tests/pack/filelimit.c


Log

Author Commit Date CI Message
Edward Thomson f0e693b1 2021-09-07T17:53:49 str: introduce `git_str` for internal, `git_buf` is external libgit2 has two distinct requirements that were previously solved by `git_buf`. We require: 1. A general purpose string class that provides a number of utility APIs for manipulating data (eg, concatenating, truncating, etc). 2. A structure that we can use to return strings to callers that they can take ownership of. By using a single class (`git_buf`) for both of these purposes, we have confused the API to the point that refactorings are difficult and reasoning about correctness is also difficult. Move the utility class `git_buf` to be called `git_str`: this represents its general purpose, as an internal string buffer class. The name also is an homage to Junio Hamano ("gitstr"). The public API remains `git_buf`, and has a much smaller footprint. It is generally only used as an "out" param with strict requirements that follow the documentation. (Exceptions exist for some legacy APIs to avoid breaking callers unnecessarily.) Utility functions exist to convert a user-specified `git_buf` to a `git_str` so that we can call internal functions, then converting it back again.
lhchavez 322c15ee 2020-08-01T18:24:41 Make the pack and mwindow implementations data-race-free This change fixes a packfile heap corruption that can happen when interacting with multiple packfiles concurrently across multiple threads. This is exacerbated by setting a lower mwindow open file limit. This change: * Renames most of the internal methods in pack.c to clearly indicate that they expect to be called with a certain lock held, making reasoning about the state of locks a bit easier. * Splits the `git_pack_file` lock in two: the one in `git_pack_file` only protects the `index_map`. The protection to `git_mwindow_file` is now in that struct. * Explicitly checks for freshness of the `git_pack_file` in `git_packfile_unpack_header`: this allows the mwindow implementation to close files whenever there is enough cache pressure, and `git_packfile_unpack_header` will reopen the packfile if needed. * After a call to `p_munmap()`, the `data` and `len` fields are poisoned with `NULL` to make use-after-frees more evident and crash rather than being open to the possibility of heap corruption. * Adds a test case to prevent this from regressing in the future. Fixes: #5591
Edward Thomson e316b0d3 2020-05-15T11:47:09 runtime: move init/shutdown into the "runtime" Provide a mechanism for system components to register for initialization and shutdown of the libgit2 runtime.
lhchavez 92d42eb3 2020-07-12T09:53:10 Minor nits and style formatting
lhchavez d88994da 2020-06-27T07:34:36 Create the repository within the test This change moves the humongous static repository with 1025 commits into the test file, now with a more modest 16 commits.
lhchavez eab2b044 2020-06-26T16:10:30 Review feedback * Change the default of the file limit to 0 (unlimited). * Changed the heuristic to close files to be the file that contains the least-recently-used window such that the window is the most-recently-used in the file, and the file does not have in-use windows. * Parameterized the filelimit test to check for a limit of 1 and 100 open windows.
lhchavez 9679df57 2020-02-08T20:47:24 mwindow: set limit on number of open files There are some cases in which repositories accrue a large number of packfiles. The existing mwindow limit applies only to the total size of mmap'd files, not on their number. This leads to a situation in which having lots of small packfiles could exhaust the allowed number of open files, particularly on macOS, where the default ulimit is very low (256). This change adds a new configuration parameter (GIT_OPT_SET_MWINDOW_FILE_LIMIT) that sets the maximum number of open packfiles, with a default of 128. This is low enough so that even macOS users should not hit it during normal use. Based on PR #5386, originally written by @josharian. Fixes: #2758