+extern void call_error_cb(meshlink_handle_t *mesh, meshlink_errno_t meshlink_errno);
+
+/// Per-instance PRNG
+static inline int prng(meshlink_handle_t *mesh, uint64_t max) {
+ return xoshiro(mesh->prng_state) % max;
+}
+
+/// Fudge value of ~0.1 seconds, in microseconds.
+static const unsigned int TIMER_FUDGE = 0x20000;