Performance logging and counters:

* Tally and duration counters for Job Queue tasks and RPC calls
    optionally rendered by server_info and server_state, and
    optionally printed to a distinct log file.
    - Tally each Job Queue task as it is queued, starts, and
      finishes running. Track total duration queued and running.
    - Tally each RPC call as it starts and either finishes
      successfully or throws an exception. Track total running
      duration for each.
  * Track currently executing Job Queue tasks and RPC methods
    along with durations.
  * Json-formatted performance log file written by a dedicated
    thread, for above-described data.
  * New optional parameter, "counters", for server_info and
    server_state. If set, render Job Queue and RPC call counters
    as well as currently executing tasks.
  * New configuration section, "[perf]", to optionally control
    performance logging to a file.
  * Support optional sub-second periods when rendering human-readable
    time points.

src/test/consensus/Consensus_test.cpp

@@ -146,7 +146,7 @@ public:
 
         // Connected trust and network graphs with single fixed delay
         peers.trustAndConnect(
-            peers, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+            peers, date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
 
         // everyone submits their own ID as a TX
         for (Peer * p : peers)
@@ -194,10 +194,11 @@ public:
 
             // Fast and slow network connections
             fast.connect(
-                fast, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+                fast, date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
 
             slow.connect(
-                network, round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
+                network,
+                date::round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
 
             // All peers submit their own ID as a transaction
             for (Peer* peer : network)
@@ -250,10 +251,12 @@ public:
 
                 // Fast and slow network connections
                 fast.connect(
-                    fast, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+                    fast,
+                    date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
 
                 slow.connect(
-                    network, round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
+                    network,
+                    date::round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
 
                 for (Peer* peer : slow)
                     peer->runAsValidator = isParticipant;
@@ -377,7 +380,7 @@ public:
 
         network.trust(network);
         network.connect(
-            network, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+            network, date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
 
         // Run consensus without skew until we have a short close time
         // resolution
@@ -447,7 +450,7 @@ public:
             PeerGroup network = minority + majority;
 
             SimDuration delay =
-                round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
+                date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
             minority.trustAndConnect(minority + majorityA, delay);
             majority.trustAndConnect(majority, delay);
 
@@ -552,7 +555,8 @@ public:
 
             PeerGroup network = loner + clique;
             network.connect(
-                network, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+                network,
+                date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
 
             // initial round to set prior state
             sim.run(1);
@@ -606,9 +610,10 @@ public:
 
             // Fast and slow network connections
             fast.connect(
-                fast, round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
+                fast, date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY));
             slow.connect(
-                network, round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
+                network,
+                date::round<milliseconds>(1.1 * parms.ledgerGRANULARITY));
 
             // Run to the ledger *prior* to decreasing the resolution
             sim.run(increaseLedgerTimeResolutionEvery - 2);
@@ -757,7 +762,7 @@ public:
             PeerGroup network = a + b;
 
             SimDuration delay =
-                round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
+                date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
             a.trustAndConnect(a, delay);
             b.trustAndConnect(b, delay);
 
@@ -804,7 +809,7 @@ public:
         center.trust(validators);
 
         SimDuration delay =
-                round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
+                date::round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
         validators.connect(center, delay);
 
         center[0]->runAsValidator = false;
@@ -928,8 +933,10 @@ public:
         PeerGroup groupNotFastC = groupABD + groupCsplit;
         PeerGroup network = groupABD + groupCsplit + groupCfast;
 
-        SimDuration delay = round<milliseconds>(0.2 * parms.ledgerGRANULARITY);
-        SimDuration fDelay = round<milliseconds>(0.1 * parms.ledgerGRANULARITY);
+        SimDuration delay = date::round<milliseconds>(
+            0.2 * parms.ledgerGRANULARITY);
+        SimDuration fDelay = date::round<milliseconds>(
+            0.1 * parms.ledgerGRANULARITY);
 
         network.trust(network);
         // C must have a shorter delay to see all the validations before the