diff options
author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-09-17 18:18:44 +0000 |
---|---|---|
committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-09-17 18:18:44 +0000 |
commit | 57623d42ebb04f0a0b9e6eb7c0847a3ece2aa0ff (patch) | |
tree | 25d07d14e920d31c0b1947c9ca586f2a01fc32d8 /nuttx/sched/sem_unlink.c | |
download | px4-firmware-57623d42ebb04f0a0b9e6eb7c0847a3ece2aa0ff.tar.gz px4-firmware-57623d42ebb04f0a0b9e6eb7c0847a3ece2aa0ff.tar.bz2 px4-firmware-57623d42ebb04f0a0b9e6eb7c0847a3ece2aa0ff.zip |
Resync new repository with old repo r5166
git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5153 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/sched/sem_unlink.c')
-rw-r--r-- | nuttx/sched/sem_unlink.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/nuttx/sched/sem_unlink.c b/nuttx/sched/sem_unlink.c new file mode 100644 index 000000000..6fe011540 --- /dev/null +++ b/nuttx/sched/sem_unlink.c @@ -0,0 +1,140 @@ +/**************************************************************************** + * sched/sem_unlink.c + * + * Copyright (C) 2007-2009 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 <stdbool.h> +#include <semaphore.h> +#include <sched.h> +#include <queue.h> + +#include "os_internal.h" +#include "sem_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: sem_unlink + * + * Description: + * This function removes the semaphore named by the input parameter 'name.' + * If the semaphore named by 'name' is currently referenced by other task, + * the sem_unlink() will have no effect on the state of the semaphore. If + * one or more processes have the semaphore open when sem_unlink() is + * called, destruction of the semaphore will be postponed until all + * references to the semaphore have been destroyed by calls of sem_close(). + * + * Parameters: + * name - Semaphore name + * + * Return Value: + * 0 (OK), or -1 (ERROR) if unsuccessful. + * + * Assumptions: + * + ****************************************************************************/ + +int sem_unlink(FAR const char *name) +{ + FAR nsem_t *psem; + int ret = ERROR; + + /* Verify the input values */ + + if (name) + { + sched_lock(); + + /* Find the named semaphore */ + + psem = sem_findnamed(name); + + /* Check if the semaphore was found */ + + if (psem) + { + /* If the named semaphore was found and if there are no + * connects to it, then deallocate it + */ + + if (!psem->nconnect) + { + dq_rem((FAR dq_entry_t*)psem, &g_nsems); + sched_free(psem); + } + + /* If one or more process still has the semaphore open, + * then just mark it as unlinked. The unlinked semaphore will + * be deleted when the final process closes the semaphore. + */ + + else + { + psem->unlinked = true; + } + ret = OK; + } + + sched_unlock(); + } + + return ret; +} |