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Diffstat (limited to 'nuttx/net/netdev_sem.c')
| -rw-r--r-- | nuttx/net/netdev_sem.c | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/nuttx/net/netdev_sem.c b/nuttx/net/netdev_sem.c deleted file mode 100644 index ba6299c62..000000000 --- a/nuttx/net/netdev_sem.c +++ /dev/null @@ -1,178 +0,0 @@ -/**************************************************************************** - * net/netdev_sem.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> - -#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 - -#include <sys/types.h> - -#include <unistd.h> -#include <semaphore.h> -#include <assert.h> -#include <errno.h> - -#include "net_internal.h" - -/**************************************************************************** - * Definitions - ****************************************************************************/ - -#define NO_HOLDER (pid_t)-1 - -/**************************************************************************** - * Priviate Types - ****************************************************************************/ - -/* There is at least on context in which recursive semaphores are required: - * When netdev_foreach is used with a telnet client, we will deadlock if we - * do not provide this capability. - */ - -struct netdev_sem_s -{ - sem_t sem; - pid_t holder; - unsigned int count; -}; - -/**************************************************************************** - * Private Data - ****************************************************************************/ - -/**************************************************************************** - * Public Data - ****************************************************************************/ - -static struct netdev_sem_s g_devlock; - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/**************************************************************************** - * Global Functions - ****************************************************************************/ - -/**************************************************************************** - * Function: netdev_seminit - * - * Description: - * Initialize the network device semaphore. - * - ****************************************************************************/ - -void netdev_seminit(void) -{ - sem_init(&g_devlock.sem, 0, 1); - g_devlock.holder = NO_HOLDER; - g_devlock.count = 0; -} - -/**************************************************************************** - * Function: netdev_semtake - * - * Description: - * Get exclusive access to the network device list. - * - ****************************************************************************/ - -void netdev_semtake(void) -{ - pid_t me = getpid(); - - /* Does this thread already hold the semaphore? */ - - if (g_devlock.holder == me) - { - /* Yes.. just increment the reference count */ - - g_devlock.count++; - } - else - { - /* No.. take the semaphore (perhaps waiting) */ - - while (uip_lockedwait(&g_devlock.sem) != 0) - { - /* The only case that an error should occur here is if - * the wait was awakened by a signal. - */ - - ASSERT(errno == EINTR); - } - - /* Now this thread holds the semaphore */ - - g_devlock.holder = me; - g_devlock.count = 1; - } -} - -/**************************************************************************** - * Function: netdev_semtake - * - * Description: - * Release exclusive access to the network device list - * - ****************************************************************************/ - -void netdev_semgive(void) -{ - DEBUGASSERT(g_devlock.holder == getpid() && g_devlock.count > 0); - - /* If the count would go to zero, then release the semaphore */ - - if (g_devlock.count == 1) - { - /* We no longer hold the semaphore */ - - g_devlock.holder = NO_HOLDER; - g_devlock.count = 0; - sem_post(&g_devlock.sem); - } - else - { - /* We still hold the semaphore. Just decrement the count */ - - g_devlock.count--; - } -} - -#endif /* CONFIG_NET && CONFIG_NSOCKET_DESCRIPTORS */ |