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Diffstat (limited to 'nuttx/sched/sem_open.c')
| -rw-r--r-- | nuttx/sched/sem_open.c | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/nuttx/sched/sem_open.c b/nuttx/sched/sem_open.c deleted file mode 100644 index b2b76fe38..000000000 --- a/nuttx/sched/sem_open.c +++ /dev/null @@ -1,208 +0,0 @@ -/**************************************************************************** - * sched/sem_open.c - * - * Copyright (C) 2007, 2008, 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 <sys/types.h> -#include <stdbool.h> -#include <stdarg.h> -#include <limits.h> -#include <fcntl.h> -#include <string.h> -#include <semaphore.h> -#include <errno.h> - -#include <nuttx/kmalloc.h> - -#include "sem_internal.h" - -/**************************************************************************** - * Pre-processor Definitions - ****************************************************************************/ - -/**************************************************************************** - * Private Type Declarations - ****************************************************************************/ - -/**************************************************************************** - * Global Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Variables - ****************************************************************************/ - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: sem_open - * - * Description: - * This function establishes a connection between named semaphores and a - * task. Following a call to sem_open() with the semaphore name, the task - * may reference the semaphore associated with name using the address - * returned by this call. The semaphore may be used in subsequent calls - * to sem_wait(), sem_trywait(), and sem_post(). The semaphore remains - * usable until the semaphore is closed by a successful call to sem_close(). - * - * If a task makes multiple calls to sem_open() with the same name, then - * the same semaphore address is returned (provided there have been no - * calls to sem_unlink()). - * - * Parameters: - * name - Semaphore name - * oflag - Semaphore creation options. This may either or both of the - * following bit settings. - * oflag = 0: Connect to the semaphore only if it already exists. - * oflag = O_CREAT: Connect to the semaphore if it exists, otherwise - * create the semaphore. - * oflag = O_CREAT|O_EXCL: Create a new semaphore - * unless one of this name already exists. - * Optional parameters. When the O_CREAT flag is specified, two optional - * parameters are expected: - * 1. mode_t mode (ignored), and - * 2. unsigned int value. This initial value of the semaphore. Valid - * initial values of the semaphore must be less than or equal to - * SEM_VALUE_MAX. - * - * Return Value: - * A pointer to sem_t or -1 (ERROR) if unsuccessful. - * - * Assumptions: - * - ****************************************************************************/ - -FAR sem_t *sem_open (FAR const char *name, int oflag, ...) -{ - int namelen; - FAR nsem_t *psem; - FAR sem_t *sem = (FAR sem_t*)ERROR; - va_list arg; /* Points to each un-named argument */ - unsigned int value; /* Semaphore value parameter */ - - /* Make sure that a non-NULL name is supplied */ - - if (name) - { - /* The POSIX specification requires that the "check for the - * existence of a semaphore and the creation of the semaphore - * if it does not exist shall be atomic with respect to other - * processes executing sem_open()..." A simple sched_lock() - * should be sufficient to meet this requirement. - */ - - sched_lock(); - namelen = strlen(name); - if (namelen > 0) - { - /* See if the semaphore already exists */ - - psem = sem_findnamed(name); - if (psem) - { - /* It does. Check if the caller wanted to created - * a new semahore with this name. - */ - - if (!(oflag & O_CREAT) || !(oflag & O_EXCL)) - { - /* Allow a new connection to the semaphore */ - - psem->nconnect++; - sem = &psem->sem; - } - } - - /* It doesn't exist. Should we create one? */ - - else if ((oflag & O_CREAT) != 0) - { - /* Set up to get the optional arguments needed to create - * a message queue. - */ - - va_start(arg, oflag); - (void)va_arg(arg, mode_t); /* Creation mode parameter (ignored) */ - value = va_arg(arg, unsigned int); - - /* Verify that a legal initial value was selected. */ - - if (value <= SEM_VALUE_MAX) - { - /* Allocate memory for the new semaphore */ - - psem = (FAR nsem_t*)kmalloc((sizeof(nsem_t) + namelen + 1)); - if (psem) - { - /* Initialize the named semaphore */ - - sem = &psem->sem; - sem_init(sem, 0, value); - - psem->nconnect = 1; - psem->unlinked = false; - psem->name = (FAR char*)psem + sizeof(nsem_t); - strcpy(psem->name, name); - - /* Add the new semaphore to the list of named - * semaphores - */ - - dq_addfirst((FAR dq_entry_t*)psem, &g_nsems); - } - - /* Clean-up variable argument stuff */ - - va_end(arg); - } - } - } - - sched_unlock(); - } - - return sem; -} - |