Changes for version 1.64
- Survive a process killed mid-update. The page start marker now doubles as an in-progress flag: cleared (low bit) before a page's structure is changed, set again before unlock. A process that locks a page and finds the flag still clear knows the previous holder died holding the lock, and reinitialises the page instead of trusting it. Slot offsets and entry lengths are bounds-checked wherever they are followed, so a corrupt page is a miss plus a repair at unlock, not a segfault. Repairs are reported with warn(); new repaired_pages() method. No file format change: the two marker values are the old magic and old-magic-minus-one, so older versions see a mid-update page as "magic not found" rather than misreading it. init_file is no longer needed for safety. See KILLED WRITERS AND PAGE REPAIR.
- Tightened the page header sanity checks at lock time (slot table and free data must fit inside the page) and repair rather than fail a page that doesn't pass them.
- mmc_do_expunge no longer leaks its buffers when the underlying fd check fails.
Modules
Uses an mmap'ed file to act as a shared memory interprocess cache