+2004-07-14 Paul Jakma <paul@dishone.st>
+
+ * sigevent.c: (quagga_signal_handler) add a global caught flag, set
+ the flags to a constant rather increment to be kinder.
+ (quagga_sigevent_process) new function, to do core of what
+ quagga_signal_timer did. dont block signals at all as sig->caught
+ is volatile sig_atomic_t and should be safe to access from signal
+ and normal contexts. The signal blocking is unneeded paranoia, but
+ is left intact under an ifdef, should some platform require it.
+ Check global caught flag before iterating through array.
+ (quagga_signal_timer) nearly everything moved to
+ quagga_sigevent_process. Left in under ifdef, in case some
+ platform could use a regular timer check for signals.
+ * sigevent.h: quagga_sigevent_process declaration.
+ * thread.c: (thread_fetch) check for signals at beginning of
+ scheduler loop, check for signals if select returns EINTR.
+
2004-07-13 Greg Troxel <gdt@poblano.ir.bbn.com>
* sigevent.c: Don't block SIGTRAP and SIGKILL. Blocking SIGTRAP
#include <sigevent.h>
#include <log.h>
+/* master signals descriptor struct */
struct quagga_sigevent_master_t
{
- struct thread_master *tm;
struct thread *t;
- struct quagga_signal_t *signals;
+ struct quagga_signal_t *signals;
int sigc;
-
-} sigmaster;
+
+ volatile sig_atomic_t caught;
+} sigmaster;
/* Generic signal handler
* Schedules signal event thread
sig = &(sigmaster.signals[i]);
if (sig->signal == signo)
- sig->caught++;
+ sig->caught = 1;
}
+
+ sigmaster.caught = 1;
}
+/* check if signals have been caught and run appropriate handlers */
int
-quagga_signal_timer (struct thread *t)
+quagga_sigevent_process (void)
{
- sigset_t newmask, oldmask;
- struct quagga_sigevent_master_t *sigm;
struct quagga_signal_t *sig;
int i;
+#ifdef SIGEVENT_BLOCK_SIGNALS
+ /* shouldnt need to block signals, but potentially may be needed */
+ sigset_t newmask, oldmask;
- sigm = THREAD_ARG (t);
-
/*
* Block most signals, but be careful not to defer SIGTRAP because
* doing so breaks gdb, at least on NetBSD 2.0. Avoid asking to
sigfillset (&newmask);
sigdelset (&newmask, SIGTRAP);
sigdelset (&newmask, SIGKILL);
-
+
if ( (sigprocmask (SIG_BLOCK, &newmask, &oldmask)) < 0)
{
zlog_err ("quagga_signal_timer: couldnt block signals!");
- sigm->t = thread_add_timer (sigm->tm, quagga_signal_timer,
- &sigmaster, QUAGGA_SIGNAL_TIMER_INTERVAL);
return -1;
}
-
- for (i = 0; i < sigm->sigc; i++)
+#endif /* SIGEVENT_BLOCK_SIGNALS */
+
+ if (sigmaster.caught > 0)
{
- sig = &(sigm->signals[i]);
- if (sig->caught > 0)
+ sigmaster.caught = 0;
+ /* must not read or set sigmaster.caught after here,
+ * race condition with per-sig caught flags if one does
+ */
+
+ for (i = 0; i < sigmaster.sigc; i++)
{
- sig->caught = 0;
- sig->handler();
+ sig = &(sigmaster.signals[i]);
+
+ if (sig->caught > 0)
+ {
+ sig->caught = 0;
+ sig->handler ();
+ }
}
}
-
- sigm->t = thread_add_timer (sigm->tm, quagga_signal_timer, &sigmaster,
- QUAGGA_SIGNAL_TIMER_INTERVAL);
+#ifdef SIGEVENT_BLOCK_SIGNALS
if ( sigprocmask (SIG_UNBLOCK, &oldmask, NULL) < 0 );
return -1;
-
+#endif /* SIGEVENT_BLOCK_SIGNALS */
+
return 0;
}
+#ifdef SIGEVENT_SCHEDULE_THREAD
+/* timer thread to check signals. Shouldnt be needed */
+int
+quagga_signal_timer (struct thread *t)
+{
+ struct quagga_sigevent_master_t *sigm;
+ struct quagga_signal_t *sig;
+ int i;
+
+ sigm = THREAD_ARG (t);
+ sigm->t = thread_add_timer (sigm->t->master, quagga_signal_timer, &sigmaster,
+ QUAGGA_SIGNAL_TIMER_INTERVAL);
+ return quagga_sigevent_process ();
+}
+#endif /* SIGEVENT_SCHEDULE_THREAD */
+
/* Initialization of signal handles. */
/* Signale wrapper. */
int
}
void
-signal_init (struct thread_master *m,
- int sigc, struct quagga_signal_t signals[])
+signal_init (struct thread_master *m, int sigc,
+ struct quagga_signal_t signals[])
{
int i = 0;
sigmaster.sigc = sigc;
sigmaster.signals = signals;
- sigmaster.tm = m;
-
+
+#ifdef SIGEVENT_SCHEDULE_THREAD
sigmaster.t =
thread_add_timer (m, quagga_signal_timer, &sigmaster,
QUAGGA_SIGNAL_TIMER_INTERVAL);
-
+#endif /* SIGEVENT_SCHEDULE_THREAD */
}
-
#ifndef _QUAGGA_SIGNAL_H
#define _QUAGGA_SIGNAL_H
+
#include <thread.h>
#define QUAGGA_SIGNAL_TIMER_INTERVAL 2L
void signal_init (struct thread_master *m, int sigc,
struct quagga_signal_t *signals);
+/* check whether there are signals to handle, process any found */
+int quagga_sigevent_process (void);
+
#endif /* _QUAGGA_SIGNAL_H */
#include "log.h"
#include "hash.h"
#include "command.h"
+#include "sigevent.h"
\f
static struct hash *cpu_record = NULL;
\f
while (1)
{
- /* Normal event is the highest priority. */
+ /* Signals are highest priority */
+ quagga_sigevent_process ();
+
+ /* Normal event are the next highest priority. */
if ((thread = thread_trim_head (&m->event)) != NULL)
- return thread_run (m, thread, fetch);
+ return thread_run (m, thread, fetch);
/* Execute timer. */
gettimeofday (&timer_now, NULL);
for (thread = m->timer.head; thread; thread = thread->next)
- if (timeval_cmp (timer_now, thread->u.sands) >= 0)
- {
- thread_list_delete (&m->timer, thread);
- return thread_run (m, thread, fetch);
- }
+ if (timeval_cmp (timer_now, thread->u.sands) >= 0)
+ {
+ thread_list_delete (&m->timer, thread);
+ return thread_run (m, thread, fetch);
+ }
/* If there are any ready threads, process top of them. */
if ((thread = thread_trim_head (&m->ready)) != NULL)
- return thread_run (m, thread, fetch);
+ return thread_run (m, thread, fetch);
/* Structure copy. */
readfd = m->readfd;
num = select (FD_SETSIZE, &readfd, &writefd, &exceptfd, timer_wait);
if (num == 0)
- continue;
+ continue;
if (num < 0)
- {
- if (errno == EINTR)
- continue;
-
- zlog_warn ("select() error: %s", strerror (errno));
- return NULL;
- }
+ {
+ if (errno == EINTR)
+ {
+ /* signal received */
+ quagga_sigevent_process ();
+ continue;
+ }
+
+ zlog_warn ("select() error: %s", strerror (errno));
+ return NULL;
+ }
/* Normal priority read thead. */
ready = thread_process_fd (m, &m->read, &readfd, &m->readfd);
ready = thread_process_fd (m, &m->write, &writefd, &m->writefd);
if ((thread = thread_trim_head (&m->ready)) != NULL)
- return thread_run (m, thread, fetch);
+ return thread_run (m, thread, fetch);
}
}
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