Ticket #189: monotonic_timers.patch

auto/unix

@@ -297 +297 @@
     fi
 fi
 
+ngx_feature="clock_gettime(CLOCK_MONOTONIC)"
+ngx_feature_name="NGX_HAVE_CLOCK_MONOTONIC"
+ngx_feature_run=no
+ngx_feature_incs="#include <time.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="struct timespec monotime; clock_gettime(CLOCK_MONOTONIC, &monotime);"
+. auto/feature
+
+
+if [ $ngx_found != yes ]; then
+
+    ngx_feature="clock_gettime(CLOCK_MONOTONIC) in librt"
+    ngx_feature_libs="-lrt"
+    . auto/feature
+
+    if [ $ngx_found = yes ]; then
+        CORE_LIBS="$CORE_LIBS -lrt"
+    fi
+fi
 
 ngx_feature="SO_SETFIB"
 ngx_feature_name="NGX_HAVE_SETFIB"

contrib/vim/syntax/nginx.vim

@@ -240 +240 @@
 syn keyword ngxDirective min_delete_depth
 syn keyword ngxDirective modern_browser
 syn keyword ngxDirective modern_browser_value
+syn keyword ngxDirective monotonic_timers
 syn keyword ngxDirective mp4
 syn keyword ngxDirective mp4_buffer_size
 syn keyword ngxDirective mp4_max_buffer_size

src/core/nginx.c

@@ -133 +133 @@
       0,
       NULL },
 
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    { ngx_string("monotonic_timers"),
+      NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      0,
+      offsetof(ngx_core_conf_t, monotonic_timers),
+      NULL },
+#endif
+
       ngx_null_command
 };
 
@@ -968 +977 @@
     ccf->daemon = NGX_CONF_UNSET;
     ccf->master = NGX_CONF_UNSET;
     ccf->timer_resolution = NGX_CONF_UNSET_MSEC;
+    ccf->monotonic_timers = NGX_CONF_UNSET;
 
     ccf->worker_processes = NGX_CONF_UNSET;
     ccf->debug_points = NGX_CONF_UNSET;
@@ -996 +1006 @@
     ngx_conf_init_value(ccf->daemon, 1);
     ngx_conf_init_value(ccf->master, 1);
     ngx_conf_init_msec_value(ccf->timer_resolution, 0);
+    ngx_conf_init_value(ccf->monotonic_timers, 0);
 
     ngx_conf_init_value(ccf->worker_processes, 1);
     ngx_conf_init_value(ccf->debug_points, 0);

src/core/ngx_cycle.h

@@ -103 +103 @@
 
      ngx_array_t              env;
      char                   **environment;
+
+     ngx_flag_t               monotonic_timers;
 } ngx_core_conf_t;
 
 

src/core/ngx_times.c

@@ -24 +24 @@
 static ngx_atomic_t      ngx_time_lock;
 
 volatile ngx_msec_t      ngx_current_msec;
+volatile ngx_msec_t      ngx_mono_msec;
 volatile ngx_time_t     *ngx_cached_time;
 volatile ngx_str_t       ngx_cached_err_log_time;
 volatile ngx_str_t       ngx_cached_http_time;
@@ -59 +60 @@
 static char  *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
                            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
 
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+static ngx_flag_t enable_monotonic = 0;
+#endif
+
 void
 ngx_time_init(void)
 {
@@ -73 +78 @@
     ngx_time_update();
 }
 
+void
+ngx_time_enable_monotonic(ngx_flag_t enable)
+{
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    enable_monotonic = enable;
+    ngx_time_update();
+#endif
+}
 
 void
 ngx_time_update(void)
@@ -95 +108 @@
 
     ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;
 
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    if (enable_monotonic) {
+        struct timespec monotime;
+        clock_gettime(CLOCK_MONOTONIC, &monotime);
+        ngx_mono_msec = (ngx_msec_t) (monotime.tv_sec) * 1000 + (monotime.tv_nsec / 1000 / 1000);
+    } else {
+#endif
+        ngx_mono_msec = ngx_current_msec;
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    }
+#endif
+
+
     tp = &cached_time[slot];
 
     if (tp->sec == sec) {

src/core/ngx_times.h

@@ -21 +21 @@
 
 
 void ngx_time_init(void);
+void ngx_time_enable_monotonic(ngx_flag_t enable);
 void ngx_time_update(void);
 void ngx_time_sigsafe_update(void);
 u_char *ngx_http_time(u_char *buf, time_t t);
@@ -47 +48 @@
  * used in event timers
  */
 extern volatile ngx_msec_t  ngx_current_msec;
+extern volatile ngx_msec_t  ngx_mono_msec;
 
 
 #endif /* _NGX_TIMES_H_INCLUDED_ */

src/event/ngx_event.c

@@ -602 +602 @@
     ngx_queue_init(&ngx_posted_accept_events);
     ngx_queue_init(&ngx_posted_events);
 
+    /*
+     * Monotonic time must be enabled before the first timer is created. Otherwise
+     * monotonic and realtime timestamps would be mixed in the rbtree.
+     */
+    ngx_time_enable_monotonic(ccf->monotonic_timers);
     if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
         return NGX_ERROR;
     }

src/event/ngx_event_timer.c

@@ -44 +44 @@
 
     node = ngx_rbtree_min(root, sentinel);
 
-    timer = (ngx_msec_int_t) (node->key - ngx_current_msec);
+    timer = (ngx_msec_int_t) (node->key - ngx_mono_msec);
 
     return (ngx_msec_t) (timer > 0 ? timer : 0);
 }
@@ -69 +69 @@
 
         /* node->key > ngx_current_time */
 
-        if ((ngx_msec_int_t) (node->key - ngx_current_msec) > 0) {
+        if ((ngx_msec_int_t) (node->key - ngx_mono_msec) > 0) {
             return;
         }
 

src/event/ngx_event_timer.h

@@ -53 +53 @@
     ngx_msec_t      key;
     ngx_msec_int_t  diff;
 
-    key = ngx_current_msec + timer;
+    key = ngx_mono_msec + timer;
 
     if (ev->timer_set) {