perf evlist: Add reference count checking

Now the evlist is reference counted, add reference count checking so
that gets and puts are paired and easy to debug. Reference count
checking is documented here:
https://perfwiki.github.io/main/reference-count-checking/

This large patch is adding accessors to evlist functions and switching
to their use. There was some minor renaming as evlist__mmap is now an
accessor to the mmap variable, and the original evlist__mmap is
renamed to evlist__do_mmap.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alice Rogers <alice.mei.rogers@gmail.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

1 files changed, 64 insertions, 26 deletions

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 5482b68b8c0b..58d8644bf06a 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1546,7 +1546,7 @@ static int pyrf_evlist__init(struct pyrf_evlist *pevlist,
 	}
 	threads = ((struct pyrf_thread_map *)pthreads)->threads;
 	cpus = ((struct pyrf_cpu_map *)pcpus)->cpus;
-	perf_evlist__set_maps(&pevlist->evlist->core, cpus, threads);
+	perf_evlist__set_maps(evlist__core(pevlist->evlist), cpus, threads);
 
 	return 0;
 }
@@ -1559,23 +1559,29 @@ static void pyrf_evlist__delete(struct pyrf_evlist *pevlist)
 
 static PyObject *pyrf_evlist__all_cpus(struct pyrf_evlist *pevlist)
 {
-	struct pyrf_cpu_map *pcpu_map = PyObject_New(struct pyrf_cpu_map, &pyrf_cpu_map__type);
+	struct pyrf_cpu_map *pcpu_map;
+
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
 
+	pcpu_map = PyObject_New(struct pyrf_cpu_map, &pyrf_cpu_map__type);
 	if (pcpu_map)
-		pcpu_map->cpus = perf_cpu_map__get(pevlist->evlist->core.all_cpus);
+		pcpu_map->cpus = perf_cpu_map__get(evlist__core(pevlist->evlist)->all_cpus);
 
 	return (PyObject *)pcpu_map;
 }
 
 static PyObject *pyrf_evlist__metrics(struct pyrf_evlist *pevlist)
 {
-	PyObject *list = PyList_New(/*len=*/0);
+	PyObject *list;
 	struct rb_node *node;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	list = PyList_New(/*len=*/0);
 	if (!list)
 		return NULL;
 
-	for (node = rb_first_cached(&pevlist->evlist->metric_events.entries); node;
+	for (node = rb_first_cached(&evlist__metric_events(pevlist->evlist)->entries); node;
 	     node = rb_next(node)) {
 		struct metric_event *me = container_of(node, struct metric_event, nd);
 		struct list_head *pos;
@@ -1678,10 +1684,12 @@ static PyObject *pyrf_evlist__compute_metric(struct pyrf_evlist *pevlist,
 	double result = 0;
 	struct evsel *metric_evsel = NULL;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
 	if (!PyArg_ParseTuple(args, "sii", &metric, &cpu, &thread))
 		return NULL;
 
-	for (node = rb_first_cached(&pevlist->evlist->metric_events.entries);
+	for (node = rb_first_cached(&evlist__metric_events(pevlist->evlist)->entries);
 	     mexp == NULL && node;
 	     node = rb_next(node)) {
 		struct metric_event *me = container_of(node, struct metric_event, nd);
@@ -1742,15 +1750,18 @@ done:
 static PyObject *pyrf_evlist__mmap(struct pyrf_evlist *pevlist,
 				   PyObject *args, PyObject *kwargs)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
 	static char *kwlist[] = { "pages", "overwrite", NULL };
 	int pages = 128, overwrite = false;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ii", kwlist,
 					 &pages, &overwrite))
 		return NULL;
 
-	if (evlist__mmap(evlist, pages) < 0) {
+	if (evlist__do_mmap(evlist, pages) < 0) {
 		PyErr_SetFromErrno(PyExc_OSError);
 		return NULL;
 	}
@@ -1762,10 +1773,13 @@ static PyObject *pyrf_evlist__mmap(struct pyrf_evlist *pevlist,
 static PyObject *pyrf_evlist__poll(struct pyrf_evlist *pevlist,
 				   PyObject *args, PyObject *kwargs)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
 	static char *kwlist[] = { "timeout", NULL };
 	int timeout = -1, n;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i", kwlist, &timeout))
 		return NULL;
 
@@ -1782,13 +1796,18 @@ static PyObject *pyrf_evlist__get_pollfd(struct pyrf_evlist *pevlist,
 					 PyObject *args __maybe_unused,
 					 PyObject *kwargs __maybe_unused)
 {
-	struct evlist *evlist = pevlist->evlist;
-        PyObject *list = PyList_New(0);
+	struct evlist *evlist;
+	PyObject *list;
 	int i;
 
-	for (i = 0; i < evlist->core.pollfd.nr; ++i) {
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
+	list = PyList_New(0);
+
+	for (i = 0; i < evlist__core(evlist)->pollfd.nr; ++i) {
 		PyObject *file;
-		file = PyFile_FromFd(evlist->core.pollfd.entries[i].fd, "perf", "r", -1,
+		file = PyFile_FromFd(evlist__core(evlist)->pollfd.entries[i].fd, "perf", "r", -1,
 				     NULL, NULL, NULL, 0);
 		if (file == NULL)
 			goto free_list;
@@ -1811,28 +1830,33 @@ static PyObject *pyrf_evlist__add(struct pyrf_evlist *pevlist,
 				  PyObject *args,
 				  PyObject *kwargs __maybe_unused)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
 	PyObject *pevsel;
 	struct evsel *evsel;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
 	if (!PyArg_ParseTuple(args, "O!", &pyrf_evsel__type, &pevsel))
 		return NULL;
 
 	CHECK_INITIALIZED(((struct pyrf_evsel *)pevsel)->evsel, "evsel");
 
 	evsel = ((struct pyrf_evsel *)pevsel)->evsel;
-	evsel->core.idx = evlist->core.nr_entries;
+	CHECK_INITIALIZED(evsel, "evsel");
+
+	evsel->core.idx = evlist__nr_entries(evlist);
 	evlist__add(evlist, evsel__get(evsel));
 
-	return Py_BuildValue("i", evlist->core.nr_entries);
+	return Py_BuildValue("i", evlist__nr_entries(evlist));
 }
 
 static struct mmap *get_md(struct evlist *evlist, int cpu)
 {
 	int i;
 
-	for (i = 0; i < evlist->core.nr_mmaps; i++) {
-		struct mmap *md = &evlist->mmap[i];
+	for (i = 0; i < evlist__core(evlist)->nr_mmaps; i++) {
+		struct mmap *md = &evlist__mmap(evlist)[i];
 
 		if (md->core.cpu.cpu == cpu)
 			return md;
@@ -1844,13 +1868,16 @@ static struct mmap *get_md(struct evlist *evlist, int cpu)
 static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 					  PyObject *args, PyObject *kwargs)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
 	union perf_event *event;
 	int sample_id_all = 1, cpu;
 	static char *kwlist[] = { "cpu", "sample_id_all", NULL };
 	struct mmap *md;
 	int err;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|i", kwlist,
 					 &cpu, &sample_id_all))
 		return NULL;
@@ -1901,8 +1928,11 @@ end:
 static PyObject *pyrf_evlist__open(struct pyrf_evlist *pevlist,
 				   PyObject *args, PyObject *kwargs)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
+
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
 
+	evlist = pevlist->evlist;
 	if (evlist__open(evlist) < 0) {
 		PyErr_SetFromErrno(PyExc_OSError);
 		return NULL;
@@ -1914,8 +1944,11 @@ static PyObject *pyrf_evlist__open(struct pyrf_evlist *pevlist,
 
 static PyObject *pyrf_evlist__close(struct pyrf_evlist *pevlist)
 {
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
 
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
+
+	evlist = pevlist->evlist;
 	evlist__close(evlist);
 
 	Py_INCREF(Py_None);
@@ -1940,8 +1973,11 @@ static PyObject *pyrf_evlist__config(struct pyrf_evlist *pevlist)
 		.no_buffering        = true,
 		.no_inherit          = true,
 	};
-	struct evlist *evlist = pevlist->evlist;
+	struct evlist *evlist;
+
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
 
+	evlist = pevlist->evlist;
 	evlist__config(evlist, &opts, &callchain_param);
 	Py_INCREF(Py_None);
 	return Py_None;
@@ -1949,6 +1985,7 @@ static PyObject *pyrf_evlist__config(struct pyrf_evlist *pevlist)
 
 static PyObject *pyrf_evlist__disable(struct pyrf_evlist *pevlist)
 {
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
 	evlist__disable(pevlist->evlist);
 	Py_INCREF(Py_None);
 	return Py_None;
@@ -1956,6 +1993,7 @@ static PyObject *pyrf_evlist__disable(struct pyrf_evlist *pevlist)
 
 static PyObject *pyrf_evlist__enable(struct pyrf_evlist *pevlist)
 {
+	CHECK_INITIALIZED(pevlist->evlist, "evlist");
 	evlist__enable(pevlist->evlist);
 	Py_INCREF(Py_None);
 	return Py_None;
@@ -2050,7 +2088,7 @@ static Py_ssize_t pyrf_evlist__length(PyObject *obj)
 	if (!pevlist->evlist)
 		return 0;
 
-	return pevlist->evlist->core.nr_entries;
+	return evlist__nr_entries(pevlist->evlist);
 }
 
 static PyObject *pyrf_evsel__from_evsel(struct evsel *evsel)
@@ -2069,7 +2107,7 @@ static PyObject *pyrf_evlist__item(PyObject *obj, Py_ssize_t i)
 	struct pyrf_evlist *pevlist = (void *)obj;
 	struct evsel *pos;
 
-	if (!pevlist->evlist || i >= pevlist->evlist->core.nr_entries) {
+	if (!pevlist->evlist || i >= evlist__nr_entries(pevlist->evlist)) {
 		PyErr_SetString(PyExc_IndexError, "Index out of range");
 		return NULL;
 	}
@@ -2297,7 +2335,7 @@ static PyObject *pyrf__parse_events(PyObject *self, PyObject *args)
 	cpus = pcpus ? ((struct pyrf_cpu_map *)pcpus)->cpus : NULL;
 
 	parse_events_error__init(&err);
-	perf_evlist__set_maps(&evlist->core, cpus, threads);
+	perf_evlist__set_maps(evlist__core(evlist), cpus, threads);
 	if (parse_events(evlist, input, &err)) {
 		parse_events_error__print(&err, input);
 		PyErr_SetFromErrno(PyExc_OSError);
@@ -2330,7 +2368,7 @@ static PyObject *pyrf__parse_metrics(PyObject *self, PyObject *args)
 	threads = pthreads ? ((struct pyrf_thread_map *)pthreads)->threads : NULL;
 	cpus = pcpus ? ((struct pyrf_cpu_map *)pcpus)->cpus : NULL;
 
-	perf_evlist__set_maps(&evlist->core, cpus, threads);
+	perf_evlist__set_maps(evlist__core(evlist), cpus, threads);
 	ret = metricgroup__parse_groups(evlist, pmu ?: "all", input,
 					/*metric_no_group=*/ false,
 					/*metric_no_merge=*/ false,