#include <sched.h>
#include <fcntl.h>
#include <poll.h>
+#include <regex.h>
-#include <urcu.h>
+#include <urcu-bp.h>
#include "marker.h"
#include "tracer.h"
char consumer_stack[10000];
+/* This should only be accessed by the constructor, before the creation
+ * of the listener, and then only by the listener.
+ */
+s64 pidunique = -1LL;
+
struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
static struct ustcomm_app ustcomm_app;
uint16_t command;
};
-//struct listener_arg {
-// int pipe_fd;
-//};
+/* volatile because shared between the listener and the main thread */
+volatile sig_atomic_t buffers_to_export = 0;
struct trctl_msg {
/* size: the size of all the fields except size itself */
struct list_head list;
};
+static long long make_pidunique(void)
+{
+ s64 retval;
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+
+ retval = tv.tv_sec;
+ retval <<= 32;
+ retval |= tv.tv_usec;
+
+ return retval;
+}
+
static void print_markers(FILE *fp)
{
struct marker_iter iter;
marker_iter_start(&iter);
while(iter.marker) {
- fprintf(fp, "marker: %s_%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
+ fprintf(fp, "marker: %s/%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
marker_iter_next(&iter);
}
unlock_markers();
}
}
-static void inform_consumer_daemon(void)
+/* Ask the daemon to collect a trace called trace_name and being
+ * produced by this pid.
+ *
+ * The trace must be at least allocated. (It can also be started.)
+ * This is because _ltt_trace_find is used.
+ */
+
+static void inform_consumer_daemon(const char *trace_name)
{
- ustcomm_request_consumer(getpid(), "metadata");
- ustcomm_request_consumer(getpid(), "ust");
+ int i;
+ struct ltt_trace_struct *trace;
+ pid_t pid = getpid();
+ int result;
+
+ ltt_lock_traces();
+
+ trace = _ltt_trace_find(trace_name);
+ if(trace == NULL) {
+ WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
+ goto finish;
+ }
+
+ for(i=0; i < trace->nr_channels; i++) {
+ result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
+ if(result == -1) {
+ WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
+ /* continue even if fail */
+ }
+ buffers_to_export++;
+ }
+
+ finish:
+ ltt_unlock_traces();
}
void process_blocked_consumers(void)
continue;
}
- DBG("received a message! it's: %s\n", recvbuf);
+ DBG("received a message! it's: %s", recvbuf);
len = strlen(recvbuf);
if(!strcmp(recvbuf, "print_markers")) {
return (void *)1;
}
- inform_consumer_daemon();
+ inform_consumer_daemon(trace_name);
result = ltt_trace_start(trace_name);
if(result < 0) {
break;
}
}
+
+ buffers_to_export--;
}
else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
struct ltt_trace_struct *trace;
WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
}
}
+ else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
+ char *reply;
+
+ asprintf(&reply, "%lld", pidunique);
+
+ result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
+ if(result) {
+ ERR("listener: get_pidunique: ustcomm_send_reply failed");
+ goto next_cmd;
+ }
+
+ free(reply);
+ }
// else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
// struct ltt_trace_struct *trace;
// char trace_name[] = "auto";
}
}
-int have_listener = 0;
+volatile sig_atomic_t have_listener = 0;
void create_listener(void)
{
#ifdef USE_CLONE
static char listener_stack[16384];
+ int result;
#else
pthread_t thread;
#endif
- if(have_listener)
+ if(have_listener) {
+ WARN("not creating listener because we already had one");
return;
+ }
#ifdef USE_CLONE
- result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
+ result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
if(result == -1) {
perror("clone");
return;
have_listener = 1;
}
-/* The signal handler itself. Signals must be setup so there cannot be
- nested signals. */
-
-void sighandler(int sig)
-{
- static char have_listener = 0;
- DBG("sighandler");
-
- if(!have_listener) {
- create_listener();
- have_listener = 1;
- }
-}
-
-/* Called by the app signal handler to chain it to us. */
-
-void chain_signal(void)
-{
- sighandler(USTSIGNAL);
-}
-
static int init_socket(void)
{
return ustcomm_init_app(getpid(), &ustcomm_app);
}
-/* FIXME: reenable this to delete socket file. */
+#define AUTOPROBE_DISABLED 0
+#define AUTOPROBE_ENABLE_ALL 1
+#define AUTOPROBE_ENABLE_REGEX 2
+static int autoprobe_method = AUTOPROBE_DISABLED;
+static regex_t autoprobe_regex;
-#if 0
-static void destroy_socket(void)
+static void auto_probe_connect(struct marker *m)
{
int result;
- if(mysocketfile[0] == '\0')
- return;
-
- result = unlink(mysocketfile);
- if(result == -1) {
- PERROR("unlink");
- }
-}
-#endif
-
-static int init_signal_handler(void)
-{
- /* Attempt to handler SIGIO. If the main program wants to
- * handle it, fine, it'll override us. They it'll have to
- * use the chaining function.
- */
-
- int result;
- struct sigaction act;
+ char* concat_name = NULL;
+ const char *probe_name = "default";
- result = sigemptyset(&act.sa_mask);
- if(result == -1) {
- PERROR("sigemptyset");
- return -1;
+ if(autoprobe_method == AUTOPROBE_DISABLED) {
+ return;
}
-
- act.sa_handler = sighandler;
- act.sa_flags = SA_RESTART;
-
- /* Only defer ourselves. Also, try to restart interrupted
- * syscalls to disturb the traced program as little as possible.
- */
- result = sigaction(SIGIO, &act, NULL);
- if(result == -1) {
- PERROR("sigaction");
- return -1;
+ else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
+ result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
+ if(result == -1) {
+ ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
+ m->channel, m->name);
+ return;
+ }
+ if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
+ free(concat_name);
+ return;
+ }
+ free(concat_name);
}
- return 0;
-}
-
-static void auto_probe_connect(struct marker *m)
-{
- int result;
-
- result = ltt_marker_connect(m->channel, m->name, "default");
+ result = ltt_marker_connect(m->channel, m->name, probe_name);
if(result && result != -EEXIST)
ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
- DBG("just auto connected marker %s %s to probe default", m->channel, m->name);
-}
+ DBG("auto connected marker %s %s to probe default", m->channel, m->name);
-static void __attribute__((constructor(101))) init0()
-{
- DBG("UST_AUTOPROBE constructor");
}
-static void __attribute__((constructor(1000))) init()
+static void __attribute__((constructor)) init()
{
int result;
+ char* autoprobe_val = NULL;
+
+ /* Assign the pidunique, to be able to differentiate the processes with same
+ * pid, (before and after an exec).
+ */
+ pidunique = make_pidunique();
/* Initialize RCU in case the constructor order is not good. */
urcu_init();
/* It is important to do this before events start to be generated. */
ust_register_thread();
- DBG("UST_TRACE constructor");
+ DBG("Tracectl constructor");
/* Must create socket before signal handler to prevent races.
*/
ERR("init_socket error");
return;
}
- result = init_signal_handler();
- if(result == -1) {
- ERR("init_signal_handler error");
- return;
- }
- if(getenv("UST_AUTOPROBE")) {
+ create_listener();
+
+ autoprobe_val = getenv("UST_AUTOPROBE");
+ if(autoprobe_val) {
struct marker_iter iter;
- DBG("IN AUTOPROBE\n");
+ DBG("Autoprobe enabled.");
/* Ensure markers are initialized */
//init_markers();
/* first, set the callback that will connect the
* probe on new markers
*/
+ if(autoprobe_val[0] == '/') {
+ result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
+ if (result) {
+ char regexerr[150];
+
+ regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
+ ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
+ /* don't crash the application just for this */
+ }
+ else {
+ autoprobe_method = AUTOPROBE_ENABLE_REGEX;
+ }
+ }
+ else {
+ /* just enable all instrumentation */
+ autoprobe_method = AUTOPROBE_ENABLE_ALL;
+ }
+
marker_set_new_marker_cb(auto_probe_connect);
/* Now, connect the probes that were already registered. */
marker_iter_reset(&iter);
marker_iter_start(&iter);
- DBG("now iterating on markers already registered\n");
+ DBG("now iterating on markers already registered");
while(iter.marker) {
- DBG("now iterating on marker %s\n", iter.marker->name);
+ DBG("now iterating on marker %s", iter.marker->name);
auto_probe_connect(iter.marker);
marker_iter_next(&iter);
}
ERR("ltt_trace_start failed");
return;
}
- inform_consumer_daemon();
+
+ /* Do this after the trace is started in order to avoid creating confusion
+ * if the trace fails to start. */
+ inform_consumer_daemon(trace_name);
}
}
/* This is only called if we terminate normally, not with an unhandled signal,
- * so we cannot rely on it. */
+ * so we cannot rely on it. However, for now, LTTV requires that the header of
+ * the last sub-buffer contain a valid end time for the trace. This is done
+ * automatically only when the trace is properly stopped.
+ *
+ * If the traced program crashed, it is always possible to manually add the
+ * right value in the header, or to open the trace in text mode.
+ *
+ * FIXME: Fix LTTV so it doesn't need this.
+ */
-/* This destructor probably isn't needed, because ustd can do crash recovery. */
-#if 0
-static void __attribute__((destructor)) fini()
+static void destroy_traces(void)
{
int result;
if(result == -1) {
ERR("ltt_trace_destroy error");
}
+}
- destroy_socket();
+static int trace_recording(void)
+{
+ int retval = 0;
+ struct ltt_trace_struct *trace;
+
+ ltt_lock_traces();
+
+ list_for_each_entry(trace, <t_traces.head, list) {
+ if(trace->active) {
+ retval = 1;
+ break;
+ }
+ }
+
+ ltt_unlock_traces();
+
+ return retval;
+}
+
+#if 0
+static int have_consumer(void)
+{
+ return !list_empty(&blocked_consumers);
}
#endif
+int restarting_usleep(useconds_t usecs)
+{
+ struct timespec tv;
+ int result;
+
+ tv.tv_sec = 0;
+ tv.tv_nsec = usecs * 1000;
+
+ do {
+ result = nanosleep(&tv, &tv);
+ } while(result == -1 && errno == EINTR);
+
+ return result;
+}
+
+/* This destructor keeps the process alive for a few seconds in order
+ * to leave time to ustd to connect to its buffers. This is necessary
+ * for programs whose execution is very short. It is also useful in all
+ * programs when tracing is started close to the end of the program
+ * execution.
+ *
+ * FIXME: For now, this only works for the first trace created in a
+ * process.
+ */
+
+static void __attribute__((destructor)) keepalive()
+{
+ if(trace_recording() && buffers_to_export) {
+ int total = 0;
+ DBG("Keeping process alive for consumer daemon...");
+ while(buffers_to_export) {
+ const int interv = 200000;
+ restarting_usleep(interv);
+ total += interv;
+
+ if(total >= 3000000) {
+ WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
+ break;
+ }
+ }
+ DBG("Finally dying...");
+ }
+
+ destroy_traces();
+
+ ustcomm_fini_app(&ustcomm_app);
+}
+
+void ust_potential_exec(void)
+{
+ trace_mark(ust, potential_exec, MARK_NOARGS);
+
+ DBG("test");
+
+ keepalive();
+}
+
/* Notify ust that there was a fork. This needs to be called inside
* the new process, anytime a process whose memory is not shared with
* the parent is created. If this function is not called, the events
void ust_fork(void)
{
+ struct blocked_consumer *bc;
+ struct blocked_consumer *deletable_bc = NULL;
+ int result;
+
DBG("ust: forking");
ltt_trace_stop("auto");
ltt_trace_destroy("auto");
- ltt_trace_alloc("auto");
- ltt_trace_start("auto");
- init_socket();
+ /* Delete all active connections */
+ ustcomm_close_all_connections(&ustcomm_app.server);
+
+ /* Delete all blocked consumers */
+ list_for_each_entry(bc, &blocked_consumers, list) {
+ close(bc->fd_producer);
+ close(bc->fd_consumer);
+ free(deletable_bc);
+ deletable_bc = bc;
+ list_del(&bc->list);
+ }
+
have_listener = 0;
create_listener();
- ustcomm_request_consumer(getpid(), "metadata");
- ustcomm_request_consumer(getpid(), "ust");
+ init_socket();
+ ltt_trace_setup("auto");
+ result = ltt_trace_set_type("auto", "ustrelay");
+ if(result < 0) {
+ ERR("ltt_trace_set_type failed");
+ return;
+ }
+
+ ltt_trace_alloc("auto");
+ ltt_trace_start("auto");
+ inform_consumer_daemon("auto");
}