Use iterator on tracepoint probes instead of tracepoints per se

[lttng-ust.git] / liblttng-ust / lttng-ust-abi.c

diff --git a/liblttng-ust/lttng-ust-abi.c b/liblttng-ust/lttng-ust-abi.c
index dbf533069f9b252a88327f91b5c6b106f2489983..900f7834e196bcefeb4a953ac39d041d1ebec895 100644 (file)
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -28,16 +28,11 @@
 #include <urcu/compiler.h>
 #include <urcu/list.h>
 #include <lttng/ust-events.h>
-#include <lttng/usterr-signal-safe.h>
 #include <lttng/ust-version.h>
+#include <usterr-signal-safe.h>
+#include <helper.h>
 #include "ltt-tracer.h"
 #include "tracepoint-internal.h"
-#include <helper.h>
-
-struct ltt_tracepoint_list {
-       struct tracepoint_iter iter;
-       int got_first;
-};
 
 static int lttng_ust_abi_close_in_progress;
 
@@ -334,13 +329,14 @@ void lttng_metadata_create_events(int channel_objd)
                .name = "lttng_ust:metadata",
        };
        struct ltt_event *event;
+       int ret;
 
        /*
         * We tolerate no failure path after event creation. It will stay
         * invariant for the rest of the session.
         */
-       event = ltt_event_create(channel, &metadata_params, NULL);
-       if (!event) {
+       ret = ltt_event_create(channel, &metadata_params, NULL, &event);
+       if (ret < 0) {
                goto create_error;
        }
        return;
@@ -501,47 +497,26 @@ static const struct lttng_ust_objd_ops lttng_session_ops = {
        .cmd = lttng_session_cmd,
 };
 
-/*
- * beware: we don't keep the mutex over the send, but we must walk the
- * whole list each time we are called again. So sending one tracepoint
- * at a time means this is O(n^2). TODO: do as in the kernel and send
- * multiple tracepoints for each call to amortize this cost.
- */
-static
-void ltt_tracepoint_list_get(struct ltt_tracepoint_list *list,
-               char *tp_list_entry)
-{
-next:
-       if (!list->got_first) {
-               tracepoint_iter_start(&list->iter);
-               list->got_first = 1;
-               goto copy;
-       }
-       tracepoint_iter_next(&list->iter);
-copy:
-       if (!list->iter.tracepoint) {
-               tp_list_entry[0] = '\0';        /* end of list */
-       } else {
-               if (!strcmp((*list->iter.tracepoint)->name,
-                               "lttng_ust:metadata"))
-                       goto next;
-               memcpy(tp_list_entry, (*list->iter.tracepoint)->name,
-                       LTTNG_UST_SYM_NAME_LEN);
-       }
-}
-
 static
 long lttng_tracepoint_list_cmd(int objd, unsigned int cmd, unsigned long arg)
 {
-       struct ltt_tracepoint_list *list = objd_private(objd);
-       char *str = (char *) arg;
+       struct lttng_ust_tracepoint_list *list = objd_private(objd);
+       struct lttng_ust_tracepoint_iter *tp =
+               (struct lttng_ust_tracepoint_iter *) arg;
+       struct lttng_ust_tracepoint_iter *iter;
 
        switch (cmd) {
        case LTTNG_UST_TRACEPOINT_LIST_GET:
-               ltt_tracepoint_list_get(list, str);
-               if (str[0] == '\0')
+       {
+       retry:
+               iter = lttng_ust_tracepoint_list_get_iter_next(list);
+               if (!iter)
                        return -ENOENT;
+               if (!strcmp(iter->name, "lttng_ust:metadata"))
+                       goto retry;
+               memcpy(tp, iter, sizeof(*tp));
                return 0;
+       }
        default:
                return -EINVAL;
        }
@@ -551,7 +526,7 @@ static
 int lttng_abi_tracepoint_list(void)
 {
        int list_objd, ret;
-       struct ltt_tracepoint_list *list;
+       struct lttng_ust_tracepoint_list *list;
 
        list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops);
        if (list_objd < 0) {
@@ -565,8 +540,15 @@ int lttng_abi_tracepoint_list(void)
        }
        objd_set_private(list_objd, list);
 
+       /* populate list by walking on all registered probes. */
+       ret = ltt_probes_get_event_list(list);
+       if (ret) {
+               goto list_error;
+       }
        return list_objd;
 
+list_error:
+       free(list);
 alloc_error:
        {
                int err;
@@ -581,10 +563,10 @@ objd_error:
 static
 int lttng_release_tracepoint_list(int objd)
 {
-       struct ltt_tracepoint_list *list = objd_private(objd);
+       struct lttng_ust_tracepoint_list *list = objd_private(objd);
 
        if (list) {
-               tracepoint_iter_stop(&list->iter);
+               ltt_probes_prune_event_list(list);
                free(list);
                return 0;
        } else {
@@ -656,9 +638,8 @@ int lttng_abi_create_event(int channel_objd,
         * We tolerate no failure path after event creation. It will stay
         * invariant for the rest of the session.
         */
-       event = ltt_event_create(channel, event_param, NULL);
-       if (!event) {
-               ret = -EINVAL;
+       ret = ltt_event_create(channel, event_param, NULL, &event);
+       if (ret < 0) {
                goto event_error;
        }
        objd_set_private(event_objd, event);