40cdc187bb
This commit repartitions the logic by moving some of the changes from mm_sem.c into task_getpid.c. The logic is equivalent for the case of mm_trysemaphore(), but no has wider impact since it potentially affects all callers of getpid(). Hence, this change may also introduce some other issues that will need to be addressed.
115 lines
4.2 KiB
C
115 lines
4.2 KiB
C
/****************************************************************************
|
|
* sched/task/task_getpid.c
|
|
*
|
|
* Copyright (C) 2007, 2009, 2014, 2018 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 <sys/types.h>
|
|
#include <unistd.h>
|
|
#include <sched.h>
|
|
|
|
#include "sched/sched.h"
|
|
#include "task/task.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: getpid
|
|
*
|
|
* Description:
|
|
* Get the task ID of the currently executing task.
|
|
*
|
|
* Input parameters:
|
|
* None
|
|
*
|
|
* Returned Value:
|
|
* Normally when called from user applications, getpid() will return the
|
|
* task ID of the currently executing task, that is, the task at the head
|
|
* of the ready-to-run list. There is no specification for any errors
|
|
* returned from getpid().
|
|
*
|
|
* getpid(), however, may be called from within the OS in some cases.
|
|
* There are certain situations during context switching when the OS data
|
|
* structures are in flux and where the current task at the head of the
|
|
* ready-to-run task list) is not actually running. In that case,
|
|
* getpid() will return the error: -ESRCH
|
|
*
|
|
****************************************************************************/
|
|
|
|
pid_t getpid(void)
|
|
{
|
|
FAR struct tcb_s *rtcb;
|
|
|
|
/* Get the TCB at the head of the ready-to-run task list. That
|
|
* will usually be the currently executing task. There is are two
|
|
* exceptions to this:
|
|
*
|
|
* 1. Early in the start-up sequence, the ready-to-run list may be
|
|
* empty! This case, of course, the CPU0 start-up/IDLE thread with
|
|
* pid == 0 must be running, and
|
|
* 2. As described above, during certain context-switching conditions the
|
|
* task at the head of the ready-to-run list may not actually be
|
|
* running.
|
|
*/
|
|
|
|
rtcb = this_task();
|
|
if (rtcb != NULL)
|
|
{
|
|
/* Check if the task is actually running */
|
|
|
|
if (rtcb->task_state == TSTATE_TASK_RUNNING)
|
|
{
|
|
/* Yes.. Return the task ID from the TCB at the head of the
|
|
* ready-to-run task list
|
|
*/
|
|
|
|
return rtcb->pid;
|
|
}
|
|
|
|
/* No.. return -ESRCH to indicate this condition */
|
|
|
|
return (pid_t)-ESRCH;
|
|
}
|
|
|
|
/* We must have been called earlier in the start up sequence from the
|
|
* start-up/IDLE thread before the ready-to-run list has been initialized.
|
|
*/
|
|
|
|
return (pid_t)0;
|
|
}
|