perf tools: Use an accessor to read thread comm

As the thread comm is going to be implemented by way of a more
complicated data structure than just a pointer to a string from the
thread struct, convert the readers of comm to use an accessor instead of
accessing it directly.

The accessor will be later overriden to support an enhanced comm
implementation.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-wr683zwy94hmj4ibogmnv9ce@git.kernel.org
[ Rename thread__comm_curr() to thread__comm_str() ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[ Fixed up some minor const pointer issues ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -721,10 +721,10 @@ int perf_event__preprocess_sample(const union perf_event *event,
 		return -1;
 
 	if (symbol_conf.comm_list &&
-	    !strlist__has_entry(symbol_conf.comm_list, thread->comm))
+	    !strlist__has_entry(symbol_conf.comm_list, thread__comm_str(thread)))
 		goto out_filtered;
 
-	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->tid);
+	dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), thread->tid);
 	/*
 	 * Have we already created the kernel maps for this machine?
 	 *

tools/perf/util/scripting-engines/trace-event-perl.c

@@ -273,7 +273,7 @@ static void perl_process_tracepoint(union perf_event *perf_event __maybe_unused,
 	int cpu = sample->cpu;
 	void *data = sample->raw_data;
 	unsigned long long nsecs = sample->time;
-	char *comm = thread->comm;
+	const char *comm = thread__comm_str(thread);
 
 	dSP;
 

tools/perf/util/scripting-engines/trace-event-python.c

@@ -250,7 +250,7 @@ static void python_process_tracepoint(union perf_event *perf_event
 	int cpu = sample->cpu;
 	void *data = sample->raw_data;
 	unsigned long long nsecs = sample->time;
-	char *comm = thread->comm;
+	const char *comm = thread__comm_str(thread);
 
 	t = PyTuple_New(MAX_FIELDS);
 	if (!t)
@@ -389,7 +389,7 @@ static void python_process_general_event(union perf_event *perf_event
 	pydict_set_item_string_decref(dict, "raw_buf", PyString_FromStringAndSize(
 			(const char *)sample->raw_data, sample->raw_size));
 	pydict_set_item_string_decref(dict, "comm",
-			PyString_FromString(thread->comm));
+			PyString_FromString(thread__comm_str(thread)));
 	if (al->map) {
 		pydict_set_item_string_decref(dict, "dso",
 			PyString_FromString(al->map->dso->name));

tools/perf/util/sort.c

@@ -42,7 +42,7 @@ static int repsep_snprintf(char *bf, size_t size, const char *fmt, ...)
 	return n;
 }
 
-static int64_t cmp_null(void *l, void *r)
+static int64_t cmp_null(const void *l, const void *r)
 {
 	if (!l && !r)
 		return 0;
@@ -63,8 +63,9 @@ sort__thread_cmp(struct hist_entry *left, struct hist_entry *right)
 static int hist_entry__thread_snprintf(struct hist_entry *he, char *bf,
 				       size_t size, unsigned int width)
 {
+	const char *comm = thread__comm_str(he->thread);
 	return repsep_snprintf(bf, size, "%*s:%5d", width - 6,
-			      he->thread->comm ?: "", he->thread->tid);
+			       comm ?: "", he->thread->tid);
 }
 
 struct sort_entry sort_thread = {
@@ -85,8 +86,8 @@ sort__comm_cmp(struct hist_entry *left, struct hist_entry *right)
 static int64_t
 sort__comm_collapse(struct hist_entry *left, struct hist_entry *right)
 {
-	char *comm_l = left->thread->comm;
-	char *comm_r = right->thread->comm;
+	const char *comm_l = thread__comm_str(left->thread);
+	const char *comm_r = thread__comm_str(right->thread);
 
 	if (!comm_l || !comm_r)
 		return cmp_null(comm_l, comm_r);
@@ -97,7 +98,7 @@ sort__comm_collapse(struct hist_entry *left, struct hist_entry *right)
 static int hist_entry__comm_snprintf(struct hist_entry *he, char *bf,
 				     size_t size, unsigned int width)
 {
-	return repsep_snprintf(bf, size, "%*s", width, he->thread->comm);
+	return repsep_snprintf(bf, size, "%*s", width, thread__comm_str(he->thread));
 }
 
 struct sort_entry sort_comm = {

tools/perf/util/thread.c

@@ -45,6 +45,11 @@ int thread__set_comm(struct thread *thread, const char *comm)
 	return err;
 }
 
+const char *thread__comm_str(const struct thread *thread)
+{
+	return thread->comm;
+}
+
 int thread__comm_len(struct thread *thread)
 {
 	if (!thread->comm_len) {
@@ -58,7 +63,7 @@ int thread__comm_len(struct thread *thread)
 
 size_t thread__fprintf(struct thread *thread, FILE *fp)
 {
-	return fprintf(fp, "Thread %d %s\n", thread->tid, thread->comm) +
+	return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 	       map_groups__fprintf(&thread->mg, verbose, fp);
 }
 

tools/perf/util/thread.h

@@ -35,6 +35,7 @@ static inline void thread__exited(struct thread *thread)
 
 int thread__set_comm(struct thread *self, const char *comm);
 int thread__comm_len(struct thread *self);
+const char *thread__comm_str(const struct thread *thread);
 void thread__insert_map(struct thread *self, struct map *map);
 int thread__fork(struct thread *self, struct thread *parent);
 size_t thread__fprintf(struct thread *thread, FILE *fp);