[ovs-dev] [PATCH 1/4] rconn: Make rconn_packet_counter thread-safe.

Ethan Jackson ethan at nicira.com
Fri Oct 11 15:50:54 UTC 2013


Acked-by: Ethan Jackson <ethan at nicira.com>


On Fri, Oct 11, 2013 at 12:23 AM, Ben Pfaff <blp at nicira.com> wrote:
> Signed-off-by: Ben Pfaff <blp at nicira.com>
> ---
>  lib/rconn.c       |   61 ++++++++++++++++++++++++++++++++++++++++++++---------
>  lib/rconn.h       |   14 ++++++++----
>  ofproto/connmgr.c |   14 +++++++-----
>  3 files changed, 70 insertions(+), 19 deletions(-)
>
> diff --git a/lib/rconn.c b/lib/rconn.c
> index 64cc6d0..9273cff 100644
> --- a/lib/rconn.c
> +++ b/lib/rconn.c
> @@ -664,7 +664,7 @@ int
>  rconn_send_with_limit(struct rconn *rc, struct ofpbuf *b,
>                        struct rconn_packet_counter *counter, int queue_limit)
>  {
> -    if (counter->n_packets < queue_limit) {
> +    if (rconn_packet_counter_n_packets(counter) < queue_limit) {
>          return rconn_send(rc, b, counter);
>      } else {
>          COVERAGE_INC(rconn_overflow);
> @@ -863,7 +863,10 @@ struct rconn_packet_counter *
>  rconn_packet_counter_create(void)
>  {
>      struct rconn_packet_counter *c = xzalloc(sizeof *c);
> +    ovs_mutex_init(&c->mutex);
> +    ovs_mutex_lock(&c->mutex);
>      c->ref_cnt = 1;
> +    ovs_mutex_unlock(&c->mutex);
>      return c;
>  }
>
> @@ -871,8 +874,15 @@ void
>  rconn_packet_counter_destroy(struct rconn_packet_counter *c)
>  {
>      if (c) {
> +        bool dead;
> +
> +        ovs_mutex_lock(&c->mutex);
>          ovs_assert(c->ref_cnt > 0);
> -        if (!--c->ref_cnt && !c->n_packets) {
> +        dead = !--c->ref_cnt && !c->n_packets;
> +        ovs_mutex_unlock(&c->mutex);
> +
> +        if (dead) {
> +            ovs_mutex_destroy(&c->mutex);
>              free(c);
>          }
>      }
> @@ -881,25 +891,56 @@ rconn_packet_counter_destroy(struct rconn_packet_counter *c)
>  void
>  rconn_packet_counter_inc(struct rconn_packet_counter *c, unsigned int n_bytes)
>  {
> +    ovs_mutex_lock(&c->mutex);
>      c->n_packets++;
>      c->n_bytes += n_bytes;
> +    ovs_mutex_unlock(&c->mutex);
>  }
>
>  void
>  rconn_packet_counter_dec(struct rconn_packet_counter *c, unsigned int n_bytes)
>  {
> -    ovs_assert(c->n_packets > 0);
> -    ovs_assert(c->n_bytes >= n_bytes);
> +    bool dead = false;
>
> -    c->n_bytes -= n_bytes;
> +    ovs_mutex_lock(&c->mutex);
> +    ovs_assert(c->n_packets > 0);
> +    ovs_assert(c->n_packets == 1
> +               ? c->n_bytes == n_bytes
> +               : c->n_bytes > n_bytes);
>      c->n_packets--;
> -    if (!c->n_packets) {
> -        ovs_assert(!c->n_bytes);
> -        if (!c->ref_cnt) {
> -            free(c);
> -        }
> +    c->n_bytes -= n_bytes;
> +    dead = !c->n_packets && !c->ref_cnt;
> +    ovs_mutex_unlock(&c->mutex);
> +
> +    if (dead) {
> +        ovs_mutex_destroy(&c->mutex);
> +        free(c);
>      }
>  }
> +
> +unsigned int
> +rconn_packet_counter_n_packets(const struct rconn_packet_counter *c)
> +{
> +    unsigned int n;
> +
> +    ovs_mutex_lock(&c->mutex);
> +    n = c->n_packets;
> +    ovs_mutex_unlock(&c->mutex);
> +
> +    return n;
> +}
> +
> +unsigned int
> +rconn_packet_counter_n_bytes(const struct rconn_packet_counter *c)
> +{
> +    unsigned int n;
> +
> +    ovs_mutex_lock(&c->mutex);
> +    n = c->n_bytes;
> +    ovs_mutex_unlock(&c->mutex);
> +
> +    return n;
> +}
>
>  /* Set rc->target and rc->name to 'target' and 'name', respectively.  If 'name'
>   * is null, 'target' is used.
> diff --git a/lib/rconn.h b/lib/rconn.h
> index aa30238..d943203 100644
> --- a/lib/rconn.h
> +++ b/lib/rconn.h
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
> + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
>   *
>   * Licensed under the Apache License, Version 2.0 (the "License");
>   * you may not use this file except in compliance with the License.
> @@ -21,6 +21,7 @@
>  #include <stdint.h>
>  #include <time.h>
>  #include "openvswitch/types.h"
> +#include "ovs-thread.h"
>
>  /* A wrapper around vconn that provides queuing and optionally reliability.
>   *
> @@ -91,9 +92,10 @@ unsigned int rconn_count_txqlen(const struct rconn *);
>
>  /* Counts packets and bytes queued into an rconn by a given source. */
>  struct rconn_packet_counter {
> -    unsigned int n_packets;     /* Number of packets queued. */
> -    unsigned int n_bytes;       /* Number of bytes queued. */
> -    int ref_cnt;                /* Number of owners. */
> +    struct ovs_mutex mutex;
> +    unsigned int n_packets OVS_GUARDED; /* Number of packets queued. */
> +    unsigned int n_bytes OVS_GUARDED;   /* Number of bytes queued. */
> +    int ref_cnt OVS_GUARDED;            /* Number of owners. */
>  };
>
>  struct rconn_packet_counter *rconn_packet_counter_create(void);
> @@ -101,4 +103,8 @@ void rconn_packet_counter_destroy(struct rconn_packet_counter *);
>  void rconn_packet_counter_inc(struct rconn_packet_counter *, unsigned n_bytes);
>  void rconn_packet_counter_dec(struct rconn_packet_counter *, unsigned n_bytes);
>
> +unsigned int rconn_packet_counter_n_packets(
> +    const struct rconn_packet_counter *);
> +unsigned int rconn_packet_counter_n_bytes(const struct rconn_packet_counter *);
> +
>  #endif /* rconn.h */
> diff --git a/ofproto/connmgr.c b/ofproto/connmgr.c
> index 8a4195d..ab9a556 100644
> --- a/ofproto/connmgr.c
> +++ b/ofproto/connmgr.c
> @@ -1238,7 +1238,7 @@ ofconn_reconfigure(struct ofconn *ofconn, const struct ofproto_controller *c)
>  static bool
>  ofconn_may_recv(const struct ofconn *ofconn)
>  {
> -    int count = ofconn->reply_counter->n_packets;
> +    int count = rconn_packet_counter_n_packets(ofconn->reply_counter);
>      return (!ofconn->blocked || ofconn->retry) && count < OFCONN_REPLY_MAX;
>  }
>
> @@ -1934,10 +1934,12 @@ ofmonitor_flush(struct connmgr *mgr)
>          struct ofpbuf *msg, *next;
>
>          LIST_FOR_EACH_SAFE (msg, next, list_node, &ofconn->updates) {
> +            unsigned int n_bytes;
> +
>              list_remove(&msg->list_node);
>              ofconn_send(ofconn, msg, ofconn->monitor_counter);
> -            if (!ofconn->monitor_paused
> -                && ofconn->monitor_counter->n_bytes > 128 * 1024) {
> +            n_bytes = rconn_packet_counter_n_bytes(ofconn->monitor_counter);
> +            if (!ofconn->monitor_paused && n_bytes > 128 * 1024) {
>                  struct ofpbuf *pause;
>
>                  COVERAGE_INC(ofmonitor_pause);
> @@ -1980,7 +1982,8 @@ ofmonitor_run(struct connmgr *mgr)
>      struct ofconn *ofconn;
>
>      LIST_FOR_EACH (ofconn, node, &mgr->all_conns) {
> -        if (ofconn->monitor_paused && !ofconn->monitor_counter->n_packets) {
> +        if (ofconn->monitor_paused
> +            && !rconn_packet_counter_n_packets(ofconn->monitor_counter)) {
>              COVERAGE_INC(ofmonitor_resume);
>              ofmonitor_resume(ofconn);
>          }
> @@ -1993,7 +1996,8 @@ ofmonitor_wait(struct connmgr *mgr)
>      struct ofconn *ofconn;
>
>      LIST_FOR_EACH (ofconn, node, &mgr->all_conns) {
> -        if (ofconn->monitor_paused && !ofconn->monitor_counter->n_packets) {
> +        if (ofconn->monitor_paused
> +            && !rconn_packet_counter_n_packets(ofconn->monitor_counter)) {
>              poll_immediate_wake();
>          }
>      }
> --
> 1.7.10.4
>
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