typedef struct
{
    void *pc;
} tcb_t;
//тра-та-та
static inline __attribute__((always_inline)) TH_label(tcb_t *tcb)
{
  tcb->pc = &&label;
label:
;
}

pc = &&Label; return pt_YIELDING; Label:

static inline __attribute__((always_inline)) void *TH_label_yield(tcb_t *pc, const void *label_ret)
{
    pc->pc = &&label;
    return label_ret;
    label:;
}
// заготовки такие:
#define THREAD_BEGIN if(my->tcb.pc != NULL) goto *my->tcb.pc;
#define THREAD_END _Y_i_e_l_d_: return 0; _H_a_l_t_: return 1;
#define yield() goto *TH_label_yield(&my->tcb, &&_Y_i_e_l_d_);

#include <stddef.h>
#include <stdint.h>
typedef struct
{
void *pc;
uint_fast8_t lock;
} tcb_t;

static inline __attribute__((always_inline)) void *TH_label(void)
{
return &&label;
label:;
}

#define THREAD_DEF(proc,param_type) uint_fast8_t proc(param_type *my)
/*
Typical stackless thread solution
typedef struct
{
tcb_t tcb;
int local_param;
} func_param_t;
// Define thread function with 1 parameter
THREAD_DEF(func, func_param_t)
{
// the default parameter name is always "my"
// i.e. to access parameter type my->local_param

THREAD_BEGIN // starting bracket
// -------THIS IS A THREAD BODY --------
wait(can_read()); //thread blocks until can_read() != 0
if(calc_condition()) halt(); //thread returns 1 - meaning that it is may be halted by caller

too_long_calculation(); // if the time spent is too long then we need to relax the system
yield(0); // that is mean immediatedly return and continue execution
// at the next point after yield() during further call
if(need_restart()) restart(); // threads may be restarted at any point of execution

repeat // this is a pascal-like implementation of the yield-loops
do_something(); // first we do
do_something_else(); // something
until(end_doing()); // and then yield if condition is not "true" else we continue execution

wait(timer() > TIMEOUT); // the thread will block while condition is false

spawn(sub_thread, &sub_params); // the thread will block until sub_thread is halted
// ------------ END OF THREAD BODY -----------------
THREAD_END // ending bracket
}
*/

#define THREAD_BEGIN if(my->tcb.pc != NULL) goto *my->tcb.pc;
#define THREAD_END _Y_i_e_l_d_: return 0; _H_a_l_t_: return 1;

#define STR_CONCAT2(s1, s2) s1##s2
#define STR_CONCAT(s1, s2) STR_CONCAT2(s1, s2)

#define yield() do{my->tcb.pc = &&STR_CONCAT(label,__LINE__); goto_Y_i_e_l_d_;STR_CONCAT2(label,__LINE__):;}while(0);

#define halt() do{goto _H_a_l_t_;}while(0);
#define restart() do{my->tcb.pc=NULL; goto _Y_i_e_l_d_;}while(0);

#define repeat do{my->tcb.pc=TH_label();}while(0);
#define until(cond) do{if(!(cond)) goto _Y_i_e_l_d_;}while(0);
#define wait(condition) do{repeat until((condition));}while(0);
#define spawn(name,param) wait(name(param))