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Diffstat (limited to 'nuttx/sched/pthread_cancel.c')
-rw-r--r-- | nuttx/sched/pthread_cancel.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/nuttx/sched/pthread_cancel.c b/nuttx/sched/pthread_cancel.c new file mode 100644 index 000000000..5e34eeaba --- /dev/null +++ b/nuttx/sched/pthread_cancel.c @@ -0,0 +1,148 @@ +/************************************************************************** + * sched/pthread_cancel.c + * + * Copyright (C) 2007, 2009 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 <nuttx/config.h> + +#include <sys/types.h> +#include <unistd.h> +#include <pthread.h> +#include <errno.h> + +#include "os_internal.h" +#include "pthread_internal.h" + +/************************************************************************** + * Private Definitions + **************************************************************************/ + +/************************************************************************** + * Private Types + **************************************************************************/ + +/************************************************************************** + * Private Function Prototypes + **************************************************************************/ + +/************************************************************************** + * Global Variables + **************************************************************************/ + +/************************************************************************** + * Private Variables + **************************************************************************/ + +/************************************************************************** + * Private Functions + **************************************************************************/ + +/************************************************************************** + * Public Functions + **************************************************************************/ + +int pthread_cancel(pthread_t thread) +{ + _TCB *tcb; + + /* First, make sure that the handle references a valid thread */ + + if (!thread) + { + /* pid == 0 is the IDLE task. Callers cannot cancel the + * IDLE task. + */ + + return ESRCH; + } + + tcb = sched_gettcb((pid_t)thread); + if (!tcb) + { + /* The pid does not correspond to any known thread */ + + return ESRCH; + } + + /* Check to see if this thread has the non-cancelable bit set in its + * flags. Suppress context changes for a bit so that the flags are stable. + * (the flags should not change in interrupt handling. + */ + + sched_lock(); + if ((tcb->flags & TCB_FLAG_NONCANCELABLE) != 0) + { + /* Then we cannot cancel the thread now. Here is how this is + * supposed to work: + * + * "When cancelability is disabled, all cancels are held pending + * in the target thread until the thread changes the cancelability. + * When cancelability is deferred, all cancels are held pending in + * the target thread until the thread changes the cancelability, calls + * a function which is a cancellation point or calls pthread_testcancel(), + * thus creating a cancellation point. When cancelability is asynchronous, + * all cancels are acted upon immediately, interrupting the thread with its + * processing." + */ + + tcb->flags |= TCB_FLAG_CANCEL_PENDING; + sched_unlock(); + return OK; + } + + sched_unlock(); + + /* Check to see if the ID refers to ourselves.. this would be the + * same as pthread_exit(PTHREAD_CANCELED). + */ + + if (tcb == (_TCB*)g_readytorun.head) + { + pthread_exit(PTHREAD_CANCELED); + } + + /* Complete pending join operations */ + + (void)pthread_completejoin((pid_t)thread, PTHREAD_CANCELED); + + /* Then let pthread_delete do the real work */ + + task_delete((pid_t)thread); + return OK; +} + + |