1 files changed, 42 insertions, 0 deletions
diff --git a/simpleperf/IOEventLoop_test.cpp b/simpleperf/IOEventLoop_test.cpp
index 09f64522..658fe820 100644
--- a/simpleperf/IOEventLoop_test.cpp
+++ b/simpleperf/IOEventLoop_test.cpp
@@ -250,3 +250,45 @@ TEST(IOEventLoop, exit_before_loop) {
   IOEventLoop loop;
   ASSERT_TRUE(loop.ExitLoop());
 }
+
+TEST(IOEventLoop, priority) {
+  int low_priority_fd[2];
+  ASSERT_EQ(0, pipe(low_priority_fd));
+  int high_priority_fd[2];
+  ASSERT_EQ(0, pipe(high_priority_fd));
+
+  IOEventLoop loop;
+  int count = 0;
+
+  ASSERT_NE(nullptr, loop.AddReadEvent(
+                         low_priority_fd[0],
+                         [&]() {
+                           char c;
+                           read(low_priority_fd[0], &c, 1);
+                           CHECK_EQ(count, 1);
+                           count++;
+                           return loop.ExitLoop();
+                         },
+                         IOEventLowPriority));
+
+  ASSERT_NE(nullptr, loop.AddReadEvent(
+                         high_priority_fd[0],
+                         [&]() {
+                           char c;
+                           read(high_priority_fd[0], &c, 1);
+                           CHECK_EQ(count, 0);
+                           count++;
+                           return true;
+                         },
+                         IOEventHighPriority));
+
+  char c;
+  CHECK_EQ(write(low_priority_fd[1], &c, 1), 1);
+  CHECK_EQ(write(high_priority_fd[1], &c, 1), 1);
+  ASSERT_TRUE(loop.RunLoop());
+  ASSERT_EQ(2, count);
+  for (int i = 0; i < 2; i++) {
+    close(low_priority_fd[i]);
+    close(high_priority_fd[i]);
+  }
+}