Add unit tests for EventManager

src/sim/SConscript

@@ -121,6 +121,7 @@ GTest('bufval.test', 'bufval.test.cc', 'bufval.cc')
 GTest('byteswap.test', 'byteswap.test.cc', '../base/types.cc')
 GTest('globals.test', 'globals.test.cc', 'globals.cc',
     with_tag('gem5 serialize'))
+GTest('eventq.test', 'eventq.test.cc', with_tag('gem5 events'))
 GTest('guest_abi.test', 'guest_abi.test.cc')
 GTest('port.test', 'port.test.cc', 'port.cc')
 GTest('proxy_ptr.test', 'proxy_ptr.test.cc')

src/sim/eventq.test.cc

@@ -0,0 +1,114 @@
+#include <gtest/gtest.h>
+
+#include "sim/eventq.hh"
+
+using namespace gem5;
+
+class EventManagerTest : public testing::Test {
+  protected:
+    EventQueue *eq;
+    EventManager *em;
+
+    void SetUp() override {
+        eq = new EventQueue("test_queue");
+        em = new EventManager(eq);
+        curEventQueue(eq);
+    }
+
+    void TearDown() override {
+        delete em;
+        delete eq;
+        curEventQueue(nullptr);
+    }
+};
+
+class TestEvent : public Event {
+  public:
+    int processCount = 0;
+    bool *deleted = nullptr;
+
+    TestEvent() : Event() {}
+    TestEvent(bool auto_delete, bool *deleted_flag = nullptr)
+        : Event(Default_Pri, auto_delete ? AutoDelete : 0), deleted(deleted_flag) {}
+
+    ~TestEvent() {
+        if (deleted) *deleted = true;
+    }
+
+    void process() override {
+        processCount++;
+    }
+
+    const char *description() const override { return "TestEvent"; }
+};
+
+TEST_F(EventManagerTest, ScheduleEvent) {
+    TestEvent event;
+    em->schedule(&event, 10);
+    EXPECT_TRUE(event.scheduled());
+    EXPECT_EQ(event.when(), 10);
+
+    eq->serviceEvents(10);
+    EXPECT_FALSE(event.scheduled());
+    EXPECT_EQ(event.processCount, 1);
+    EXPECT_EQ(eq->getCurTick(), 10);
+}
+
+TEST_F(EventManagerTest, RescheduleEvent) {
+    TestEvent event;
+    em->schedule(&event, 10);
+    EXPECT_TRUE(event.scheduled());
+    EXPECT_EQ(event.when(), 10);
+
+    em->reschedule(&event, 20);
+    EXPECT_TRUE(event.scheduled());
+    EXPECT_EQ(event.when(), 20);
+
+    // Ensure it doesn't run at tick 10
+    eq->serviceEvents(10);
+    EXPECT_TRUE(event.scheduled());
+    EXPECT_EQ(event.processCount, 0);
+
+    // Ensure it runs at tick 20
+    eq->serviceEvents(20);
+    EXPECT_FALSE(event.scheduled());
+    EXPECT_EQ(event.processCount, 1);
+    EXPECT_EQ(eq->getCurTick(), 20);
+}
+
+TEST_F(EventManagerTest, DescheduleEvent) {
+    TestEvent event;
+    em->schedule(&event, 10);
+    EXPECT_TRUE(event.scheduled());
+
+    em->deschedule(&event);
+    EXPECT_FALSE(event.scheduled());
+
+    eq->serviceEvents(10);
+    EXPECT_EQ(event.processCount, 0);
+    EXPECT_EQ(eq->getCurTick(), 10);
+}
+
+TEST_F(EventManagerTest, ScheduleInPast) {
+    TestEvent event;
+    // Advance time to 10
+    eq->setCurTick(10);
+
+    // Scheduling at 5 should fail assertion
+    // Note: EXPECT_DEATH requires that the assertion calls abort() or exit()
+    EXPECT_DEATH(em->schedule(&event, 5), "");
+}
+
+TEST_F(EventManagerTest, AutoDelete) {
+    bool deleted = false;
+    // Dynamically allocate event
+    TestEvent *event = new TestEvent(true, &deleted);
+
+    em->schedule(event, 10);
+    EXPECT_TRUE(event->scheduled());
+
+    eq->serviceEvents(10);
+
+    // Event should have been processed and deleted
+    EXPECT_TRUE(deleted);
+}