[igt-dev] [PATCH i-g-t 01/74] lib: Introduce typed cleanups
Mauro Carvalho Chehab
mauro.chehab at linux.intel.com
Thu Sep 1 06:36:09 UTC 2022
From: Chris Wilson <chris at chris-wilson.co.uk>
Start introducing standard types with automatic cleanup courtesy of
gcc's __attribute__((cleanup)). As an example, we start with an fd
that will automatically call close() on going out of scope, and
crucially before atexit where we will want to check for resource leaks.
Suggested-by: Andrzej Hajda <andrzej.hajda at intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Andrzej Hajda <andrzej.hajda at intel.com>
Cc: Petri Latvala <petri.latvala at intel.com>
Acked-by: Nirmoy Das <nirmoy.das at linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at kernel.org>
---
lib/igt_core.c | 6 ++
lib/igt_core.h | 2 +
lib/igt_types.c | 17 +++++
lib/igt_types.h | 47 ++++++++++++
lib/meson.build | 1 +
lib/tests/bad_subtest_type.c | 19 +++++
lib/tests/igt_types.c | 136 +++++++++++++++++++++++++++++++++++
lib/tests/meson.build | 2 +
8 files changed, 230 insertions(+)
create mode 100644 lib/igt_types.c
create mode 100644 lib/igt_types.h
create mode 100644 lib/tests/bad_subtest_type.c
create mode 100644 lib/tests/igt_types.c
diff --git a/lib/igt_core.c b/lib/igt_core.c
index e7425326b7f0..dc6486c841f0 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -624,6 +624,12 @@ uint64_t igt_nsec_elapsed(struct timespec *start)
(uint64_t)NSEC_PER_SEC*(now.tv_sec - start->tv_sec));
}
+void __igt_assert_in_outer_scope(void)
+{
+ internal_assert(!in_subtest,
+ "must only be called outside of a subtest");
+}
+
bool __igt_fixture(void)
{
internal_assert(!in_fixture,
diff --git a/lib/igt_core.h b/lib/igt_core.h
index aa98e8ed8deb..f21723dec4bc 100644
--- a/lib/igt_core.h
+++ b/lib/igt_core.h
@@ -135,6 +135,8 @@ struct _GKeyFile *igt_load_igtrc(void);
*/
#define IGT_EXIT_ABORT 112
+void __igt_assert_in_outer_scope(void);
+
bool __igt_fixture(void);
void __igt_fixture_complete(void);
__noreturn void __igt_fixture_end(void);
diff --git a/lib/igt_types.c b/lib/igt_types.c
new file mode 100644
index 000000000000..7416b0fffc04
--- /dev/null
+++ b/lib/igt_types.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MIT
+/*
+* Copyright © 2022 Intel Corporation
+*/
+
+#include <unistd.h>
+
+#include "igt_types.h"
+
+void igt_cleanup_fd(int *fd)
+{
+ if (!fd || *fd < 0)
+ return;
+
+ close(*fd);
+ *fd = -1;
+}
diff --git a/lib/igt_types.h b/lib/igt_types.h
new file mode 100644
index 000000000000..1852026969ae
--- /dev/null
+++ b/lib/igt_types.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef IGT_TYPES_H
+#define IGT_TYPES_H
+
+/*
+ * GCC can automatically cleanup variables that go out of scope, but only
+ * through normal means. Breaking out of scope using longjmp (i.e. igt_skip)
+ * is not handled automatically by GCC. Such scoped variables must be tracked
+ * in an outer scope to the skipping subtest.
+ *
+ * BAD:
+ * igt_subtest("bad") {
+ * igt_fd_t(fd);
+ *
+ * fd = drm_open_driver();
+ * }
+ *
+ * GOOD:
+ * igt_subtest_group() {
+ * igt_fd_t(fd);
+ *
+ * igt_fixture {
+ * fd = drm_open_driver();
+ * }
+ *
+ * igt_subtest("good")
+ * ;
+ * }
+ *
+ * A rule of thumb is that anything that is initialised through a fixture can
+ * be combined with automatic cleanup.
+ */
+
+#define cleanup_with(fn) __attribute__((__cleanup__(fn)))
+
+/* Prevent use within the inner scope subtests, it will be broken by igt_skip */
+#define IGT_OUTER_SCOPE_INIT(x) ({ __igt_assert_in_outer_scope(); x; })
+
+void igt_cleanup_fd(int *fd);
+#define igt_fd_t(x__) \
+ int x__ cleanup_with(igt_cleanup_fd) = IGT_OUTER_SCOPE_INIT(-1)
+
+#endif /* IGT_TYPES_H */
diff --git a/lib/meson.build b/lib/meson.build
index 6910c061e9b9..c85a5b1a0801 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -38,6 +38,7 @@ lib_sources = [
'igt_sysrq.c',
'igt_taints.c',
'igt_thread.c',
+ 'igt_types.c',
'igt_vec.c',
'igt_vgem.c',
'igt_x86.c',
diff --git a/lib/tests/bad_subtest_type.c b/lib/tests/bad_subtest_type.c
new file mode 100644
index 000000000000..7f5efdfba8e2
--- /dev/null
+++ b/lib/tests/bad_subtest_type.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+/*
+* Copyright © 2022 Intel Corporation
+*/
+
+#include "igt_core.h"
+#include "igt_types.h"
+
+igt_main
+{
+ igt_subtest("bad-scoped-variable") {
+ /*
+ * Not allowed to nest a scoped variable inside a subtest as
+ * we expect to longjmp out of the subtest on failure/skip
+ * and automatic cleanup is not invoked for such jmps.
+ */
+ igt_fd_t(f);
+ }
+}
diff --git a/lib/tests/igt_types.c b/lib/tests/igt_types.c
new file mode 100644
index 000000000000..0316fd51b459
--- /dev/null
+++ b/lib/tests/igt_types.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: MIT
+/*
+* Copyright © 2022 Intel Corporation
+*/
+
+#include "igt_core.h"
+#include "igt_types.h"
+
+/* a lookalike of igt_fd_t for testing */
+#define scoped_int_t(x__) \
+ int x__ cleanup_with(cleanup) = IGT_OUTER_SCOPE_INIT(-1)
+
+static int cleanup_called;
+
+static void cleanup(int *x)
+{
+ cleanup_called++;
+ *x = -1;
+}
+
+static void delegate(void)
+{
+ scoped_int_t(x);
+
+ igt_fixture
+ x = 1;
+
+ igt_subtest("empty-subtest")
+ x = 2;
+
+ igt_fixture {
+ /* Check that we went through both blocks without cleanup */
+ igt_assert(!cleanup_called);
+ igt_assert(x == 2);
+ }
+}
+
+static void skip_delegate(void)
+{
+ scoped_int_t(x);
+
+ igt_fixture
+ x = 1;
+
+ igt_subtest("skipped-subtest") {
+ igt_skip("Early skip for testing\n");
+ x = 2; /* not reached due to lonjmp from igt_skip */
+ }
+
+ igt_fixture {
+ /* Check that we went through both blocks without cleanup */
+ igt_assert(!cleanup_called);
+ igt_assert(x == 1);
+ }
+}
+
+igt_main
+{
+ /* Basic check that scopes will call their destructor */
+ cleanup_called = 0;
+ igt_fixture {
+ scoped_int_t(x);
+ }
+ igt_subtest("cleanup-after-fixture")
+ igt_assert(cleanup_called);
+
+ /* But not before we go out of scope! */
+ cleanup_called = 0;
+ igt_subtest_group {
+ scoped_int_t(x);
+
+ igt_fixture {
+ x = 0xdeadbeef;
+ }
+
+ igt_subtest("cleanup-not-before-subtest-group") {
+ /* Check no scope destructor was called */
+ igt_assert(cleanup_called == 0);
+ /* Confirm that we did pass through a scoped block */
+ igt_assert_eq_u32(x, 0xdeadbeef);
+ }
+ }
+ igt_subtest("cleanup-after-subtest-group")
+ igt_assert(cleanup_called);
+
+ /* longjmp and __attribute__(cleanup) do not mix well together */
+#if 0 /* See bad_subtest_type, this is caught by an internal assertion */
+ cleanup_called = 0;
+ igt_subtest("skip-subtest") {
+ scoped_int_t(x);
+
+ igt_skip("Checking scoped cleanup on skip\n");
+ }
+ igt_subtest("cleanup-after-skip")
+ igt_assert_f(!cleanup_called,
+ "scoped closure was not compatible with igt_skip\n");
+#endif
+
+ /*
+ * However, if we igt_skip inside another block (subtest-group), then we
+ * will get cleanup on the outer scope.
+ */
+ cleanup_called = 0;
+ igt_subtest_group {
+ scoped_int_t(x);
+
+ igt_subtest("skip-subtest-group")
+ igt_skip("Checking scoped cleanup after skip\n");
+ }
+ igt_subtest("cleanup-after-skip-group")
+ igt_assert(cleanup_called);
+
+ /* Check the same holds true for function calls */
+ cleanup_called = 0;
+ delegate();
+ igt_subtest("cleanup-after-delegation")
+ igt_assert(cleanup_called);
+
+ cleanup_called = 0;
+ igt_subtest_group
+ delegate();
+ igt_subtest("cleanup-after-group-delegation")
+ igt_assert(cleanup_called);
+
+ /* Check what happens with a igt_skip inside a function */
+ cleanup_called = 0;
+ skip_delegate();
+ igt_subtest("cleanup-after-skipped-delegation")
+ igt_assert(cleanup_called);
+
+ cleanup_called = 0;
+ igt_subtest_group
+ skip_delegate();
+ igt_subtest("cleanup-after-group-skipped-0delegation")
+ igt_assert(cleanup_called);
+}
diff --git a/lib/tests/meson.build b/lib/tests/meson.build
index ceaf548b2b2f..d5666c246146 100644
--- a/lib/tests/meson.build
+++ b/lib/tests/meson.build
@@ -19,10 +19,12 @@ lib_tests = [
'igt_stats',
'igt_subtest_group',
'igt_thread',
+ 'igt_types',
'i915_perf_data_alignment',
]
lib_fail_tests = [
+ 'bad_subtest_type',
'igt_no_subtest',
'igt_simple_test_subtests',
'igt_timeout',
--
2.37.2
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