9fb02d624f
sys_pipe.c
83 lines
2.5 KiB
C
83 lines
2.5 KiB
C
/*
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Copyright (C) 2004 Michael J. Silbersack. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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SUCH DAMAGE.
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*/
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#include <stdio.h>
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#include <unistd.h>
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#include <sys/stat.h>
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/*
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* $FreeBSD$
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* The goal of this program is to see if fstat reports the correct
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* data count for a pipe. Prior to revision 1.172 of sys_pipe.c,
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* 0 would be returned once the pipe entered direct write mode.
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*
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* Linux (2.6) always returns zero, so it's not a valuable platform
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* for comparison.
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*/
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int main (void)
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{
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char buffer[32768], buffer2[32768];
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int desc[2];
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int error, successes;
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struct stat status;
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pid_t new_pid;
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error = pipe(desc);
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if (error)
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err(0, "Couldn't allocate fds\n");
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new_pid = fork();
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if (new_pid == 0) {
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write(desc[1], &buffer, 145);
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usleep(1000000);
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write(desc[1], &buffer, 2048);
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usleep(1000000);
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write(desc[1], &buffer, 4096);
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usleep(1000000);
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write(desc[1], &buffer, 8191);
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usleep(1000000);
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write(desc[1], &buffer, 8192);
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usleep(1000000);
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} else {
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while (successes < 5) {
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usleep(3000);
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fstat(desc[0], &status);
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error = read(desc[0], &buffer2, 32768);
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if (status.st_size != error)
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err(0, "FAILURE: stat size %d read size %d\n", (int)status.st_size, error);
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if (error > 0) {
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printf("SUCCESS at stat size %d read size %d\n", (int)status.st_size, error);
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successes++;
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/* Sleep to avoid the natural race in reading st_size. */
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usleep(1000000);
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}
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}
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}
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}
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