<b>Description:</b>
The <code>pause()</code> function will suspend the calling thread until delivery of a non-blocked signal.
</p>
<b>Input Parameters:</b>
<ul>
<li><i>None</i>
</ul>
<p>
<b>Returned Value:</b>
Since <code>pause()</code> suspends thread execution indefinitely unless interrupted a signal, there is no successful completion return value.
A value of -1 (<code>ERROR</code> will always be returned and errno set to indicate the error (<code>EINTR</code>).
</p>
<p>
<b>Assumptions/Limitations:</b>
</p>
<p>
<b>POSIX Compatibility:</b>
In the POSIX description of this function is the <code>pause()</code> function will suspend the calling thread until delivery of a signal whose action is either to execute a signal-catching function or to terminate the process.
This implementation only waits for any non-blocked signal to be recieved.
</p>
<table width ="100%">
<tr bgcolor="#e4e4e4">
<td>
@ -6711,6 +6745,7 @@ pid_t getpid(void);
void _exit(int status) noreturn_function;
unsigned int sleep(unsigned int seconds);
void usleep(unsigned long usec);
int pause(void);
int close(int fd);
int dup(int fd);
@ -8187,6 +8222,7 @@ notify a task when a message is available on a queue.
</td>
<td valign="top" width="33%">
<li><a href="#OS_Interfaces">OS Interfaces</a></li>
<li><a href="#pause">pause</a></li>
<li><a href="#pipe">pipe</a></li>
<li><a href="#poll">poll</a></li>
<li><a href="#drvrpollops">poll.h</a></li>

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@ -133,6 +133,7 @@ EXTERN pid_t getpid(void);
EXTERN void _exit(int status) noreturn_function;
EXTERN unsigned int sleep(unsigned int seconds);
EXTERN int usleep(useconds_t usec);
EXTERN int pause(void);
/* File descriptor operations */

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@ -94,7 +94,7 @@ SIGNAL_SRCS = sig_initialize.c \
sig_findaction.c sig_allocatependingsigaction.c \
sig_releasependingsigaction.c sig_unmaskpendingsignal.c \
sig_removependingsignal.c sig_releasependingsignal.c sig_lowest.c \
sig_mqnotempty.c sig_cleanup.c sig_received.c sig_deliver.c
sig_mqnotempty.c sig_cleanup.c sig_received.c sig_deliver.c pause.c
MQUEUE_SRCS = mq_open.c mq_close.c mq_unlink.c mq_send.c mq_timedsend.c\
mq_sndinternal.c mq_receive.c mq_timedreceive.c mq_rcvinternal.c \

110
sched/pause.c Normal file
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@ -0,0 +1,110 @@
/****************************************************************************
* sched/pause.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <signal.h>
/****************************************************************************
* Preprocessor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Definitions
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pause
*
* Description:
* The pause() function will suspend the calling thread until delivery of a
* non-blocked signal.
*
* Input Parameters:
* None
*
* Returned Value:
* Since pause() suspends thread execution indefinitely unless interrupted
* a signal, there is no successful completion return value. A value of -1
* will always be returned and errno set to indicate the error (EINTR).
*
* POSIX compatibility:
* In the POSIX description of this function is the pause() function will
* suspend the calling thread until delivery of a signal whose action is
* either to execute a signal-catching function or to terminate the
* process. This implementation only waits for any non-blocked signal
* to be recieved.
*
****************************************************************************/
int pause(void)
{
sigset_t set;
struct siginfo value;
/* Set up for the sleep. Using the empty set means that we are not
* waiting for any particualar signal. However, any unmasked signal
* can still awaken sigtimedwait().
*/
(void)sigemptyset(&set);
/* sigtwaitinfo() cannot succeed. It should always return error EINTR
* meaning that some unblocked signal was caught.
*/
return sigwaitinfo(&set, &value);
}