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/*
* Copyright (c) 2017-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <mutex>
namespace basics {
class Basic {
public:
Basic() {}
void set(int new_value) {
not_guarded = new_value;
mutex_.lock();
well_guarded = new_value;
suspiciously_read = new_value;
mutex_.unlock();
suspiciously_written = new_value;
}
int get1() {
int result;
mutex_.lock();
result = well_guarded;
mutex_.unlock();
return result;
}
int get2() {
int result;
mutex_.lock();
result = suspiciously_written;
mutex_.unlock();
return result;
}
int get3() { return not_guarded; }
int get4() { return suspiciously_read; }
int get5() { return get_private_suspiciously_read(); }
void write_array_under_lock_ok(char* arr1) {
mutex_.lock();
arr1[2] = 'c';
mutex_.unlock();
}
int read_array_outside_lock_ok(char* arr2, int i) { return arr2[i]; }
void set_double(int new_value) {
mutex_.lock();
mutex_2.lock();
double_lock_guarded = new_value;
mutex_2.unlock();
single_lock_guarded = new_value;
single_lock_suspiciously_read = new_value;
mutex_.unlock();
}
int test_double_lock_1_ok() {
int result;
mutex_2.lock();
result = double_lock_guarded;
mutex_2.unlock();
return result;
}
int test_double_lock_2_ok() {
int result;
mutex_.lock();
result = single_lock_guarded;
mutex_.unlock();
return result;
}
int test_double_lock_bad() { return single_lock_suspiciously_read; }
private:
int well_guarded;
int suspiciously_read;
int suspiciously_written;
int not_guarded;
int double_lock_guarded;
int single_lock_guarded;
int single_lock_suspiciously_read;
std::mutex mutex_;
std::mutex mutex_2;
int get_private_suspiciously_read() { return suspiciously_read; }
};
} // namespace basics