Improved support for exceptions in threads spawned by unit tests:

Unit tests that wish to spawn threads for testing concurrency may now do so
by using unit_test::thread as a replacement for std::thread. These threads
propagate unhandled exceptions to the unit test, and work with the abort on
failure feature.

beast/unit_test/suite.h

@@ -29,6 +29,8 @@
 namespace beast {
 namespace unit_test {
 
+class thread;
+
 /** A testsuite class.
     Derived classes execute a series of testcases, where each testcase is
     a series of pass/fail tests. To provide a unit test using this class,
@@ -46,9 +48,19 @@ public:
 
 private:
     bool abort_ = false;
+    bool aborted_ = false;
     runner* runner_ = nullptr;
 
-    struct abort_exception;
+    // This exception is thrown internally to stop the current suite
+    // in the event of a failure, if the option to stop is set.
+    struct abort_exception : public std::exception
+    {
+        char const*
+        what() const noexcept override
+        {
+            return "suite aborted";
+        }
+    };
 
     // Memberspace
     class log_t
@@ -105,16 +117,6 @@ private:
         /** @} */
     };
 
-    // Hacks to make this header-only
-    
-    template <class = void>
-    void
-    run (runner& r);
-
-    template <class = void>
-    void
-    do_fail (std::string const& reason);
-
 public:
     /** Type for scoped stream logging.
         To use this type, declare a local variable of the type
@@ -180,42 +182,34 @@ public:
     unexpected (Condition shouldBeFalse, std::string const& reason = "");
 
     /** Record a successful test condition. */
+    template <class = void>
     void
-    pass()
+    pass();
-    {
-        runner_->pass();
-    }
 
     /** Record a failure. */
+    template <class = void>
     void
     fail (std::string const& reason = "");
 
 private:
+    friend class thread;
+
     /** Runs the suite. */
     virtual
     void
     run() = 0;
+
+    template <class = void>
+    void
+    propagate_abort();
+
+    template <class = void>
+    void
+    run (runner& r);
 };
 
 //------------------------------------------------------------------------------
 
-// This exception is thrown internally to stop the current suite
-// in the event of a failure, if the option to stop is set.
-struct suite::abort_exception : public std::exception
-{
-    char const*
-    what() const noexcept override;
-};
-
-inline
-char const*
-suite::abort_exception::what() const noexcept
-{
-    return "suite aborted on failed condition";
-}
-
-//------------------------------------------------------------------------------
-
 template <class T>
 inline
 abstract_ostream::scoped_stream_type
@@ -323,6 +317,66 @@ suite::testcase_t::operator<< (T const& t)
 
 //------------------------------------------------------------------------------
 
+inline
+void
+suite::operator() (runner& r)
+{
+    run (r);
+}
+
+template <class Condition>
+inline
+bool
+suite::expect (Condition shouldBeTrue, std::string const& reason)
+{
+    if (shouldBeTrue)
+        pass();
+    else
+        fail (reason);
+    return shouldBeTrue;
+}
+
+template <class Condition>
+inline
+bool
+suite::unexpected (Condition shouldBeFalse, std::string const& reason)
+{
+    if (! shouldBeFalse)
+        pass();
+    else
+        fail (reason);
+    return ! shouldBeFalse;
+}
+
+template <class>
+void
+suite::pass()
+{
+    propagate_abort();
+    runner_->pass();
+}
+
+template <class>
+void
+suite::fail (std::string const& reason)
+{
+    propagate_abort();
+    runner_->fail (reason);
+    if (abort_)
+    {
+        aborted_ = true;
+        throw abort_exception();
+    }
+}
+
+template <class>
+void
+suite::propagate_abort()
+{
+    if (abort_ && aborted_)
+        throw abort_exception();
+}
+
 template <class>
 void
 suite::run (runner& r)
@@ -341,62 +395,15 @@ suite::run (runner& r)
     }
     catch (std::exception const& e)
     {
-        fail (std::string ("unhandled exception: ") +
+        runner_->fail ("unhandled exception: " +
             std::string (e.what()));
     }
     catch (...)
     {
-        fail ("unhandled exception");
+        runner_->fail ("unhandled exception");
     }
 }
 
-inline
-void
-suite::operator() (runner& r)
-{
-    run (r);
-}
-
-template <class Condition>
-inline
-bool
-suite::expect (Condition shouldBeTrue, std::string const& reason)
-{
-    if (shouldBeTrue)
-        pass();
-    else
-        do_fail (reason);
-    return shouldBeTrue;
-}
-
-template <class Condition>
-inline
-bool
-suite::unexpected (Condition shouldBeFalse, std::string const& reason)
-{
-    if (! shouldBeFalse)
-        pass();
-    else
-        do_fail (reason);
-    return ! shouldBeFalse;
-}
-
-template <class>
-void
-suite::do_fail (std::string const& reason)
-{
-    runner_->fail (reason);
-    if (abort_)
-        throw abort_exception();
-}
-
-inline
-void
-suite::fail (std::string const& reason)
-{
-    do_fail (reason);
-}
-
 } // unit_test
 } // beast
 

beast/unit_test/thread.h

@@ -0,0 +1,122 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    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.
+*/
+//==============================================================================
+
+#ifndef BEAST_UNIT_TEST_THREAD_H_INCLUDED
+#define BEAST_UNIT_TEST_THREAD_H_INCLUDED
+
+#include <beast/utility/noexcept.h>
+#include <beast/unit_test/suite.h>
+#include <functional>
+#include <thread>
+#include <utility>
+
+namespace beast {
+namespace unit_test {
+
+/** Replacement for std::thread that handles exceptions in unit tests. */
+class thread
+{
+private:
+    suite* s_ = nullptr;
+    std::thread t_;
+
+public:
+    using id = std::thread::id;
+    using native_handle_type = std::thread::native_handle_type;
+
+    thread() = default;
+    thread (thread const&) = delete;
+    thread& operator= (thread const&) = delete;
+
+    thread (thread&& other)
+        : s_ (other.s_)
+        , t_ (std::move(other.t_))
+    {
+    }
+
+    thread& operator= (thread&& other)
+    {
+        s_ = other.s_;
+        t_ = std::move(other.t_);
+        return *this;
+    }
+
+    template <class F, class... Args>
+    explicit
+    thread (suite& s, F&& f, Args&&... args)
+        : s_ (&s)
+    {
+        std::function<void(void)> b = 
+            std::bind(std::forward<F>(f),
+                std::forward<Args>(args)...);
+        t_ = std::thread (&thread::run, this,
+            std::move(b));
+    }
+
+    bool
+    joinable() const
+    {
+        return t_.joinable();
+    }
+
+    std::thread::id
+    get_id() const
+    {
+        return t_.get_id();
+    }
+
+    static
+    unsigned
+    hardware_concurrency() noexcept
+    {
+        return std::thread::hardware_concurrency();
+    }
+
+    void
+    join()
+    {
+        t_.join();
+        s_->propagate_abort();
+    }
+
+    void
+    swap (thread& other)
+    {
+        std::swap(s_, other.s_);
+        std::swap(t_, other.t_);
+    }
+
+private:
+    void
+    run (std::function <void(void)> f)
+    {
+        try
+        {
+            f();
+        }
+        catch (suite::abort_exception const&)
+        {
+        }
+    }
+};
+
+} // unit_test
+} // beast
+
+#endif