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authorHarshavardhana <harsha@harshavardhana.net>2013-10-10 04:19:16 -0700
committerAnand Avati <avati@redhat.com>2013-10-15 00:14:57 -0700
commit6836118b214bb45ff94ae1bc176a6eefb1a17a6a (patch)
treeb600fc4deaab0c62c37241c6deef6f604d0088f1 /rpc/rpc-lib
parent793f8491789e58791b090a74472959df117e404b (diff)
libglusterfs: Add monotonic clocking counter for timer thread
gettimeofday() returns the current wall clock time and timezone. Using these functions in order to measure the passage of time (how long an operation took) therefore seems like a no-brainer. This time suffer's from some limitations: a. They have a low resolution: “High-performance” timing by definition, requires clock resolutions into the microseconds or better. b. They can jump forwards and backwards in time: Computer clocks all tick at slightly different rates, which causes the time to drift. Most systems have NTP enabled which periodically adjusts the system clock to keep them in sync with “actual” time. The adjustment can cause the clock to suddenly jump forward (artificially inflating your timing numbers) or jump backwards (causing your timing calculations to go negative or hugely positive). In such cases timer thread could go into an infinite loop. From 'man gettimeofday': ---------- .. .. The time returned by gettimeofday() is affected by discontinuous jumps in the system time (e.g., if the system administrator manually changes the system time). If you need a monotonically increasing clock, see clock_gettime(2). .. .. ---------- Rationale: For calculating interval timing for Timer thread, all that’s needed should be clock as a simple counter that increments at a stable rate. This is necessary to avoid the jumps which are caused by using "wall time", this counter must be monotonic that can never “tick” backwards, ever. Change-Id: I701d31e71a85a73d21a6c5cd15583e7a5a645eeb BUG: 1017993 Signed-off-by: Harshavardhana <harsha@harshavardhana.net> Reviewed-on: http://review.gluster.org/6070 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
Diffstat (limited to 'rpc/rpc-lib')
-rw-r--r--rpc/rpc-lib/src/rpc-clnt.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/rpc/rpc-lib/src/rpc-clnt.c b/rpc/rpc-lib/src/rpc-clnt.c
index b1d004a..9ff712f 100644
--- a/rpc/rpc-lib/src/rpc-clnt.c
+++ b/rpc/rpc-lib/src/rpc-clnt.c
@@ -145,7 +145,7 @@ call_bail (void *data)
struct saved_frame *trav = NULL;
struct saved_frame *tmp = NULL;
char frame_sent[256] = {0,};
- struct timeval timeout = {0,};
+ struct timespec timeout = {0,};
struct iovec iov = {0,};
GF_VALIDATE_OR_GOTO ("client", data, out);
@@ -163,7 +163,7 @@ call_bail (void *data)
call-once timer */
if (conn->timer) {
timeout.tv_sec = 10;
- timeout.tv_usec = 0;
+ timeout.tv_nsec = 0;
gf_timer_call_cancel (clnt->ctx, conn->timer);
conn->timer = gf_timer_call_after (clnt->ctx,
@@ -226,7 +226,7 @@ __save_frame (struct rpc_clnt *rpc_clnt, call_frame_t *frame,
struct rpc_req *rpcreq)
{
rpc_clnt_connection_t *conn = NULL;
- struct timeval timeout = {0, };
+ struct timespec timeout = {0, };
struct saved_frame *saved_frame = NULL;
conn = &rpc_clnt->conn;
@@ -240,7 +240,7 @@ __save_frame (struct rpc_clnt *rpc_clnt, call_frame_t *frame,
/* TODO: make timeout configurable */
if (conn->timer == NULL) {
timeout.tv_sec = 10;
- timeout.tv_usec = 0;
+ timeout.tv_nsec = 0;
conn->timer = gf_timer_call_after (rpc_clnt->ctx,
timeout,
call_bail,
@@ -397,7 +397,7 @@ rpc_clnt_reconnect (void *trans_ptr)
{
rpc_transport_t *trans = NULL;
rpc_clnt_connection_t *conn = NULL;
- struct timeval tv = {0, 0};
+ struct timespec ts = {0, 0};
int32_t ret = 0;
struct rpc_clnt *clnt = NULL;
@@ -416,14 +416,15 @@ rpc_clnt_reconnect (void *trans_ptr)
conn->reconnect = 0;
if (conn->connected == 0) {
- tv.tv_sec = 3;
+ ts.tv_sec = 3;
+ ts.tv_nsec = 0;
gf_log (trans->name, GF_LOG_TRACE,
"attempting reconnect");
ret = rpc_transport_connect (trans,
conn->config.remote_port);
conn->reconnect =
- gf_timer_call_after (clnt->ctx, tv,
+ gf_timer_call_after (clnt->ctx, ts,
rpc_clnt_reconnect,
trans);
} else {
@@ -831,7 +832,7 @@ rpc_clnt_notify (rpc_transport_t *trans, void *mydata,
int ret = -1;
rpc_request_info_t *req_info = NULL;
rpc_transport_pollin_t *pollin = NULL;
- struct timeval tv = {0, };
+ struct timespec ts = {0, };
conn = mydata;
if (conn == NULL) {
@@ -850,10 +851,11 @@ rpc_clnt_notify (rpc_transport_t *trans, void *mydata,
{
if (!conn->rpc_clnt->disabled
&& (conn->reconnect == NULL)) {
- tv.tv_sec = 10;
+ ts.tv_sec = 10;
+ ts.tv_nsec = 0;
conn->reconnect =
- gf_timer_call_after (clnt->ctx, tv,
+ gf_timer_call_after (clnt->ctx, ts,
rpc_clnt_reconnect,
conn->trans);
}
@@ -1695,4 +1697,3 @@ rpc_clnt_reconfig (struct rpc_clnt *rpc, struct rpc_clnt_config *config)
rpc->conn.config.remote_host = gf_strdup (config->remote_host);
}
}
-