remove rcu initialization as it is not needed with urcu-bp

[ust.git] / libust / tracectl.c

diff --git a/libust/tracectl.c b/libust/tracectl.c
index d4cb3efbcb7a97b5963106143b37640090b38822..57218a6bd62765b217a27338104b1cbb88a21061 100644 (file)
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -27,8 +27,6 @@
 #include <poll.h>
 #include <regex.h>
 
-#include <urcu-bp.h>
-
 #include <ust/marker.h>
 #include <ust/tracectl.h>
 #include "tracer.h"
@@ -125,15 +123,6 @@ static void print_markers(FILE *fp)
 
 static int init_socket(void);
 
-/* 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;
 void notif_cb(void)
 {
@@ -357,10 +346,7 @@ static int do_cmd_get_shmid(const char *recvbuf, struct ustcomm_source *src)
                }
        }
 
-       if(found) {
-               buffers_to_export--;
-       }
-       else {
+       if(!found) {
                ERR("channel not found (%s)", channel_and_cpu);
        }
 
@@ -509,7 +495,7 @@ static int do_cmd_get_subbuf_size(const char *recvbuf, struct ustcomm_source *sr
        return retval;
 }
 
-unsigned int poweroftwo(unsigned int x)
+static unsigned int poweroftwo(unsigned int x)
 {
     unsigned int power2 = 1;
     unsigned int hardcoded = 2147483648; /* FIX max 2^31 */
@@ -552,7 +538,6 @@ static int do_cmd_set_subbuf_size(const char *recvbuf, struct ustcomm_source *sr
        trace = _ltt_trace_find_setup(trace_name);
        if(trace == NULL) {
                ERR("cannot find trace!");
-               ltt_unlock_traces();
                retval = -1;
                goto end;
        }
@@ -573,9 +558,8 @@ static int do_cmd_set_subbuf_size(const char *recvbuf, struct ustcomm_source *sr
                ERR("unable to find channel");
        }
 
-       ltt_unlock_traces();
-
        end:
+       ltt_unlock_traces();
        return retval;
 }
 
@@ -608,7 +592,6 @@ static int do_cmd_set_subbuf_num(const char *recvbuf, struct ustcomm_source *src
        trace = _ltt_trace_find_setup(trace_name);
        if(trace == NULL) {
                ERR("cannot find trace!");
-               ltt_unlock_traces();
                retval = -1;
                goto end;
        }
@@ -629,9 +612,8 @@ static int do_cmd_set_subbuf_num(const char *recvbuf, struct ustcomm_source *src
                ERR("unable to find channel");
        }
 
-       ltt_unlock_traces();
-
        end:
+       ltt_unlock_traces();
        return retval;
 }
 
@@ -662,24 +644,19 @@ static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 
        ltt_lock_traces();
        trace = _ltt_trace_find(trace_name);
-       ltt_unlock_traces();
 
        if(trace == NULL) {
-               char *reply;
                int result;
 
                WARN("Cannot find trace. It was likely destroyed by the user.");
-               asprintf(&reply, "%s", "NOTFOUND");
-               result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
+               result = ustcomm_send_reply(&ustcomm_app.server, "NOTFOUND", src);
                if(result) {
                        ERR("ustcomm_send_reply failed");
-                       free(reply);
                        retval = -1;
-                       goto free_short_chan_name;
+                       goto unlock_traces;
                }
 
-               free(reply);
-               goto free_short_chan_name;
+               goto unlock_traces;
        }
 
        for(i=0; i<trace->nr_channels; i++) {
@@ -694,7 +671,7 @@ static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
                        bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
                        if(bc == NULL) {
                                ERR("malloc returned NULL");
-                               goto free_short_chan_name;
+                               goto unlock_traces;
                        }
                        bc->fd_consumer = src->fd;
                        bc->fd_producer = buf->data_ready_fd_read;
@@ -704,6 +681,14 @@ static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 
                        list_add(&bc->list, &blocked_consumers);
 
+                       /* Being here is the proof the daemon has mapped the buffer in its
+                        * memory. We may now decrement buffers_to_export.
+                        */
+                       if(atomic_long_read(&buf->consumed) == 0) {
+                               DBG("decrementing buffers_to_export");
+                               buffers_to_export--;
+                       }
+
                        break;
                }
        }
@@ -711,6 +696,9 @@ static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
                ERR("unable to find channel");
        }
 
+       unlock_traces:
+       ltt_unlock_traces();
+
        free_short_chan_name:
        free(ch_name);
 
@@ -765,21 +753,17 @@ static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 
        ltt_lock_traces();
        trace = _ltt_trace_find(trace_name);
-       ltt_unlock_traces();
 
        if(trace == NULL) {
                WARN("Cannot find trace. It was likely destroyed by the user.");
-               asprintf(&reply, "%s", "NOTFOUND");
-               result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
+               result = ustcomm_send_reply(&ustcomm_app.server, "NOTFOUND", src);
                if(result) {
                        ERR("ustcomm_send_reply failed");
-                       free(reply);
                        retval = -1;
-                       goto free_short_chan_name;
+                       goto unlock_traces;
                }
 
-               free(reply);
-               goto free_short_chan_name;
+               goto unlock_traces;
        }
 
        for(i=0; i<trace->nr_channels; i++) {
@@ -805,7 +789,7 @@ static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
                                ERR("ustcomm_send_reply failed");
                                free(reply);
                                retval = -1;
-                               goto free_channel_and_cpu;
+                               goto unlock_traces;
                        }
 
                        free(reply);
@@ -816,6 +800,8 @@ static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
                ERR("unable to find channel");
        }
 
+       unlock_traces:
+       ltt_unlock_traces();
        free_short_chan_name:
        free(ch_name);
        free_consumed_old_str:
@@ -831,8 +817,6 @@ void *listener_main(void *p)
 {
        int result;
 
-       ust_register_thread();
-
        DBG("LISTENER");
 
        for(;;) {
@@ -972,7 +956,7 @@ void *listener_main(void *p)
 
                        DBG("trace destroy");
 
-                       result = ltt_trace_destroy(trace_name);
+                       result = ltt_trace_destroy(trace_name, 0);
                        if(result < 0) {
                                ERR("ltt_trace_destroy failed");
                                return (void *)1;
@@ -1194,16 +1178,8 @@ static void __attribute__((constructor)) init()
         */
        pidunique = make_pidunique();
 
-       /* Initialize RCU in case the constructor order is not good. */
-       rcu_init();
-
-       /* It is important to do this before events start to be generated. */
-       ust_register_thread();
-
        DBG("Tracectl constructor");
 
-       /* Must create socket before signal handler to prevent races.
-         */
        result = init_socket();
        if(result == -1) {
                ERR("init_socket error");
@@ -1356,7 +1332,7 @@ static void destroy_traces(void)
                ERR("ltt_trace_stop error");
        }
 
-       result = ltt_trace_destroy("auto");
+       result = ltt_trace_destroy("auto", 0);
        if(result == -1) {
                ERR("ltt_trace_destroy error");
        }
@@ -1461,9 +1437,14 @@ static void ust_fork(void)
        struct blocked_consumer *deletable_bc = NULL;
        int result;
 
+       /* FIXME: technically, the locks could have been taken before the fork */
        DBG("ust: forking");
+
+       /* break lock if necessary */
+       ltt_unlock_traces();
+
        ltt_trace_stop("auto");
-       ltt_trace_destroy("auto");
+       ltt_trace_destroy("auto", 1);
        /* Delete all active connections */
        ustcomm_close_all_connections(&ustcomm_app.server);
 
@@ -1476,9 +1457,12 @@ static void ust_fork(void)
                list_del(&bc->list);
        }
 
+       ustcomm_free_app(&ustcomm_app);
+
+       buffers_to_export = 0;
        have_listener = 0;
-       create_listener();
        init_socket();
+       create_listener();
        ltt_trace_setup("auto");
        result = ltt_trace_set_type("auto", "ustrelay");
        if(result < 0) {