diff options
Diffstat (limited to 'callback.h')
| -rw-r--r-- | callback.h | 20 |
1 files changed, 19 insertions, 1 deletions
@@ -1,6 +1,6 @@ /* * This file is part of ltrace. - * Copyright (C) 2011,2012 Petr Machata, Red Hat Inc. + * Copyright (C) 2011,2012,2013 Petr Machata, Red Hat Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as @@ -39,6 +39,21 @@ * thing as CBS_STOP. There's no provision for returning error * states. Errors need to be signaled to the caller via DATA, * together with any other data that the callback needs. + * + * A richer iteration interface looks like this: + * + * struct each_foo_t { + * foo *restart; + * int status; + * } each_foo(foo *start_after, + * enum callback_status (*cb)(foo *f, void *data), + * void *data); + * + * These provide error handling. The two-part structure encodes both + * the restart cookie and status. Status of 0 means success, negative + * values signify failures. Status of -1 is dedicated to failures in + * user callback (such that the callback returns CBS_FAIL). Other + * negative values signal failures in the iteration mechanism itself. */ enum callback_status { CBS_STOP, /* The iteration should stop. */ @@ -47,4 +62,7 @@ enum callback_status { * and return error. */ }; +#define CBS_STOP_IF(X) ((X) ? CBS_STOP : CBS_CONT) +#define CBS_CONT_IF(X) ((X) ? CBS_CONT : CBS_STOP) + #endif /* _CALLBACK_H_ */ |