In order to make libtraceevent into a proper library, its API
should be straightforward. The tep_register_event_handler()
functions returns -1 in case it successfully registers the
new event handler. Such return code is used by the other library
APIs in case of an error. To unify the return logic of
tep_register_event_handler() with the other APIs, this patch
introduces enum tep_reg_handler, which is used by this function
as return value, to handle all possible successful return cases.
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
---
.../libtraceevent-reg_event_handler.txt | 12 +++++++++---
tools/lib/traceevent/event-parse.c | 10 ++++++++--
tools/lib/traceevent/event-parse.h | 5 +++++
3 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/tools/lib/traceevent/Documentation/libtraceevent-reg_event_handler.txt b/tools/lib/traceevent/Documentation/libtraceevent-reg_event_handler.txt
index 1a9269039f6c..ee9aa3a4151b 100644
--- a/tools/lib/traceevent/Documentation/libtraceevent-reg_event_handler.txt
+++ b/tools/lib/traceevent/Documentation/libtraceevent-reg_event_handler.txt
@@ -12,6 +12,11 @@ SYNOPSIS
--
*#include <event-parse.h>*
+enum *tep_reg_handler* {
+ _TEP_REGISTER_SUCCESS_,
+ _TEP_REGISTER_SUCCESS_OVERWRITE_,
+};
+
int *tep_register_event_handler*(struct tep_handle pass:[*]_tep_, int _id_, const char pass:[*]_sys_name_, const char pass:[*]_event_name_, tep_event_handler_func _func_, void pass:[*]_context_);
int *tep_unregister_event_handler*(struct tep_handle pass:[*]tep, int id, const char pass:[*]sys_name, const char pass:[*]event_name, tep_event_handler_func func, void pass:[*]_context_);
@@ -48,9 +53,10 @@ _context_ is custom context, set when the custom event handler is registered.
RETURN VALUE
------------
-The _tep_register_event_handler()_ function returns 0 in case of success.
-If there is not enough memory to complete the registration,
-TEP_ERRNO__MEM_ALLOC_FAILED is returned.
+The _tep_register_event_handler()_ function returns _TEP_REGISTER_SUCCESS_
+if the new handler is registered successfully or _TEP_REGISTER_SUCCESS_OVERWRITE_ if
+an existing handler is overwritten. If there is not enough memory to complete
+the registration, TEP_ERRNO__MEM_ALLOC_FAILED is returned.
The _tep_unregister_event_handler()_ function returns 0 if _func_ was removed
successful or, -1 if the event was not found.
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 2970358b4c10..a5048c1b9bec 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -6624,6 +6624,12 @@ static struct tep_event *search_event(struct tep_handle *pevent, int id,
*
* If @id is >= 0, then it is used to find the event.
* else @sys_name and @event_name are used.
+ *
+ * Returns:
+ * TEP_REGISTER_SUCCESS_OVERWRITE if an existing handler is overwritten
+ * TEP_REGISTER_SUCCESS if a new handler is registered successfully
+ * negative TEP_ERRNO_... in case of an error
+ *
*/
int tep_register_event_handler(struct tep_handle *pevent, int id,
const char *sys_name, const char *event_name,
@@ -6641,7 +6647,7 @@ int tep_register_event_handler(struct tep_handle *pevent, int id,
event->handler = func;
event->context = context;
- return 0;
+ return TEP_REGISTER_SUCCESS_OVERWRITE;
not_found:
/* Save for later use. */
@@ -6671,7 +6677,7 @@ int tep_register_event_handler(struct tep_handle *pevent, int id,
pevent->handlers = handle;
handle->context = context;
- return -1;
+ return TEP_REGISTER_SUCCESS;
}
static int handle_matches(struct event_handler *handler, int id,
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index c6bdebf0a0ed..e5bdce43b3b4 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -484,6 +484,11 @@ int tep_print_func_field(struct trace_seq *s, const char *fmt,
struct tep_event *event, const char *name,
struct tep_record *record, int err);
+enum tep_reg_handler {
+ TEP_REGISTER_SUCCESS = 0,
+ TEP_REGISTER_SUCCESS_OVERWRITE,
+};
+
int tep_register_event_handler(struct tep_handle *pevent, int id,
const char *sys_name, const char *event_name,
tep_event_handler_func func, void *context);
--
2.19.1
|