diff options
Diffstat (limited to 'support/pma.h')
| -rw-r--r-- | support/pma.h | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/support/pma.h b/support/pma.h index f5851d96..f2cebc70 100644 --- a/support/pma.h +++ b/support/pma.h @@ -1,6 +1,9 @@ /* "pma", a persistent memory allocator (interface) Copyright (C) 2022 Terence Kelly Contact: tpkelly @ { acm.org, cs.princeton.edu, eecs.umich.edu } + Home: http://web.eecs.umich.edu/~tpkelly/pma/ [or "https"] + Design: HTML: https://queue.acm.org/detail.cfm?id=3534855 + PDF: https://dl.acm.org/doi/pdf/10.1145/3534855 This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by @@ -20,7 +23,7 @@ #define PMA_H_INCLUDED // version strings of interface and implementation should match -#define PMA_H_VERSION "2022.05May.01 (Avon 5) + gawk" +#define PMA_H_VERSION "2022.07Jul.19.1658299753 (Avon 6)" extern const char pma_version[]; /* May contain line number in pma.c where something went wrong if one @@ -31,17 +34,28 @@ extern int pma_errno; called, otherwise behavior is undefined. Available verbosity levels are: 0 => no diagnostic printouts, 1 => errors only printed to stderr, 2 => also warnings, 3 => also very verbose "FYI" - messages. Use verbosity level 2 by default. File argument - specifies backing file containing persistent heap, initially an - empty sparse file whose size is a multiple of the system page - size. If file argument is NULL, fall back on standard memory + messages. Verbosity level 2 is recommended. Verbosity may be + over-ridden via environment variable PMA_VERBOSITY. File argument + specifies backing file containing persistent heap, which must + initially be an empty (logically all zeros) file, and ideally also + a sparse file. Backing file size must be a multiple of the system + page size on first use; ideally the backing file should also be a + multiple of the address alignment enforced in the implementation. + The backing file does not grow so it must be large enough to hold + the largest persistent heap that the application might need (if + the file is sparse, its storage resource footprint is "pay as you + go," so there's no downside to making it generously large). If + file argument is NULL, pma will fall back on standard memory allocator: pma_malloc passes the buck to ordinary malloc, pma_free calls ordinary free, etc. In fallback-to-standard-malloc mode, only pma_malloc/calloc/realloc/free may be used; other functions such as pma_get/set_root must not be used. The implementation may store a copy of the file argument, i.e., the pointer, so both this - pointer and the memory to which it points (*file) must not - change. */ + pointer and the memory to which it points (*file) must not change. + Initialization may perform an integrity check on the heap; this + check may be slow depending on the complexity of the heap. Any + non-zero return value indicates trouble; inspect both the value + returned and also pma_errno. */ extern int pma_init(int verbose, const char *file); /* The following four functions may be used like their standard |