1f08c3bdfSopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later 2f08c3bdfSopenharmony_ci/* 3f08c3bdfSopenharmony_ci * Copyright (c) International Business Machines Corp., 2001 4f08c3bdfSopenharmony_ci */ 5f08c3bdfSopenharmony_ci 6f08c3bdfSopenharmony_ci/*\ 7f08c3bdfSopenharmony_ci * [Description] 8f08c3bdfSopenharmony_ci * 9f08c3bdfSopenharmony_ci * Testcase to check if read() successfully sets errno to EAGAIN when read from 10f08c3bdfSopenharmony_ci * a pipe (fifo, opened in O_NONBLOCK mode) without writing to it. 11f08c3bdfSopenharmony_ci */ 12f08c3bdfSopenharmony_ci 13f08c3bdfSopenharmony_ci#include <stdio.h> 14f08c3bdfSopenharmony_ci#include <fcntl.h> 15f08c3bdfSopenharmony_ci#include "tst_test.h" 16f08c3bdfSopenharmony_ci 17f08c3bdfSopenharmony_cistatic char fifo[100]; 18f08c3bdfSopenharmony_cistatic int rfd, wfd; 19f08c3bdfSopenharmony_ci 20f08c3bdfSopenharmony_cistatic void verify_read(void) 21f08c3bdfSopenharmony_ci{ 22f08c3bdfSopenharmony_ci int c; 23f08c3bdfSopenharmony_ci 24f08c3bdfSopenharmony_ci TST_EXP_FAIL(read(rfd, &c, 1), EAGAIN, 25f08c3bdfSopenharmony_ci "read() when nothing is written to a pipe"); 26f08c3bdfSopenharmony_ci} 27f08c3bdfSopenharmony_ci 28f08c3bdfSopenharmony_cistatic void setup(void) 29f08c3bdfSopenharmony_ci{ 30f08c3bdfSopenharmony_ci struct stat buf; 31f08c3bdfSopenharmony_ci 32f08c3bdfSopenharmony_ci sprintf(fifo, "fifo.%d", getpid()); 33f08c3bdfSopenharmony_ci 34f08c3bdfSopenharmony_ci SAFE_MKNOD(fifo, S_IFIFO | 0777, 0); 35f08c3bdfSopenharmony_ci SAFE_STAT(fifo, &buf); 36f08c3bdfSopenharmony_ci 37f08c3bdfSopenharmony_ci if ((buf.st_mode & S_IFIFO) == 0) 38f08c3bdfSopenharmony_ci tst_brk(TBROK, "Mode does not indicate fifo file"); 39f08c3bdfSopenharmony_ci 40f08c3bdfSopenharmony_ci rfd = SAFE_OPEN(fifo, O_RDONLY | O_NONBLOCK); 41f08c3bdfSopenharmony_ci wfd = SAFE_OPEN(fifo, O_WRONLY | O_NONBLOCK); 42f08c3bdfSopenharmony_ci} 43f08c3bdfSopenharmony_ci 44f08c3bdfSopenharmony_cistatic void cleanup(void) 45f08c3bdfSopenharmony_ci{ 46f08c3bdfSopenharmony_ci SAFE_CLOSE(rfd); 47f08c3bdfSopenharmony_ci SAFE_CLOSE(wfd); 48f08c3bdfSopenharmony_ci SAFE_UNLINK(fifo); 49f08c3bdfSopenharmony_ci} 50f08c3bdfSopenharmony_ci 51f08c3bdfSopenharmony_cistatic struct tst_test test = { 52f08c3bdfSopenharmony_ci .needs_tmpdir = 1, 53f08c3bdfSopenharmony_ci .setup = setup, 54f08c3bdfSopenharmony_ci .cleanup = cleanup, 55f08c3bdfSopenharmony_ci .test_all = verify_read, 56f08c3bdfSopenharmony_ci}; 57