nuttx/sched/task/task_delete.c
Alin Jerpelea eb9030c891 sched: migrate to SPDX identifier
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2024-09-12 01:10:14 +08:00

181 lines
5.6 KiB
C

/****************************************************************************
* sched/task/task_delete.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 <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/sched.h>
#include "sched/sched.h"
#include "task/task.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxtask_delete
*
* Description:
* This function causes a specified task to cease to exist. Its stack and
* TCB will be deallocated.
*
* The logic in this function only deletes non-running tasks. If the
* 'pid' parameter refers to the currently running task, then processing
* is redirected to exit(). This can only happen if a task calls
* nxtask_delete() in order to delete itself.
*
* This function obeys the semantics of pthread cancellation: task
* deletion is deferred if cancellation is disabled or if deferred
* cancellation is supported (with cancellation points enabled).
*
* Input Parameters:
* pid - The task ID of the task to delete. A pid of zero
* signifies the calling task.
*
* Returned Value:
* OK on success; or negated errno on failure
*
****************************************************************************/
int nxtask_delete(pid_t pid)
{
FAR struct tcb_s *dtcb;
FAR struct tcb_s *rtcb;
/* Check if the task to delete is the calling task: PID=0 means to delete
* the calling task. In this case, task_delete() is much like exit()
* except that it obeys the cancellation semantics.
*/
rtcb = this_task();
if (pid == 0)
{
pid = rtcb->pid;
}
/* Get the TCB of the task to be deleted */
dtcb = nxsched_get_tcb(pid);
if (dtcb == NULL)
{
/* The pid does not correspond to any known thread. The task
* has probably already exited.
*/
return -ESRCH;
}
/* Only tasks and kernel threads can be deleted with this interface
* (The semantics of the call should be sufficient to prohibit this).
*/
DEBUGASSERT((dtcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_PTHREAD);
/* Non-privileged tasks and pthreads may not delete privileged kernel
* threads.
*
* REVISIT: We will need to look at this again in the future if/when
* permissions are supported and a user task might also be privileged.
*/
if (((rtcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL) &&
((dtcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL))
{
return -EACCES;
}
/* Check if the task to delete is the calling task */
if (pid == rtcb->pid)
{
/* If it is, then what we really wanted to do was exit. Note that we
* don't bother to unlock the TCB since it will be going away.
*/
_exit(EXIT_SUCCESS);
}
/* Notify the target if the non-cancelable or deferred cancellation set */
if (nxnotify_cancellation(dtcb))
{
return OK;
}
/* Otherwise, perform the asynchronous cancellation, letting
* nxtask_terminate() do all of the heavy lifting.
*/
return nxtask_terminate(pid);
}
/****************************************************************************
* Name: task_delete
*
* Description:
* This function causes a specified task to cease to exist. Its stack and
* TCB will be deallocated. This function is the companion to
* task_create(). This is the version of the function exposed to the
* user; it is simply a wrapper around the internal, nxtask_terminate
* function.
*
* The logic in this function only deletes non-running tasks. If the
* 'pid' parameter refers to the currently running task, then processing
* is redirected to exit(). This can only happen if a task calls
* task_delete()in order to delete itself.
*
* This function obeys the semantics of pthread cancellation: task
* deletion is deferred if cancellation is disabled or if deferred
* cancellation is supported (with cancellation points enabled).
*
* Input Parameters:
* pid - The task ID of the task to delete. A pid of zero
* signifies the calling task.
*
* Returned Value:
* OK on success; or ERROR on failure with the errno variable set
* appropriately.
*
****************************************************************************/
#ifndef CONFIG_BUILD_KERNEL
int task_delete(pid_t pid)
{
int ret = nxtask_delete(pid);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}
#endif