[PATCH v2 7/7] libtracefs: Add API tracefs_synth_complete()

[Steven Rostedt <rostedt@goodmis.org>]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Add tracefs_synth_complete() to tell if the synthetic event is a full
synthetic event (can create a synthetic event) or not, where it has only
enough information to create the starting histogram.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 Documentation/libtracefs-synth2.txt |  4 ++++
 include/tracefs.h                   |  1 +
 src/tracefs-hist.c                  | 13 +++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/Documentation/libtracefs-synth2.txt b/Documentation/libtracefs-synth2.txt
index 5d34c4f60469..44693b394f29 100644
--- a/Documentation/libtracefs-synth2.txt
+++ b/Documentation/libtracefs-synth2.txt
@@ -17,6 +17,7 @@ int tracefs_synth_destroy(struct tracefs_instance pass:[*]instance,
 			  struct tracefs_synth pass:[*]synth);
 int tracefs_synth_show(struct trace_seq pass:[*]seq, struct tracefs_instance pass:[*]instance,
 		       struct tracefs_synth pass:[*]synth);
+bool tracefs_synth_complete(struct tracefs_synth pass:[*]synth);
 struct tracefs_hist pass:[*]tracefs_synth_get_start_hist(struct tracefs_synth pass:[*]synth);
 
 --
@@ -53,6 +54,9 @@ this may fail as busy.
 the synthetic event in the given _instance_, it will write the echo commands to
 manually create it in the _seq_ given.
 
+*tracefs_synth_complete*() returns true if the synthetic event _synth_ has both
+a starting and ending event.
+
 *tracefs_synth_get_start_hist*() returns a struct tracefs_hist descriptor describing
 the histogram used to create the synthetic event.
 
diff --git a/include/tracefs.h b/include/tracefs.h
index 8148bd57224b..55f82392b004 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -467,6 +467,7 @@ int tracefs_synth_append_end_filter(struct tracefs_synth *synth,
 				    const char *field,
 				    enum tracefs_compare compare,
 				    const char *val);
+bool tracefs_synth_complete(struct tracefs_synth *synth);
 struct tracefs_hist *tracefs_synth_get_start_hist(struct tracefs_synth *synth);
 int tracefs_synth_create(struct tracefs_instance *instance,
 			 struct tracefs_synth *synth);
diff --git a/src/tracefs-hist.c b/src/tracefs-hist.c
index 379f75c7de24..305e3e720341 100644
--- a/src/tracefs-hist.c
+++ b/src/tracefs-hist.c
@@ -1354,6 +1354,19 @@ static int verify_state(struct tracefs_synth *synth)
 	return 0;
 }
 
+/**
+ * tracefs_synth_complete - tell if the tracefs_synth is complete or not
+ * @synth: The synthetic event to get the start hist from.
+ *
+ * Retruns true if the synthetic event @synth has both a start and
+ * end event (ie. a synthetic event, or just a histogram), and
+ * false otherwise.
+ */
+bool tracefs_synth_complete(struct tracefs_synth *synth)
+{
+	return synth && synth->start_event && synth->end_event;
+}
+
 /**
  * tracefs_synth_get_start_hist - Return the histogram of the start event
  * @synth: The synthetic event to get the start hist from.
-- 
2.30.2