1527. [cleanup] Reduce the number of gettimeofday() calls without

			losing necessary timer granularity.

(reviewed by marka and Kurt)

diff --git a/CHANGES b/CHANGES
index f38401df1916cf1ceca3ca8b165adf3cdf38f1ba..7eef922d3969cb827a82b45477ecbc0a67f7be71 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,7 @@
 1528.  [placeholder]
 
-1527.  [placeholder]
+1527.  [cleanup]       Reduce the number of gettimeofday() calls without
+                       losing necessary timer granularity.
 
 1526.  [placeholder]
 

diff --git a/bin/named/client.c b/bin/named/client.c
index 9ac61d7772269c81fa34d4cfb5c0bd82e98f7d07..5c14abf32253cba8caecbe355ba0df28931da586 100644 (file)
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: client.c,v 1.216 2003/07/04 04:38:54 marka Exp $ */
+/* $Id: client.c,v 1.217 2003/10/25 00:09:13 jinmei Exp $ */
 
 #include <config.h>
 
@@ -1129,8 +1129,6 @@ client_request(isc_task_t *task, isc_event_t *event) {
        REQUIRE(NS_CLIENT_VALID(client));
        REQUIRE(task == client->task);
 
-       UNUSED(task);
-
        INSIST(client->recursionquota == NULL);
 
        INSIST(client->state ==
@@ -1174,7 +1172,7 @@ client_request(isc_task_t *task, isc_event_t *event) {
                goto cleanup;
        client->state = client->newstate = NS_CLIENTSTATE_WORKING;
 
-       isc_stdtime_get(&client->requesttime);
+       isc_task_getcurrenttime(task, &client->requesttime);
        client->now = client->requesttime;
 
        if (result != ISC_R_SUCCESS) {

diff --git a/lib/isc/include/isc/task.h b/lib/isc/include/isc/task.h
index 78fd9845b01f583bdc8d9952e2a4212b53787233..33d828ad5a3bc760c39a64af0d5bdab15d52c986 100644 (file)
--- a/lib/isc/include/isc/task.h
+++ b/lib/isc/include/isc/task.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: task.h,v 1.49 2001/02/13 04:11:44 gson Exp $ */
+/* $Id: task.h,v 1.50 2003/10/25 00:09:14 jinmei Exp $ */
 
 #ifndef ISC_TASK_H
 #define ISC_TASK_H 1
@@ -58,9 +58,10 @@
  *** Imports.
  ***/
 
+#include <isc/eventclass.h>
 #include <isc/lang.h>
+#include <isc/stdtime.h>
 #include <isc/types.h>
-#include <isc/eventclass.h>
 
 #define ISC_TASKEVENT_FIRSTEVENT       (ISC_EVENTCLASS_TASK + 0)
 #define ISC_TASKEVENT_SHUTDOWN         (ISC_EVENTCLASS_TASK + 1)
@@ -518,6 +519,19 @@ isc_task_endexclusive(isc_task_t *task);
  *             exclusive access by calling isc_task_spl().
  */
 
+void
+isc_task_getcurrenttime(isc_task_t *task, isc_stdtime_t *t);
+/*
+ * Provide the most recent timestamp on the task.  The timestamp is considered
+ * as the "current time" in the second-order granularity.
+ *
+ * Requires:
+ *     'task' is a valid task.
+ *     't' is a valid non NULL pointer.
+ *
+ * Ensures:
+ *     '*t' has the "current time".
+ */
 
 /*****
  ***** Task Manager.

diff --git a/lib/isc/task.c b/lib/isc/task.c
index dba0f9fdad81feba053d8e3d34bd03d2317877a2..4d8431915ba298c103d0228b5d3fc6fc870b212c 100644 (file)
--- a/lib/isc/task.c
+++ b/lib/isc/task.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: task.c,v 1.88 2002/07/19 03:39:43 marka Exp $ */
+/* $Id: task.c,v 1.89 2003/10/25 00:09:13 jinmei Exp $ */
 
 /*
  * Principal Author: Bob Halley
@@ -82,6 +82,7 @@ struct isc_task {
        isc_eventlist_t                 on_shutdown;
        unsigned int                    quantum;
        unsigned int                    flags;
+       isc_stdtime_t                   now;
 #ifdef ISC_TASK_NAMES
        char                            name[16];
        void *                          tag;
@@ -196,6 +197,7 @@ isc_task_create(isc_taskmgr_t *manager, unsigned int quantum,
        INIT_LIST(task->on_shutdown);
        task->quantum = quantum;
        task->flags = 0;
+       task->now = 0;
 #ifdef ISC_TASK_NAMES
        memset(task->name, 0, sizeof(task->name));
        task->tag = NULL;
@@ -717,6 +719,17 @@ isc_task_gettag(isc_task_t *task) {
        return (task->tag);
 }
 
+void
+isc_task_getcurrenttime(isc_task_t *task, isc_stdtime_t *t) {
+       REQUIRE(VALID_TASK(task));
+       REQUIRE(t != NULL);
+
+       LOCK(&task->lock);
+
+       *t = task->now;
+
+       UNLOCK(&task->lock);
+}
 
 /***
  *** Task Manager.
@@ -838,6 +851,7 @@ dispatch(isc_taskmgr_t *manager) {
                        task->state = task_state_running;
                        XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
                                              ISC_MSG_RUNNING, "running"));
+                       isc_stdtime_get(&task->now);
                        do {
                                if (!EMPTY(task->events)) {
                                        event = HEAD(task->events);

diff --git a/lib/isc/unix/app.c b/lib/isc/unix/app.c
index 9a4dd0a90224c0b88f509ea4a0230805b548b01d..ef8b581e922898167ae27fe255be0c81336d4f72 100644 (file)
--- a/lib/isc/unix/app.c
+++ b/lib/isc/unix/app.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: app.c,v 1.48 2002/05/10 06:41:54 marka Exp $ */
+/* $Id: app.c,v 1.49 2003/10/25 00:09:14 jinmei Exp $ */
 
 #include <config.h>
 
@@ -304,12 +304,14 @@ evloop() {
                fd_set readfds, writefds;
                int maxfd;
                isc_boolean_t readytasks;
+               isc_boolean_t call_timer_dispatch = ISC_FALSE;
 
                readytasks = isc__taskmgr_ready();
                if (readytasks) {
                        tv.tv_sec = 0;
                        tv.tv_usec = 0;
                        tvp = &tv;
+                       call_timer_dispatch = ISC_TRUE;
                } else {
                        result = isc__timermgr_nextevent(&when);
                        if (result != ISC_R_SUCCESS)
@@ -319,6 +321,8 @@ evloop() {
 
                                TIME_NOW(&now);
                                us = isc_time_microdiff(&when, &now);
+                               if (us == 0)
+                                       call_timer_dispatch = ISC_TRUE;
                                tv.tv_sec = us / 1000000;
                                tv.tv_usec = us % 1000000;
                                tvp = &tv;
@@ -328,7 +332,23 @@ evloop() {
                isc__socketmgr_getfdsets(&readfds, &writefds, &maxfd);
                n = select(maxfd, &readfds, &writefds, NULL, tvp);
 
-               isc__timermgr_dispatch();
+               if (n == 0 || call_timer_dispatch) {
+                       /*
+                        * We call isc__timermgr_dispatch() only when
+                        * necessary, in order to reduce overhead.  If the
+                        * select() call indicates a timeout, we need the
+                        * dispatch.  Even if not, if we set the 0-timeout 
+                        * for the select() call, we need to check the timer
+                        * events.  In the 'readytasks' case, there may be no
+                        * timeout event actually, but there is no other way
+                        * to reduce the overhead.
+                        * Note that we do not have to worry about the case
+                        * where a new timer is inserted during the select()
+                        * call, since this loop only runs in the non-thread
+                        * mode.
+                        */
+                       isc__timermgr_dispatch();
+               }
                if (n > 0)
                        (void)isc__socketmgr_dispatch(&readfds, &writefds,
                                                      maxfd);
@@ -367,16 +387,16 @@ static isc_boolean_t signalled = ISC_FALSE;
 isc_result_t
 isc__nothread_wait_hack(isc_condition_t *cp, isc_mutex_t *mp) {
        isc_result_t result;
-       
+
        UNUSED(cp);
        UNUSED(mp);
-       
+
        INSIST(!in_recursive_evloop);
        in_recursive_evloop = ISC_TRUE;
 
        INSIST(*mp == 1); /* Mutex must be locked on entry. */
        --*mp;
-       
+
        result = evloop();
        if (result == ISC_R_RELOAD)
                want_reload = ISC_TRUE;
@@ -394,7 +414,7 @@ isc_result_t
 isc__nothread_signal_hack(isc_condition_t *cp) {
 
        UNUSED(cp);
-       
+
        INSIST(in_recursive_evloop);
 
        want_shutdown = ISC_TRUE;