/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
*
* log.c: Logging functions.
*
*/
#include <config.h>
#include "all.h"
#include "shmlog.h"
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#if !defined(__OpenBSD__)
#include <pthread.h>
#endif
#if defined(__APPLE__)
#include <sys/sysctl.h>
#endif
static bool debug_logging = false;
static bool verbose = false;
static FILE *errorfile;
char *errorfilename;
/* SHM logging variables */
/* The name for the SHM (/i3-log-%pid). Will end up on /dev/shm on most
* systems. Global so that we can clean up at exit. */
char *shmlogname = "";
/* Size limit for the SHM log, by default 25 MiB. Can be overwritten using the
* flag --shmlog-size. */
int shmlog_size = 0;
/* If enabled, logbuffer will point to a memory mapping of the i3 SHM log. */
static char *logbuffer;
/* A pointer (within logbuffer) where data will be written to next. */
static char *logwalk;
/* A pointer to the shmlog header */
static i3_shmlog_header *header;
/* A pointer to the byte where we last wrapped. Necessary to not print the
* left-overs at the end of the ringbuffer. */
static char *loglastwrap;
/* Size (in bytes) of the i3 SHM log. */
static int logbuffer_size;
/* File descriptor for shm_open. */
static int logbuffer_shm;
/* Size (in bytes) of physical memory */
static long long physical_mem_bytes;
/*
* Writes the offsets for the next write and for the last wrap to the
* shmlog_header.
* Necessary to print the i3 SHM log in the correct order.
*
*/
static void store_log_markers(void) {
header->offset_next_write = (logwalk - logbuffer);
header->offset_last_wrap = (loglastwrap - logbuffer);
header->size = logbuffer_size;
}
/*
* Initializes logging by creating an error logfile in /tmp (or
* XDG_RUNTIME_DIR, see get_process_filename()).
*
* Will be called twice if --shmlog-size is specified.
*
*/
void init_logging(void) {
if (!errorfilename) {
if (!(errorfilename = get_process_filename("errorlog")))
fprintf(stderr, "Could not initialize errorlog\n");
else {
errorfile = fopen(errorfilename, "w");
if (!errorfile) {
fprintf(stderr, "Could not initialize errorlog on %s: %s\n",
errorfilename, strerror(errno));
} else {
if (fcntl(fileno(errorfile), F_SETFD, FD_CLOEXEC)) {
fprintf(stderr, "Could not set close-on-exec flag\n");
}
}
}
}
if (physical_mem_bytes == 0) {
#if defined(__APPLE__)
int mib[2] = {CTL_HW, HW_MEMSIZE};
size_t length = sizeof(long long);
sysctl(mib, 2, &physical_mem_bytes, &length, NULL, 0);
#else
physical_mem_bytes = (long long)sysconf(_SC_PHYS_PAGES) *
sysconf(_SC_PAGESIZE);
#endif
}
/* Start SHM logging if shmlog_size is > 0. shmlog_size is SHMLOG_SIZE by
* default on development versions, and 0 on release versions. If it is
* not > 0, the user has turned it off, so let's close the logbuffer. */
if (shmlog_size > 0 && logbuffer == NULL)
open_logbuffer();
else if (shmlog_size <= 0 && logbuffer)
close_logbuffer();
atexit(purge_zerobyte_logfile);
}
/*
* Opens the logbuffer.
*
*/
void open_logbuffer(void) {
/* Reserve 1% of the RAM for the logfile, but at max 25 MiB.
* For 512 MiB of RAM this will lead to a 5 MiB log buffer.
* At the moment (2011-12-10), no testcase leads to an i3 log
* of more than ~ 600 KiB. */
logbuffer_size = min(physical_mem_bytes * 0.01, shmlog_size);
#if defined(__FreeBSD__)
sasprintf(&shmlogname, "/tmp/i3-log-%d", getpid());
#else
sasprintf(&shmlogname, "/i3-log-%d", getpid());
#endif
logbuffer_shm = shm_open(shmlogname, O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
if (logbuffer_shm == -1) {
fprintf(stderr, "Could not shm_open SHM segment for the i3 log: %s\n", strerror(errno));
return;
}
#if defined(__OpenBSD__) || defined(__APPLE__)
if (ftruncate(logbuffer_shm, logbuffer_size) == -1) {
fprintf(stderr, "Could not ftruncate SHM segment for the i3 log: %s\n", strerror(errno));
#else
int ret;
if ((ret = posix_fallocate(logbuffer_shm, 0, logbuffer_size)) != 0) {
fprintf(stderr, "Could not ftruncate SHM segment for the i3 log: %s\n", strerror(ret));
#endif
close(logbuffer_shm);
shm_unlink(shmlogname);
return;
}
logbuffer = mmap(NULL, logbuffer_size, PROT_READ | PROT_WRITE, MAP_SHARED, logbuffer_shm, 0);
if (logbuffer == MAP_FAILED) {
close_logbuffer();
fprintf(stderr, "Could not mmap SHM segment for the i3 log: %s\n", strerror(errno));
return;
}
/* Initialize with 0-bytes, just to be sure… */
memset(logbuffer, '\0', logbuffer_size);
header = (i3_shmlog_header *)logbuffer;
#if !defined(__OpenBSD__)
pthread_condattr_t cond_attr;
pthread_condattr_init(&cond_attr);
if (pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED) != 0)
fprintf(stderr, "pthread_condattr_setpshared() failed, i3-dump-log -f will not work!\n");
pthread_cond_init(&(header->condvar), &cond_attr);
#endif
logwalk = logbuffer + sizeof(i3_shmlog_header);
loglastwrap = logbuffer + logbuffer_size;
store_log_markers();
}
/*
* Closes the logbuffer.
*
*/
void close_logbuffer(void) {
close(logbuffer_shm);
shm_unlink(shmlogname);
free(shmlogname);
logbuffer = NULL;
shmlogname = "";
}
/*
* Set verbosity of i3. If verbose is set to true, informative messages will
* be printed to stdout. If verbose is set to false, only errors will be
* printed.
*
*/
void set_verbosity(bool _verbose) {
verbose = _verbose;
}
/*
* Get debug logging.
*
*/
bool get_debug_logging(void) {
return debug_logging;
}
/*
* Set debug logging.
*
*/
void set_debug_logging(const bool _debug_logging) {
debug_logging = _debug_logging;
}
/*
* Logs the given message to stdout (if print is true) while prefixing the
* current time to it. Additionally, the message will be saved in the i3 SHM
* log if enabled.
* This is to be called by *LOG() which includes filename/linenumber/function.
*
*/
static void vlog(const bool print, const char *fmt, va_list args) {
/* Precisely one page to not consume too much memory but to hold enough
* data to be useful. */
static char message[4096];
static struct tm result;
static time_t t;
static struct tm *tmp;
static size_t len;
/* Get current time */
t = time(NULL);
/* Convert time to local time (determined by the locale) */
tmp = localtime_r(&t, &result);
/* Generate time prefix */
len = strftime(message, sizeof(message), "%x %X - ", tmp);
/*
* logbuffer print
* ----------------
* true true format message, save, print
* true false format message, save
* false true print message only
* false false INVALID, never called
*/
if (!logbuffer) {
#ifdef DEBUG_TIMING
struct timeval tv;
gettimeofday(&tv, NULL);
printf("%s%d.%d - ", message, tv.tv_sec, tv.tv_usec);
#else
printf("%s", message);
#endif
vprintf(fmt, args);
} else {
len += vsnprintf(message + len, sizeof(message) - len, fmt, args);
if (len >= sizeof(message)) {
fprintf(stderr, "BUG: single log message > 4k\n");
/* vsnprintf returns the number of bytes that *would have been written*,
* not the actual amount written. Thus, limit len to sizeof(message) to avoid
* memory corruption and outputting garbage later. */
len = sizeof(message);
/* Punch in a newline so the next log message is not dangling at
* the end of the truncated message. */
message[len - 2] = '\n';
}
/* If there is no space for the current message in the ringbuffer, we
* need to wrap and write to the beginning again. */
if (len >= (size_t)(logbuffer_size - (logwalk - logbuffer))) {
loglastwrap = logwalk;
logwalk = logbuffer + sizeof(i3_shmlog_header);
store_log_markers();
header->wrap_count++;
}
/* Copy the buffer, move the write pointer to the byte after our
* current message. */
strncpy(logwalk, message, len);
logwalk += len;
store_log_markers();
#if !defined(__OpenBSD__)
/* Wake up all (i3-dump-log) processes waiting for condvar. */
pthread_cond_broadcast(&(header->condvar));
#endif
if (print)
fwrite(message, len, 1, stdout);
}
}
/*
* Logs the given message to stdout while prefixing the current time to it,
* but only if verbose mode is activated.
*
*/
void verboselog(char *fmt, ...) {
va_list args;
if (!logbuffer && !verbose)
return;
va_start(args, fmt);
vlog(verbose, fmt, args);
va_end(args);
}
/*
* Logs the given message to stdout while prefixing the current time to it.
*
*/
void errorlog(char *fmt, ...) {
va_list args;
va_start(args, fmt);
vlog(true, fmt, args);
va_end(args);
/* also log to the error logfile, if opened */
va_start(args, fmt);
vfprintf(errorfile, fmt, args);
fflush(errorfile);
va_end(args);
}
/*
* Logs the given message to stdout while prefixing the current time to it,
* but only if debug logging was activated.
* This is to be called by DLOG() which includes filename/linenumber
*
*/
void debuglog(char *fmt, ...) {
va_list args;
if (!logbuffer && !(debug_logging))
return;
va_start(args, fmt);
vlog(debug_logging, fmt, args);
va_end(args);
}
/*
* Deletes the unused log files. Useful if i3 exits immediately, eg.
* because --get-socketpath was called. We don't care for syscall
* failures. This function is invoked automatically when exiting.
*/
void purge_zerobyte_logfile(void) {
struct stat st;
char *slash;
if (!errorfilename)
return;
/* don't delete the log file if it contains something */
if ((stat(errorfilename, &st)) == -1 || st.st_size > 0)
return;
if (unlink(errorfilename) == -1)
return;
if ((slash = strrchr(errorfilename, '/')) != NULL) {
*slash = '\0';
/* possibly fails with ENOTEMPTY if there are files (or
* sockets) left. */
rmdir(errorfilename);
}
}