X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libust%2Ftracectl.c;h=b20fe696139ea413cbf419daea0190fb27ef675b;hb=b7ea1a1c8ed1cea410bb43c7cc6621c951e4b621;hp=277dbcd75d773f31f9c19f1056d49715d7dfabde;hpb=acbf228bbea7ed81ed3bfcb0158fc9d0547fe71d;p=ust.git diff --git a/libust/tracectl.c b/libust/tracectl.c index 277dbcd..b20fe69 100644 --- a/libust/tracectl.c +++ b/libust/tracectl.c @@ -1,3 +1,20 @@ +/* Copyright (C) 2009 Pierre-Marc Fournier + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + #define _GNU_SOURCE #include #include @@ -8,6 +25,9 @@ #include #include #include +#include + +#include #include "marker.h" #include "tracer.h" @@ -26,6 +46,11 @@ 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; @@ -35,6 +60,9 @@ struct tracecmd { /* no padding */ uint16_t command; }; +/* volatile because shared between the listener and the main thread */ +volatile sig_atomic_t buffers_to_export = 0; + //struct listener_arg { // int pipe_fd; //}; @@ -70,6 +98,20 @@ struct blocked_consumer { 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; @@ -79,18 +121,21 @@ static void print_markers(FILE *fp) 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(); } -void do_command(struct tracecmd *cmd) -{ -} +static int init_socket(void); -void receive_commands() +/* This needs to be called whenever a new thread is created. It notifies + * liburcu of the new thread. + */ + +void ust_register_thread(void) { + rcu_register_thread(); } int fd_notif = -1; @@ -115,10 +160,39 @@ void notif_cb(void) } } -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) @@ -147,7 +221,8 @@ void process_blocked_consumers(void) idx++; } - result = poll(fds, n_fds, 0); + while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR) + /* nothing */; if(result == -1) { PERROR("poll"); return; @@ -206,6 +281,8 @@ void *listener_main(void *p) { int result; + ust_register_thread(); + DBG("LISTENER"); for(;;) { @@ -227,7 +304,7 @@ void *listener_main(void *p) 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")) { @@ -266,7 +343,7 @@ void *listener_main(void *p) return (void *)1; } - inform_consumer_daemon(); + inform_consumer_daemon(trace_name); result = ltt_trace_start(trace_name); if(result < 0) { @@ -372,6 +449,8 @@ void *listener_main(void *p) break; } } + + buffers_to_export--; } else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) { struct ltt_trace_struct *trace; @@ -622,6 +701,19 @@ void *listener_main(void *p) 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"; @@ -680,22 +772,31 @@ void *listener_main(void *p) } } +volatile sig_atomic_t have_listener = 0; + void create_listener(void) { #ifdef USE_CLONE static char listener_stack[16384]; +#else + pthread_t thread; #endif + if(have_listener) + 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); if(result == -1) { perror("clone"); + return; } #else - pthread_t thread; pthread_create(&thread, NULL, listener_main, NULL); #endif + + have_listener = 1; } /* The signal handler itself. Signals must be setup so there cannot be @@ -703,12 +804,10 @@ void create_listener(void) void sighandler(int sig) { - static char have_listener = 0; DBG("sighandler"); if(!have_listener) { create_listener(); - have_listener = 1; } } @@ -724,23 +823,6 @@ static int init_socket(void) return ustcomm_init_app(getpid(), &ustcomm_app); } -/* FIXME: reenable this to delete socket file. */ - -#if 0 -static void destroy_socket(void) -{ - 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 @@ -772,30 +854,61 @@ static int init_signal_handler(void) return 0; } +#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; + static void auto_probe_connect(struct marker *m) { int result; - result = ltt_marker_connect(m->channel, m->name, "default"); + char* concat_name = NULL; + const char *probe_name = "default"; + + if(autoprobe_method == AUTOPROBE_DISABLED) { + return; + } + 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); + } + + 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"); - if(getenv("UST_AUTOPROBE")) { - marker_set_new_marker_cb(auto_probe_connect); - } } static void __attribute__((constructor(1000))) 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. */ @@ -810,6 +923,53 @@ static void __attribute__((constructor(1000))) init() return; } + autoprobe_val = getenv("UST_AUTOPROBE"); + if(autoprobe_val) { + struct marker_iter iter; + + DBG("Autoprobe enabled."); + + /* Ensure markers are initialized */ + //init_markers(); + + /* Ensure marker control is initialized, for the probe */ + init_marker_control(); + + /* 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"); + while(iter.marker) { + DBG("now iterating on marker %s", iter.marker->name); + auto_probe_connect(iter.marker); + marker_iter_next(&iter); + } + } + if(getenv("UST_TRACE")) { char trace_name[] = "auto"; char trace_type[] = "ustrelay"; @@ -851,7 +1011,10 @@ static void __attribute__((constructor(1000))) init() 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); } @@ -862,11 +1025,17 @@ static void __attribute__((constructor(1000))) init() } /* This is only called if we terminate normally, not with an unhandled signal, - * so we cannot rely on it. */ - -/* This destructor probably isn't needed, because ustd can do crash recovery. */ -#if 0 -static void __attribute__((destructor)) fini() + * 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. + */ + +static void destroy_traces(void) { int result; @@ -883,7 +1052,128 @@ static void __attribute__((destructor)) fini() if(result == -1) { ERR("ltt_trace_destroy error"); } +} + +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; +} - destroy_socket(); +#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); + + 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 + * of the new process will not be collected. + */ + +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"); + /* 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(); + 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"); +} +