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author | Gregory Nutt <gnutt@nuttx.org> | 2014-12-13 12:02:25 -0600 |
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committer | Gregory Nutt <gnutt@nuttx.org> | 2014-12-13 12:02:25 -0600 |
commit | 5e6140dbe524432a75a99e4c16f52ef04f0211dc (patch) | |
tree | 5622e2bd02486707d2b6a81d2ebf6a9a942be817 | |
parent | 9dddaadfe4bd8417ec8b2648f7e4c4892b754f76 (diff) | |
download | nuttx-5e6140dbe524432a75a99e4c16f52ef04f0211dc.tar.gz nuttx-5e6140dbe524432a75a99e4c16f52ef04f0211dc.tar.bz2 nuttx-5e6140dbe524432a75a99e4c16f52ef04f0211dc.zip |
Sempahores: Add logic to clean up after task_delete() or pthread_cancel() if the task happens to be waiting on a semaphore when it is cancelled
-rw-r--r-- | nuttx/sched/semaphore/Make.defs | 2 | ||||
-rw-r--r-- | nuttx/sched/semaphore/sem_recover.c | 148 | ||||
-rw-r--r-- | nuttx/sched/semaphore/semaphore.h | 4 | ||||
-rw-r--r-- | nuttx/sched/task/task_recover.c | 33 | ||||
-rw-r--r-- | nuttx/sched/wdog/Make.defs | 2 | ||||
-rw-r--r-- | nuttx/sched/wdog/wd_recover.c | 115 | ||||
-rw-r--r-- | nuttx/sched/wdog/wdog.h | 22 |
7 files changed, 304 insertions, 22 deletions
diff --git a/nuttx/sched/semaphore/Make.defs b/nuttx/sched/semaphore/Make.defs index 97f7660ec..5349d58b4 100644 --- a/nuttx/sched/semaphore/Make.defs +++ b/nuttx/sched/semaphore/Make.defs @@ -34,7 +34,7 @@ ############################################################################ CSRCS += sem_destroy.c sem_wait.c sem_trywait.c sem_timedwait.c -CSRCS += sem_post.c +CSRCS += sem_post.c sem_recover.c ifneq ($(CONFIG_DISABLE_SIGNALS),y) CSRCS += sem_waitirq.c diff --git a/nuttx/sched/semaphore/sem_recover.c b/nuttx/sched/semaphore/sem_recover.c new file mode 100644 index 000000000..fd40e6b7d --- /dev/null +++ b/nuttx/sched/semaphore/sem_recover.c @@ -0,0 +1,148 @@ +/**************************************************************************** + * sched/semaphore/sem_recover.c + * + * Copyright (C) 2014 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 <nuttx/arch.h> +#include <nuttx/sched.h> + +#include "semaphore/semaphore.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: sem_recover + * + * Description: + * This function is called from task_recover() when a task is deleted via + * task_delete() or via pthread_cancel(). It current only checks on the + * case where a task is waiting for semaphore at the time that is was + * killed. + * + * REVISIT: A more complete implementation would release counts on all + * semaphores held by the thread. That would, however, require some + * significant extension to the semaphore data structures because given + * only the task, there is not mechanism to traverse all of the semaphores + * with counts held by the task. + * + * Inputs: + * tcb - The TCB of the terminated task or thread + * + * Return Value: + * None. + * + * Assumptions: + * This function is called from task deletion logic in a safe context. + * + ****************************************************************************/ + +void sem_recover(FAR struct tcb_s *tcb) +{ + irqstate_t flags; + + /* The task is being deleted. If it is waiting for a semphore, then + * increment the count on the semaphores. This logic is almost identical + * to what you see in sem_waitirq() except that no attempt is made to + * restart the exiting task. + * + * NOTE: In the case that the task is waiting we can assume: (1) That the + * task state is TSTATE_WAIT_SEM and (2) that the 'waitsem' in the TCB is + * non-null. If we get here via pthread_cancel() or via task_delete(), + * then the task state should be preserved; it will be altered in other + * cases but in those cases waitsem should be NULL anyway (but we do not + * enforce that here). + */ + + flags = irqsave(); + if (tcb->task_state == TSTATE_WAIT_SEM) + { + sem_t *sem = tcb->waitsem; + DEBUGASSERT(sem != NULL && sem->semcount < 0); + + /* Restore the correct priority of all threads that hold references + * to this semaphore. + */ + + sem_canceled(tcb, sem); + + /* And increment the count on the semaphore. This releases the count + * that was taken by sem_post(). This count decremented the semaphore + * count to negative and caused the thread to be blocked in the first + * place. + */ + + sem->semcount++; + + /* Clear the semaphore to assure that it is not reused. But leave the + * state as TSTATE_WAIT_SEM. This is necessary because this is a + * necessary indication that the TCB still resides in the waiting-for- + * semaphore list. + */ + + tcb->waitsem = NULL; + } + + irqrestore(flags); +} diff --git a/nuttx/sched/semaphore/semaphore.h b/nuttx/sched/semaphore/semaphore.h index d8ed3ecd7..55e83abbf 100644 --- a/nuttx/sched/semaphore/semaphore.h +++ b/nuttx/sched/semaphore/semaphore.h @@ -85,6 +85,10 @@ void sem_initialize(void); void sem_waitirq(FAR struct tcb_s *wtcb, int errcode); #endif +/* Recover semaphore resources with a task or thread is destroyed */ + +void sem_recover(FAR struct tcb_s *tcb); + /* Special logic needed only by priority inheritance to manage collections of * holders of semaphores. */ diff --git a/nuttx/sched/task/task_recover.c b/nuttx/sched/task/task_recover.c index 797a75605..f1ed0608e 100644 --- a/nuttx/sched/task/task_recover.c +++ b/nuttx/sched/task/task_recover.c @@ -43,11 +43,13 @@ #include <nuttx/wdog.h> #include <nuttx/sched.h> +#include "semaphore/semaphore.h" +#include "wdog/wdog.h" #include "mqueue/mqueue.h" #include "task/task.h" /**************************************************************************** - * Definitions + * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** @@ -78,9 +80,9 @@ * Name: task_recover * * Description: - * This function is called when a task is deleted via task_deleted or - * via pthread_cancel. I checks if the task was waiting for a message - * queue event and adjusts counts appropriately. + * This function is called when a task is deleted via task_delete() or + * via pthread_cancel. I checks checks for semaphores, message queue, and + * watchdog timer resources stranded in bad conditions. * * Inputs: * tcb - The TCB of the terminated task or thread @@ -95,28 +97,19 @@ void task_recover(FAR struct tcb_s *tcb) { - irqstate_t flags; + /* The task is being deleted. Cancel in pending timeout events. */ - /* The task is being deleted. If it is waiting for any timed event, then - * tcb->waitdog will be non-NULL. Cancel the watchdog now so that no - * events occur after the watchdog expires. Obviously there are lots of - * race conditions here so this will most certainly have to be revisited in - * the future. - */ + wd_recover(tcb); - flags = irqsave(); - if (tcb->waitdog) - { - (void)wd_cancel(tcb->waitdog); - (void)wd_delete(tcb->waitdog); - tcb->waitdog = NULL; - } + /* If the thread holds semaphore counts or is waiting for a semaphore count, + * then release the counts. + */ - irqrestore(flags); + sem_recover(tcb); +#ifndef CONFIG_DISABLE_MQUEUE /* Handle cases where the thread was waiting for a message queue event */ -#ifndef CONFIG_DISABLE_MQUEUE mq_recover(tcb); #endif } diff --git a/nuttx/sched/wdog/Make.defs b/nuttx/sched/wdog/Make.defs index 77fcb7389..c5107bd43 100644 --- a/nuttx/sched/wdog/Make.defs +++ b/nuttx/sched/wdog/Make.defs @@ -34,7 +34,7 @@ ############################################################################ CSRCS += wd_initialize.c wd_create.c wd_start.c wd_cancel.c wd_delete.c -CSRCS += wd_gettime.c +CSRCS += wd_gettime.c wd_recover.c # Include wdog build support diff --git a/nuttx/sched/wdog/wd_recover.c b/nuttx/sched/wdog/wd_recover.c new file mode 100644 index 000000000..bc1b3a839 --- /dev/null +++ b/nuttx/sched/wdog/wd_recover.c @@ -0,0 +1,115 @@ +/**************************************************************************** + * sched/wdog/wdog_recover.c + * + * Copyright (C) 2014 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 <nuttx/arch.h> +#include <nuttx/wdog.h> +#include <nuttx/sched.h> + +#include "wdog/wdog.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: wd_recover + * + * Description: + * This function is called from task_recover() when a task is deleted via + * task_delete() or via pthread_cancel(). It checks if the deleted task + * is waiting for a timed event and if so cancels the timeout + * + * Inputs: + * tcb - The TCB of the terminated task or thread + * + * Return Value: + * None. + * + * Assumptions: + * This function is called from task deletion logic in a safe context. + * + ****************************************************************************/ + +void wd_recover(FAR struct tcb_s *tcb) +{ + irqstate_t flags; + + /* The task is being deleted. If it is waiting for any timed event, then + * tcb->waitdog will be non-NULL. Cancel the watchdog now so that no + * events occur after the watchdog expires. Obviously there are lots of + * race conditions here so this will most certainly have to be revisited in + * the future. + */ + + flags = irqsave(); + if (tcb->waitdog) + { + (void)wd_cancel(tcb->waitdog); + (void)wd_delete(tcb->waitdog); + tcb->waitdog = NULL; + } + + irqrestore(flags); +} diff --git a/nuttx/sched/wdog/wdog.h b/nuttx/sched/wdog/wdog.h index 6ee640867..f26b90f91 100644 --- a/nuttx/sched/wdog/wdog.h +++ b/nuttx/sched/wdog/wdog.h @@ -144,6 +144,28 @@ unsigned int wd_timer(int ticks); void wd_timer(void); #endif +/**************************************************************************** + * Name: wd_recover + * + * Description: + * This function is called from task_recover() when a task is deleted via + * task_delete() or via pthread_cancel(). It checks if the deleted task + * is waiting for a timed event and if so cancels the timeout + * + * Inputs: + * tcb - The TCB of the terminated task or thread + * + * Return Value: + * None. + * + * Assumptions: + * This function is called from task deletion logic in a safe context. + * + ****************************************************************************/ + +struct tcb_s; +void wd_recover(FAR struct tcb_s *tcb); + #undef EXTERN #ifdef __cplusplus } |