thread-mg-share.c

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

int test__thread_mg_share(struct test *test __maybe_unused, int subtest __maybe_unused)
{
    struct machines machines;
    struct machine *machine;

    /* thread group */
    struct thread *leader;
    struct thread *t1, *t2, *t3;
    struct map_groups *mg;

    /* other process */
    struct thread *other, *other_leader;
    struct map_groups *other_mg;

    /*
     * This test create 2 processes abstractions (struct thread)
     * with several threads and checks they properly share and
     * maintain map groups info (struct map_groups).
     *
     * 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);

    mg = leader->mg;
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 4);

    /* test the map groups pointer is shared */
    TEST_ASSERT_VAL("map groups don't match", mg == t1->mg);
    TEST_ASSERT_VAL("map groups don't match", mg == t2->mg);
    TEST_ASSERT_VAL("map groups don't match", mg == t3->mg);

    /*
     * Verify the other leader was created by previous call.
     * It should have shared map groups 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_mg = other->mg;
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&other_mg->refcnt), 2);

    TEST_ASSERT_VAL("map groups don't match", other_mg == other_leader->mg);

    /* release thread group */
    thread__put(leader);
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 3);

    thread__put(t1);
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 2);

    thread__put(t2);
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 1);

    thread__put(t3);

    /* release other group  */
    thread__put(other_leader);
    TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&other_mg->refcnt), 1);

    thread__put(other);

    machines__exit(&machines);
    return 0;
}