#include <u.h>#include <libc.h>#include <thread.h> intchanprint(Channel *c, char *fmt, ...){	va_list arg;	char *p;	int n; 	va_start(arg, fmt);	p = vsmprint(fmt, arg);	va_end(arg);	if(p == nil)		sysfatal("vsmprint failed: %r");	n = sendp(c, p);	yield();	/* let recipient handle message immediately */	return n;}