[dpdk-dev,v3,16/16] timer: add support to non-EAL thread

Message ID 1422491072-5114-17-git-send-email-cunming.liang@intel.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

Cunming Liang Jan. 29, 2015, 12:24 a.m. UTC
Allow to setup timers only for EAL (lcore) threads (__lcore_id < MAX_LCORE_ID).
E.g. – dynamically created thread will be able to reset/stop timer for lcore thread,
but it will be not allowed to setup timer for itself or another non-lcore thread.
rte_timer_manage() for non-lcore thread would simply do nothing and return straightway.

Signed-off-by: Cunming Liang <cunming.liang@intel.com>
---
 lib/librte_timer/rte_timer.c | 40 +++++++++++++++++++++++++++++++---------
 lib/librte_timer/rte_timer.h |  2 +-
 2 files changed, 32 insertions(+), 10 deletions(-)
  

Patch

diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c
index 269a992..601c159 100644
--- a/lib/librte_timer/rte_timer.c
+++ b/lib/librte_timer/rte_timer.c
@@ -79,9 +79,10 @@  static struct priv_timer priv_timer[RTE_MAX_LCORE];
 
 /* when debug is enabled, store some statistics */
 #ifdef RTE_LIBRTE_TIMER_DEBUG
-#define __TIMER_STAT_ADD(name, n) do {				\
-		unsigned __lcore_id = rte_lcore_id();		\
-		priv_timer[__lcore_id].stats.name += (n);	\
+#define __TIMER_STAT_ADD(name, n) do {					\
+		unsigned __lcore_id = rte_lcore_id();			\
+		if (__lcore_id < RTE_MAX_LCORE)				\
+			priv_timer[__lcore_id].stats.name += (n);	\
 	} while(0)
 #else
 #define __TIMER_STAT_ADD(name, n) do {} while(0)
@@ -127,15 +128,26 @@  timer_set_config_state(struct rte_timer *tim,
 	unsigned lcore_id;
 
 	lcore_id = rte_lcore_id();
+	if (lcore_id >= RTE_MAX_LCORE)
+		lcore_id = LCORE_ID_ANY;
 
 	/* wait that the timer is in correct status before update,
 	 * and mark it as being configured */
 	while (success == 0) {
 		prev_status.u32 = tim->status.u32;
 
+		/*
+		 * prevent race condition of non-EAL threads
+		 * to update the timer. When 'owner == LCORE_ID_ANY',
+		 * it means updated by a non-EAL thread.
+		 */
+		if (lcore_id == (unsigned)LCORE_ID_ANY &&
+		    (uint16_t)lcore_id == prev_status.owner)
+			return -1;
+
 		/* timer is running on another core, exit */
 		if (prev_status.state == RTE_TIMER_RUNNING &&
-		    (unsigned)prev_status.owner != lcore_id)
+		    prev_status.owner != (uint16_t)lcore_id)
 			return -1;
 
 		/* timer is being configured on another core */
@@ -366,9 +378,13 @@  __rte_timer_reset(struct rte_timer *tim, uint64_t expire,
 
 	/* round robin for tim_lcore */
 	if (tim_lcore == (unsigned)LCORE_ID_ANY) {
-		tim_lcore = rte_get_next_lcore(priv_timer[lcore_id].prev_lcore,
-					       0, 1);
-		priv_timer[lcore_id].prev_lcore = tim_lcore;
+		if (lcore_id < RTE_MAX_LCORE) {
+			tim_lcore = rte_get_next_lcore(
+				priv_timer[lcore_id].prev_lcore,
+				0, 1);
+			priv_timer[lcore_id].prev_lcore = tim_lcore;
+		} else
+			tim_lcore = rte_get_next_lcore(LCORE_ID_ANY, 0, 1);
 	}
 
 	/* wait that the timer is in correct status before update,
@@ -378,7 +394,8 @@  __rte_timer_reset(struct rte_timer *tim, uint64_t expire,
 		return -1;
 
 	__TIMER_STAT_ADD(reset, 1);
-	if (prev_status.state == RTE_TIMER_RUNNING) {
+	if (prev_status.state == RTE_TIMER_RUNNING &&
+	    lcore_id < RTE_MAX_LCORE) {
 		priv_timer[lcore_id].updated = 1;
 	}
 
@@ -455,7 +472,8 @@  rte_timer_stop(struct rte_timer *tim)
 		return -1;
 
 	__TIMER_STAT_ADD(stop, 1);
-	if (prev_status.state == RTE_TIMER_RUNNING) {
+	if (prev_status.state == RTE_TIMER_RUNNING &&
+	    lcore_id < RTE_MAX_LCORE) {
 		priv_timer[lcore_id].updated = 1;
 	}
 
@@ -499,6 +517,10 @@  void rte_timer_manage(void)
 	uint64_t cur_time;
 	int i, ret;
 
+	/* timer manager only runs on EAL thread */
+	if (lcore_id >= RTE_MAX_LCORE)
+		return;
+
 	__TIMER_STAT_ADD(manage, 1);
 	/* optimize for the case where per-cpu list is empty */
 	if (priv_timer[lcore_id].pending_head.sl_next[0] == NULL)
diff --git a/lib/librte_timer/rte_timer.h b/lib/librte_timer/rte_timer.h
index 4907cf5..5c5df91 100644
--- a/lib/librte_timer/rte_timer.h
+++ b/lib/librte_timer/rte_timer.h
@@ -76,7 +76,7 @@  extern "C" {
 #define RTE_TIMER_RUNNING 2 /**< State: timer function is running. */
 #define RTE_TIMER_CONFIG  3 /**< State: timer is being configured. */
 
-#define RTE_TIMER_NO_OWNER -1 /**< Timer has no owner. */
+#define RTE_TIMER_NO_OWNER -2 /**< Timer has no owner. */
 
 /**
  * Timer type: Periodic or single (one-shot).