enhancements to the constructor system
[ust.git] / libust / tracectl.c
index 8be2cd03228edcde4196f7d211623a5a36b14d4f..cf2b89ef1dcdd4f8e1f97974715801e625828712 100644 (file)
@@ -1,3 +1,21 @@
+/* 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 <stdio.h>
 #include <stdint.h>
 #include <signal.h>
 #include <fcntl.h>
 #include <poll.h>
 
+#include <urcu.h>
+
 #include "marker.h"
 #include "tracer.h"
 #include "localerr.h"
 #include "ustcomm.h"
 #include "relay.h" /* FIXME: remove */
+#include "marker-control.h"
 
 //#define USE_CLONE
 
@@ -83,12 +104,15 @@ static void print_markers(FILE *fp)
        unlock_markers();
 }
 
-void do_command(struct tracecmd *cmd)
-{
-}
+static int init_socket(void);
+
+/* This needs to be called whenever a new thread is created. It notifies
+ * liburcu of the new thread.
+ */
 
-void receive_commands()
+void ust_register_thread(void)
 {
+       rcu_register_thread();
 }
 
 int fd_notif = -1;
@@ -113,7 +137,7 @@ void notif_cb(void)
        }
 }
 
-static int inform_consumer_daemon(void)
+static void inform_consumer_daemon(void)
 {
        ustcomm_request_consumer(getpid(), "metadata");
        ustcomm_request_consumer(getpid(), "ust");
@@ -145,10 +169,11 @@ 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 -1;
+               return;
        }
 
        list_for_each_entry(bc, &blocked_consumers, list) {
@@ -200,16 +225,15 @@ void process_blocked_consumers(void)
 
 }
 
-int listener_main(void *p)
+void *listener_main(void *p)
 {
        int result;
 
+       ust_register_thread();
+
        DBG("LISTENER");
 
        for(;;) {
-               uint32_t size;
-               struct sockaddr_un addr;
-               socklen_t addrlen = sizeof(addr);
                char trace_name[] = "auto";
                char trace_type[] = "ustrelay";
                char *recvbuf;
@@ -252,19 +276,19 @@ int listener_main(void *p)
                        result = ltt_trace_setup(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_setup failed");
-                               return;
+                               return (void *)1;
                        }
 
                        result = ltt_trace_set_type(trace_name, trace_type);
                        if(result < 0) {
                                ERR("ltt_trace_set_type failed");
-                               return;
+                               return (void *)1;
                        }
 
                        result = ltt_trace_alloc(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_alloc failed");
-                               return;
+                               return (void *)1;
                        }
 
                        inform_consumer_daemon();
@@ -281,13 +305,13 @@ int listener_main(void *p)
                        result = ltt_trace_setup(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_setup failed");
-                               return;
+                               return (void *)1;
                        }
 
                        result = ltt_trace_set_type(trace_name, trace_type);
                        if(result < 0) {
                                ERR("ltt_trace_set_type failed");
-                               return;
+                               return (void *)1;
                        }
                }
                else if(!strcmp(recvbuf, "trace_alloc")) {
@@ -296,7 +320,7 @@ int listener_main(void *p)
                        result = ltt_trace_alloc(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_alloc failed");
-                               return;
+                               return (void *)1;
                        }
                }
                else if(!strcmp(recvbuf, "trace_start")) {
@@ -314,7 +338,7 @@ int listener_main(void *p)
                        result = ltt_trace_stop(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_stop failed");
-                               return;
+                               return (void *)1;
                        }
                }
                else if(!strcmp(recvbuf, "trace_destroy")) {
@@ -324,7 +348,7 @@ int listener_main(void *p)
                        result = ltt_trace_destroy(trace_name);
                        if(result < 0) {
                                ERR("ltt_trace_destroy failed");
-                               return;
+                               return (void *)1;
                        }
                }
                else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
@@ -346,15 +370,14 @@ int listener_main(void *p)
                        ltt_unlock_traces();
 
                        if(trace == NULL) {
-                               CPRINTF("cannot find trace!");
-                               return 1;
+                               ERR("cannot find trace!");
+                               return (void *)1;
                        }
 
                        for(i=0; i<trace->nr_channels; i++) {
                                struct rchan *rchan = trace->channels[i].trans_channel_data;
                                struct rchan_buf *rbuf = rchan->buf;
                                struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
-                               struct ltt_channel_buf_struct *ltt_buf = ltt_channel->buf;
 
                                if(!strcmp(trace->channels[i].channel_name, channel_name)) {
                                        char *reply;
@@ -394,8 +417,8 @@ int listener_main(void *p)
                        ltt_unlock_traces();
 
                        if(trace == NULL) {
-                               CPRINTF("cannot find trace!");
-                               return 1;
+                               ERR("cannot find trace!");
+                               return (void *)1;
                        }
 
                        for(i=0; i<trace->nr_channels; i++) {
@@ -404,8 +427,8 @@ int listener_main(void *p)
                                if(!strcmp(trace->channels[i].channel_name, channel_name)) {
                                        char *reply;
 
-                                       DBG("the n_subbufs for the requested channel is %d", rchan->n_subbufs);
-                                       asprintf(&reply, "%d", rchan->n_subbufs);
+                                       DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
+                                       asprintf(&reply, "%zd", rchan->n_subbufs);
 
                                        result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
                                        if(result) {
@@ -438,8 +461,8 @@ int listener_main(void *p)
                        ltt_unlock_traces();
 
                        if(trace == NULL) {
-                               CPRINTF("cannot find trace!");
-                               return 1;
+                               ERR("cannot find trace!");
+                               return (void *)1;
                        }
 
                        for(i=0; i<trace->nr_channels; i++) {
@@ -448,8 +471,8 @@ int listener_main(void *p)
                                if(!strcmp(trace->channels[i].channel_name, channel_name)) {
                                        char *reply;
 
-                                       DBG("the subbuf_size for the requested channel is %d", rchan->subbuf_size);
-                                       asprintf(&reply, "%d", rchan->subbuf_size);
+                                       DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
+                                       asprintf(&reply, "%zd", rchan->subbuf_size);
 
                                        result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
                                        if(result) {
@@ -489,8 +512,8 @@ int listener_main(void *p)
                        ltt_unlock_traces();
 
                        if(trace == NULL) {
-                               CPRINTF("cannot find trace!");
-                               return 1;
+                               ERR("cannot find trace!");
+                               return (void *)1;
                        }
 
                        for(i=0; i<trace->nr_channels; i++) {
@@ -499,9 +522,6 @@ int listener_main(void *p)
                                if(!strcmp(trace->channels[i].channel_name, channel_name)) {
                                        struct rchan_buf *rbuf = rchan->buf;
                                        struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
-                                       char *reply;
-                                       long consumed_old=0;
-                                       int fd;
                                        struct blocked_consumer *bc;
 
                                        bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
@@ -555,8 +575,8 @@ int listener_main(void *p)
                        ltt_unlock_traces();
 
                        if(trace == NULL) {
-                               CPRINTF("cannot find trace!");
-                               return 1;
+                               ERR("cannot find trace!");
+                               return (void *)1;
                        }
 
                        for(i=0; i<trace->nr_channels; i++) {
@@ -571,11 +591,11 @@ int listener_main(void *p)
                                        result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
                                        if(result < 0) {
                                                WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
-                                               asprintf(&reply, "%s", "ERROR", consumed_old);
+                                               asprintf(&reply, "%s", "ERROR");
                                        }
                                        else {
                                                DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
-                                               asprintf(&reply, "%s", "OK", consumed_old);
+                                               asprintf(&reply, "%s", "OK");
                                        }
 
                                        result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
@@ -597,7 +617,6 @@ int listener_main(void *p)
                        char *channel_slash_name = nth_token(recvbuf, 1);
                        char channel_name[256]="";
                        char marker_name[256]="";
-                       struct marker_iter iter;
 
                        result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 
@@ -616,7 +635,6 @@ int listener_main(void *p)
                        char *channel_slash_name = nth_token(recvbuf, 1);
                        char *marker_name;
                        char *channel_name;
-                       struct marker_iter iter;
 
                        result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 
@@ -648,8 +666,8 @@ int listener_main(void *p)
 //                     ltt_unlock_traces();
 //
 //                     if(trace == NULL) {
-//                             CPRINTF("cannot find trace!");
-//                             return 1;
+//                             ERR("cannot find trace!");
+//                             return (void *)1;
 //                     }
 //
 //                     for(i=0; i<trace->nr_channels; i++) {
@@ -687,24 +705,31 @@ int listener_main(void *p)
        }
 }
 
-static char listener_stack[16384];
+int have_listener = 0;
 
 void create_listener(void)
 {
-       int result;
+#ifdef USE_CLONE
        static char listener_stack[16384];
-       //char *listener_stack = malloc(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
@@ -733,18 +758,22 @@ 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");
-//     }
+       int result;
+
+       if(mysocketfile[0] == '\0')
+               return;
+
+       result = unlink(mysocketfile);
+       if(result == -1) {
+               PERROR("unlink");
+       }
 }
+#endif
 
 static int init_signal_handler(void)
 {
@@ -782,8 +811,8 @@ static void auto_probe_connect(struct marker *m)
        int result;
 
        result = ltt_marker_connect(m->channel, m->name, "default");
-       if(result)
-               ERR("ltt_marker_connect");
+       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);
 }
@@ -791,17 +820,18 @@ static void auto_probe_connect(struct marker *m)
 static void __attribute__((constructor(101))) init0()
 {
        DBG("UST_AUTOPROBE constructor");
-       if(getenv("UST_AUTOPROBE")) {
-               marker_set_new_marker_cb(auto_probe_connect);
-       }
 }
 
-static void fini(void);
-
 static void __attribute__((constructor(1000))) init()
 {
        int result;
 
+       /* 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");
 
        /* Must create socket before signal handler to prevent races.
@@ -817,6 +847,34 @@ static void __attribute__((constructor(1000))) init()
                return;
        }
 
+       if(getenv("UST_AUTOPROBE")) {
+               struct marker_iter iter;
+
+               DBG("IN AUTOPROBE\n");
+
+               /* 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
+                */
+               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");
+               while(iter.marker) {
+                       DBG("now iterating on marker %s\n", iter.marker->name);
+                       auto_probe_connect(iter.marker);
+                       marker_iter_next(&iter);
+               }
+       }
+
        if(getenv("UST_TRACE")) {
                char trace_name[] = "auto";
                char trace_type[] = "ustrelay";
@@ -871,6 +929,8 @@ 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()
 {
        int result;
@@ -889,9 +949,27 @@ static void __attribute__((destructor)) fini()
                ERR("ltt_trace_destroy error");
        }
 
-       /* FIXME: wait for the consumer to be done */
-       //DBG("waiting 5 sec for consume");
-       //sleep(5);
-
        destroy_socket();
 }
+#endif
+
+/* 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)
+{
+       DBG("ust: forking");
+       ltt_trace_stop("auto");
+       ltt_trace_destroy("auto");
+       ltt_trace_alloc("auto");
+       ltt_trace_start("auto");
+       init_socket();
+       have_listener = 0;
+       create_listener();
+       ustcomm_request_consumer(getpid(), "metadata");
+       ustcomm_request_consumer(getpid(), "ust");
+}
+
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