import t, c
import stdio
import testcheck
import atom


# G6: verify the atom module's inline-asm atomic operations.
# Compiled with TPC to validate atom behavior in this area.


def test_atomic_test_and_set():
    testcheck.section("Test 1: __atomic_test_and_set")
    flag: uint8 = 0
    result: bool = atom.__atomic_test_and_set(&flag, atom.ATOMIC_ACQUIRE)
    # test_and_set returns the old value: flag=0 returns 0 and sets flag=1
    testcheck.check(result == bool(0), "first set returns old value 0", "expect 0")
    testcheck.check(flag == 1, "flag is 1 after set", "expect 1")

    # Second set returns 1 because the old value is now 1.
    result2: bool = atom.__atomic_test_and_set(&flag, atom.ATOMIC_ACQUIRE)
    testcheck.check(result2 == bool(1), "second set returns old value 1", "expect 1")


def test_atomic_clear():
    testcheck.section("Test 2: __atomic_clear")
    flag: uint8 = 1
    atom.__atomic_clear(&flag, atom.ATOMIC_RELEASE)
    testcheck.check(flag == 0, "flag is 0 after clear", "expect 0")


def test_atomic_thread_fence():
    testcheck.section("Test 3: __atomic_thread_fence")
    # Only checks that the call does not crash.
    atom.__atomic_thread_fence(atom.ATOMIC_SEQ_CST)
    testcheck.ok("mfence executed OK")


def test_atomic_lock_free():
    testcheck.section("Test 4: __atomic_is_lock_free")
    flag: uint8 = 0
    result: bool = atom.__atomic_is_lock_free(1, &flag)
    testcheck.check(result == bool(1), "1-byte is lock free", "expect 1")


def test_atomic_spinlock():
    testcheck.section("Test 5: spinlock pattern (test_and_set + clear)")
    lock: uint8 = 0

    # Acquire the lock
    while atom.__atomic_test_and_set(&lock, atom.ATOMIC_ACQUIRE) == bool(1):
        pass
    testcheck.check(lock == 1, "lock acquired", "expect lock=1")

    # Release the lock
    atom.__atomic_clear(&lock, atom.ATOMIC_RELEASE)
    testcheck.check(lock == 0, "lock released", "expect lock=0")


def main() -> int:
    testcheck.begin("G6: atom module (inline asm atomic operations)")
    test_atomic_test_and_set()
    test_atomic_clear()
    test_atomic_thread_fence()
    test_atomic_lock_free()
    test_atomic_spinlock()
    return testcheck.end()