Detect when a unit test child process crashes (RIPD-1592):

When a test suite starts and ends, it informs the parent process. If the parent
has received a start message without a matching end message it reports that a
child may have crashed in that suite.

src/test/basics/DetectCrash_test.cpp

@@ -0,0 +1,46 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <BeastConfig.h>
+#include <beast/unit_test/suite.hpp>
+
+#include <exception>
+
+namespace ripple {
+namespace test {
+
+struct DetectCrash_test : public beast::unit_test::suite
+{
+    void testDetectCrash ()
+    {
+        testcase ("Detect Crash");
+        // Kill the process. This is used to test that the multi-process
+        // unit test will correctly report the crash.
+        std::terminate();
+    }
+    void run() override
+    {
+        testDetectCrash();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE_MANUAL(DetectCrash,unit_test,beast);
+
+} // test
+} // ripple