nuttx/libs/libc/pthread/pthread_cleanup.c

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/****************************************************************************
* libs/libc/pthread/pthread_cleanup.c
*
* 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 <pthread.h>
#include <sched.h>
#include <assert.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include <nuttx/tls.h>
#include <nuttx/pthread.h>
#ifdef CONFIG_PTHREAD_CLEANUP
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_cleanup_pop_tls
*
* Description:
* The pthread_cleanup_pop_tcb() function will remove the routine at the
* top of the calling thread's cancellation cleanup stack and optionally
* invoke it (if 'execute' is non-zero).
*
* Input Parameters:
* tcb - The TCB of the pthread that is exiting or being canceled.
*
* Returned Value:
* None
*
* Assumptions:
* The scheduler is locked.
*
****************************************************************************/
static void pthread_cleanup_pop_tls(FAR struct tls_info_s *tls, int execute)
{
if (tls->tos > 0)
{
unsigned int ndx;
/* Get the index to the last cleaner function pushed onto the stack */
ndx = tls->tos - 1;
DEBUGASSERT(ndx >= 0 && ndx < CONFIG_PTHREAD_CLEANUP_STACKSIZE);
/* Should we execute the cleanup routine at the top of the stack? */
if (execute != 0)
{
FAR struct pthread_cleanup_s *cb;
/* Yes.. Execute the clean-up routine.
*
* REVISIT: This is a security problem In the PROTECTED and KERNEL
* builds: We must not call the registered function in supervisor
* mode! See also on_exit() and atexit() callbacks.
*/
cb = &tls->stack[ndx];
cb->pc_cleaner(cb->pc_arg);
}
tls->tos = ndx;
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_cleanup_push
* pthread_cleanup_pop
*
* Description:
* The pthread_cleanup_pop() function will remove the routine at the top
* of the calling thread's cancellation cleanup stack and optionally
* invoke it (if 'execute' is non-zero).
*
* The pthread_cleanup_push() function will push the specified cancellation
* cleanup handler routine onto the calling thread's cancellation cleanup
* stack. The cancellation cleanup handler will be popped from the
* cancellation cleanup stack and invoked with the argument arg when:
*
* - The thread exits (that is, calls pthread_exit()).
* - The thread acts upon a cancellation request.
* - The thread calls pthread_cleanup_pop() with non-zero execute argument.
*
* Input Parameters:
* routine - The cleanup routine to be pushed on the cleanup stack.
* arg - An argument that will accompany the callback.
* execute - Execute the popped cleanup function immediately.
*
* Returned Value:
* None
*
****************************************************************************/
void pthread_cleanup_pop(int execute)
{
FAR struct tls_info_s *tls = up_tls_info();
DEBUGASSERT(tls != NULL);
/* sched_lock() should provide sufficient protection. We only need to
* have this TCB stationary; the pthread cleanup stack should never be
* modified by interrupt level logic.
*/
sched_lock();
pthread_cleanup_pop_tls(tls, execute);
sched_unlock();
}
void pthread_cleanup_push(pthread_cleanup_t routine, FAR void *arg)
{
FAR struct tls_info_s *tls = up_tls_info();
DEBUGASSERT(tls != NULL);
DEBUGASSERT(tls->tos < CONFIG_PTHREAD_CLEANUP_STACKSIZE);
/* sched_lock() should provide sufficient protection. We only need to
* have this TCB stationary; the pthread cleanup stack should never be
* modified by interrupt level logic.
*/
sched_lock();
if (tls->tos < CONFIG_PTHREAD_CLEANUP_STACKSIZE)
{
unsigned int ndx = tls->tos;
tls->tos++;
tls->stack[ndx].pc_cleaner = routine;
tls->stack[ndx].pc_arg = arg;
}
sched_unlock();
}
/****************************************************************************
* Name: pthread_cleanup_popall
*
* Description:
* The pthread_cleanup_popall() is an internal function that will pop and
* execute all clean-up functions. This function is only called from
* within the pthread_exit() and pthread_cancellation() logic
*
* Input Parameters:
* tls - The local storage info of the exiting thread
*
* Returned Value:
* None
*
****************************************************************************/
void pthread_cleanup_popall(FAR struct tls_info_s *tls)
{
DEBUGASSERT(tls != NULL);
sched_lock();
while (tls->tos > 0)
{
pthread_cleanup_pop_tls(tls, 1);
}
sched_unlock();
}
#endif /* CONFIG_PTHREAD_CLEANUP */