src/errors.c

   1 /* nbdkit
   2  * Copyright (C) 2013-2017 Red Hat Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *
  12  * * Redistributions in binary form must reproduce the above copyright
  13  * notice, this list of conditions and the following disclaimer in the
  14  * documentation and/or other materials provided with the distribution.
  15  *
  16  * * Neither the name of Red Hat nor the names of its contributors may be
  17  * used to endorse or promote products derived from this software without
  18  * specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <stdarg.h>
  39 #include <string.h>
  40 #include <errno.h>
  41 #include <assert.h>
  42 #include <pthread.h>
  43
  44 #include "nbdkit-plugin.h"
  45 #include "internal.h"
  46
  47 /* Used to group piecemeal message construction into atomic output. */
  48 static pthread_mutex_t errors_lock = PTHREAD_MUTEX_INITIALIZER;
  49
  50 static void
  51 lock (void)
  52 {
  53   int r = pthread_mutex_lock (&errors_lock);
  54   assert (!r);
  55 }
  56
  57 static void
  58 unlock (void)
  59 {
  60   int r = pthread_mutex_unlock (&errors_lock);
  61   assert (!r);
  62 }
  63
  64 /* Called with lock taken. */
  65 static void
  66 prologue (const char *type)
  67 {
  68   const char *name = threadlocal_get_name ();
  69   size_t instance_num = threadlocal_get_instance_num ();
  70
  71   fprintf (stderr, "%s: ", program_name);
  72
  73   if (name) {
  74     fprintf (stderr, "%s", name);
  75     if (instance_num > 0)
  76       fprintf (stderr, "[%zu]", instance_num);
  77     fprintf (stderr, ": ");
  78   }
  79
  80   fprintf (stderr, "%s: ", type);
  81 }
  82
  83 /* Note: preserves the previous value of errno. */
  84 void
  85 nbdkit_vdebug (const char *fs, va_list args)
  86 {
  87   int err = errno;
  88
  89   if (!verbose)
  90     return;
  91
  92   lock ();
  93   prologue ("debug");
  94
  95   vfprintf (stderr, fs, args);
  96
  97   fprintf (stderr, "\n");
  98   unlock ();
  99
 100   errno = err;
 101 }
 102
 103 /* Note: preserves the previous value of errno. */
 104 void
 105 nbdkit_debug (const char *fs, ...)
 106 {
 107   va_list args;
 108   int err = errno;
 109
 110   if (!verbose)
 111     return;
 112
 113   lock ();
 114   prologue ("debug");
 115
 116   va_start (args, fs);
 117   vfprintf (stderr, fs, args);
 118   va_end (args);
 119
 120   fprintf (stderr, "\n");
 121   unlock ();
 122
 123   errno = err;
 124 }
 125
 126 /* Note: preserves the previous value of errno. */
 127 void
 128 nbdkit_verror (const char *fs, va_list args)
 129 {
 130   int err = errno;
 131
 132   lock ();
 133   prologue ("error");
 134
 135   vfprintf (stderr, fs, args);
 136
 137   fprintf (stderr, "\n");
 138   unlock ();
 139
 140   errno = err;
 141 }
 142
 143 /* Note: preserves the previous value of errno. */
 144 void
 145 nbdkit_error (const char *fs, ...)
 146 {
 147   va_list args;
 148   int err = errno;
 149
 150   lock ();
 151   prologue ("error");
 152
 153   va_start (args, fs);
 154   vfprintf (stderr, fs, args);
 155   va_end (args);
 156
 157   fprintf (stderr, "\n");
 158   unlock ();
 159
 160   errno = err;
 161 }
 162
 163 void
 164 nbdkit_set_error (int err)
 165 {
 166   threadlocal_set_error (err);
 167 }