xref: /llvm-project/libc/test/src/sys/select/select_ui_test.cpp (revision 3eb1e6d8e930f5aff17b8d6bcc160f5bbf8cabc7)
1be4e4257SSiva Chandra Reddy //===-- Interactive unittests for select ----------------------------------===//
2be4e4257SSiva Chandra Reddy //
3be4e4257SSiva Chandra Reddy // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4be4e4257SSiva Chandra Reddy // See https://llvm.org/LICENSE.txt for license information.
5be4e4257SSiva Chandra Reddy // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6be4e4257SSiva Chandra Reddy //
7be4e4257SSiva Chandra Reddy //===----------------------------------------------------------------------===//
8be4e4257SSiva Chandra Reddy 
9af783db7SSiva Chandra Reddy #include "src/errno/libc_errno.h"
10be4e4257SSiva Chandra Reddy #include "src/sys/select/select.h"
11be4e4257SSiva Chandra Reddy #include "src/unistd/read.h"
12af1315c2SSiva Chandra Reddy #include "test/UnitTest/Test.h"
13be4e4257SSiva Chandra Reddy 
14be4e4257SSiva Chandra Reddy #include <sys/select.h>
15be4e4257SSiva Chandra Reddy #include <unistd.h>
16be4e4257SSiva Chandra Reddy 
17be4e4257SSiva Chandra Reddy // This test is not be run automatically as part of the libc testsuite.
18be4e4257SSiva Chandra Reddy // Instead, one has to run it manually and press a key on the keyboard
19be4e4257SSiva Chandra Reddy // to make the test succeed.
TEST(LlvmLibcSelectTest,ReadStdinAfterSelect)20be4e4257SSiva Chandra Reddy TEST(LlvmLibcSelectTest, ReadStdinAfterSelect) {
21*3eb1e6d8Smichaelrj-google   LIBC_NAMESPACE::libc_errno = 0;
22be4e4257SSiva Chandra Reddy   constexpr int STDIN_FD = 0;
23be4e4257SSiva Chandra Reddy   fd_set set;
24be4e4257SSiva Chandra Reddy   FD_ZERO(&set);
25be4e4257SSiva Chandra Reddy   FD_SET(STDIN_FD, &set);
26be4e4257SSiva Chandra Reddy   struct timeval zero {
27be4e4257SSiva Chandra Reddy     0, 0
28be4e4257SSiva Chandra Reddy   }; // No wait
29be4e4257SSiva Chandra Reddy   struct timeval hr {
30be4e4257SSiva Chandra Reddy     3600, 0
31be4e4257SSiva Chandra Reddy   }; // Wait for an hour.
32be4e4257SSiva Chandra Reddy 
33be4e4257SSiva Chandra Reddy   // Zero timeout means we don't wait for input. So, select should return
34be4e4257SSiva Chandra Reddy   // immediately.
35b6bc9d72SGuillaume Chatelet   int count =
36b6bc9d72SGuillaume Chatelet       LIBC_NAMESPACE::select(STDIN_FD + 1, &set, nullptr, nullptr, &zero);
37be4e4257SSiva Chandra Reddy   // The set should indicate that stdin is NOT ready for reading.
38be4e4257SSiva Chandra Reddy   ASSERT_EQ(0, FD_ISSET(STDIN_FD, &set));
39be4e4257SSiva Chandra Reddy 
40be4e4257SSiva Chandra Reddy   FD_SET(STDIN_FD, &set);
41be4e4257SSiva Chandra Reddy   // Wait for an hour and give the user a chance to hit a key.
42b6bc9d72SGuillaume Chatelet   count = LIBC_NAMESPACE::select(STDIN_FD + 1, &set, nullptr, nullptr, &hr);
43be4e4257SSiva Chandra Reddy   ASSERT_EQ(count, 1);
44be4e4257SSiva Chandra Reddy   // The set should indicate that stdin is ready for reading.
45be4e4257SSiva Chandra Reddy   ASSERT_EQ(1, FD_ISSET(STDIN_FD, &set));
46be4e4257SSiva Chandra Reddy 
47be4e4257SSiva Chandra Reddy   // Verify that atleast one character can be read.
48be4e4257SSiva Chandra Reddy   char c;
49b6bc9d72SGuillaume Chatelet   ASSERT_EQ(LIBC_NAMESPACE::read(STDIN_FD, &c, 1), ssize_t(1));
50be4e4257SSiva Chandra Reddy }
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