1 files changed, 327 insertions, 0 deletions
diff --git a/lib/qpnexus.c b/lib/qpnexus.c
new file mode 100644
index 00000000..3b014be2
--- /dev/null
+++ b/lib/qpnexus.c
@@ -0,0 +1,327 @@
+/* Quagga Pthreads support -- header
+ * Copyright (C) 2009 Chris Hall (GMCH), Highwayman
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <zebra.h>
+#include <stdbool.h>
+
+#include "qpnexus.h"
+#include "memory.h"
+#include "thread.h"
+#include "sigevent.h"
+
+/* prototypes */
+static void* qpn_start(void* arg);
+static void qpn_in_thread_init(qpn_nexus qpn);
+
+/*==============================================================================
+ * Quagga Nexus Interface -- qpn_xxxx
+ *
+
+ */
+
+/*==============================================================================
+ * Initialisation, add hook, free etc.
+ *
+ */
+
+/*------------------------------------------------------------------------------
+ *  Initialise a nexus -- allocating it if required.
+ *
+ * If main_thread is set then no new thread will be created
+ * when qpn_exec() is called, instead the finite state machine will be
+ * run in the calling thread.  The main thread will only block the
+ * message queue's signal.  Non-main threads will block most signals.
+ *
+ * Returns the qpn_nexus.
+ */
+extern qpn_nexus
+qpn_init_new(qpn_nexus qpn, bool main_thread)
+{
+  if (qpn == NULL)
+    qpn = XCALLOC(MTYPE_QPN_NEXUS, sizeof(struct qpn_nexus)) ;
+  else
+    memset(qpn, 0,  sizeof(struct qpn_nexus)) ;
+
+  qpn->selection   = qps_selection_init_new(qpn->selection);
+  qpn->pile        = qtimer_pile_init_new(qpn->pile);
+  qpn->queue       = mqueue_init_new(qpn->queue, mqt_signal_unicast);
+  qpn->main_thread = main_thread;
+  qpn->start       = qpn_start;
+
+  if (main_thread)
+    qpn->thread_id = qpt_thread_self();
+
+  return qpn;
+}
+
+/*------------------------------------------------------------------------------
+ * Add a hook function to the given nexus.
+ */
+extern void
+qpn_add_hook_function(qpn_hook_list list, void* hook)
+{
+  passert(list->count < qpn_hooks_max) ;
+  list->hooks[list->count++] = hook ;
+} ;
+
+/*------------------------------------------------------------------------------
+ * Reset given nexus and, if required, free the nexus structure.
+ *
+ * Free timers, selection, message queue and its thread signal.
+ *
+ * Leaves all pointers to these things NULL -- which generally means that the
+ * object is empty or otherwise out of action.
+ */
+extern qpn_nexus
+qpn_reset(qpn_nexus qpn, bool free_structure)
+{
+  qps_file qf;
+  qtimer qtr;
+
+  if (qpn == NULL)
+    return NULL;
+
+  /* timers and the pile */
+  if (qpn->pile != NULL)
+    {
+      while ((qtr = qtimer_pile_ream(qpn->pile, 1)))
+          qtimer_free(qtr);
+      qpn->pile = NULL ;
+    }
+
+  /* files and selection */
+  if (qpn->selection != NULL)
+    {
+      while ((qf = qps_selection_ream(qpn->selection, 1)))
+          qps_file_free(qf);
+      qpn->selection = NULL ;
+    }
+
+  if (qpn->queue != NULL)
+    qpn->queue = mqueue_reset(qpn->queue, 1);
+
+  if (qpn->mts != NULL)
+    qpn->mts = mqueue_thread_signal_reset(qpn->mts, 1);
+
+  if (free_structure)
+    XFREE(MTYPE_QPN_NEXUS, qpn) ;       /* sets qpn = NULL      */
+
+  return qpn ;
+} ;
+
+/*==============================================================================
+ * Execution of a nexus
+ */
+
+/*------------------------------------------------------------------------------
+ * If not main qpthread create new qpthread.
+ *
+ * For all qpthreads: start the thread !
+ */
+extern void
+qpn_exec(qpn_nexus qpn)
+{
+  if (qpn->main_thread)
+    qpn->start(qpn);
+  else
+    qpt_thread_create(qpn->start, qpn, NULL) ;
+} ;
+
+/*------------------------------------------------------------------------------
+ * Pthread routine
+ *
+ * Processes:
+ *
+ *   1) Main thread only -- signals.
+ *
+ *   2) High priority pending work -- event hooks.
+ *
+ *   3) Messages coming from other pthreads -- mqueue_queue.
+ *
+ *   4) All priority pending work -- event hooks.
+ *
+ *   5) I/O -- qpselect
+ *
+ *      This deals with all active sockets for read/write/connect/accept.
+ *
+ *      Each time a socket is readable, one message is read and dispatched.
+ *      The pselect timeout is set to be when the next timer is due.
+ *
+ *   6) Timers -- qtimers
+ *
+ */
+static void*
+qpn_start(void* arg)
+{
+  qpn_nexus qpn = arg;
+  mqueue_block mqb;
+  int actions;
+  qtime_mono_t now ;
+  qtime_t      max_wait ;
+  unsigned i;
+  unsigned done ;
+  unsigned wait ;
+
+  /* now in our thread, complete initialisation                         */
+  qpn_in_thread_init(qpn);
+
+  /* custom in-thread initialization                                    */
+  for (i = 0; i < qpn->in_thread_init.count ;)
+    ((qpn_init_function*)(qpn->in_thread_init.hooks[i++]))() ;
+
+  /* Until required to terminate, loop                                  */
+  done = 1 ;
+  while (!qpn->terminate)
+    {
+      /* Signals are highest priority -- only execute for main thread   */
+      if (qpn->main_thread)
+        done |= quagga_sigevent_process() ;
+
+      /* Foreground hooks, if any.                                      */
+      for (i = 0; i < qpn->foreground.count ;)
+        done |= ((qpn_hook_function*)(qpn->foreground.hooks[i++]))() ;
+
+      /* take stuff from the message queue
+       *
+       * If nothing done the last time around the loop then may wait this
+       * time if the queue is empty first time through.
+       */
+      wait = (done == 0) ;      /* may wait this time only if nothing
+                                   found to do on the last pass         */
+      done = 0 ;
+      do
+        {
+          mqb = mqueue_dequeue(qpn->queue, wait, qpn->mts) ;
+          if (mqb == NULL)
+            break;
+
+          mqb_dispatch(mqb, mqb_action);
+
+          ++done ;              /* done another                         */
+          wait = 0 ;            /* done something, so turn off wait     */
+        } while (done < 200) ;
+
+      /* block for some input, output, signal or timeout
+       *
+       * wait will be true iff did nothing the last time round the loop, and
+       * not found anything to be done up to this point either.
+       */
+      if (wait)
+        max_wait = qtimer_pile_top_wait(qpn->pile, QTIME(MAX_PSELECT_WAIT)) ;
+      else
+        max_wait = 0 ;
+
+      actions = qps_pselect(qpn->selection, max_wait) ;
+      done |= actions ;
+
+      if (wait)
+        mqueue_done_waiting(qpn->queue, qpn->mts);
+
+      /* process I/O actions                                            */
+      while (actions)
+        actions = qps_dispatch_next(qpn->selection) ;
+
+      /* process timers                                                 */
+      now = qt_get_monotonic() ;
+      while (qtimer_pile_dispatch_next(qpn->pile, now))
+        done = 1 ;
+
+      /* If nothing done in this pass, see if anything in the background */
+      if (done == 0)
+        for (i = 0; i < qpn->background.count ; ++i)
+          done |= ((qpn_hook_function*)(qpn->background.hooks[i]))() ;
+    } ;
+
+  /* custom in-thread finalization                                      */
+  for (i = qpn->in_thread_final.count; i > 0 ;)
+    ((qpn_init_function*)(qpn->in_thread_final.hooks[--i]))() ;
+
+  return NULL;
+}
+
+/*------------------------------------------------------------------------------
+ * Now running in our thread, do common initialisation
+ */
+static void
+qpn_in_thread_init(qpn_nexus qpn)
+{
+  sigset_t newmask;
+
+  qpn->thread_id = qpt_thread_self();
+
+  if (qpn->main_thread)
+    {
+      /* Main thread, block the message queue's signal */
+      sigemptyset (&newmask);
+      sigaddset (&newmask, SIGMQUEUE);
+    }
+  else
+    {
+      /*
+       * Not main thread.  Block most signals, but be careful not to
+       * defer SIGTRAP because doing so breaks gdb, at least on
+       * NetBSD 2.0.  Avoid asking to block SIGKILL, just because
+       * we shouldn't be able to do so.  Avoid blocking SIGFPE,
+       * SIGILL, SIGSEGV, SIGBUS as this is undefined by POSIX.
+       * Don't block SIGPIPE so that is gets ignored on this thread.
+       */
+      sigfillset (&newmask);
+      sigdelset (&newmask, SIGTRAP);
+      sigdelset (&newmask, SIGKILL);
+      sigdelset (&newmask, SIGPIPE);
+      sigdelset (&newmask, SIGFPE);
+      sigdelset (&newmask, SIGILL);
+      sigdelset (&newmask, SIGSEGV);
+      sigdelset (&newmask, SIGBUS);
+    }
+
+  if (qpthreads_enabled)
+    qpt_thread_sigmask(SIG_BLOCK, &newmask, NULL);
+  else
+    {
+      if (sigprocmask(SIG_BLOCK, &newmask, NULL) != 0)
+        zabort_errno("sigprocmask failed") ;
+    }
+
+  /* Now we have thread_id and mask, prep for using message queue. */
+  if (qpn->queue != NULL)
+    qpn->mts = mqueue_thread_signal_init(qpn->mts, qpn->thread_id, SIGMQUEUE);
+  if (qpn->selection != NULL)
+    qps_set_signal(qpn->selection, SIGMQUEUE, newmask);
+}
+
+/*------------------------------------------------------------------------------
+ * Ask the thread to terminate itself quickly and cleanly.
+ *
+ * Does nothing if terminate already set.
+ */
+void
+qpn_terminate(qpn_nexus qpn)
+{
+  if (!qpn->terminate)
+    {
+      qpn->terminate = true ;
+
+      /* wake up any pselect */
+      if (qpthreads_enabled)
+        qpt_thread_signal(qpn->thread_id, SIGMQUEUE);
+    } ;
+}