Permalink
Browse files

i3-dump-log: enable shmlog on demand

fixes #3055
  • Loading branch information...
stapelberg committed Nov 26, 2017
1 parent c07936d commit 1facb450c0088d662c4c76ee97f0b0151f746288
Showing with 78 additions and 16 deletions.
  1. +77 −15 i3-dump-log/main.c
  2. +1 −1 testcases/t/207-shmlog.t
View
@@ -25,6 +25,7 @@
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <signal.h>
#include "libi3.h"
#include "shmlog.h"
@@ -38,6 +39,29 @@ static uint32_t wrap_count;
static i3_shmlog_header *header;
static char *logbuffer,
*walk;
static int ipcfd = -1;
static volatile bool interrupted = false;
static void sighandler(int signal) {
interrupted = true;
}
static void disable_shmlog(void) {
const char *disablecmd = "debuglog off; shmlog off";
if (ipc_send_message(ipcfd, strlen(disablecmd),
I3_IPC_MESSAGE_TYPE_COMMAND, (uint8_t *)disablecmd) != 0)
err(EXIT_FAILURE, "IPC send");
/* Ensure the command was sent by waiting for the reply: */
uint32_t reply_length = 0;
uint8_t *reply = NULL;
if (ipc_recv_message(ipcfd, I3_IPC_REPLY_TYPE_COMMAND,
&reply_length, &reply) != 0) {
err(EXIT_FAILURE, "IPC recv");
}
free(reply);
}
static int check_for_wrap(void) {
if (wrap_count == header->wrap_count)
@@ -59,6 +83,14 @@ static void print_till_end(void) {
walk += len;
}
void errorlog(char *fmt, ...) {
va_list args;
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
}
int main(int argc, char *argv[]) {
int o, option_index = 0;
bool verbose = false;
@@ -123,15 +155,35 @@ int main(int argc, char *argv[]) {
exit(1);
}
if (root_atom_contents("I3_CONFIG_PATH", conn, screen) != NULL) {
fprintf(stderr, "i3-dump-log: ERROR: i3 is running, but SHM logging is not enabled.\n\n");
if (!is_debug_build()) {
fprintf(stderr, "i3-dump-log: ERROR: i3 is running, but SHM logging is not enabled. Enabling SHM log until cancelled\n\n");
ipcfd = ipc_connect(NULL);
const char *enablecmd = "debuglog on; shmlog 5242880";
if (ipc_send_message(ipcfd, strlen(enablecmd),
I3_IPC_MESSAGE_TYPE_COMMAND, (uint8_t *)enablecmd) != 0)
err(EXIT_FAILURE, "IPC send");
/* By the time we receive a reply, I3_SHMLOG_PATH is set: */
uint32_t reply_length = 0;
uint8_t *reply = NULL;
if (ipc_recv_message(ipcfd, I3_IPC_REPLY_TYPE_COMMAND,
&reply_length, &reply) != 0) {
err(EXIT_FAILURE, "IPC recv");
}
free(reply);
atexit(disable_shmlog);
/* Retry: */
shmname = root_atom_contents("I3_SHMLOG_PATH", NULL, 0);
if (shmname == NULL && !is_debug_build()) {
fprintf(stderr, "You seem to be using a release version of i3:\n %s\n\n", I3_VERSION);
fprintf(stderr, "Release versions do not use SHM logging by default,\ntherefore i3-dump-log does not work.\n\n");
fprintf(stderr, "Please follow this guide instead:\nhttps://i3wm.org/docs/debugging-release-version.html\n");
exit(1);
}
}
errx(EXIT_FAILURE, "Cannot get I3_SHMLOG_PATH atom contents. Is i3 running on this display?");
if (shmname == NULL) {
errx(EXIT_FAILURE, "Cannot get I3_SHMLOG_PATH atom contents. Is i3 running on this display?");
}
}
if (*shmname == '\0')
@@ -182,22 +234,32 @@ int main(int argc, char *argv[]) {
print_till_end();
#if !defined(__OpenBSD__)
if (follow) {
/* Since pthread_cond_wait() expects a mutex, we need to provide one.
if (!follow) {
return 0;
}
/* Handle SIGINT gracefully to invoke atexit handlers, if any. */
struct sigaction action;
action.sa_handler = sighandler;
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
sigaction(SIGINT, &action, NULL);
/* Since pthread_cond_wait() expects a mutex, we need to provide one.
* To not lock i3 (that’s bad, mhkay?) we just define one outside of
* the shared memory. */
pthread_mutex_t dummy_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_lock(&dummy_mutex);
while (1) {
pthread_cond_wait(&(header->condvar), &dummy_mutex);
/* If this was not a spurious wakeup, print the new lines. */
if (header->offset_next_write != offset_next_write) {
offset_next_write = header->offset_next_write;
print_till_end();
}
pthread_mutex_t dummy_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_lock(&dummy_mutex);
while (!interrupted) {
pthread_cond_wait(&(header->condvar), &dummy_mutex);
/* If this was not a spurious wakeup, print the new lines. */
if (header->offset_next_write != offset_next_write) {
offset_next_write = header->offset_next_write;
print_till_end();
}
}
#endif
#endif
exit(0);
return 0;
}
View
@@ -54,7 +54,7 @@ like($stderr, qr#^$#, 'stderr empty');
# 3: change size of the shared memory log buffer and verify old content is gone
################################################################################
cmd 'shmlog ' . (23 * 1024 * 1024);
cmd 'shmlog ' . (1 * 1024 * 1024);
run [ 'i3-dump-log' ],
'>', \$stdout,

0 comments on commit 1facb45

Please sign in to comment.