add a userspace tracing example

using lttng-ust, perf and tshark

traces can be shown in tracecompass

Signed-off-by: Manuel Traut <manut@linutronix.de>

1 files changed, 42 insertions, 0 deletions

diff --git a/application-devel/tracing/lttng-c/hellolttngust.c b/application-devel/tracing/lttng-c/hellolttngust.c
new file mode 100644
index 0000000..11c8bd7
--- /dev/null
+++ b/application-devel/tracing/lttng-c/hellolttngust.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include "hello-tp.h"
+
+int main(int argc, char *argv[])
+{
+    int x;
+
+    puts("Hello, World!\nPress Enter to continue...");
+
+    /*
+     * The following getchar() call is only placed here for the purpose
+     * of this demonstration, to pause the application in order for
+     * you to have time to list its tracepoints. It is not
+     * needed otherwise.
+     */
+    getchar();
+
+    /*
+     * A tracepoint() call.
+     *
+     * Arguments, as defined in hello-tp.h:
+     *
+     * 1. Tracepoint provider name   (required)
+     * 2. Tracepoint name            (required)
+     * 3. my_integer_arg             (first user-defined argument)
+     * 4. my_string_arg              (second user-defined argument)
+     *
+     * Notice the tracepoint provider and tracepoint names are
+     * NOT strings: they are in fact parts of variables that the
+     * macros in hello-tp.h create.
+     */
+    tracepoint(hello_world, my_first_tracepoint, 23, "hi there!");
+
+    for (x = 0; x < argc; ++x) {
+        tracepoint(hello_world, my_first_tracepoint, x, argv[x]);
+    }
+
+    puts("Quitting now!");
+    tracepoint(hello_world, my_first_tracepoint, x * x, "x^2");
+
+    return 0;
+}