test_dtpthread_recursive.c

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/*
    This file is part of Ansel,
    Copyright (C) 2026 Aurélien PIERRE.
 
    Ansel is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    Ansel is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with Ansel.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#include "external/ThreadSafetyAnalysis.h"
#include "system/dtpthread.h"
 
#include <pthread.h>
#include <stdarg.h>
#include <stddef.h>
// cmocka.h declares `extern jmp_buf global_expect_assert_env' at file scope without including
// <setjmp.h> itself. Same suppression as the other tests here, and for the same reason.
#include <setjmp.h>  // NOLINT(misc-include-cleaner)
#include <stdint.h>
#include <cmocka.h>
 
/*
 * These four exercise re-entrant locking on purpose, which is exactly the pattern clang's
 * thread-safety analysis is built to reject: it models a lock as held or not held, so a
 * second acquisition by the owner reads as "acquiring a lock that is already held" and the
 * matching second release as "releasing a lock that was not held". The behaviour under test
 * is real and deliberate (see dtpthread.h); the analysis simply has no way to express it.
 * Exempting the test bodies keeps the tree's finding count honest -- these are not defects
 * anyone can fix, and left in they would mask ones that are.
 */
 
static void _a_null_attr_mutex_is_recursive(void **state) NO_THREAD_SAFETY_ANALYSIS
{
  (void)state;
  dt_pthread_mutex_t mutex;
  assert_int_equal(dt_pthread_mutex_init(&mutex, NULL), 0);
 
  assert_int_equal(dt_pthread_mutex_lock(&mutex), 0);
 
  // On a non-recursive mutex this returns EBUSY (NORMAL) or EDEADLK (ERRORCHECK).
  assert_int_equal(dt_pthread_mutex_trylock(&mutex), 0);
  assert_int_equal(dt_pthread_mutex_unlock(&mutex), 0);
 
  assert_int_equal(dt_pthread_mutex_unlock(&mutex), 0);
  assert_int_equal(dt_pthread_mutex_destroy(&mutex), 0);
}
 
static void _the_blocking_lock_also_re_enters(void **state) NO_THREAD_SAFETY_ANALYSIS
{
  (void)state;
  dt_pthread_mutex_t mutex;
  assert_int_equal(dt_pthread_mutex_init(&mutex, NULL), 0);
 
  for(int depth = 0; depth < 4; depth++) assert_int_equal(dt_pthread_mutex_lock(&mutex), 0);
  for(int depth = 0; depth < 4; depth++) assert_int_equal(dt_pthread_mutex_unlock(&mutex), 0);
 
  // Fully released: a fresh acquisition still succeeds.
  assert_int_equal(dt_pthread_mutex_trylock(&mutex), 0);
  assert_int_equal(dt_pthread_mutex_unlock(&mutex), 0);
  assert_int_equal(dt_pthread_mutex_destroy(&mutex), 0);
}
 
static void _an_explicit_attribute_is_honoured(void **state) NO_THREAD_SAFETY_ANALYSIS
{
  (void)state;
  pthread_mutexattr_t errorcheck;
  assert_int_equal(pthread_mutexattr_init(&errorcheck), 0);
  assert_int_equal(pthread_mutexattr_settype(&errorcheck, PTHREAD_MUTEX_ERRORCHECK), 0);
 
  dt_pthread_mutex_t mutex;
  assert_int_equal(dt_pthread_mutex_init(&mutex, &errorcheck), 0);
  assert_int_equal(dt_pthread_mutex_lock(&mutex), 0);
 
  // Not recursive, because the caller asked for something else.
  assert_int_not_equal(dt_pthread_mutex_trylock(&mutex), 0);
 
  assert_int_equal(dt_pthread_mutex_unlock(&mutex), 0);
  assert_int_equal(dt_pthread_mutex_destroy(&mutex), 0);
  pthread_mutexattr_destroy(&errorcheck);
}
 
static void _an_rwlock_writer_may_re_enter(void **state) NO_THREAD_SAFETY_ANALYSIS
{
  (void)state;
  dt_pthread_rwlock_t lock;
  assert_int_equal(dt_pthread_rwlock_init(&lock, NULL), 0);
 
  assert_int_equal(dt_pthread_rwlock_wrlock(&lock), 0);
  assert_int_equal(dt_pthread_rwlock_wrlock(&lock), 0);   // same thread, as writer
  assert_int_equal(dt_pthread_rwlock_rdlock(&lock), 0);   // same thread, as reader
 
  assert_int_equal(dt_pthread_rwlock_unlock(&lock), 0);
  assert_int_equal(dt_pthread_rwlock_unlock(&lock), 0);
  assert_int_equal(dt_pthread_rwlock_unlock(&lock), 0);
 
  assert_int_equal(dt_pthread_rwlock_destroy(&lock), 0);
}
 
int main(void)
{
  const struct CMUnitTest tests[] = {
    cmocka_unit_test(_a_null_attr_mutex_is_recursive),
    cmocka_unit_test(_the_blocking_lock_also_re_enters),
    cmocka_unit_test(_an_explicit_attribute_is_honoured),
    cmocka_unit_test(_an_rwlock_writer_may_re_enter),
  };
 
  return cmocka_run_group_tests(tests, NULL, NULL);
}
 
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