3 files changed, 12 insertions, 5 deletions
diff --git a/libs/ui/BufferHubEventFd.cpp b/libs/ui/BufferHubEventFd.cpp
index 978b3526f3..bffc2ca803 100644
--- a/libs/ui/BufferHubEventFd.cpp
+++ b/libs/ui/BufferHubEventFd.cpp
@@ -23,6 +23,8 @@ namespace android {
 
 BufferHubEventFd::BufferHubEventFd() : mFd(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)) {}
 
+BufferHubEventFd::BufferHubEventFd(int fd) : mFd(fd) {}
+
 status_t BufferHubEventFd::signal() const {
     if (!isValid()) {
         ALOGE("%s: cannot signal an invalid eventfd.", __FUNCTION__);
diff --git a/libs/ui/include/ui/BufferHubEventFd.h b/libs/ui/include/ui/BufferHubEventFd.h
index 0e856bdb67..8772304c0f 100644
--- a/libs/ui/include/ui/BufferHubEventFd.h
+++ b/libs/ui/include/ui/BufferHubEventFd.h
@@ -30,6 +30,12 @@ public:
     BufferHubEventFd();
 
     /**
+     * Constructs from a valid event fd. Caller is responsible for the validity of the fd. Takes
+     * ownership.
+     */
+    BufferHubEventFd(int fd);
+
+    /**
      * Returns whether this BufferHubEventFd holds a valid event_fd.
      */
     bool isValid() const { return get() >= 0; }
diff --git a/libs/ui/tests/BufferHubEventFd_test.cpp b/libs/ui/tests/BufferHubEventFd_test.cpp
index 92fb33ff48..2c9aa576fe 100644
--- a/libs/ui/tests/BufferHubEventFd_test.cpp
+++ b/libs/ui/tests/BufferHubEventFd_test.cpp
@@ -91,22 +91,21 @@ TEST_F(BufferHubEventFdTest, EventFd_testDupEventFd) {
     // Technically, the dupliated eventFd and the original eventFd are pointing
     // to the same kernel object. This test signals the duplicated eventFd but epolls the origianl
     // eventFd.
-    base::unique_fd dupedEventFd(dup(eventFd.get()));
+    BufferHubEventFd dupedEventFd(dup(eventFd.get()));
     ASSERT_GE(dupedEventFd.get(), 0);
 
     std::array<epoll_event, 1> events;
     EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
 
-    eventfd_write(dupedEventFd.get(), 1);
+    dupedEventFd.signal();
     EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 1);
 
     // The epoll fd is edge triggered, so it only responds to the eventFd once.
     EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
 
-    eventfd_write(dupedEventFd.get(), 1);
+    dupedEventFd.signal();
 
-    eventfd_t value;
-    eventfd_read(dupedEventFd.get(), &value);
+    dupedEventFd.clear();
     EXPECT_EQ(epoll_wait(epollFd.get(), events.data(), events.size(), 0), 0);
 }