Ticket #189: monotonic_timers.2.patch

auto/unix

@@ -299 +299 @@
     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
+
+if [ $ngx_found = yes ]; then
+        # We have clock_gettime with CLOCK_MONOTONIC. Now we test for faster
+        # variants (CLOCK_MONOTONIC_(FAST|COARSE)). ngx_feature_libs is set
+        # by previous tests to include librt if necessary.
+        ngx_feature="clock_gettime(CLOCK_MONOTONIC_FAST)"
+        ngx_feature_name="NGX_HAVE_CLOCK_MONOTONIC_FAST"
+        ngx_feature_test="struct timespec monotime; clock_gettime(CLOCK_MONOTONIC_FAST, &monotime);"
+        . auto/feature
+
+        ngx_feature="clock_gettime(CLOCK_MONOTONIC_COARSE)"
+        ngx_feature_name="NGX_HAVE_CLOCK_MONOTONIC_COARSE"
+        ngx_feature_test="struct timespec monotime; clock_gettime(CLOCK_MONOTONIC_COARSE, &monotime);"
+        . auto/feature
+fi
 
 ngx_feature="sched_setaffinity()"
 ngx_feature_name="NGX_HAVE_SCHED_SETAFFINITY"

contrib/vim/syntax/nginx.vim

@@ -334 +334 @@
 syn keyword ngxDirective contained min_delete_depth
 syn keyword ngxDirective contained modern_browser
 syn keyword ngxDirective contained modern_browser_value
+syn keyword ngxDirective contained monotonic_timers
 syn keyword ngxDirective contained mp4
 syn keyword ngxDirective contained mp4_buffer_size
 syn keyword ngxDirective contained mp4_max_buffer_size

src/core/nginx.c

@@ -152 +152 @@
       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
 };
 
@@ -1028 +1037 @@
     ccf->master = NGX_CONF_UNSET;
     ccf->timer_resolution = NGX_CONF_UNSET_MSEC;
     ccf->shutdown_timeout = NGX_CONF_UNSET_MSEC;
+    ccf->monotonic_timers = NGX_CONF_UNSET;
 
     ccf->worker_processes = NGX_CONF_UNSET;
     ccf->debug_points = NGX_CONF_UNSET;
@@ -1057 +1067 @@
     ngx_conf_init_value(ccf->master, 1);
     ngx_conf_init_msec_value(ccf->timer_resolution, 0);
     ngx_conf_init_msec_value(ccf->shutdown_timeout, 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

@@ -114 +114 @@
 
     ngx_array_t               env;
     char                    **environment;
+
+    ngx_flag_t                monotonic_timers;
 } ngx_core_conf_t;
 
 

src/core/ngx_times.c

@@ -59 +59 @@
 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;
+static clockid_t monotonic_clock;
+#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)
+    struct timespec monotime;
+
+    if (enable) {
+        /* Hack for the 'else if's to work correctly with the '#if's */
+        if (0) {
+        }
+#if (NGX_HAVE_CLOCK_MONOTONIC_FAST)
+        else if (clock_gettime(CLOCK_MONOTONIC_FAST, &monotime) == 0) {
+            monotonic_clock = CLOCK_MONOTONIC_FAST;
+        }
+#endif
+#if (NGX_HAVE_CLOCK_MONOTONIC_COARSE)
+        else if (clock_gettime(CLOCK_MONOTONIC_COARSE, &monotime) == 0) {
+            monotonic_clock = CLOCK_MONOTONIC_COARSE;
+        }
+#endif
+        else if (clock_gettime(CLOCK_MONOTONIC, &monotime) == 0) {
+            monotonic_clock = CLOCK_MONOTONIC;
+        } else {
+            /* No monotonic clock found at runtime, must disable. FIXME should this emit a warning? */
+            enable = 0;
+        }
+    }
+    enable_monotonic = enable;
+    ngx_time_update();
+#endif
+}
 
 void
 ngx_time_update(void)
@@ -93 +129 @@
     sec = tv.tv_sec;
     msec = tv.tv_usec / 1000;
 
-    ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    if (enable_monotonic) {
+        struct timespec monotime;
+        clock_gettime(monotonic_clock, &monotime);
+        ngx_current_msec = (ngx_msec_t) (monotime.tv_sec) * 1000 + (monotime.tv_nsec / 1000 / 1000);
+    } else {
+#endif
+        ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;
+#if (NGX_HAVE_CLOCK_MONOTONIC)
+    }
+#endif
+
 
     tp = &cached_time[slot];
 

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);

src/event/ngx_event.c

@@ -601 +601 @@
     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;
     }