mirror of
https://github.com/apache/nuttx.git
synced 2026-08-16 01:43:15 +00:00
40c6af6dec
This reverts commit 300992203a to
fix a problem with `esp32-devkitc:blewifi`, which fails to boot up
if `CONFIG_DEBUG_ASSERTIONS=y`.
Introduced by https://github.com/apache/nuttx/pull/16176 with the
following description:
> The DEBUGASSERTS in nxsem_wait and nxsem_trywait are
non-functional, they don't check anything. These were broken in
previous commits.
The above statements are not valid. Originally, there was no
problem calling `nxsem_trywait` from the interrupt and the
`DEBUGASSERT` simply checked a corner case: if ran from the
interrupt context, the current (interrupted) task may be the idle
task. This case is allowed only if called from an interrupt and
that's what the original commit checks with:
```
DEBUGASSERT(!OSINIT_IDLELOOP() || !sched_idletask() ||
up_interrupt_context());
```
139 lines
4.2 KiB
C
139 lines
4.2 KiB
C
/****************************************************************************
|
|
* libs/libc/semaphore/sem_trywait.c
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <errno.h>
|
|
#include <assert.h>
|
|
#include <sched.h>
|
|
|
|
#include <nuttx/init.h>
|
|
#include <nuttx/semaphore.h>
|
|
#include <nuttx/atomic.h>
|
|
#include <nuttx/irq.h>
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: sem_trywait
|
|
*
|
|
* Description:
|
|
* This function locks the specified semaphore only if the semaphore is
|
|
* currently not locked. In either case, the call returns without
|
|
* blocking.
|
|
*
|
|
* Input Parameters:
|
|
* sem - the semaphore descriptor
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success or -1 (ERROR) if unsuccessful. If this function
|
|
* returns -1(ERROR), then the cause of the failure will be reported in
|
|
* errno variable as:
|
|
*
|
|
* EINVAL - Invalid attempt to get the semaphore
|
|
* EAGAIN - The semaphore is not available.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int sem_trywait(FAR sem_t *sem)
|
|
{
|
|
int ret;
|
|
|
|
if (sem == NULL)
|
|
{
|
|
set_errno(EINVAL);
|
|
return ERROR;
|
|
}
|
|
|
|
/* Let nxsem_trywait do the real work */
|
|
|
|
ret = nxsem_trywait(sem);
|
|
if (ret < 0)
|
|
{
|
|
set_errno(-ret);
|
|
ret = ERROR;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: nxsem_trywait
|
|
*
|
|
* Description:
|
|
* This function locks the specified semaphore only if the semaphore is
|
|
* currently not locked. In either case, the call returns without
|
|
* blocking.
|
|
*
|
|
* Input Parameters:
|
|
* sem - the semaphore descriptor
|
|
*
|
|
* Returned Value:
|
|
* This is an internal OS interface and should not be used by applications.
|
|
* It follows the NuttX internal error return policy: Zero (OK) is
|
|
* returned on success. A negated errno value is returned on failure.
|
|
* Possible returned errors:
|
|
*
|
|
* - EINVAL - Invalid attempt to get the semaphore
|
|
* - EAGAIN - The semaphore is not available.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int nxsem_trywait(FAR sem_t *sem)
|
|
{
|
|
DEBUGASSERT(sem != NULL);
|
|
|
|
/* This API should not be called from the idleloop or interrupt */
|
|
|
|
#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
|
|
DEBUGASSERT(!OSINIT_IDLELOOP() || !sched_idletask() ||
|
|
up_interrupt_context());
|
|
#endif
|
|
|
|
/* We don't do atomic fast path in case of LIBC_ARCH_ATOMIC because that
|
|
* uses spinlocks, which can't be called from userspace. Also in the kernel
|
|
* taking the slow path directly is faster than locking first in here
|
|
*/
|
|
|
|
#ifndef CONFIG_LIBC_ARCH_ATOMIC
|
|
|
|
if ((sem->flags & SEM_TYPE_MUTEX)
|
|
#if defined(CONFIG_PRIORITY_PROTECT) || defined(CONFIG_PRIORITY_INHERITANCE)
|
|
&& (sem->flags & SEM_PRIO_MASK) == SEM_PRIO_NONE
|
|
#endif
|
|
)
|
|
{
|
|
int32_t old = 1;
|
|
return atomic_try_cmpxchg_acquire(NXSEM_COUNT(sem), &old, 0) ?
|
|
OK : -EAGAIN;
|
|
}
|
|
|
|
#endif
|
|
|
|
return nxsem_trywait_slow(sem);
|
|
}
|