eval_jump.c

/* -*-c-*- */
/*
 * from eval.c
 */

#include "eval_intern.h"

/* exit */

void
rb_call_end_proc(VALUE data)
{
    rb_proc_call(data, rb_ary_new());
}

/*
 *  call-seq:
 *     at_exit { block } -> proc
 *
 *  Converts _block_ to a +Proc+ object (and therefore
 *  binds it at the point of call) and registers it for execution when
 *  the program exits. If multiple handlers are registered, they are
 *  executed in reverse order of registration.
 *
 *     def do_at_exit(str1)
 *       at_exit { print str1 }
 *     end
 *     at_exit { puts "cruel world" }
 *     do_at_exit("goodbye ")
 *     exit
 *
 *  <em>produces:</em>
 *
 *     goodbye cruel world
 */

static VALUE
rb_f_at_exit(void)
{
    VALUE proc;

    if (!rb_block_given_p()) {
	rb_raise(rb_eArgError, "called without a block");
    }
    proc = rb_block_proc();
    rb_set_end_proc(rb_call_end_proc, proc);
    return proc;
}

struct end_proc_data {
    void (*func) ();
    VALUE data;
    int safe;
    struct end_proc_data *next;
};

void
rb_set_end_proc(void (*func)(VALUE), VALUE data)
{
    struct end_proc_data *link = ALLOC(struct end_proc_data);
    struct end_proc_data **list;
    rb_thread_t *th = GET_THREAD();

    if (th->top_wrapper) {
	list = th->vm->end_procs + end_proc_ephemeral;
    }
    else {
	list = th->vm->end_procs + end_proc_ordinary;
    }
    link->next = *list;
    link->func = func;
    link->data = data;
    link->safe = rb_safe_level();
    *list = link;
}

void
rb_mark_end_proc(struct end_proc_data **endp)
{
    struct end_proc_data *link;
    int i;

    for (i = 0; i < end_proc_count; ++i) {
	link = endp[i];
	while (link) {
	    rb_gc_mark(link->data);
	    link = link->next;
	}
    }
}

void
rb_exec_end_proc(struct end_proc_data **end_procs)
{
    struct end_proc_data *volatile link;
    struct end_proc_data *tmp;
    int status, i;
    volatile int safe = rb_safe_level();

    i = end_proc_ephemeral;
    do {
	while ((link = end_procs[i]) != 0) {
	    end_procs[i] = 0;
	    end_procs[end_proc_temporary] = link;
	    while (link) {
		PUSH_TAG();
		if ((status = EXEC_TAG()) == 0) {
		    rb_set_safe_level_force(link->safe);
		    (*link->func) (link->data);
		}
		POP_TAG();
		if (status) {
		    error_handle(status);
		}
		tmp = link;
		end_procs[end_proc_temporary] = link = link->next;
		xfree(tmp);
	    }
	}
    } while (i-- > end_proc_ordinary);
    rb_set_safe_level_force(safe);
}

void
Init_jump(void)
{
}

void
InitVM_jump(void)
{
    rb_define_global_function("at_exit", rb_f_at_exit, 0);
}