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148 lines
5.1 KiB
148 lines
5.1 KiB
/************************************************************************** |
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* sched/pthread_cancel.c |
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* |
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* Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved. |
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* Author: Gregory Nutt <gnutt@nuttx.org> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* 3. Neither the name NuttX nor the names of its contributors may be |
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* used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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**************************************************************************/ |
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/************************************************************************** |
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* Included Files |
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**************************************************************************/ |
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#include <nuttx/config.h> |
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#include <sys/types.h> |
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#include <unistd.h> |
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#include <pthread.h> |
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#include <errno.h> |
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#include "os_internal.h" |
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#include "pthread_internal.h" |
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/************************************************************************** |
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* Private Definitions |
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**************************************************************************/ |
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/************************************************************************** |
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* Private Types |
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**************************************************************************/ |
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/************************************************************************** |
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* Private Function Prototypes |
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**************************************************************************/ |
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/************************************************************************** |
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* Global Variables |
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**************************************************************************/ |
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/************************************************************************** |
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* Private Variables |
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**************************************************************************/ |
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/************************************************************************** |
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* Private Functions |
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**************************************************************************/ |
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/************************************************************************** |
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* Public Functions |
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**************************************************************************/ |
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int pthread_cancel(pthread_t thread) |
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{ |
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_TCB *tcb; |
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/* First, make sure that the handle references a valid thread */ |
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if (!thread) |
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{ |
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/* pid == 0 is the IDLE task. Callers cannot cancel the |
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* IDLE task. |
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*/ |
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return ESRCH; |
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} |
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tcb = sched_gettcb((pid_t)thread); |
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if (!tcb) |
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{ |
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/* The pid does not correspond to any known thread */ |
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return ESRCH; |
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} |
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/* Check to see if this thread has the non-cancelable bit set in its |
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* flags. Suppress context changes for a bit so that the flags are stable. |
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* (the flags should not change in interrupt handling. |
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*/ |
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sched_lock(); |
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if ((tcb->flags & TCB_FLAG_NONCANCELABLE) != 0) |
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{ |
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/* Then we cannot cancel the thread now. Here is how this is |
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* supposed to work: |
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* |
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* "When cancelability is disabled, all cancels are held pending |
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* in the target thread until the thread changes the cancelability. |
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* When cancelability is deferred, all cancels are held pending in |
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* the target thread until the thread changes the cancelability, calls |
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* a function which is a cancellation point or calls pthread_testcancel(), |
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* thus creating a cancellation point. When cancelability is asynchronous, |
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* all cancels are acted upon immediately, interrupting the thread with its |
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* processing." |
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*/ |
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tcb->flags |= TCB_FLAG_CANCEL_PENDING; |
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sched_unlock(); |
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return OK; |
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} |
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sched_unlock(); |
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/* Check to see if the ID refers to ourselves.. this would be the |
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* same as pthread_exit(PTHREAD_CANCELED). |
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*/ |
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if (tcb == (_TCB*)g_readytorun.head) |
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{ |
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pthread_exit(PTHREAD_CANCELED); |
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} |
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/* Complete pending join operations */ |
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(void)pthread_completejoin((pid_t)thread, PTHREAD_CANCELED); |
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/* Then let pthread_delete do the real work */ |
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task_delete((pid_t)thread); |
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return OK; |
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} |
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