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Diffstat (limited to 'nuttx/sched/sig_received.c')
| -rw-r--r-- | nuttx/sched/sig_received.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/nuttx/sched/sig_received.c b/nuttx/sched/sig_received.c new file mode 100644 index 000000000..cf4d00165 --- /dev/null +++ b/nuttx/sched/sig_received.c @@ -0,0 +1,404 @@ +/************************************************************************ + * sched/sig_received.c + * + * Copyright (C) 2007, 2009, 2011 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 <string.h> +#include <signal.h> +#include <unistd.h> +#include <sched.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/arch.h> + +#include "os_internal.h" +#include "sem_internal.h" +#include "sig_internal.h" +#include "mq_internal.h" + +/************************************************************************ + * Definitions + ************************************************************************/ + +/************************************************************************ + * Private Type Declarations + ************************************************************************/ + +/************************************************************************ + * Global Variables + ************************************************************************/ + +/************************************************************************ + * Private Variables + ************************************************************************/ + +/************************************************************************ + * Private Functions + ************************************************************************/ + +/************************************************************************ + * Name: sig_queueaction + * + * Description: + * Queue a signal action for delivery to a task. + * + ************************************************************************/ + +static int sig_queueaction(FAR _TCB *stcb, siginfo_t *info) +{ + FAR sigactq_t *sigact; + FAR sigq_t *sigq; + irqstate_t saved_state; + int ret = OK; + + sched_lock(); + + /* Find the sigaction associated with this signal */ + + sigact = sig_findaction(stcb, info->si_signo); + + /* Check if a valid signal handler is available and if the signal is + * unblocked. NOTE: There is no default action. + */ + + if ((sigact) && (sigact->act.sa_u._sa_sigaction)) + { + /* Allocate a new element for the signal queue. NOTE: sig_allocatependingsigaction + * will force a system crash if it is unable to allocate memory for the + * signal data */ + + sigq = sig_allocatependingsigaction(); + if (!sigq) ret = ERROR; + else + { + /* Populate the new signal queue element */ + + sigq->action.sighandler = sigact->act.sa_u._sa_sigaction; + sigq->mask = sigact->act.sa_mask; + memcpy(&sigq->info, info, sizeof(siginfo_t)); + + /* Put it at the end of the pending signals list */ + + saved_state = irqsave(); + sq_addlast((FAR sq_entry_t*)sigq, &(stcb->sigpendactionq)); + irqrestore(saved_state); + } + } + + sched_unlock(); + return ret; +} + +/************************************************************************ + * Name: sig_findpendingsignal + * + * Description: + * Find a specified element in the pending signal list + * + ************************************************************************/ + +static FAR sigpendq_t *sig_findpendingsignal(FAR _TCB *stcb, int signo) +{ + FAR sigpendq_t *sigpend = NULL; + irqstate_t saved_state; + + /* Verify the caller's sanity */ + + if (stcb) + { + /* Pending sigals can be added from interrupt level. */ + + saved_state = irqsave(); + + /* Seach the list for a sigpendion on this signal */ + + for(sigpend = (FAR sigpendq_t*)stcb->sigpendingq.head; + (sigpend && sigpend->info.si_signo != signo); + sigpend = sigpend->flink); + irqrestore(saved_state); + } + + return sigpend; +} + +/************************************************************************ + * Name: sig_allocatependingsignal + * + * Description: + * Allocate a pending signal list entry + * + ************************************************************************/ + +static FAR sigpendq_t *sig_allocatependingsignal(void) +{ + FAR sigpendq_t *sigpend; + irqstate_t saved_state; + + /* Check if we were called from an interrupt handler. */ + + if (up_interrupt_context()) + { + /* Try to get the pending signal structure from the free list */ + + sigpend = (FAR sigpendq_t*)sq_remfirst(&g_sigpendingsignal); + if (!sigpend) + { + /* If no pending signal structure is available in the free list, + * then try the special list of structures reserved for + * interrupt handlers + */ + + sigpend = (FAR sigpendq_t*)sq_remfirst(&g_sigpendingirqsignal); + } + } + + /* If we were not called from an interrupt handler, then we are + * free to allocate pending action structures if necessary. */ + + else + { + /* Try to get the pending signal structure from the free list */ + + saved_state = irqsave(); + sigpend = (FAR sigpendq_t*)sq_remfirst(&g_sigpendingsignal); + irqrestore(saved_state); + + /* Check if we got one. */ + + if (!sigpend) + { + /* No... Allocate the pending signal */ + + if (!sigpend) + { + sigpend = (FAR sigpendq_t *)kmalloc((sizeof (sigpendq_t))); + } + + /* Check if we got an allocated message */ + + if (sigpend) + { + sigpend->type = SIG_ALLOC_DYN; + } + } + } + + return sigpend; +} + +/************************************************************************ + * Name: sig_addpendingsignal + * + * Description: + * Add the specified signal to the signal pending list. NOTE: This + * function will queue only one entry for each pending signal. This + * was done intentionally so that a run-away sender cannot consume + * all of memory. + * + ************************************************************************/ + +static FAR sigpendq_t *sig_addpendingsignal(FAR _TCB *stcb, + siginfo_t *info) +{ + FAR sigpendq_t *sigpend; + irqstate_t saved_state; + + /* Check if the signal is already pending */ + + sigpend = sig_findpendingsignal(stcb, info->si_signo); + if (sigpend) + { + /* The signal is already pending... retain only one copy */ + + memcpy(&sigpend->info, info, sizeof(siginfo_t)); + } + + /* No... There is nothing pending for this signo */ + + else + { + /* Allocate a new pending signal entry */ + + sigpend = sig_allocatependingsignal(); + if (sigpend) + { + /* Put the signal information into the allocated structure */ + + memcpy(&sigpend->info, info, sizeof(siginfo_t)); + + /* Add the structure to the pending signal list */ + + saved_state = irqsave(); + sq_addlast((FAR sq_entry_t*)sigpend, &stcb->sigpendingq); + irqrestore(saved_state); + } + } + + return sigpend; +} + +/************************************************************************ + * Public Functions + ************************************************************************/ + +/************************************************************************ + * Name: sig_received + * + * Description: + * All signals received the task (whatever the source) go through this + * function to be processed. This function is responsible for: + * + * - Determining if the signal is blocked. + * - Queuing and dispatching signal actions + * - Unblocking tasks that are waiting for signals + * - Queuing pending signals. + * + ************************************************************************/ + +int sig_received(FAR _TCB *stcb, siginfo_t *info) +{ + irqstate_t saved_state; + int ret = ERROR; + + sdbg("TCB=0x%08x signo=%d code=%d value=%d mask=%08x\n", + stcb, info->si_signo, info->si_code, + info->si_value.sival_int, stcb->sigprocmask); + + if (stcb && info) + { + ret = OK; + + /****************** MASKED SIGNAL HANDLING ******************/ + + /* Check if the signal is masked -- if it is, it will be added to the + * list of pending signals. + */ + + if (sigismember(&stcb->sigprocmask, info->si_signo)) + { + /* Check if the task is waiting for this pending signal. If so, + * then unblock it. This must be performed in a critical section + * because signals can be queued from the interrupt level. + */ + + saved_state = irqsave(); + if (stcb->task_state == TSTATE_WAIT_SIG && + sigismember(&stcb->sigwaitmask, info->si_signo)) + { + memcpy(&stcb->sigunbinfo, info, sizeof(siginfo_t)); + stcb->sigwaitmask = NULL_SIGNAL_SET; + up_unblock_task(stcb); + irqrestore(saved_state); + } + + /* Its not one we are waiting for... Add it to the list of pending + * signals. + */ + + else + { + irqrestore(saved_state); + if (!sig_addpendingsignal(stcb, info)) + { + PANIC(OSERR_FAILEDTOADDSIGNAL); + } + } + } + + /****************** UNMASKED SIGNAL HANDLING ******************/ + + else + { + /* Queue any sigaction's requested by this task. */ + + ret = sig_queueaction(stcb, info); + + /* Then schedule execution of the signal handling action on + * the recipients thread. + */ + + up_schedule_sigaction(stcb, sig_deliver); + + /* Check if the task is waiting for an unmasked signal. If so, + * then unblock it. This must be performed in a critical section + * because signals can be queued from the interrupt level. + */ + + saved_state = irqsave(); + if (stcb->task_state == TSTATE_WAIT_SIG) + { + memcpy(&stcb->sigunbinfo, info, sizeof(siginfo_t)); + stcb->sigwaitmask = NULL_SIGNAL_SET; + up_unblock_task(stcb); + } + irqrestore(saved_state); + + /* If the task neither was waiting for the signal nor had a signal + * handler attached to the signal, then the default action is + * simply to ignore the signal + */ + + /****************** OTHER SIGNAL HANDLING ******************/ + + /* If the task is blocked waiting for a semaphore, then that + * task must be unblocked when a signal is received. + */ + + if (stcb->task_state == TSTATE_WAIT_SEM) + { + sem_waitirq(stcb, EINTR); + } + + /* If the task is blocked waiting on a message queue, then that + * task must be unblocked when a signal is received. + */ + +#ifndef CONFIG_DISABLE_MQUEUE + if (stcb->task_state == TSTATE_WAIT_MQNOTEMPTY || + stcb->task_state == TSTATE_WAIT_MQNOTFULL) + { + mq_waitirq(stcb, EINTR); + } +#endif + } + } + + return ret; +} |