tools/perf/tests/thread-maps-share.c

Source file repositories/reference/linux-study-clean/tools/perf/tests/thread-maps-share.c

File Facts

System
Linux kernel
Corpus path
tools/perf/tests/thread-maps-share.c
Extension
.c
Size
3011 bytes
Lines
101
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
#include "tests.h"
#include "machine.h"
#include "thread.h"
#include "debug.h"

static int test__thread_maps_share(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
	struct machines machines;
	struct machine *machine;

	/* thread group */
	struct thread *leader;
	struct thread *t1, *t2, *t3;
	struct maps *maps;

	/* other process */
	struct thread *other, *other_leader;
	struct maps *other_maps;

	/*
	 * This test create 2 processes abstractions (struct thread)
	 * with several threads and checks they properly share and
	 * maintain maps info (struct maps).
	 *
	 * thread group (pid: 0, tids: 0, 1, 2, 3)
	 * other  group (pid: 4, tids: 4, 5)
	*/

	machines__init(&machines);
	machine = &machines.host;

	/* create process with 4 threads */
	leader = machine__findnew_thread(machine, 0, 0);
	t1     = machine__findnew_thread(machine, 0, 1);
	t2     = machine__findnew_thread(machine, 0, 2);
	t3     = machine__findnew_thread(machine, 0, 3);

	/* and create 1 separated process, without thread leader */
	other  = machine__findnew_thread(machine, 4, 5);

	TEST_ASSERT_VAL("failed to create threads",
			leader && t1 && t2 && t3 && other);

	maps = thread__maps(leader);
	TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 4);

	/* test the maps pointer is shared */
	TEST_ASSERT_VAL("maps don't match", maps__equal(maps, thread__maps(t1)));
	TEST_ASSERT_VAL("maps don't match", maps__equal(maps, thread__maps(t2)));
	TEST_ASSERT_VAL("maps don't match", maps__equal(maps, thread__maps(t3)));

	/*
	 * Verify the other leader was created by previous call.
	 * It should have shared maps with no change in
	 * refcnt.
	 */
	other_leader = machine__find_thread(machine, 4, 4);
	TEST_ASSERT_VAL("failed to find other leader", other_leader);

	/*
	 * Ok, now that all the rbtree related operations were done,
	 * lets remove all of them from there so that we can do the
	 * refcounting tests.
	 */
	machine__remove_thread(machine, leader);
	machine__remove_thread(machine, t1);
	machine__remove_thread(machine, t2);
	machine__remove_thread(machine, t3);
	machine__remove_thread(machine, other);
	machine__remove_thread(machine, other_leader);

	other_maps = thread__maps(other);
	TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(other_maps)), 2);

	TEST_ASSERT_VAL("maps don't match", maps__equal(other_maps, thread__maps(other_leader)));

	/* release thread group */
	thread__put(t3);
	TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 3);

	thread__put(t2);
	TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 2);

	thread__put(t1);
	TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 1);

	thread__put(leader);

	/* release other group  */

Annotation

Implementation Notes