server/debug.c

   1 /* nbdkit
   2  * Copyright (C) 2013-2018 Red Hat Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <config.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <stdarg.h>
  38 #include <string.h>
  39 #include <errno.h>
  40
  41 #include "internal.h"
  42
  43 /* Called with flockfile (stderr) taken. */
  44 static void
  45 prologue (void)
  46 {
  47   const char *name = threadlocal_get_name ();
  48   size_t instance_num = threadlocal_get_instance_num ();
  49
  50   fprintf (stderr, "%s: ", program_name);
  51
  52   if (name) {
  53     fprintf (stderr, "%s", name);
  54     if (instance_num > 0)
  55       fprintf (stderr, "[%zu]", instance_num);
  56     fprintf (stderr, ": ");
  57   }
  58
  59   fprintf (stderr, "debug: ");
  60 }
  61
  62 /* Note: preserves the previous value of errno. */
  63 void
  64 nbdkit_vdebug (const char *fs, va_list args)
  65 {
  66   int err = errno;
  67
  68   if (!verbose)
  69     return;
  70   flockfile (stderr);
  71   prologue ();
  72
  73   vfprintf (stderr, fs, args);
  74
  75   fprintf (stderr, "\n");
  76   funlockfile (stderr);
  77
  78   errno = err;
  79 }
  80
  81 /* Note: preserves the previous value of errno. */
  82 void
  83 nbdkit_debug (const char *fs, ...)
  84 {
  85   va_list args;
  86   int err = errno;
  87
  88   if (!verbose)
  89     return;
  90
  91   flockfile (stderr);
  92   prologue ();
  93
  94   va_start (args, fs);
  95   vfprintf (stderr, fs, args);
  96   va_end (args);
  97
  98   fprintf (stderr, "\n");
  99   funlockfile (stderr);
 100
 101   errno = err;
 102 }