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