Set a maximum message time allowed for a block of MsgSends
#include <qvm/utils.h>
int qvm_msgblock_start(const vdev_t *vdp, unsigned mult)
This function sets the maximum message time for all MsgSends until you call qvm_msgblock_stop().
Use this function when you are communication with an untrusted server, and you don't know how many MsgSends there will be. Wrap your messages with qvm_msgblock_start() and qvm_msgblock_stop() calls to make sure that you don't block if a server doesn't reply within the prescribed time.
To set the maximum message time for a single MsgSend, call qvm_msgblock_oneshot().
EOK if successful; otherwise an errno value.