Edit
kc3-lang/gnulib/tests/test-nonblocking-reader.h
Simon Josefsson
- tests/test-nonblocking-reader.h
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/* The reader part of a test program for non-blocking communication. Copyright (C) 2011-2023 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ /* This program implements 4 tests: test == 0: Test blocking write() with blocking read(). Timeline Main process Child process 0 s Start Start, read(10000) 1 s write(20000) Return from read(10000) 2 s Next read(10000) 2 s Return from write(20000) Return from read(10000) test == 1: Test non-blocking write() with blocking read(). Timeline Main process Child process 0 s Start Start, read(10000) 1 s write(20000) Return from read(10000) Return with at least 10000, Repeatedly continue write() of the rest 2 s Next read(10000) 2 s Return from write(10000) Return from read(10000) test == 2: Test blocking write() with non-blocking read(). Timeline Main process Child process 0 s Start Start, read(10000) repeatedly polling 1 s write(20000) Return from read(10000) 2 s Next read(10000) 2 s Return from write(20000) Return from read(10000) test == 3: Test non-blocking write() with non-blocking read(). */ #include "test-nonblocking-misc.h" static ssize_t full_read (size_t fd, void *buf, size_t count) { size_t bytes_read; bytes_read = 0; while (bytes_read < count) { TIMING_DECLS ssize_t ret; int saved_errno; dbgfprintf (stderr, "%s: >> read (%lu)\n", PROG_ROLE, (unsigned long) (count - bytes_read)); START_TIMING ret = read (fd, (char *) buf + bytes_read, count - bytes_read); saved_errno = errno; END_TIMING dbgfprintf (stderr, "%s: << read -> %ld%s\n", PROG_ROLE, (long) ret, dbgstrerror (ret < 0, saved_errno)); if (ret < 0) return -1; else { ASSERT (ret > 0); bytes_read += ret; } } return bytes_read; } static ssize_t full_read_from_nonblocking_fd (size_t fd, void *buf, size_t count) { size_t bytes_read; bytes_read = 0; while (bytes_read < count) { TIMING_DECLS ssize_t ret; int saved_errno; dbgfprintf (stderr, "%s: >> read (%lu)\n", PROG_ROLE, (unsigned long) (count - bytes_read)); START_TIMING ret = read (fd, (char *) buf + bytes_read, count - bytes_read); saved_errno = errno; END_TIMING dbgfprintf (stderr, "%s: << read -> %ld%s\n", PROG_ROLE, (long) ret, dbgstrerror (ret < 0, saved_errno)); /* This assertion fails if the non-blocking flag is effectively not set on fd. */ ASSERT (spent_time < 0.5); if (ret < 0) { ASSERT (saved_errno == EAGAIN || saved_errno == EWOULDBLOCK); usleep (SMALL_DELAY); } else { ASSERT (ret > 0); bytes_read += ret; } } return bytes_read; } /* Execute the reader loop. */ static void main_reader_loop (int test, size_t data_block_size, int fd) { unsigned char *expected; unsigned char *data; /* Set up the expected data. */ expected = init_data (data_block_size); data = (unsigned char *) malloc (2 * data_block_size); ASSERT (data != NULL); switch (test) { TIMING_DECLS ssize_t ret; case 0: /* Test blocking write() with blocking read(). */ case 1: /* Test non-blocking write() with blocking read(). */ START_TIMING ret = full_read (fd, data, data_block_size); END_TIMING ASSERT (ret == data_block_size); ASSERT (memcmp (data, expected, data_block_size) == 0); ASSERT (spent_time > 0.5); /* This assertion fails if data_block_size is very large and ENABLE_DEBUGGING is 1. */ ASSERT (spent_time < 1.5); usleep (1000000); START_TIMING ret = full_read (fd, data, data_block_size); END_TIMING ASSERT (ret == data_block_size); ASSERT (memcmp (data, expected + data_block_size, data_block_size) == 0); /* This assertion fails if data_block_size is much larger than needed and SMALL_DELAY is too large. */ ASSERT (spent_time < 0.5); break; case 2: /* Test blocking write() with non-blocking read(). */ case 3: /* Test non-blocking write() with non-blocking read(). */ START_TIMING ret = full_read_from_nonblocking_fd (fd, data, data_block_size); END_TIMING ASSERT (ret == data_block_size); ASSERT (memcmp (data, expected, data_block_size) == 0); ASSERT (spent_time > 0.5); /* This assertion fails if data_block_size is much larger than needed and SMALL_DELAY is too large, or if data_block_size is very large and ENABLE_DEBUGGING is 1. */ ASSERT (spent_time < 1.5); usleep (1000000); START_TIMING ret = full_read_from_nonblocking_fd (fd, data, data_block_size); END_TIMING ASSERT (ret == data_block_size); ASSERT (memcmp (data, expected + data_block_size, data_block_size) == 0); /* This assertion fails if data_block_size is much larger than needed and SMALL_DELAY is too large. */ ASSERT (spent_time < 0.5); break; default: abort (); } free (data); free (expected); }