This commit makes the main thread wake up all other threads when time is
warped.
Signed-off-by: Alex Wang <al...@nicira.com>
---
v1 -> v2:
- change the code to make main thread wake up all other threads when time
is warped.
- change the commit log.
---
lib/poll-loop.c | 5 +++++
lib/timeval.c | 21 +++++++++++++++++++++
lib/timeval.h | 2 ++
3 files changed, 28 insertions(+)
diff --git a/lib/poll-loop.c b/lib/poll-loop.c
index 4eb1187..97e4a2a 100644
--- a/lib/poll-loop.c
+++ b/lib/poll-loop.c
@@ -226,6 +226,11 @@ poll_block(void)
COVERAGE_INC(poll_zero_timeout);
}
+ /* For threads other than main thread, wait for timewarp. */
+ if (ovsthread_id_self()) {
+ timewarp_wait();
+ }
+
retval = time_poll(loop->pollfds, loop->n_waiters,
loop->timeout_when, &elapsed);
if (retval < 0) {
diff --git a/lib/timeval.c b/lib/timeval.c
index 223ed30..9c3646d 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -33,6 +33,7 @@
#include "hmap.h"
#include "ovs-thread.h"
#include "signals.h"
+#include "seq.h"
#include "unixctl.h"
#include "util.h"
#include "vlog.h"
@@ -57,6 +58,12 @@ static struct clock wall_clock; /* CLOCK_REALTIME. */
/* The monotonic time at which the time module was initialized. */
static long long int boot_time;
+/* Reference to the seq struct. Threads other than main thread can
+ * wait on timewarp_seq and be waken up when time is warped. */
+static struct seq *timewarp_seq;
+/* Last value of 'timewarp_seq' for each thread. */
+DEFINE_STATIC_PER_THREAD_DATA(uint64_t, last_seq, 0);
+
/* Monotonic time in milliseconds at which to die with SIGALRM (if not
* LLONG_MAX). */
static long long int deadline = LLONG_MAX;
@@ -79,6 +86,7 @@ init_clock(struct clock *c, clockid_t id)
ovs_mutex_init(&c->mutex);
atomic_init(&c->slow_path, false);
xclock_gettime(c->id, &c->cache);
+ timewarp_seq = seq_create();
}
static void
@@ -312,6 +320,17 @@ xclock_gettime(clock_t id, struct timespec *ts)
}
}
+/* Makes threads wait on timewarp_seq and
+ * be waken up when time is warped. */
+void
+timewarp_wait(void)
+{
+ uint64_t *last_seq = last_seq_get();
+
+ *last_seq = seq_read(timewarp_seq);
+ seq_wait(timewarp_seq, *last_seq);
+}
+
static long long int
timeval_diff_msec(const struct timeval *a, const struct timeval *b)
{
@@ -509,6 +528,8 @@ timeval_warp_cb(struct unixctl_conn *conn,
ovs_mutex_lock(&monotonic_clock.mutex);
atomic_store(&monotonic_clock.slow_path, true);
timespec_add(&monotonic_clock.warp, &monotonic_clock.warp, &ts);
+ /* Changes 'timewarp_seq' to wake up all waiting thread. */
+ seq_change(timewarp_seq);
ovs_mutex_unlock(&monotonic_clock.mutex);
unixctl_command_reply(conn, "warped");
diff --git a/lib/timeval.h b/lib/timeval.h
index 99b3af0..1bbfd5c 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -69,6 +69,8 @@ int get_cpu_usage(void);
long long int time_boot_msec(void);
+void timewarp_wait(void);
+
#ifdef __cplusplus
}
#endif
--
1.7.9.5
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