Bug 17592: Clean up connection timeout logic.

This unifies CircuitIdleTimeout and PredictedCircsRelevanceTime into a single
option, and randomizes it.

It also gives us control over the default value as well as relay-to-relay
connection lifespan through the consensus.

Conflicts:
	src/or/circuituse.c
	src/or/config.c
	src/or/main.c
	src/test/testing_common.c

1 files changed, 10 insertions, 1 deletions

diff --git a/src/or/or.h b/src/or/or.h
index 02c43a5eac..cd00fbb815 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3301,6 +3301,13 @@ typedef struct origin_circuit_t {
    * adjust_exit_policy_from_exitpolicy_failure.
    */
   smartlist_t *prepend_policy;
+
+  /** How long do we wait before closing this circuit if it remains
+   * completely idle after it was built, in seconds? This value
+   * is randomized on a per-circuit basis from CircuitsAvailableTimoeut
+   * to 2*CircuitsAvailableTimoeut. */
+  int circuit_idle_timeout;
+
 } origin_circuit_t;
 
 struct onion_queue_t;
@@ -3882,6 +3889,8 @@ typedef struct {
                             * adaptive algorithm learns a new value. */
   int CircuitIdleTimeout; /**< Cull open clean circuits that were born
                            * at least this many seconds ago. */
+  int CircuitsAvailableTimeout; /**< Try to have an open circuit for at
+                                     least this long after last activity */
   int CircuitStreamTimeout; /**< If non-zero, detach streams from circuits
                              * and try a new circuit if the stream has been
                              * waiting for this many seconds. If zero, use
@@ -4826,7 +4835,7 @@ typedef uint32_t build_time_t;
 double circuit_build_times_quantile_cutoff(void);
 
 /** How often in seconds should we build a test circuit */
-#define CBT_DEFAULT_TEST_FREQUENCY 60
+#define CBT_DEFAULT_TEST_FREQUENCY 10
 #define CBT_MIN_TEST_FREQUENCY 1
 #define CBT_MAX_TEST_FREQUENCY INT32_MAX