diff options
Diffstat (limited to 'nuttx/lib/misc/lib_filesem.c')
-rw-r--r-- | nuttx/lib/misc/lib_filesem.c | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/nuttx/lib/misc/lib_filesem.c b/nuttx/lib/misc/lib_filesem.c deleted file mode 100644 index 1d1f25c2f..000000000 --- a/nuttx/lib/misc/lib_filesem.c +++ /dev/null @@ -1,145 +0,0 @@ -/************************************************************************ - * lib/misc/lib_filesem.c - * - * Copyright (C) 2007, 2009, 2011 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 <unistd.h> -#include <semaphore.h> -#include <errno.h> -#include <assert.h> - -#include "lib_internal.h" - -#if CONFIG_STDIO_BUFFER_SIZE > 0 - -/************************************************************************ - * Pre-processor Definitions - ************************************************************************/ - -/************************************************************************ - * Private Data - ************************************************************************/ - -/************************************************************************ - * Global Functions - ************************************************************************/ - -/************************************************************************ - * lib_sem_initialize - ************************************************************************/ - -void lib_sem_initialize(FAR struct file_struct *stream) -{ - /* Initialize the LIB semaphore to one (to support one-at- - * a-time access to private data sets. - */ - - (void)sem_init(&stream->fs_sem, 0, 1); - - stream->fs_holder = -1; - stream->fs_counts = 0; -} - -/************************************************************************ - * lib_take_semaphore - ************************************************************************/ - -void lib_take_semaphore(FAR struct file_struct *stream) -{ - pid_t my_pid = getpid(); - - /* Do I already have the semaphore? */ - - if (stream->fs_holder == my_pid) - { - /* Yes, just increment the number of references that I have */ - - stream->fs_counts++; - } - else - { - /* Take the semaphore (perhaps waiting) */ - - while (sem_wait(&stream->fs_sem) != 0) - { - /* The only case that an error should occr here is if - * the wait was awakened by a signal. - */ - - ASSERT(get_errno() == EINTR); - } - - /* We have it. Claim the stak and return */ - - stream->fs_holder = my_pid; - stream->fs_counts = 1; - } -} - -/************************************************************************ - * lib_give_semaphore - ************************************************************************/ - -void lib_give_semaphore(FAR struct file_struct *stream) -{ - pid_t my_pid = getpid(); - - /* I better be holding at least one reference to the semaphore */ - - ASSERT(stream->fs_holder == my_pid); - - /* Do I hold multiple references to the semphore */ - - if (stream->fs_counts > 1) - { - /* Yes, just release one count and return */ - - stream->fs_counts--; - } - else - { - /* Nope, this is the last reference I have */ - - stream->fs_holder = -1; - stream->fs_counts = 0; - ASSERT(sem_post(&stream->fs_sem) == 0); - } -} -#endif /* CONFIG_STDIO_BUFFER_SIZE */ |