1explain_timerfd_create(3)  Library Functions Manual  explain_timerfd_create(3)
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NAME

6       explain_timerfd_create - explain timerfd_create(2) errors
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SYNOPSIS

9       #include <libexplain/timerfd_create.h>
10       const char *explain_timerfd_create(int clockid, int flags);
11       const char *explain_errno_timerfd_create(int errnum, int clockid, int
12       flags);
13       void explain_message_timerfd_create(char *message, int message_size,
14       int clockid, int flags);
15       void explain_message_errno_timerfd_create(char *message, int mes‐
16       sage_size, int errnum, int clockid, int flags);
17

DESCRIPTION

19       These functions may be used to obtain explanations for errors  returned
20       by the timerfd_create(2) system call.
21
22   explain_timerfd_create
23       const char *explain_timerfd_create(int clockid, int flags);
24
25       The explain_timerfd_create function is used to obtain an explanation of
26       an error returned by the timerfd_create(2) system call. The  least  the
27       message  will  contain  is the value of strerror(errno), but usually it
28       will do much better, and indicate the underlying cause in more detail.
29
30       The errno global variable will be used to obtain the error value to  be
31       decoded.
32
33       clockid The  original  clockid,  exactly  as passed to the timerfd_cre‐
34               ate(2) system call.
35
36       flags   The original flags, exactly as passed to the  timerfd_create(2)
37               system call.
38
39       Returns:
40               The message explaining the error. This message buffer is shared
41               by all libexplain functions which do not  supply  a  buffer  in
42               their argument list.  This will be overwritten by the next call
43               to any libexplain function which shares this buffer,  including
44               other threads.
45
46       Note: This function is not thread safe, because it shares a return buf‐
47       fer across all threads, and many other functions in this library.
48
49       Example: This function is intended to be used in a fashion  similar  to
50       the following example:
51              int result = timerfd_create(clockid, flags);
52              if (result < 0)
53              {
54                  fprintf(stderr, "%s\n", explain_timerfd_create(clockid,
55                  flags));
56                  exit(EXIT_FAILURE);
57              }
58
59       The   above   code   example   is   available   pre‐packaged   as   the
60       explain_timerfd_create_or_die(3) function.
61
62   explain_errno_timerfd_create
63       const char *explain_errno_timerfd_create(int errnum, int clockid, int
64       flags);
65
66       The explain_errno_timerfd_create function is used to obtain an explana‐
67       tion  of  an  error  returned by the timerfd_create(2) system call. The
68       least the message will contain is the  value  of  strerror(errno),  but
69       usually  it  will  do much better, and indicate the underlying cause in
70       more detail.
71
72       errnum  The error value to be decoded, usually obtained from the  errno
73               global  variable  just  before this function is called. This is
74               necessary if you need to call any code between the system  call
75               to  be explained and this function, because many libc functions
76               will alter the value of errno.
77
78       clockid The original clockid, exactly as  passed  to  the  timerfd_cre‐
79               ate(2) system call.
80
81       flags   The  original flags, exactly as passed to the timerfd_create(2)
82               system call.
83
84       Returns:
85               The message explaining the error. This message buffer is shared
86               by  all  libexplain  functions  which do not supply a buffer in
87               their argument list.  This will be overwritten by the next call
88               to  any libexplain function which shares this buffer, including
89               other threads.
90
91       Note: This function is not thread safe, because it shares a return buf‐
92       fer across all threads, and many other functions in this library.
93
94       Example:  This  function is intended to be used in a fashion similar to
95       the following example:
96              int result = timerfd_create(clockid, flags);
97              if (result < 0)
98              {
99                  int err = errno;
100                  fprintf(stderr, "%s\n", explain_errno_timerfd_create(err,
101                  clockid, flags));
102                  exit(EXIT_FAILURE);
103              }
104
105       The   above   code   example   is   available   pre‐packaged   as   the
106       explain_timerfd_create_or_die(3) function.
107
108   explain_message_timerfd_create
109       void explain_message_timerfd_create(char *message, int message_size,
110       int clockid, int flags);
111
112       The explain_message_timerfd_create function is used to obtain an expla‐
113       nation of an error returned by the timerfd_create(2) system  call.  The
114       least  the  message  will  contain is the value of strerror(errno), but
115       usually it will do much better, and indicate the  underlying  cause  in
116       more detail.
117
118       The  errno global variable will be used to obtain the error value to be
119       decoded.
120
121       message The location in which to store the returned message. If a suit‐
122               able message return buffer is supplied, this function is thread
123               safe.
124
125       message_size
126               The size in bytes  of  the  location  in  which  to  store  the
127               returned message.
128
129       clockid The  original  clockid,  exactly  as passed to the timerfd_cre‐
130               ate(2) system call.
131
132       flags   The original flags, exactly as passed to the  timerfd_create(2)
133               system call.
134
135       Example:  This  function is intended to be used in a fashion similar to
136       the following example:
137              int result = timerfd_create(clockid, flags);
138              if (result < 0)
139              {
140                  char message[3000];
141                  explain_message_timerfd_create(message, sizeof(message),
142                  clockid, flags);
143                  fprintf(stderr, "%s\n", message);
144                  exit(EXIT_FAILURE);
145              }
146
147       The   above   code   example   is   available   pre‐packaged   as   the
148       explain_timerfd_create_or_die(3) function.
149
150   explain_message_errno_timerfd_create
151       void explain_message_errno_timerfd_create(char *message, int mes‐
152       sage_size, int errnum, int clockid, int flags);
153
154       The  explain_message_errno_timerfd_create function is used to obtain an
155       explanation of an error returned by the timerfd_create(2) system  call.
156       The least the message will contain is the value of strerror(errno), but
157       usually it will do much better, and indicate the  underlying  cause  in
158       more detail.
159
160       message The location in which to store the returned message. If a suit‐
161               able message return buffer is supplied, this function is thread
162               safe.
163
164       message_size
165               The  size  in  bytes  of  the  location  in  which to store the
166               returned message.
167
168       errnum  The error value to be decoded, usually obtained from the  errno
169               global  variable  just  before this function is called. This is
170               necessary if you need to call any code between the system  call
171               to  be explained and this function, because many libc functions
172               will alter the value of errno.
173
174       clockid The original clockid, exactly as  passed  to  the  timerfd_cre‐
175               ate(2) system call.
176
177       flags   The  original flags, exactly as passed to the timerfd_create(2)
178               system call.
179
180       Example: This function is intended to be used in a fashion  similar  to
181       the following example:
182              int result = timerfd_create(clockid, flags);
183              if (result < 0)
184              {
185                  int err = errno;
186                  char message[3000];
187                  explain_message_errno_timerfd_create(message, sizeof(mes‐
188                  sage), err, clockid, flags);
189                  fprintf(stderr, "%s\n", message);
190                  exit(EXIT_FAILURE);
191              }
192
193       The   above   code   example   is   available   pre‐packaged   as   the
194       explain_timerfd_create_or_die(3) function.
195

SEE ALSO

197       timerfd_create(2)
198               timers that notify via file descriptors
199
200       explain_timerfd_create_or_die(3)
201               timers that notify via file descriptors and report errors
202
204       libexplain version 0.40
205       Copyright (C) 2009 Peter Miller
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209                                                     explain_timerfd_create(3)
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