From 68d370bec44dd6c0b9bdc76308de1a96fe34e5b8 Mon Sep 17 00:00:00 2001
From: Gavin Andresen <gavinandresen@gmail.com>
Date: Fri, 10 Apr 2015 10:31:02 -0400
Subject: [PATCH] CScheduler unit test

---
 src/Makefile.test.include    |   1 +
 src/test/scheduler_tests.cpp | 110 +++++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 src/test/scheduler_tests.cpp

diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 9aec13cce..3fba198d9 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -60,6 +60,7 @@ BITCOIN_TESTS =\
   test/pow_tests.cpp \
   test/rpc_tests.cpp \
   test/sanity_tests.cpp \
+  test/scheduler_tests.cpp \
   test/script_P2SH_tests.cpp \
   test/script_tests.cpp \
   test/scriptnum_tests.cpp \
diff --git a/src/test/scheduler_tests.cpp b/src/test/scheduler_tests.cpp
new file mode 100644
index 000000000..a26d0afae
--- /dev/null
+++ b/src/test/scheduler_tests.cpp
@@ -0,0 +1,110 @@
+// Copyright (c) 2012-2013 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "random.h"
+#include "scheduler.h"
+
+#include "test/test_bitcoin.h"
+
+#include <boost/bind.hpp>
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/random/uniform_int_distribution.hpp>
+#include <boost/thread.hpp>
+#include <boost/test/unit_test.hpp>
+
+BOOST_AUTO_TEST_SUITE(scheduler_tests)
+
+static void microTask(CScheduler& s, boost::mutex& mutex, int& counter, int delta, boost::chrono::system_clock::time_point rescheduleTime)
+{
+    {
+        boost::unique_lock<boost::mutex> lock(mutex);
+        counter += delta;
+    }
+    boost::chrono::system_clock::time_point noTime = boost::chrono::system_clock::time_point::min();
+    if (rescheduleTime != noTime) {
+        CScheduler::Function f = boost::bind(&microTask, boost::ref(s), boost::ref(mutex), boost::ref(counter), -delta + 1, noTime);
+        s.schedule(f, rescheduleTime);
+    }
+}
+
+static void MicroSleep(uint64_t n)
+{
+#if defined(HAVE_WORKING_BOOST_SLEEP_FOR)
+    boost::this_thread::sleep_for(boost::chrono::microseconds(n));
+#elif defined(HAVE_WORKING_BOOST_SLEEP)
+    boost::this_thread::sleep(boost::posix_time::microseconds(n));
+#else
+    //should never get here
+    #error missing boost sleep implementation
+#endif
+}
+
+BOOST_AUTO_TEST_CASE(manythreads)
+{
+    // Stress test: hundreds of microsecond-scheduled tasks,
+    // serviced by 10 threads.
+    //
+    // So... ten shared counters, which if all the tasks execute
+    // properly will sum to the number of tasks done.
+    // Each task adds or subtracts from one of the counters a
+    // random amount, and then schedules another task 0-1000
+    // microseconds in the future to subtract or add from
+    // the counter -random_amount+1, so in the end the shared
+    // counters should sum to the number of initial tasks performed.
+    CScheduler microTasks;
+
+    boost::thread_group microThreads;
+    for (int i = 0; i < 5; i++)
+        microThreads.create_thread(boost::bind(&CScheduler::serviceQueue, &microTasks));
+
+    boost::mutex counterMutex[10];
+    int counter[10] = { 0 };
+    boost::random::mt19937 rng(insecure_rand());
+    boost::random::uniform_int_distribution<> zeroToNine(0, 9);
+    boost::random::uniform_int_distribution<> randomMsec(-11, 1000);
+    boost::random::uniform_int_distribution<> randomDelta(-1000, 1000);
+
+    boost::chrono::system_clock::time_point start = boost::chrono::system_clock::now();
+    boost::chrono::system_clock::time_point now = start;
+
+    for (int i = 0; i < 100; i++) {
+        boost::chrono::system_clock::time_point t = now + boost::chrono::microseconds(randomMsec(rng));
+        boost::chrono::system_clock::time_point tReschedule = now + boost::chrono::microseconds(500 + randomMsec(rng));
+        int whichCounter = zeroToNine(rng);
+        CScheduler::Function f = boost::bind(&microTask, boost::ref(microTasks),
+                                             boost::ref(counterMutex[whichCounter]), boost::ref(counter[whichCounter]),
+                                             randomDelta(rng), tReschedule);
+        microTasks.schedule(f, t);
+    }
+
+    MicroSleep(600);
+    now = boost::chrono::system_clock::now();
+    // More threads and more tasks:
+    for (int i = 0; i < 5; i++)
+        microThreads.create_thread(boost::bind(&CScheduler::serviceQueue, &microTasks));
+    for (int i = 0; i < 100; i++) {
+        boost::chrono::system_clock::time_point t = now + boost::chrono::microseconds(randomMsec(rng));
+        boost::chrono::system_clock::time_point tReschedule = now + boost::chrono::microseconds(500 + randomMsec(rng));
+        int whichCounter = zeroToNine(rng);
+        CScheduler::Function f = boost::bind(&microTask, boost::ref(microTasks),
+                                             boost::ref(counterMutex[whichCounter]), boost::ref(counter[whichCounter]),
+                                             randomDelta(rng), tReschedule);
+        microTasks.schedule(f, t);
+    }
+
+    // All 2,000 tasks should be finished within 2 milliseconds. Sleep a bit longer.
+    MicroSleep(2100);
+
+    microThreads.interrupt_all();
+    microThreads.join_all();
+
+    int counterSum = 0;
+    for (int i = 0; i < 10; i++) {
+        BOOST_CHECK(counter[i] != 0);
+        counterSum += counter[i];
+    }
+    BOOST_CHECK_EQUAL(counterSum, 200);
+}
+
+BOOST_AUTO_TEST_SUITE_END()