fsmonitor--daemon: use a cookie file to sync with file system

Teach fsmonitor--daemon client threads to create a cookie file
inside the .git directory and then wait until FS events for the
cookie are observed by the FS listener thread.

This helps address the racy nature of file system events by
blocking the client response until the kernel has drained any
event backlog.

This is especially important on MacOS where kernel events are
only issued with a limited frequency.  See the `latency` argument
of `FSeventStreamCreate()`.  The kernel only signals every `latency`
seconds, but does not guarantee that the kernel queue is completely
drained, so we may have to wait more than one interval.  If we
increase the latency, the system is more likely to drop events.
We avoid these issues by having each client thread create a unique
cookie file and then wait until it is seen in the event stream.

Co-authored-by: Kevin Willford <Kevin.Willford@microsoft.com>
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 files changed
tree: 47cf5937ecd1f6c2e260a7fdc0a9f4e052bd6b9c
  1. .github/
  2. block-sha1/
  3. builtin/
  4. ci/
  5. compat/
  6. contrib/
  7. Documentation/
  8. ewah/
  9. git-gui/
  10. gitk-git/
  11. gitweb/
  12. mergetools/
  13. negotiator/
  14. perl/
  15. po/
  16. ppc/
  17. refs/
  18. reftable/
  19. sha1dc/
  20. sha256/
  21. t/
  22. templates/
  23. trace2/
  24. xdiff/
  25. .cirrus.yml
  26. .clang-format
  27. .editorconfig
  28. .gitattributes
  29. .gitignore
  30. .gitmodules
  31. .mailmap
  32. .tsan-suppressions
  33. abspath.c
  34. aclocal.m4
  35. add-interactive.c
  36. add-interactive.h
  37. add-patch.c
  38. advice.c
  39. advice.h
  40. alias.c
  41. alias.h
  42. alloc.c
  43. alloc.h
  44. apply.c
  45. apply.h
  46. archive-tar.c
  47. archive-zip.c
  48. archive.c
  49. archive.h
  50. attr.c
  51. attr.h
  52. banned.h
  53. base85.c
  54. bisect.c
  55. bisect.h
  56. blame.c
  57. blame.h
  58. blob.c
  59. blob.h
  60. bloom.c
  61. bloom.h
  62. branch.c
  63. branch.h
  64. builtin.h
  65. bulk-checkin.c
  66. bulk-checkin.h
  67. bundle.c
  68. bundle.h
  69. cache-tree.c
  70. cache-tree.h
  71. cache.h
  72. cbtree.c
  73. cbtree.h
  74. chdir-notify.c
  75. chdir-notify.h
  76. check-builtins.sh
  77. checkout.c
  78. checkout.h
  79. chunk-format.c
  80. chunk-format.h
  81. CODE_OF_CONDUCT.md
  82. color.c
  83. color.h
  84. column.c
  85. column.h
  86. combine-diff.c
  87. command-list.txt
  88. commit-graph.c
  89. commit-graph.h
  90. commit-reach.c
  91. commit-reach.h
  92. commit-slab-decl.h
  93. commit-slab-impl.h
  94. commit-slab.h
  95. commit.c
  96. commit.h
  97. common-main.c
  98. config.c
  99. config.h
  100. config.mak.dev
  101. config.mak.in
  102. config.mak.uname
  103. configure.ac
  104. connect.c
  105. connect.h
  106. connected.c
  107. connected.h
  108. convert.c
  109. convert.h
  110. copy.c
  111. COPYING
  112. credential.c
  113. credential.h
  114. csum-file.c
  115. csum-file.h
  116. ctype.c
  117. daemon.c
  118. date.c
  119. date.h
  120. decorate.c
  121. decorate.h
  122. delta-islands.c
  123. delta-islands.h
  124. delta.h
  125. detect-compiler
  126. diff-delta.c
  127. diff-lib.c
  128. diff-merges.c
  129. diff-merges.h
  130. diff-no-index.c
  131. diff.c
  132. diff.h
  133. diffcore-break.c
  134. diffcore-delta.c
  135. diffcore-order.c
  136. diffcore-pickaxe.c
  137. diffcore-rename.c
  138. diffcore-rotate.c
  139. diffcore.h
  140. dir-iterator.c
  141. dir-iterator.h
  142. dir.c
  143. dir.h
  144. editor.c
  145. entry.c
  146. entry.h
  147. environment.c
  148. environment.h
  149. exec-cmd.c
  150. exec-cmd.h
  151. fetch-negotiator.c
  152. fetch-negotiator.h
  153. fetch-pack.c
  154. fetch-pack.h
  155. fmt-merge-msg.c
  156. fmt-merge-msg.h
  157. fsck.c
  158. fsck.h
  159. fsmonitor--daemon.h
  160. fsmonitor-ipc.c
  161. fsmonitor-ipc.h
  162. fsmonitor-settings.c
  163. fsmonitor-settings.h
  164. fsmonitor.c
  165. fsmonitor.h
  166. fuzz-commit-graph.c
  167. fuzz-pack-headers.c
  168. fuzz-pack-idx.c
  169. generate-cmdlist.sh
  170. generate-configlist.sh
  171. generate-hooklist.sh
  172. gettext.c
  173. gettext.h
  174. git-add--interactive.perl
  175. git-archimport.perl
  176. git-bisect.sh
  177. git-compat-util.h
  178. git-curl-compat.h
  179. git-cvsexportcommit.perl
  180. git-cvsimport.perl
  181. git-cvsserver.perl
  182. git-difftool--helper.sh
  183. git-filter-branch.sh
  184. git-instaweb.sh
  185. git-merge-octopus.sh
  186. git-merge-one-file.sh
  187. git-merge-resolve.sh
  188. git-mergetool--lib.sh
  189. git-mergetool.sh
  190. git-p4.py
  191. git-quiltimport.sh
  192. git-request-pull.sh
  193. git-send-email.perl
  194. git-sh-i18n.sh
  195. git-sh-setup.sh
  196. git-submodule.sh
  197. git-svn.perl
  198. GIT-VERSION-GEN
  199. git-web--browse.sh
  200. git.c
  201. git.rc
  202. gpg-interface.c
  203. gpg-interface.h
  204. graph.c
  205. graph.h
  206. grep.c
  207. grep.h
  208. hash-lookup.c
  209. hash-lookup.h
  210. hash.h
  211. hashmap.c
  212. hashmap.h
  213. help.c
  214. help.h
  215. hex.c
  216. hook.c
  217. hook.h
  218. http-backend.c
  219. http-fetch.c
  220. http-push.c
  221. http-walker.c
  222. http.c
  223. http.h
  224. ident.c
  225. imap-send.c
  226. INSTALL
  227. iterator.h
  228. json-writer.c
  229. json-writer.h
  230. khash.h
  231. kwset.c
  232. kwset.h
  233. levenshtein.c
  234. levenshtein.h
  235. LGPL-2.1
  236. line-log.c
  237. line-log.h
  238. line-range.c
  239. line-range.h
  240. linear-assignment.c
  241. linear-assignment.h
  242. list-objects-filter-options.c
  243. list-objects-filter-options.h
  244. list-objects-filter.c
  245. list-objects-filter.h
  246. list-objects.c
  247. list-objects.h
  248. list.h
  249. ll-merge.c
  250. ll-merge.h
  251. lockfile.c
  252. lockfile.h
  253. log-tree.c
  254. log-tree.h
  255. ls-refs.c
  256. ls-refs.h
  257. mailinfo.c
  258. mailinfo.h
  259. mailmap.c
  260. mailmap.h
  261. Makefile
  262. match-trees.c
  263. mem-pool.c
  264. mem-pool.h
  265. merge-blobs.c
  266. merge-blobs.h
  267. merge-ort-wrappers.c
  268. merge-ort-wrappers.h
  269. merge-ort.c
  270. merge-ort.h
  271. merge-recursive.c
  272. merge-recursive.h
  273. merge.c
  274. mergesort.c
  275. mergesort.h
  276. midx.c
  277. midx.h
  278. name-hash.c
  279. notes-cache.c
  280. notes-cache.h
  281. notes-merge.c
  282. notes-merge.h
  283. notes-utils.c
  284. notes-utils.h
  285. notes.c
  286. notes.h
  287. object-file.c
  288. object-name.c
  289. object-store.h
  290. object.c
  291. object.h
  292. oid-array.c
  293. oid-array.h
  294. oidmap.c
  295. oidmap.h
  296. oidset.c
  297. oidset.h
  298. oidtree.c
  299. oidtree.h
  300. pack-bitmap-write.c
  301. pack-bitmap.c
  302. pack-bitmap.h
  303. pack-check.c
  304. pack-objects.c
  305. pack-objects.h
  306. pack-revindex.c
  307. pack-revindex.h
  308. pack-write.c
  309. pack.h
  310. packfile.c
  311. packfile.h
  312. pager.c
  313. parallel-checkout.c
  314. parallel-checkout.h
  315. parse-options-cb.c
  316. parse-options.c
  317. parse-options.h
  318. patch-delta.c
  319. patch-ids.c
  320. patch-ids.h
  321. path.c
  322. path.h
  323. pathspec.c
  324. pathspec.h
  325. pkt-line.c
  326. pkt-line.h
  327. preload-index.c
  328. pretty.c
  329. pretty.h
  330. prio-queue.c
  331. prio-queue.h
  332. progress.c
  333. progress.h
  334. promisor-remote.c
  335. promisor-remote.h
  336. prompt.c
  337. prompt.h
  338. protocol-caps.c
  339. protocol-caps.h
  340. protocol.c
  341. protocol.h
  342. prune-packed.c
  343. prune-packed.h
  344. quote.c
  345. quote.h
  346. range-diff.c
  347. range-diff.h
  348. reachable.c
  349. reachable.h
  350. read-cache.c
  351. README.md
  352. rebase-interactive.c
  353. rebase-interactive.h
  354. rebase.c
  355. rebase.h
  356. ref-filter.c
  357. ref-filter.h
  358. reflog-walk.c
  359. reflog-walk.h
  360. refs.c
  361. refs.h
  362. refspec.c
  363. refspec.h
  364. remote-curl.c
  365. remote.c
  366. remote.h
  367. replace-object.c
  368. replace-object.h
  369. repo-settings.c
  370. repository.c
  371. repository.h
  372. rerere.c
  373. rerere.h
  374. reset.c
  375. reset.h
  376. resolve-undo.c
  377. resolve-undo.h
  378. revision.c
  379. revision.h
  380. run-command.c
  381. run-command.h
  382. SECURITY.md
  383. send-pack.c
  384. send-pack.h
  385. sequencer.c
  386. sequencer.h
  387. serve.c
  388. serve.h
  389. server-info.c
  390. setup.c
  391. sh-i18n--envsubst.c
  392. sha1dc_git.c
  393. sha1dc_git.h
  394. shallow.c
  395. shallow.h
  396. shell.c
  397. shortlog.h
  398. sideband.c
  399. sideband.h
  400. sigchain.c
  401. sigchain.h
  402. simple-ipc.h
  403. sparse-index.c
  404. sparse-index.h
  405. split-index.c
  406. split-index.h
  407. stable-qsort.c
  408. strbuf.c
  409. strbuf.h
  410. streaming.c
  411. streaming.h
  412. string-list.c
  413. string-list.h
  414. strmap.c
  415. strmap.h
  416. strvec.c
  417. strvec.h
  418. sub-process.c
  419. sub-process.h
  420. submodule-config.c
  421. submodule-config.h
  422. submodule.c
  423. submodule.h
  424. symlinks.c
  425. tag.c
  426. tag.h
  427. tar.h
  428. tempfile.c
  429. tempfile.h
  430. thread-utils.c
  431. thread-utils.h
  432. tmp-objdir.c
  433. tmp-objdir.h
  434. trace.c
  435. trace.h
  436. trace2.c
  437. trace2.h
  438. trailer.c
  439. trailer.h
  440. transport-helper.c
  441. transport-internal.h
  442. transport.c
  443. transport.h
  444. tree-diff.c
  445. tree-walk.c
  446. tree-walk.h
  447. tree.c
  448. tree.h
  449. unicode-width.h
  450. unimplemented.sh
  451. unix-socket.c
  452. unix-socket.h
  453. unix-stream-server.c
  454. unix-stream-server.h
  455. unpack-trees.c
  456. unpack-trees.h
  457. upload-pack.c
  458. upload-pack.h
  459. url.c
  460. url.h
  461. urlmatch.c
  462. urlmatch.h
  463. usage.c
  464. userdiff.c
  465. userdiff.h
  466. utf8.c
  467. utf8.h
  468. varint.c
  469. varint.h
  470. version.c
  471. version.h
  472. versioncmp.c
  473. walker.c
  474. walker.h
  475. wildmatch.c
  476. wildmatch.h
  477. worktree.c
  478. worktree.h
  479. wrap-for-bin.sh
  480. wrapper.c
  481. write-or-die.c
  482. ws.c
  483. wt-status.c
  484. wt-status.h
  485. xdiff-interface.c
  486. xdiff-interface.h
  487. zlib.c
README.md

Build status

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-<commandname>.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).

Those wishing to help with error message, usage and informational message string translations (localization l10) should see po/README.md (a po file is a Portable Object file that holds the translations).

To subscribe to the list, send an email with just “subscribe git” in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.

Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.

The maintainer frequently sends the “What's cooking” reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name “git” was given by Linus Torvalds when he wrote the very first version. He described the tool as “the stupid content tracker” and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of “get” may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • “global information tracker”: you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • “goddamn idiotic truckload of sh*t”: when it breaks