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#include "test.h"
#include <threads.h>
/* note non-atomic counter! */
size_t num = 0;
long lock_var = 0;
void (*spin_lock)(void);
void (*spin_unlock)(void);
/* arbitrary number, as long as its large enough to likely allow other threads
* to spawn. */
#define THREAD_INCREMENTS 1000000
static int
loop(void *arg)
{
for (size_t i = 0; i < THREAD_INCREMENTS; ++i) {
(*spin_lock)();
num++;
(*spin_unlock)();
}
return 0;
}
#define NUM_THREADS 10
static void
run_loops()
{
thrd_t threads[NUM_THREADS];
for (size_t i = 0; i < NUM_THREADS; ++i)
ASSERT(thrd_create(&threads[i], loop, NULL) == thrd_success);
for (size_t i = 0; i < NUM_THREADS; ++i)
ASSERT(thrd_join(threads[i], NULL) == thrd_success);
ASSERT(num == NUM_THREADS * THREAD_INCREMENTS);
}
static size_t
run_test(jit_state_t *_jit, uint8_t *arena_base, size_t arena_size)
{
jit_begin(_jit, arena_base, arena_size);
/* based on https://rigtorp.se/spinlock/ */
spin_lock = jit_address(_jit);
{
size_t frame = jit_enter_jit_abi(_jit, 0, 0, 0);
void *do_exchange = jit_address(_jit);
void *while_load = jit_address(_jit);
/* do { */
/* while (atomic_load(lock_var)); */
jit_movi(_jit, JIT_R1, (jit_imm_t)&lock_var);
jit_ldr_atomic(_jit, JIT_R0, JIT_R1);
jit_patch_there(_jit, jit_bnei(_jit, JIT_R0, 0), while_load);
/* } while (atomic_exchange(lock_var, 1)); */
jit_movi(_jit, JIT_R0, 1);
jit_swap_atomic(_jit, JIT_R0, JIT_R1, JIT_R0);
jit_patch_there(_jit, jit_bnei(_jit, JIT_R0, 0), do_exchange);
jit_leave_jit_abi(_jit, 0, 0, frame);
jit_ret(_jit);
}
spin_unlock = jit_address(_jit);
{
size_t frame = jit_enter_jit_abi(_jit, 0, 0, 0);
jit_movi(_jit, JIT_R0, 0);
jit_movi(_jit, JIT_R1, (jit_imm_t)&lock_var);
jit_str_atomic(_jit, JIT_R1, JIT_R0);
jit_leave_jit_abi(_jit, 0, 0, frame);
jit_ret(_jit);
}
size_t size;
void *p = jit_end(_jit, &size);
if (p)
run_loops();
else
return size;
return 0;
}
int main(int argc, char *argv[])
{
return main_compiler(argc, argv, run_test);
}
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