2 #define I3__FILE__ "log.c"
4 * vim:ts=4:sw=4:expandtab
6 * i3 - an improved dynamic tiling window manager
7 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
9 * log.c: Logging functions.
31 #if defined(__APPLE__)
32 #include <sys/sysctl.h>
35 static bool debug_logging = false;
36 static bool verbose = false;
37 static FILE *errorfile;
40 /* SHM logging variables */
42 /* The name for the SHM (/i3-log-%pid). Will end up on /dev/shm on most
43 * systems. Global so that we can clean up at exit. */
44 char *shmlogname = "";
45 /* Size limit for the SHM log, by default 25 MiB. Can be overwritten using the
46 * flag --shmlog-size. */
48 /* If enabled, logbuffer will point to a memory mapping of the i3 SHM log. */
49 static char *logbuffer;
50 /* A pointer (within logbuffer) where data will be written to next. */
52 /* A pointer to the shmlog header */
53 static i3_shmlog_header *header;
54 /* A pointer to the byte where we last wrapped. Necessary to not print the
55 * left-overs at the end of the ringbuffer. */
56 static char *loglastwrap;
57 /* Size (in bytes) of the i3 SHM log. */
58 static int logbuffer_size;
59 /* File descriptor for shm_open. */
60 static int logbuffer_shm;
63 * Writes the offsets for the next write and for the last wrap to the
65 * Necessary to print the i3 SHM log in the correct order.
68 static void store_log_markers(void) {
69 header->offset_next_write = (logwalk - logbuffer);
70 header->offset_last_wrap = (loglastwrap - logbuffer);
71 header->size = logbuffer_size;
75 * Initializes logging by creating an error logfile in /tmp (or
76 * XDG_RUNTIME_DIR, see get_process_filename()).
78 * Will be called twice if --shmlog-size is specified.
81 void init_logging(void) {
83 if (!(errorfilename = get_process_filename("errorlog")))
84 fprintf(stderr, "Could not initialize errorlog\n");
86 errorfile = fopen(errorfilename, "w");
87 if (fcntl(fileno(errorfile), F_SETFD, FD_CLOEXEC)) {
88 fprintf(stderr, "Could not set close-on-exec flag\n");
92 /* Start SHM logging if shmlog_size is > 0. shmlog_size is SHMLOG_SIZE by
93 * default on development versions, and 0 on release versions. If it is
94 * not > 0, the user has turned it off, so let's close the logbuffer. */
95 if (shmlog_size > 0 && logbuffer == NULL)
97 else if (shmlog_size <= 0 && logbuffer)
99 atexit(purge_zerobyte_logfile);
103 * Opens the logbuffer.
106 void open_logbuffer(void) {
107 /* Reserve 1% of the RAM for the logfile, but at max 25 MiB.
108 * For 512 MiB of RAM this will lead to a 5 MiB log buffer.
109 * At the moment (2011-12-10), no testcase leads to an i3 log
110 * of more than ~ 600 KiB. */
111 long long physical_mem_bytes;
112 #if defined(__APPLE__)
113 int mib[2] = {CTL_HW, HW_MEMSIZE};
114 size_t length = sizeof(long long);
115 sysctl(mib, 2, &physical_mem_bytes, &length, NULL, 0);
117 physical_mem_bytes = (long long)sysconf(_SC_PHYS_PAGES) *
118 sysconf(_SC_PAGESIZE);
120 logbuffer_size = min(physical_mem_bytes * 0.01, shmlog_size);
121 #if defined(__FreeBSD__)
122 sasprintf(&shmlogname, "/tmp/i3-log-%d", getpid());
124 sasprintf(&shmlogname, "/i3-log-%d", getpid());
126 logbuffer_shm = shm_open(shmlogname, O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
127 if (logbuffer_shm == -1) {
128 fprintf(stderr, "Could not shm_open SHM segment for the i3 log: %s\n", strerror(errno));
132 #if defined(__OpenBSD__) || defined(__APPLE__)
133 if (ftruncate(logbuffer_shm, logbuffer_size) == -1) {
134 fprintf(stderr, "Could not ftruncate SHM segment for the i3 log: %s\n", strerror(errno));
137 if ((ret = posix_fallocate(logbuffer_shm, 0, logbuffer_size)) != 0) {
138 fprintf(stderr, "Could not ftruncate SHM segment for the i3 log: %s\n", strerror(ret));
140 close(logbuffer_shm);
141 shm_unlink(shmlogname);
145 logbuffer = mmap(NULL, logbuffer_size, PROT_READ | PROT_WRITE, MAP_SHARED, logbuffer_shm, 0);
146 if (logbuffer == MAP_FAILED) {
148 fprintf(stderr, "Could not mmap SHM segment for the i3 log: %s\n", strerror(errno));
152 /* Initialize with 0-bytes, just to be sure… */
153 memset(logbuffer, '\0', logbuffer_size);
155 header = (i3_shmlog_header *)logbuffer;
157 pthread_condattr_t cond_attr;
158 pthread_condattr_init(&cond_attr);
159 if (pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED) != 0)
160 fprintf(stderr, "pthread_condattr_setpshared() failed, i3-dump-log -f will not work!\n");
161 pthread_cond_init(&(header->condvar), &cond_attr);
163 logwalk = logbuffer + sizeof(i3_shmlog_header);
164 loglastwrap = logbuffer + logbuffer_size;
169 * Closes the logbuffer.
172 void close_logbuffer(void) {
173 close(logbuffer_shm);
174 shm_unlink(shmlogname);
181 * Set verbosity of i3. If verbose is set to true, informative messages will
182 * be printed to stdout. If verbose is set to false, only errors will be
186 void set_verbosity(bool _verbose) {
194 bool get_debug_logging(void) {
195 return debug_logging;
202 void set_debug_logging(const bool _debug_logging) {
203 debug_logging = _debug_logging;
207 * Logs the given message to stdout (if print is true) while prefixing the
208 * current time to it. Additionally, the message will be saved in the i3 SHM
210 * This is to be called by *LOG() which includes filename/linenumber/function.
213 static void vlog(const bool print, const char *fmt, va_list args) {
214 /* Precisely one page to not consume too much memory but to hold enough
215 * data to be useful. */
216 static char message[4096];
217 static struct tm result;
219 static struct tm *tmp;
222 /* Get current time */
224 /* Convert time to local time (determined by the locale) */
225 tmp = localtime_r(&t, &result);
226 /* Generate time prefix */
227 len = strftime(message, sizeof(message), "%x %X - ", tmp);
232 * true true format message, save, print
233 * true false format message, save
234 * false true print message only
235 * false false INVALID, never called
240 gettimeofday(&tv, NULL);
241 printf("%s%d.%d - ", message, tv.tv_sec, tv.tv_usec);
243 printf("%s", message);
247 len += vsnprintf(message + len, sizeof(message) - len, fmt, args);
248 if (len >= sizeof(message)) {
249 fprintf(stderr, "BUG: single log message > 4k\n");
251 /* vsnprintf returns the number of bytes that *would have been written*,
252 * not the actual amount written. Thus, limit len to sizeof(message) to avoid
253 * memory corruption and outputting garbage later. */
254 len = sizeof(message);
256 /* Punch in a newline so the next log message is not dangling at
257 * the end of the truncated message. */
258 message[len - 2] = '\n';
261 /* If there is no space for the current message in the ringbuffer, we
262 * need to wrap and write to the beginning again. */
263 if (len >= (size_t)(logbuffer_size - (logwalk - logbuffer))) {
264 loglastwrap = logwalk;
265 logwalk = logbuffer + sizeof(i3_shmlog_header);
267 header->wrap_count++;
270 /* Copy the buffer, move the write pointer to the byte after our
271 * current message. */
272 strncpy(logwalk, message, len);
277 /* Wake up all (i3-dump-log) processes waiting for condvar. */
278 pthread_cond_broadcast(&(header->condvar));
281 fwrite(message, len, 1, stdout);
286 * Logs the given message to stdout while prefixing the current time to it,
287 * but only if verbose mode is activated.
290 void verboselog(char *fmt, ...) {
293 if (!logbuffer && !verbose)
297 vlog(verbose, fmt, args);
302 * Logs the given message to stdout while prefixing the current time to it.
305 void errorlog(char *fmt, ...) {
309 vlog(true, fmt, args);
312 /* also log to the error logfile, if opened */
314 vfprintf(errorfile, fmt, args);
320 * Logs the given message to stdout while prefixing the current time to it,
321 * but only if debug logging was activated.
322 * This is to be called by DLOG() which includes filename/linenumber
325 void debuglog(char *fmt, ...) {
328 if (!logbuffer && !(debug_logging))
332 vlog(debug_logging, fmt, args);
337 * Deletes the unused log files. Useful if i3 exits immediately, eg.
338 * because --get-socketpath was called. We don't care for syscall
339 * failures. This function is invoked automatically when exiting.
341 void purge_zerobyte_logfile(void) {
348 /* don't delete the log file if it contains something */
349 if ((stat(errorfilename, &st)) == -1 || st.st_size > 0)
352 if (unlink(errorfilename) == -1)
355 if ((slash = strrchr(errorfilename, '/')) != NULL) {
357 /* possibly fails with ENOTEMPTY if there are files (or
359 rmdir(errorfilename);