rv = swapcontext(&((smx_ctx_sysv_t)context)->old_uc, &((smx_ctx_sysv_t) context)->uc);
smx_current_context = (smx_context_t)maestro_context;
rv = swapcontext(&((smx_ctx_sysv_t)context)->old_uc, &((smx_ctx_sysv_t) context)->uc);
smx_current_context = (smx_context_t)maestro_context;