[tor-commits] [tor/master] Implement connection_count_moribund() for OOS handler

[nickm at torproject.org]

commit 2bc19171ef6d3d569b3116ce49e93b20bd9b7449
Author: Andrea Shepard <andrea at torproject.org>
Date:   Thu Jun 30 13:27:35 2016 +0000

    Implement connection_count_moribund() for OOS handler
---
 src/or/connection.c | 22 +++++++++++++++++-----
 src/or/main.c       | 22 ++++++++++++++++++++++
 src/or/main.h       |  2 ++
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/or/connection.c b/src/or/connection.c
index 77ad567..6ef20b2 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -4508,7 +4508,7 @@ connection_reached_eof(connection_t *conn)
 void
 connection_handle_oos(int n_socks, int failed)
 {
-  int target_n_socks = 0;
+  int target_n_socks = 0, moribund_socks, socks_to_kill;
 
   /* Sanity-check args */
   tor_assert(n_socks >= 0);
@@ -4554,13 +4554,25 @@ connection_handle_oos(int n_socks, int failed)
     /*
      * It's an OOS!
      *
-     * TODO count moribund sockets; it'll be important that anything we decide
+     * Count moribund sockets; it's be important that anything we decide
      * to get rid of here but don't immediately close get counted as moribund
      * on subsequent invocations so we don't try to kill too many things if
-     * this gets called multiple times.
+     * connection_handle_oos() gets called multiple times.
      */
-
-    /* TODO pick what to try to close */
+    moribund_socks = connection_count_moribund();
+
+    if (moribund_socks < n_socks - target_n_socks) {
+      socks_to_kill = n_socks - target_n_socks - moribund_socks;
+      /* TODO actually kill them */
+      log_notice(LD_NET,
+                 "OOS handler wants to kill %d sockets",
+                 socks_to_kill);
+    } else {
+      log_notice(LD_NET,
+                 "Not killing any sockets for OOS because there are %d "
+                 "already moribund, and we only want to eliminate %d",
+                 moribund_socks, n_socks - target_n_socks);
+    }
   }
 }
 
diff --git a/src/or/main.c b/src/or/main.c
index 261118a..30041c5 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -651,6 +651,28 @@ close_closeable_connections(void)
   }
 }
 
+/** Count moribund connections for the OOS handler */
+int
+connection_count_moribund(void)
+{
+  int i, moribund = 0;
+  connection_t *conn;
+
+  /*
+   * Count things we'll try to kill when close_closeable_connections()
+   * runs next.
+   */
+  for (i = 0; i < smartlist_len(closeable_connection_lst); ++i) {
+    conn = smartlist_get(closeable_connection_lst, i);
+    if (conn->conn_array_index < 0 ||
+        conn->marked_for_close) {
+      ++moribund;
+    }
+  }
+
+  return moribund;
+}
+
 /** Libevent callback: this gets invoked when (connection_t*)<b>conn</b> has
  * some data to read. */
 static void
diff --git a/src/or/main.h b/src/or/main.h
index 31a22de..4f58f17 100644
--- a/src/or/main.h
+++ b/src/or/main.h
@@ -47,6 +47,8 @@ MOCK_DECL(void,connection_start_writing,(connection_t *conn));
 
 void connection_stop_reading_from_linked_conn(connection_t *conn);
 
+int connection_count_moribund(void);
+
 void directory_all_unreachable(time_t now);
 void directory_info_has_arrived(time_t now, int from_cache, int suppress_logs);