1  /*
       2   * Check effectiveness of umovestr memory caching.
       3   *
       4   * Copyright (c) 2019-2021 Dmitry V. Levin <ldv@strace.io>
       5   * All rights reserved.
       6   *
       7   * SPDX-License-Identifier: GPL-2.0-or-later
       8   */
       9  
      10  #include "tests.h"
      11  
      12  #include <stdio.h>
      13  #include <string.h>
      14  #include <unistd.h>
      15  #include <sys/uio.h>
      16  
      17  int
      18  main(void)
      19  {
      20  	char *const buf = tail_alloc(DEFAULT_STRLEN);
      21  	fill_memory_ex(buf, DEFAULT_STRLEN, 'a', 'z' - 'a' + 1);
      22  
      23  	struct iovec *const io = tail_alloc(sizeof(*io) * DEFAULT_STRLEN);
      24  	for (unsigned int i = 0; i < DEFAULT_STRLEN; ++i) {
      25  		io[i].iov_base = buf + DEFAULT_STRLEN - i;
      26  		io[i].iov_len = i;
      27  	}
      28  
      29  	tprintf("%s", "");
      30  
      31  	int rc = writev(-1, io, DEFAULT_STRLEN);
      32  	const char *errstr = sprintrc(rc);
      33  
      34  	tprintf("writev(-1, [");
      35  	for (unsigned int i = 0; i < DEFAULT_STRLEN; ++i) {
      36  		if (i)
      37  			tprintf(", ");
      38  		tprintf("{iov_base=\"%.*s\", iov_len=%u}",
      39  			(int) io[i].iov_len,
      40  			(char *) io[i].iov_base,
      41  			(unsigned int) io[i].iov_len);
      42  	}
      43  	tprintf("], %u) = %s\n", DEFAULT_STRLEN, errstr);
      44  
      45  	tprintf("+++ exited with 0 +++\n");
      46  	return 0;
      47  }