1 files changed, 80 insertions, 0 deletions
diff --git a/staging_vespalib/src/tests/singleexecutor/singleexecutor_test.cpp b/staging_vespalib/src/tests/singleexecutor/singleexecutor_test.cpp
new file mode 100644
index 00000000000..5dacaa5d204
--- /dev/null
+++ b/staging_vespalib/src/tests/singleexecutor/singleexecutor_test.cpp
@@ -0,0 +1,80 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/vespalib/testkit/testapp.h>
+
+#include <vespa/vespalib/util/singleexecutor.h>
+#include <vespa/vespalib/util/lambdatask.h>
+#include <atomic>
+
+using namespace vespalib;
+
+TEST("test that all tasks are executed") {
+
+    std::atomic<uint64_t> counter(0);
+    SingleExecutor executor(10);
+
+    for (uint64_t i(0); i < 10; i++) {
+        executor.execute(makeLambdaTask([&counter] {counter++;}));
+    }
+    executor.sync();
+    EXPECT_EQUAL(10u, counter);
+
+    counter = 0;
+    for (uint64_t i(0); i < 10000; i++) {
+        executor.execute(makeLambdaTask([&counter] {counter++;}));
+    }
+    executor.sync();
+    EXPECT_EQUAL(10000u, counter);
+}
+
+void verifyResizeTaskLimit(bool up) {
+    Monitor lock;
+    std::atomic<uint64_t> started(0);
+    std::atomic<uint64_t> allowed(0);
+    SingleExecutor executor(10);
+
+    uint32_t targetTaskLimit = up ? 20 : 5;
+    uint32_t roundedTaskLimit = roundUp2inN(targetTaskLimit);
+    EXPECT_NOT_EQUAL(16u, roundedTaskLimit);
+
+    for (uint64_t i(0); i < 10; i++) {
+        executor.execute(makeLambdaTask([&lock, &started, &allowed] {
+            started++;
+            MonitorGuard guard(lock);
+            while (allowed < started) {
+                guard.wait(1ms);
+            }
+        }));
+    }
+    while (started < 1);
+    EXPECT_EQUAL(1u, started);
+    executor.setTaskLimit(targetTaskLimit);
+    EXPECT_EQUAL(16u, executor.getTaskLimit());
+    allowed = 5;
+    while (started < 6);
+    EXPECT_EQUAL(6u, started);
+    EXPECT_EQUAL(16u, executor.getTaskLimit());
+    allowed = 10;
+    while (started < 10);
+    EXPECT_EQUAL(10u, started);
+    EXPECT_EQUAL(16u, executor.getTaskLimit());
+    executor.execute(makeLambdaTask([&lock, &started, &allowed] {
+        started++;
+        MonitorGuard guard(lock);
+        while (allowed < started) {
+            guard.wait(1ms);
+        }
+    }));
+    while (started < 11);
+    EXPECT_EQUAL(11u, started);
+    EXPECT_EQUAL(roundedTaskLimit, executor.getTaskLimit());
+    allowed = 11;
+}
+TEST("test that resizing up and down works") {
+    TEST_DO(verifyResizeTaskLimit(true));
+    TEST_DO(verifyResizeTaskLimit(false));
+
+
+}
+
+TEST_MAIN() { TEST_RUN_ALL(); }