i3
log.c
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1 /*
2  * vim:ts=4:sw=4:expandtab
3  *
4  * i3 - an improved dynamic tiling window manager
5  * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
6  *
7  * log.c: Setting of loglevels, logging functions.
8  *
9  */
10 #include <stdarg.h>
11 #include <stdio.h>
12 #include <string.h>
13 #include <stdbool.h>
14 #include <stdlib.h>
15 #include <sys/time.h>
16 #include <unistd.h>
17 #include <fcntl.h>
18 #include <sys/mman.h>
19 #include <sys/stat.h>
20 #include <errno.h>
21 
22 #include "util.h"
23 #include "log.h"
24 #include "i3.h"
25 #include "libi3.h"
26 #include "shmlog.h"
27 
28 /* loglevels.h is autogenerated at make time */
29 #include "loglevels.h"
30 
31 static uint64_t loglevel = 0;
32 static bool verbose = false;
33 static FILE *errorfile;
35 
36 /* SHM logging variables */
37 
38 /* The name for the SHM (/i3-log-%pid). Will end up on /dev/shm on most
39  * systems. Global so that we can clean up at exit. */
40 char *shmlogname = "";
41 /* Size limit for the SHM log, by default 25 MiB. Can be overwritten using the
42  * flag --shmlog-size. */
43 int shmlog_size = 0;
44 /* If enabled, logbuffer will point to a memory mapping of the i3 SHM log. */
45 static char *logbuffer;
46 /* A pointer (within logbuffer) where data will be written to next. */
47 static char *logwalk;
48 /* A pointer to the byte where we last wrapped. Necessary to not print the
49  * left-overs at the end of the ringbuffer. */
50 static char *loglastwrap;
51 /* Size (in bytes) of the i3 SHM log. */
52 static int logbuffer_size;
53 /* File descriptor for shm_open. */
54 static int logbuffer_shm;
55 
56 /*
57  * Writes the offsets for the next write and for the last wrap to the
58  * shmlog_header.
59  * Necessary to print the i3 SHM log in the correct order.
60  *
61  */
62 static void store_log_markers(void) {
64 
65  header->offset_next_write = (logwalk - logbuffer);
67  header->size = logbuffer_size;
68 }
69 
70 /*
71  * Initializes logging by creating an error logfile in /tmp (or
72  * XDG_RUNTIME_DIR, see get_process_filename()).
73  *
74  * Will be called twice if --shmlog-size is specified.
75  *
76  */
77 void init_logging(void) {
78  if (!errorfilename) {
79  if (!(errorfilename = get_process_filename("errorlog")))
80  ELOG("Could not initialize errorlog\n");
81  else {
82  errorfile = fopen(errorfilename, "w");
83  if (fcntl(fileno(errorfile), F_SETFD, FD_CLOEXEC)) {
84  ELOG("Could not set close-on-exec flag\n");
85  }
86  }
87  }
88 
89  /* If this is a debug build (not a release version), we will enable SHM
90  * logging by default, unless the user turned it off explicitly. */
91  if (logbuffer == NULL && shmlog_size > 0) {
92  /* Reserve 1% of the RAM for the logfile, but at max 25 MiB.
93  * For 512 MiB of RAM this will lead to a 5 MiB log buffer.
94  * At the moment (2011-12-10), no testcase leads to an i3 log
95  * of more than ~ 600 KiB. */
96  long long physical_mem_bytes = (long long)sysconf(_SC_PHYS_PAGES) *
97  sysconf(_SC_PAGESIZE);
98  logbuffer_size = min(physical_mem_bytes * 0.01, shmlog_size);
99  sasprintf(&shmlogname, "/i3-log-%d", getpid());
100  logbuffer_shm = shm_open(shmlogname, O_RDWR | O_CREAT | O_TRUNC, S_IREAD | S_IWRITE);
101  if (logbuffer_shm == -1) {
102  ELOG("Could not shm_open SHM segment for the i3 log: %s\n", strerror(errno));
103  return;
104  }
105 
106  if (ftruncate(logbuffer_shm, logbuffer_size) == -1) {
107  close(logbuffer_shm);
108  shm_unlink("/i3-log-");
109  ELOG("Could not ftruncate SHM segment for the i3 log: %s\n", strerror(errno));
110  return;
111  }
112 
113  logbuffer = mmap(NULL, logbuffer_size, PROT_READ | PROT_WRITE, MAP_SHARED, logbuffer_shm, 0);
114  if (logbuffer == MAP_FAILED) {
115  close(logbuffer_shm);
116  shm_unlink("/i3-log-");
117  ELOG("Could not mmap SHM segment for the i3 log: %s\n", strerror(errno));
118  logbuffer = NULL;
119  return;
120  }
121  logwalk = logbuffer + sizeof(i3_shmlog_header);
124  }
125 }
126 
127 /*
128  * Set verbosity of i3. If verbose is set to true, informative messages will
129  * be printed to stdout. If verbose is set to false, only errors will be
130  * printed.
131  *
132  */
133 void set_verbosity(bool _verbose) {
134  verbose = _verbose;
135 }
136 
137 /*
138  * Enables the given loglevel.
139  *
140  */
141 void add_loglevel(const char *level) {
142  /* Handle the special loglevel "all" */
143  if (strcasecmp(level, "all") == 0) {
144  loglevel = UINT64_MAX;
145  return;
146  }
147 
148  for (int i = 0; i < sizeof(loglevels) / sizeof(char*); i++) {
149  if (strcasecmp(loglevels[i], level) != 0)
150  continue;
151 
152  /* The position in the array (plus one) is the amount of times
153  * which we need to shift 1 to the left to get our bitmask for
154  * the specific loglevel. */
155  loglevel |= (1 << (i+1));
156  break;
157  }
158 }
159 
160 /*
161  * Logs the given message to stdout (if print is true) while prefixing the
162  * current time to it. Additionally, the message will be saved in the i3 SHM
163  * log if enabled.
164  * This is to be called by *LOG() which includes filename/linenumber/function.
165  *
166  */
167 static void vlog(const bool print, const char *fmt, va_list args) {
168  /* Precisely one page to not consume too much memory but to hold enough
169  * data to be useful. */
170  static char message[4096];
171  static struct tm result;
172  static time_t t;
173  static struct tm *tmp;
174  static size_t len;
175 
176  /* Get current time */
177  t = time(NULL);
178  /* Convert time to local time (determined by the locale) */
179  tmp = localtime_r(&t, &result);
180  /* Generate time prefix */
181  len = strftime(message, sizeof(message), "%x %X - ", tmp);
182 
183  /*
184  * logbuffer print
185  * ----------------
186  * true true format message, save, print
187  * true false format message, save
188  * false true print message only
189  * false false INVALID, never called
190  */
191  if (!logbuffer) {
192 #ifdef DEBUG_TIMING
193  struct timeval tv;
194  gettimeofday(&tv, NULL);
195  printf("%s%d.%d - ", message, tv.tv_sec, tv.tv_usec);
196 #else
197  printf("%s", message);
198 #endif
199  vprintf(fmt, args);
200  } else {
201  len += vsnprintf(message + len, sizeof(message) - len, fmt, args);
202  if (len < 0 ) {
203  fprintf(stderr, "BUG: something is overflowing here. Dropping the log entry\n");
204  return;
205  }
206 
207  if (len >= sizeof(message)) {
208  fprintf(stderr, "BUG: single log message > 4k\n");
209  }
210 
211  /* If there is no space for the current message (plus trailing
212  * nullbyte) in the ringbuffer, we need to wrap and write to the
213  * beginning again. */
214  if ((len+1) >= (logbuffer_size - (logwalk - logbuffer))) {
216  logwalk = logbuffer + sizeof(i3_shmlog_header);
217  }
218 
219  /* Copy the buffer, terminate it, move the write pointer to the byte after
220  * our current message. */
221  strncpy(logwalk, message, len);
222  logwalk[len] = '\0';
223  logwalk += len + 1;
224 
226 
227  if (print)
228  fwrite(message, len, 1, stdout);
229  }
230 }
231 
232 /*
233  * Logs the given message to stdout while prefixing the current time to it,
234  * but only if verbose mode is activated.
235  *
236  */
237 void verboselog(char *fmt, ...) {
238  va_list args;
239 
240  if (!logbuffer && !verbose)
241  return;
242 
243  va_start(args, fmt);
244  vlog(verbose, fmt, args);
245  va_end(args);
246 }
247 
248 /*
249  * Logs the given message to stdout while prefixing the current time to it.
250  *
251  */
252 void errorlog(char *fmt, ...) {
253  va_list args;
254 
255  va_start(args, fmt);
256  vlog(true, fmt, args);
257  va_end(args);
258 
259  /* also log to the error logfile, if opened */
260  va_start(args, fmt);
261  vfprintf(errorfile, fmt, args);
262  fflush(errorfile);
263  va_end(args);
264 }
265 
266 /*
267  * Logs the given message to stdout while prefixing the current time to it,
268  * but only if the corresponding debug loglevel was activated.
269  * This is to be called by DLOG() which includes filename/linenumber
270  *
271  */
272 void debuglog(uint64_t lev, char *fmt, ...) {
273  va_list args;
274 
275  if (!logbuffer && !(loglevel & lev))
276  return;
277 
278  va_start(args, fmt);
279  vlog((loglevel & lev), fmt, args);
280  va_end(args);
281 }