define alternative method
diff --git a/include/picotls.h b/include/picotls.h
index 343cf65..0e0e98c 100644
--- a/include/picotls.h
+++ b/include/picotls.h
@@ -658,6 +658,10 @@
* optional callback returning a file descriptor that becomes readable when the job is complete
*/
int (*get_fd)(struct st_ptls_async_job_t *self);
+ /**
+ * optional callback for setting a completion callback
+ */
+ void (*set_completion_callback)(struct st_ptls_async_job_t *self, void (*cb)(void *), void *cbdata);
} ptls_async_job_t;
/**
* When gerenating CertificateVerify, the core calls the callback to sign the handshake context using the certificate. This callback
