/*
* call-seq:
* fiber.transfer(args, ...) -> obj
*
* Transfers control to receiver fiber of the method call.
* Unlike <code>resume</code> the receiver wouldn't be pushed to call
* stack of fibers. Instead it will switch to the call stack of
* transferring fiber.
* When resuming a fiber that was transferred to another fiber it would
* cause double resume error. Though when the fiber is re-transferred
* and <code>Fiber.yield</code> is called, the fiber would be resumable.
*/
static mrb_value
fiber_transfer(mrb_state *mrb, mrb_value self)
{
struct mrb_context *c = fiber_check(mrb, self);
mrb_value* a;
mrb_int len;
fiber_check_cfunc(mrb, mrb->c);
mrb_get_args(mrb, "*", &a, &len);
if (c == mrb->root_c) {
mrb->c->status = MRB_FIBER_TRANSFERRED;
mrb->c = c;
c->status = MRB_FIBER_RUNNING;
MARK_CONTEXT_MODIFY(c);
mrb_write_barrier(mrb, (struct RBasic*)c->fib);
return fiber_result(mrb, a, len);
}
if (c == mrb->c) {
return fiber_result(mrb, a, len);
}
return fiber_switch(mrb, self, len, a, FALSE, FALSE);
}
bool Fiber::yield() {
Fiber *f = current;
for (auto *p = ++f ;; f++) {
if (p == &fibers.at(MAXFIBERS-1)) {
p = &fibers.at(0);
} else if (p->status == Fiber::Ready) {
f = p;
break;
}
else if (p == f) {
return false;
}
}
if (current->status != Fiber::Unused) {
current->status = Fiber::Ready;
}
f->status = Fiber::Running;
auto old_ctx = ¤t->context;
auto new_ctx = &f->context;
current = f;
fiber_switch(old_ctx, new_ctx);
return true;
}
/*
* call-seq:
* fiber.resume(args, ...) -> obj
*
* Resumes the fiber from the point at which the last <code>Fiber.yield</code>
* was called, or starts running it if it is the first call to
* <code>resume</code>. Arguments passed to resume will be the value of
* the <code>Fiber.yield</code> expression or will be passed as block
* parameters to the fiber's block if this is the first <code>resume</code>.
*
* Alternatively, when resume is called it evaluates to the arguments passed
* to the next <code>Fiber.yield</code> statement inside the fiber's block
* or to the block value if it runs to completion without any
* <code>Fiber.yield</code>
*/
static mrb_value
fiber_resume(mrb_state *mrb, mrb_value self)
{
mrb_value *a;
int len;
mrb_get_args(mrb, "*", &a, &len);
return fiber_switch(mrb, self, len, a, TRUE);
}
VALUE
rb_fiber_resume(VALUE fibval, int argc, VALUE *argv)
{
rb_fiber_t *fib;
GetFiberPtr(fibval, fib);
if (fib->prev != Qnil) {
rb_raise(rb_eFiberError, "double resume");
}
return fiber_switch(fibval, argc, argv, 1);
}
VALUE
rb_fiber_resume(VALUE fib, int argc, VALUE *argv)
{
rb_context_t *cont;
GetContPtr(fib, cont);
if (cont->prev != Qnil) {
rb_raise(rb_eFiberError, "double resume");
}
return fiber_switch(fib, argc, argv, 1);
}
/*
* call-seq:
* fiber.resume(args, ...) -> obj
*
* Resumes the fiber from the point at which the last <code>Fiber.yield</code>
* was called, or starts running it if it is the first call to
* <code>resume</code>. Arguments passed to resume will be the value of
* the <code>Fiber.yield</code> expression or will be passed as block
* parameters to the fiber's block if this is the first <code>resume</code>.
*
* Alternatively, when resume is called it evaluates to the arguments passed
* to the next <code>Fiber.yield</code> statement inside the fiber's block
* or to the block value if it runs to completion without any
* <code>Fiber.yield</code>
*/
static mrb_value
fiber_resume(mrb_state *mrb, mrb_value self)
{
mrb_value *a;
mrb_int len;
mrb_bool vmexec = FALSE;
mrb_get_args(mrb, "*", &a, &len);
if (mrb->c->ci->acc < 0) {
vmexec = TRUE;
}
return fiber_switch(mrb, self, len, a, TRUE, vmexec);
}
/* resume thread with given arguments */
MRB_API mrb_value
mrb_fiber_resume(mrb_state *mrb, mrb_value fib, mrb_int len, const mrb_value *a)
{
return fiber_switch(mrb, fib, len, a, TRUE, TRUE);
}
VALUE
rb_fiber_transfer(VALUE fib, int argc, VALUE *argv)
{
return fiber_switch(fib, argc, argv, 0);
}