timeval: Preserve quiescence across time_poll().

[sliver-openvswitch.git] / lib / timeval.c

diff --git a/lib/timeval.c b/lib/timeval.c
index 3e7719f..d2a4380 100644 (file)
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -31,6 +31,7 @@
 #include "fatal-signal.h"
 #include "hash.h"
 #include "hmap.h"
+#include "ovs-rcu.h"
 #include "ovs-thread.h"
 #include "signals.h"
 #include "seq.h"
@@ -40,6 +41,21 @@
 
 VLOG_DEFINE_THIS_MODULE(timeval);
 
+#ifdef _WIN32
+typedef unsigned int clockid_t;
+
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC 1
+#endif
+
+#ifndef CLOCK_REALTIME
+#define CLOCK_REALTIME 2
+#endif
+
+/* Number of 100 ns intervals from January 1, 1601 till January 1, 1970. */
+static ULARGE_INTEGER unix_epoch;
+#endif /* _WIN32 */
+
 struct clock {
     clockid_t id;               /* CLOCK_MONOTONIC or CLOCK_REALTIME. */
 
@@ -96,6 +112,16 @@ do_init_time(void)
 {
     struct timespec ts;
 
+#ifdef _WIN32
+    /* Calculate number of 100-nanosecond intervals till 01/01/1970. */
+    SYSTEMTIME unix_epoch_st = { 1970, 1, 0, 1, 0, 0, 0, 0};
+    FILETIME unix_epoch_ft;
+
+    SystemTimeToFileTime(&unix_epoch_st, &unix_epoch_ft);
+    unix_epoch.LowPart = unix_epoch_ft.dwLowDateTime;
+    unix_epoch.HighPart = unix_epoch_ft.dwHighDateTime;
+#endif
+
     coverage_init();
 
     init_clock(&monotonic_clock, (!clock_gettime(CLOCK_MONOTONIC, &ts)
@@ -237,6 +263,7 @@ time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles OVS_UNUSED,
 {
     long long int *last_wakeup = last_wakeup_get();
     long long int start;
+    bool quiescent;
     int retval = 0;
 
     time_init();
@@ -248,6 +275,7 @@ time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles OVS_UNUSED,
     start = time_msec();
 
     timeout_when = MIN(timeout_when, deadline);
+    quiescent = ovsrcu_is_quiescent();
 
     for (;;) {
         long long int now = time_msec();
@@ -261,6 +289,14 @@ time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles OVS_UNUSED,
             time_left = timeout_when - now;
         }
 
+        if (!quiescent) {
+            if (!time_left) {
+                ovsrcu_quiesce();
+            } else {
+                ovsrcu_quiesce_start();
+            }
+        }
+
 #ifndef _WIN32
         retval = poll(pollfds, n_pollfds, time_left);
         if (retval < 0) {
@@ -281,6 +317,10 @@ time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles OVS_UNUSED,
         }
 #endif
 
+        if (!quiescent && time_left) {
+            ovsrcu_quiesce_end();
+        }
+
         if (deadline <= time_msec()) {
 #ifndef _WIN32
             fatal_signal_handler(SIGALRM);
@@ -325,12 +365,69 @@ time_boot_msec(void)
     return boot_time;
 }
 
+#ifdef _WIN32
+static ULARGE_INTEGER
+xgetfiletime(void)
+{
+    ULARGE_INTEGER current_time;
+    FILETIME current_time_ft;
+
+    /* Returns current time in UTC as a 64-bit value representing the number
+     * of 100-nanosecond intervals since January 1, 1601 . */
+    GetSystemTimePreciseAsFileTime(&current_time_ft);
+    current_time.LowPart = current_time_ft.dwLowDateTime;
+    current_time.HighPart = current_time_ft.dwHighDateTime;
+
+    return current_time;
+}
+
+static int
+clock_gettime(clock_t id, struct timespec *ts)
+{
+    if (id == CLOCK_MONOTONIC) {
+        static LARGE_INTEGER freq;
+        LARGE_INTEGER count;
+        long long int ns;
+
+        if (!freq.QuadPart) {
+            /* Number of counts per second. */
+            QueryPerformanceFrequency(&freq);
+        }
+        /* Total number of counts from a starting point. */
+        QueryPerformanceCounter(&count);
+
+        /* Total nano seconds from a starting point. */
+        ns = (double) count.QuadPart / freq.QuadPart * 1000000000;
+
+        ts->tv_sec = count.QuadPart / freq.QuadPart;
+        ts->tv_nsec = ns % 1000000000;
+    } else if (id == CLOCK_REALTIME) {
+        ULARGE_INTEGER current_time = xgetfiletime();
+
+        /* Time from Epoch to now. */
+        ts->tv_sec = (current_time.QuadPart - unix_epoch.QuadPart) / 10000000;
+        ts->tv_nsec = ((current_time.QuadPart - unix_epoch.QuadPart) %
+                       10000000) * 100;
+    } else {
+        return -1;
+    }
+}
+#endif /* _WIN32 */
+
 void
 xgettimeofday(struct timeval *tv)
 {
+#ifndef _WIN32
     if (gettimeofday(tv, NULL) == -1) {
         VLOG_FATAL("gettimeofday failed (%s)", ovs_strerror(errno));
     }
+#else
+    ULARGE_INTEGER current_time = xgetfiletime();
+
+    tv->tv_sec = (current_time.QuadPart - unix_epoch.QuadPart) / 10000000;
+    tv->tv_usec = ((current_time.QuadPart - unix_epoch.QuadPart) %
+                   10000000) / 10;
+#endif
 }
 
 void
@@ -555,7 +652,12 @@ timeval_warp_cb(struct unixctl_conn *conn,
     timespec_add(&monotonic_clock.warp, &monotonic_clock.warp, &ts);
     ovs_mutex_unlock(&monotonic_clock.mutex);
     seq_change(timewarp_seq);
-    poll(NULL, 0, 10); /* give threads (eg. monitor) some chances to run */
+    /* give threads (eg. monitor) some chances to run */
+#ifndef _WIN32
+    poll(NULL, 0, 10);
+#else
+    Sleep(10);
+#endif
     unixctl_command_reply(conn, "warped");
 }