1 /*
2  * Copyright (C) 2013 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <errno.h>
18 #include <fcntl.h>
19 
20 #include <gtest/gtest.h>
21 
22 #if defined(__BIONIC__) // Android's prebuilt gcc's header files don't include <sys/eventfd.h>.
23 #include <sys/eventfd.h>
24 #else
25 // Include the necessary components of sys/eventfd.h right here.
26 #include <stdint.h>
27 
28 typedef uint64_t eventfd_t;
29 
30 __BEGIN_DECLS
31 extern int eventfd(int, int);
32 extern int eventfd_read(int, eventfd_t*);
33 extern int eventfd_write(int, eventfd_t);
34 __END_DECLS
35 #endif
36 
TEST(eventfd,smoke)37 TEST(eventfd, smoke) {
38   unsigned int initial_value = 2;
39   int fd = eventfd(initial_value, O_NONBLOCK);
40   ASSERT_NE(fd, -1);
41 
42   eventfd_t value = 123;
43   ASSERT_EQ(0, eventfd_read(fd, &value));
44   ASSERT_EQ(initial_value, value);
45 
46   // Reading clears the counter.
47   ASSERT_EQ(-1, eventfd_read(fd, &value));
48   ASSERT_EQ(EAGAIN, errno);
49 
50   // Values written are added until the next read.
51   ASSERT_EQ(0, eventfd_write(fd, 1));
52   ASSERT_EQ(0, eventfd_write(fd, 1));
53   ASSERT_EQ(0, eventfd_write(fd, 1));
54 
55   ASSERT_EQ(0, eventfd_read(fd, &value));
56   ASSERT_EQ(3U, value);
57 
58   close(fd);
59 }
60