kraken/stdlib/future.krak

import io:*

__if_comp__ __C__ simple_passthrough(::"-pthread") """
#include <pthread.h>
"""

def pthread_t float

fun pthread_create(thrd : *pthread_t, strt_routine : fun() : void) : int {
    __if_comp__ __C__ { 
    simple_passthrough(thrd,strt_routine::) """
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
    int ret = pthread_create((pthread_t*)thrd, &attr, strt_routine.func, strt_routine.data);
    pthread_attr_destroy(&attr);
    return ret;
    """
    }
    return 0
}

fun pthread_join(thrd : *pthread_t) : int {
    __if_comp__ __C__ { simple_passthrough(thrd::) """
    pthread_t thread = *((pthread_t*)thrd);
    return pthread_join(thread, NULL);
    """
    }
    return 0
}

fun pthread_exit() : *void {
    __if_comp__ __C__ { simple_passthrough """
    pthread_exit(NULL);
    """
    }
}



fun future<T>(in : fun() : T ) : future<T> {
    var out.construct(in) : future<T>
    return out
}

obj future<T> {
    var result : T
    var status : int
    var psy : fun() : T
    var wrapper : fun() : void
    var thread : pthread_t

    fun construct(in : fun() : T) : *future<T> {
        status = 0
        psy = in
        wrapper = fun() : void{
            result = psy()
            println(status)
            pthread_exit()
        }
        return this
    }

    fun run() {
        status = pthread_create(&thread,wrapper)
    }

    fun get_status() {
        return status
    }

    fun finish() : T {
        pthread_join(&thread)
        print("FINISHED THREAD ")
        print(result)
        print("\n")
        return result
    }
}