nuttx/sched/task/task_gettid.c
chao an c24dc389e4 sched/task: add kernel interface nxsched_* gettid/getpid/getppid
add new interface to implement getpid()/gettid()/getppid() for kernel version.

Signed-off-by: chao an <anchao@xiaomi.com>
2023-02-02 10:33:01 +08:00

111 lines
3.4 KiB
C

/****************************************************************************
* sched/task/task_gettid.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 <sys/types.h>
#include <unistd.h>
#include <sched.h>
#include <errno.h>
#include "sched/sched.h"
#include "task/task.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsched_gettid
*
* Description:
* Get the thread ID of the currently executing thread.
*
* Input parameters:
* None
*
* Returned Value:
* On success, returns the thread ID of the calling process.
*
****************************************************************************/
pid_t nxsched_gettid(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 are two
* exceptions to this:
*
* 1. Early in the start-up sequence, the ready-to-run list may be
* empty! In 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 0;
}
/****************************************************************************
* Name: gettid
*
* Description:
* Get the thread ID of the currently executing thread.
*
* Input parameters:
* None
*
* Returned Value:
* On success, returns the thread ID of the calling process.
*
****************************************************************************/
pid_t gettid(void)
{
return nxsched_gettid();
}