X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Ftimeval.c;h=c8c02bdc425746648998d74df27a3677e466eae3;hb=6d4605fd85630eb3a9ec743763114f286373a544;hp=099730e8f921a30e5bc48bbeacb748febd0750f3;hpb=279c9e030818e039bb1c26be76e2cc1e8f6b13a6;p=openvswitch

diff --git a/lib/timeval.c b/lib/timeval.c
index 099730e8..c8c02bdc 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -20,13 +20,16 @@
 #include <errno.h>
 #include <poll.h>
 #include <signal.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>
 #include "coverage.h"
+#include "dummy.h"
 #include "fatal-signal.h"
 #include "signals.h"
+#include "unixctl.h"
 #include "util.h"
 #include "vlog.h"
 
@@ -48,6 +51,9 @@ static volatile sig_atomic_t monotonic_tick = true;
 static struct timespec wall_time;
 static struct timespec monotonic_time;
 
+/* Fixed monotonic time offset, for use by unit tests. */
+static struct timespec warp_offset;
+
 /* Time at which to die with SIGALRM (if not TIME_MIN). */
 static time_t deadline = TIME_MIN;
 
@@ -59,8 +65,11 @@ static void refresh_monotonic_if_ticked(void);
 static time_t time_add(time_t, time_t);
 static void block_sigalrm(sigset_t *);
 static void unblock_sigalrm(const sigset_t *);
-static void log_poll_interval(long long int last_wakeup,
-                              const struct rusage *last_rusage);
+static void log_poll_interval(long long int last_wakeup);
+static struct rusage *get_recent_rusage(void);
+static void refresh_rusage(void);
+static void timespec_add(struct timespec *sum,
+                         const struct timespec *a, const struct timespec *b);
 
 /* Initializes the timetracking module.
  *
@@ -179,6 +188,7 @@ refresh_monotonic(void)
         refresh_wall_if_ticked();
         monotonic_time = wall_time;
     }
+    timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
 
     monotonic_tick = false;
 }
@@ -267,37 +277,44 @@ time_alarm(unsigned int secs)
 }
 
 /* Like poll(), except:
+ *
+ *      - The timeout is specified as an absolute time, as defined by
+ *        time_msec(), instead of a duration.
  *
  *      - On error, returns a negative error code (instead of setting errno).
  *
  *      - If interrupted by a signal, retries automatically until the original
- *        'timeout' expires.  (Because of this property, this function will
+ *        timeout is reached.  (Because of this property, this function will
  *        never return -EINTR.)
  *
  *      - As a side effect, refreshes the current time (like time_refresh()).
- */
+ *
+ * Stores the number of milliseconds elapsed during poll in '*elapsed'. */
 int
-time_poll(struct pollfd *pollfds, int n_pollfds, int timeout)
+time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
+          int *elapsed)
 {
     static long long int last_wakeup;
-    static struct rusage last_rusage;
     long long int start;
     sigset_t oldsigs;
     bool blocked;
     int retval;
 
     time_refresh();
-    log_poll_interval(last_wakeup, &last_rusage);
+    log_poll_interval(last_wakeup);
     coverage_clear();
     start = time_msec();
     blocked = false;
     for (;;) {
+        long long int now = time_msec();
         int time_left;
-        if (timeout > 0) {
-            long long int elapsed = time_msec() - start;
-            time_left = timeout >= elapsed ? timeout - elapsed : 0;
+
+        if (now >= timeout_when) {
+            time_left = 0;
+        } else if ((unsigned long long int) timeout_when - now > INT_MAX) {
+            time_left = INT_MAX;
         } else {
-            time_left = timeout;
+            time_left = timeout_when - now;
         }
 
         retval = poll(pollfds, n_pollfds, time_left);
@@ -318,7 +335,8 @@ time_poll(struct pollfd *pollfds, int n_pollfds, int timeout)
         unblock_sigalrm(&oldsigs);
     }
     last_wakeup = time_msec();
-    getrusage(RUSAGE_SELF, &last_rusage);
+    refresh_rusage();
+    *elapsed = last_wakeup - start;
     return retval;
 }
 
@@ -399,7 +417,24 @@ timeval_diff_msec(const struct timeval *a, const struct timeval *b)
 }
 
 static void
-log_poll_interval(long long int last_wakeup, const struct rusage *last_rusage)
+timespec_add(struct timespec *sum,
+             const struct timespec *a,
+             const struct timespec *b)
+{
+    struct timespec tmp;
+
+    tmp.tv_sec = a->tv_sec + b->tv_sec;
+    tmp.tv_nsec = a->tv_nsec + b->tv_nsec;
+    if (tmp.tv_nsec >= 1000 * 1000 * 1000) {
+        tmp.tv_nsec -= 1000 * 1000 * 1000;
+        tmp.tv_sec++;
+    }
+
+    *sum = tmp;
+}
+
+static void
+log_poll_interval(long long int last_wakeup)
 {
     static unsigned int mean_interval; /* In 16ths of a millisecond. */
     static unsigned int n_samples;
@@ -415,6 +450,7 @@ log_poll_interval(long long int last_wakeup, const struct rusage *last_rusage)
     /* Warn if we took too much time between polls: at least 50 ms and at least
      * 8X the mean interval. */
     if (n_samples > 10 && interval > mean_interval * 8 && interval > 50 * 16) {
+        const struct rusage *last_rusage = get_recent_rusage();
         struct rusage rusage;
 
         getrusage(RUSAGE_SELF, &rusage);
@@ -460,3 +496,83 @@ log_poll_interval(long long int last_wakeup, const struct rusage *last_rusage)
         mean_interval = interval;
     }
 }
+
+/* CPU usage tracking. */
+
+struct cpu_usage {
+    long long int when;         /* Time that this sample was taken. */
+    unsigned long long int cpu; /* Total user+system CPU usage when sampled. */
+};
+
+static struct rusage recent_rusage;
+static struct cpu_usage older = { LLONG_MIN, 0 };
+static struct cpu_usage newer = { LLONG_MIN, 0 };
+static int cpu_usage = -1;
+
+static struct rusage *
+get_recent_rusage(void)
+{
+    return &recent_rusage;
+}
+
+static void
+refresh_rusage(void)
+{
+    long long int now;
+
+    now = time_msec();
+    getrusage(RUSAGE_SELF, &recent_rusage);
+
+    if (now >= newer.when + 3 * 1000) {
+        older = newer;
+        newer.when = now;
+        newer.cpu = (timeval_to_msec(&recent_rusage.ru_utime) +
+                     timeval_to_msec(&recent_rusage.ru_stime));
+
+        if (older.when != LLONG_MIN && newer.cpu > older.cpu) {
+            unsigned int dividend = newer.cpu - older.cpu;
+            unsigned int divisor = (newer.when - older.when) / 100;
+            cpu_usage = divisor > 0 ? dividend / divisor : -1;
+        } else {
+            cpu_usage = -1;
+        }
+    }
+}
+
+/* Returns an estimate of this process's CPU usage, as a percentage, over the
+ * past few seconds of wall-clock time.  Returns -1 if no estimate is available
+ * (which will happen if the process has not been running long enough to have
+ * an estimate, and can happen for other reasons as well). */
+int
+get_cpu_usage(void)
+{
+    return cpu_usage;
+}
+
+/* Unixctl interface. */
+
+static void
+timeval_warp_cb(struct unixctl_conn *conn,
+                int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED)
+{
+    struct timespec ts;
+    int msecs;
+
+    msecs = atoi(argv[1]);
+    if (msecs <= 0) {
+        unixctl_command_reply(conn, 501, "invalid MSECS");
+        return;
+    }
+
+    ts.tv_sec = msecs / 1000;
+    ts.tv_nsec = (msecs % 1000) * 1000 * 1000;
+    timespec_add(&warp_offset, &warp_offset, &ts);
+    unixctl_command_reply(conn, 200, "warped");
+}
+
+void
+timeval_dummy_register(void)
+{
+    unixctl_command_register("time/warp", "MSECS", 1, 1,
+                             timeval_warp_cb, NULL);
+}