/* * Copyright (c) 2008 Bret S. Lambert * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include "local.h" void fwrite_thread(void *v) { FILE *file = v; int i; for (i = 0; i < 4096; i++) { if (fwrite(TEXT, sizeof(char), strlen(TEXT), file) == 0) { if (feof(file)) break; printf("OMG!!!\n"); fflush(stdout); break; } } } int main(void) { char sfn[24]; char buf[sizeof(TEXT)]; FILE *sfp; int fd; strlcpy(sfn, "/tmp/barnacles.XXXXXXXX", sizeof(sfn)); if ((fd = mkstemp(sfn)) == -1 || (sfp = fdopen(fd, "w+")) == NULL) { int saved_errno = errno; if (fd != -1) { unlink(sfn); close(fd); } errc(1, saved_errno, "could not open temporary file"); } run_threads(fwrite_thread, sfp); while (fread(buf, sizeof(char), strlen(TEXT), sfp)) /* verify */ if (strncmp(buf, TEXT, sizeof(TEXT))) err(1, "Thread writes were not atomic!!!"); unlink(sfn); close(fd); exit(0); }