Implement LTTNG_UST_TRACEPOINT_LIST

[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 e7ef1579a575ff1212735b9f3f3c03cde46b7ed1..4b8a8e71d9e5b4548f8e3e3d2c0e7e676e514c96 100644 (file)
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -32,6 +32,9 @@
 #include "lttng/core.h"
 #include "ltt-tracer.h"
 
+static
+int lttng_abi_tracepoint_list(void);
+
 /*
  * Object descriptor table. Should be protected from concurrent access
  * by the caller.
@@ -197,6 +200,7 @@ static const struct lttng_ust_objd_ops lttng_channel_ops;
 static const struct lttng_ust_objd_ops lttng_metadata_ops;
 static const struct lttng_ust_objd_ops lttng_event_ops;
 static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops;
+static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops;
 
 enum channel_type {
        PER_CPU_CHANNEL,
@@ -233,26 +237,6 @@ objd_error:
        return ret;
 }
 
-#if 0
-static
-int lttng_abi_tracepoint_list(void)
-{
-       int list_objd, ret;
-
-       /* TODO: Create list private data */
-       list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops);
-       if (list_objd < 0) {
-               ret = list_objd;
-               goto objd_error;
-       }
-
-       return list_objd;
-
-objd_error:
-       return ret;
-}
-#endif //0
-
 static
 long lttng_abi_tracer_version(int objd,
        struct lttng_ust_tracer_version *v)
@@ -314,8 +298,7 @@ long lttng_cmd(int objd, unsigned int cmd, unsigned long arg)
                return lttng_abi_tracer_version(objd,
                                (struct lttng_ust_tracer_version *) arg);
        case LTTNG_UST_TRACEPOINT_LIST:
-               return -ENOSYS; //TODO
-               //return lttng_abi_tracepoint_list();
+               return lttng_abi_tracepoint_list();
        case LTTNG_UST_WAIT_QUIESCENT:
                synchronize_trace();
                return 0;
@@ -511,6 +494,95 @@ 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)
+{
+       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 {
+               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);
+
+       switch (cmd) {
+       case LTTNG_UST_TRACEPOINT_LIST_GET:
+               ltt_tracepoint_list_get(list, (char *) arg);
+               return 0;
+       default:
+               return -EINVAL;
+       }
+}
+
+static
+int lttng_abi_tracepoint_list(void)
+{
+       int list_objd, ret;
+       struct ltt_tracepoint_list *list;
+
+       list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops);
+       if (list_objd < 0) {
+               ret = list_objd;
+               goto objd_error;
+       }
+       list = zmalloc(sizeof(*list));
+       if (!list) {
+               ret = -ENOMEM;
+               goto alloc_error;
+       }
+       objd_set_private(list_objd, list);
+
+       return list_objd;
+
+alloc_error:
+       {
+               int err;
+
+               err = lttng_ust_objd_unref(list_objd);
+               assert(!err);
+       }
+objd_error:
+       return ret;
+}
+
+static
+int lttng_release_tracepoint_list(int objd)
+{
+       struct ltt_tracepoint_list *list = objd_private(objd);
+
+       if (list) {
+               tracepoint_iter_stop(&list->iter);
+               free(list);
+               return 0;
+       } else {
+               return -EINVAL;
+       }
+}
+
+static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops = {
+       .release = lttng_release_tracepoint_list,
+       .cmd = lttng_tracepoint_list_cmd,
+};
+
 struct stream_priv_data {
        struct lttng_ust_lib_ring_buffer *buf;
        struct ltt_channel *ltt_chan;