logger.c

                time(&t);
                ast_localtime(&t, &tm, NULL);
                strftime(date, sizeof(date), dateformat, &tm);
                datefmt = alloca(strlen(date) + 3 + strlen(fmt) + 1);
                sprintf(datefmt, "[%s] %s", date, fmt);
                fmt = datefmt;
        }

	/* Build string */
	va_start(ap, fmt);
	res = ast_str_set_va(&buf, 0, fmt, ap);
	va_end(ap);

	/* If the build failed then we can drop this allocated message */
	if (res == AST_DYNSTR_BUILD_FAILED)
		return;

	if (!(logmsg = ast_calloc(1, sizeof(*logmsg) + res + 1)))
		return;

	strcpy(logmsg->str, buf->str);

	ast_log(LOG_VERBOSE, logmsg->str);

	/* Set type */
	logmsg->type = LOGMSG_VERBOSE;
	
	/* Add to the list and poke the thread if possible */
	if (logthread != AST_PTHREADT_NULL) {
		AST_LIST_LOCK(&logmsgs);
		AST_LIST_INSERT_TAIL(&logmsgs, logmsg, list);
		ast_cond_signal(&logcond);
		AST_LIST_UNLOCK(&logmsgs);
	} else {
		logger_print_verbose(logmsg);
		free(logmsg);
	}
}

int ast_register_verbose(void (*v)(const char *string)) 
{
	struct verb *verb;

	if (!(verb = ast_malloc(sizeof(*verb))))
		return -1;

	verb->verboser = v;

	AST_LIST_LOCK(&verbosers);
	AST_LIST_INSERT_HEAD(&verbosers, verb, list);
	AST_LIST_UNLOCK(&verbosers);
	
	return 0;
}

int ast_unregister_verbose(void (*v)(const char *string))
{
	struct verb *cur;

	AST_LIST_LOCK(&verbosers);
	AST_LIST_TRAVERSE_SAFE_BEGIN(&verbosers, cur, list) {
		if (cur->verboser == v) {
			AST_LIST_REMOVE_CURRENT(&verbosers, list);
			free(cur);
			break;
		}
	}
	AST_LIST_TRAVERSE_SAFE_END
	AST_LIST_UNLOCK(&verbosers);
	
	return cur ? 0 : -1;
}