1 files changed, 116 insertions, 0 deletions
diff --git a/src/seastar/tests/unit/alien_test.cc b/src/seastar/tests/unit/alien_test.cc
new file mode 100644
index 000000000..3aa527a4a
--- /dev/null
+++ b/src/seastar/tests/unit/alien_test.cc
@@ -0,0 +1,116 @@
+// -*- mode:C++; tab-width:4; c-basic-offset:4; indent-tabs-mode:nil -*-
+/*
+ * This file is open source software, licensed to you under the terms
+ * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership.  You may not use this file except in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Copyright (C) 2018 Red Hat
+ */
+
+#include <future>
+#include <numeric>
+#include <iostream>
+#include <seastar/core/alien.hh>
+#include <seastar/core/smp.hh>
+#include <seastar/core/app-template.hh>
+#include <seastar/core/posix.hh>
+#include <seastar/core/reactor.hh>
+#include <seastar/util/later.hh>
+
+using namespace seastar;
+
+enum {
+    ENGINE_READY = 24,
+    ALIEN_DONE   = 42,
+};
+
+int main(int argc, char** argv)
+{
+    // we need a protocol that both seastar and alien understand.
+    // and on which, a seastar future can wait.
+    int engine_ready_fd = eventfd(0, 0);
+    auto alien_done = file_desc::eventfd(0, 0);
+
+    // use the raw fd, because seastar engine want to take over the fds, if it
+    // polls on them.
+    auto zim = std::async([engine_ready_fd,
+                           alien_done=alien_done.get()] {
+        eventfd_t result = 0;
+        // wait until the seastar engine is ready
+        int r = ::eventfd_read(engine_ready_fd, &result);
+        if (r < 0) {
+            return -EINVAL;
+        }
+        if (result != ENGINE_READY) {
+            return -EINVAL;
+        }
+        std::vector<std::future<int>> counts;
+        for (auto i : boost::irange(0u, smp::count)) {
+            // send messages from alien.
+            counts.push_back(alien::submit_to(i, [i] {
+                return seastar::make_ready_future<int>(i);
+            }));
+        }
+        // std::future<void>
+        alien::submit_to(0, [] {
+            return seastar::make_ready_future<>();
+        }).wait();
+        int total = 0;
+        for (auto& count : counts) {
+            total += count.get();
+        }
+        // i am done. dismiss the engine
+        ::eventfd_write(alien_done, ALIEN_DONE);
+        return total;
+    });
+
+    seastar::app_template app;
+    eventfd_t result = 0;
+    app.run(argc, argv, [&] {
+        return seastar::now().then([engine_ready_fd] {
+            // engine ready!
+            ::eventfd_write(engine_ready_fd, ENGINE_READY);
+            return seastar::now();
+        }).then([alien_done = std::move(alien_done), &result]() mutable {
+            return do_with(seastar::pollable_fd(std::move(alien_done)), [&result] (pollable_fd& alien_done_fds) {
+                // check if alien has dismissed me.
+                return alien_done_fds.readable().then([&result, &alien_done_fds] {
+                    auto ret = alien_done_fds.get_file_desc().read(&result, sizeof(result));
+                    return make_ready_future<size_t>(*ret);
+                });
+            });
+        }).then([&result](size_t n) {
+            if (n != sizeof(result)) {
+                throw std::runtime_error("read from eventfd failed");
+            }
+            if (result != ALIEN_DONE) {
+                throw std::logic_error("alien failed to dismiss me");
+            }
+            return seastar::now();
+        }).handle_exception([](auto ep) {
+            std::cerr << "Error: " << ep << std::endl;
+        }).finally([] {
+            seastar::engine().exit(0);
+        });
+    });
+    int total = zim.get();
+    const auto shards = boost::irange(0u, smp::count);
+    auto expected = std::accumulate(std::begin(shards), std::end(shards), 0);
+    if (total != expected) {
+        std::cerr << "Bad total: " << total << " != " << expected << std::endl;
+        return 1;
+    }
+}