Function resume

sources/system/unix/common.cpp:386–428

		}

		void resume(const fiber_t &fi_p)
		{
			static cs_fiber_ucontext_t global_ctx;
			unix_fiber *fi = static_cast<unix_fiber *>(fi_p.get());
			if (fi == nullptr)
				throw internal_error("Resuming a corrupted fiber.");
			if (fi->state == fiber_state::running || fi->state == fiber_state::finished)
				throw lang_error("Fiber is not reentrant.");
			if (fi->state == fiber_state::ready) {
				memset(&fi->ctx, 0, sizeof(fi->ctx));
				cs_fiber_getcontext(&fi->ctx);
				fi->ctx.uc_stack.ss_sp = fi->stack.get_sp();
				fi->ctx.uc_stack.ss_size = fi->stack.get_ss();
				fi->ctx.uc_link = nullptr;
				cs_fiber_makecontext(&fi->ctx, reinterpret_cast<void (*)()>(unix_fiber::entry), 0);
				if (!current_process->fiber_stack.empty())
					fi->prev_ctx = &static_cast<unix_fiber *>(current_process->fiber_stack.top().get())->ctx;
				else
					fi->prev_ctx = &global_ctx;
			}
			else if (fi->state == fiber_state::suspended) {
				if (fi->prev_ctx == nullptr)
					throw internal_error("Fiber context corrupted.");
				fi->state = fiber_state::running;
			}
			fi->state = fiber_state::running;
			current_process->fiber_stack.push(fi_p);
			fi->cs_swap_in();
			cs_fiber_swapcontext(fi->prev_ctx, &fi->ctx);
			if (!current_process->fiber_stack.empty())
				current_process->fiber_stack.pop();
			else
				throw internal_error("Fiber stack corrupted.");
			if (!current_process->fiber_stack.empty())
				static_cast<unix_fiber *>(current_process->fiber_stack.top().get())->cs_swap_in();
			else
				fi->cs_swap_out();
			if (fi->eptr != nullptr) {
				std::exception_ptr e = nullptr;
				std::swap(fi->eptr, e);
				std::rethrow_exception(e);
			}
		}

		void yield()
		{