NORETURN cilk_fiber_sysdep::jump_to_resume_other_sysdep(cilk_fiber_sysdep* other)
{
#if SUPPORT_GET_CURRENT_FIBER
cilkos_set_tls_cilk_fiber(other);
#endif
CILK_ASSERT(!this->is_resumable());
// Jump to the other fiber. But we are never coming back because
// this fiber is being reset.
resume_other_sysdep(other);
// We should never come back here...
__cilkrts_bug("Should not get here");
}
void cilk_fiber_sysdep::suspend_self_and_resume_other_sysdep(cilk_fiber_sysdep* other)
{
#if SUPPORT_GET_CURRENT_FIBER
cilkos_set_tls_cilk_fiber(other);
#endif
CILK_ASSERT(this->is_resumable());
// Jump to the other fiber. We expect to come back.
if (! CILK_SETJMP(m_resume_jmpbuf)) {
resume_other_sysdep(other);
}
// Return here when another fiber resumes me.
// If the fiber that switched to me wants to be deallocated, do it now.
do_post_switch_actions();
}
cilk_fiber* cilk_fiber::allocate_from_thread()
{
void* retmem = __cilkrts_malloc(sizeof(cilk_fiber_sysdep));
CILK_ASSERT(retmem);
cilk_fiber_sysdep* ret = ::new(retmem) cilk_fiber_sysdep(from_thread);
// A fiber allocated from a thread begins with a reference count
// of 2. The first is for being created, and the second is for
// being running.
//
// Suspending this fiber will decrement the count down to 1.
ret->init_ref_count(2);
#if SUPPORT_GET_CURRENT_FIBER
// We're creating the main fiber for this thread. Set this fiber as the
// current fiber.
cilkos_set_tls_cilk_fiber(ret);
#endif
return ret;
}
int cilk_fiber::deallocate_from_thread()
{
CILK_ASSERT(this->is_allocated_from_thread());
#if SUPPORT_GET_CURRENT_FIBER
CILK_ASSERT(this == cilkos_get_tls_cilk_fiber());
// Reverse of "allocate_from_thread".
cilkos_set_tls_cilk_fiber(NULL);
#endif
this->assert_ref_count_at_least(2);
// Suspending the fiber should conceptually decrement the ref
// count by 1.
cilk_fiber_sysdep* self = this->sysdep();
self->convert_fiber_back_to_thread();
// Then, freeing the fiber itself decrements the ref count again.
int ref_count = this->sub_from_ref_count(2);
if (ref_count == 0) {
self->~cilk_fiber_sysdep();
__cilkrts_free(self);
}
return ref_count;
}