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Diffstat (limited to 'nuttx/sched/sig_deliver.c')
| -rw-r--r-- | nuttx/sched/sig_deliver.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/nuttx/sched/sig_deliver.c b/nuttx/sched/sig_deliver.c new file mode 100644 index 0000000000..dfbbc1092d --- /dev/null +++ b/nuttx/sched/sig_deliver.c @@ -0,0 +1,164 @@ +/************************************************************ + * sig_deliver.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 Gregory Nutt 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 <sys/types.h> +#include <signal.h> +#include <unistd.h> +#include <sched.h> +#include <debug.h> +#include <nuttx/arch.h> +#include "os_internal.h" +#include "sem_internal.h" +#include "sig_internal.h" + +/************************************************************ + * Definitions + ************************************************************/ + +/************************************************************ + * Private Type Declarations + ************************************************************/ + +/************************************************************ + * Global Variables + ************************************************************/ + +/************************************************************ + * Private Variables + ************************************************************/ + +/************************************************************ + * Private Functions + ************************************************************/ + +/************************************************************ + * Public Functions + ************************************************************/ + +/************************************************************ + * Function: sig_deliver + * + * Description: + * This function is called on the thread of execution of + * the signal receiving task. It processes all queued + * signals then returns. + * + ************************************************************/ + +void sig_deliver(_TCB *stcb) +{ + pid_t rpid; + sigq_t *sigq; + sigq_t *next; + sigset_t savesigprocmask; + uint32 saved_state; + int saved_errno; + + sched_lock(); + + /* Save the thread errno. When we finished dispatching the + * signal actions and resume the task, the errno value must + * be unchanged by the operation of the signal handling. In + * particular, the EINTR indication that says that the task + * was reawakened by a signal must be retained. + */ + + saved_errno = stcb->errno; + for (sigq = (sigq_t*)stcb->sigpendactionq.head; (sigq); sigq = next) + { + next = sigq->flink; + dbg("sig_deliver: Sending signal sigq=0x%x\n", sigq); + + /* Remove the signal structure from the sigpendactionq and place it + * in the sigpostedq. NOTE: Since signals are processed one at a + * time, there should never be more than one signal in the sigpostedq + */ + + saved_state = irqsave(); + sq_rem((sq_entry_t*)sigq, &(stcb->sigpendactionq)); + sq_addlast((sq_entry_t*)sigq, &(stcb->sigpostedq)); + irqrestore(saved_state); + + /* Call the signal handler (unless the signal was cancelled) + * + * Save a copy of the old sigprocmask and install the new + * (temporary) sigprocmask. The new sigprocmask is the union + * of the current sigprocmask and the sa_mask for the signal being + * delivered plus the signal being delivered. + */ + + savesigprocmask = stcb->sigprocmask; + stcb->sigprocmask = savesigprocmask | sigq->mask | SIGNO2SET(sigq->info.si_signo); + + /* The current tasks process.ID. We'll need this later to see if + * the signal handler caused a context switch. + */ + + rpid = getpid(); + + /* Deliver the signal using its address environment */ + + (*sigq->action.sighandler)(sigq->info.si_signo, &sigq->info, NULL); + + /* Restore the original sigprocmask */ + + stcb->sigprocmask = savesigprocmask; + + /* Now, handle the (rare?) case where (a) a blocked signal was + * received while the signal handling executed but (b) restoring the + * original sigprocmask will unblock the signal. + */ + + sig_unmaskpendingsignal(); + + /* Remove the signal from the sigpostedq */ + + saved_state = irqsave(); + sq_rem((sq_entry_t*)sigq, &(stcb->sigpostedq)); + irqrestore(saved_state); + + /* Then deallocate it */ + + sig_releasependingsigaction(sigq); + } + + stcb->errno = saved_errno; + sched_unlock(); +} + |