This is based on ds/maintenance-part-3. After sitting with the background maintenance as it has been cooking, I wanted to come back around and implement the background maintenance for Windows. However, I noticed that there were some things bothering me with background maintenance on my macOS machine. These are detailed in PATCH 3, but the tl;dr is that 'cron' is not recommended by Apple and instead 'launchd' satisfies our needs. This series implements the background scheduling so git maintenance (start|stop) works on those platforms. I've been operating with these schedules for a while now without the problems described in the patches. There is a particularly annoying case about console windows popping up on Windows, but PATCH 4 describes a plan to get around that. Updates in V5 ============= * Fixed docs from PATCH 2 to match those in v3. * Despite my best efforts, I was unable to make the macOS tests work on Windows, so they are still marked with "!MINGW". I updated the commit message to describe my problems there. * The Windows platform now uses xmks_tempfile() to create the XML files for 'schtasks'. This led to some test fallout since the pathnames are no longer predictable. Thanks, -Stolee Derrick Stolee (4): maintenance: extract platform-specific scheduling maintenance: include 'cron' details in docs maintenance: use launchctl on macOS maintenance: use Windows scheduled tasks Documentation/git-maintenance.txt | 116 +++++++++ builtin/gc.c | 416 ++++++++++++++++++++++++++++-- t/t7900-maintenance.sh | 110 +++++++- t/test-lib.sh | 7 +- 4 files changed, 615 insertions(+), 34 deletions(-) base-commit: 0016b618182f642771dc589cf0090289f9fe1b4f Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-776%2Fderrickstolee%2Fmaintenance%2FmacOS-v5 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-776/derrickstolee/maintenance/macOS-v5 Pull-Request: https://github.com/gitgitgadget/git/pull/776 Range-diff vs v4: 1: 4807342b00 = 1: 4807342b00 maintenance: extract platform-specific scheduling 2: 99170df462 ! 2: 7cc70a8fe7 maintenance: include 'cron' details in docs @@ Documentation/git-maintenance.txt: Further, the `git gc` command should not be c +--------------------------------------- + +The standard mechanism for scheduling background tasks on POSIX systems -+is `cron`. This tool executes commands based on a given schedule. The ++is cron(8). This tool executes commands based on a given schedule. The +current list of user-scheduled tasks can be found by running `crontab -l`. +The schedule written by `git maintenance start` is similar to this: + @@ Documentation/git-maintenance.txt: Further, the `git gc` command should not be c +Any modifications within this region will be completely deleted by +`git maintenance stop` or overwritten by `git maintenance start`. + -+The `<path>` string is loaded to specifically use the location for the -+`git` executable used in the `git maintenance start` command. This allows -+for multiple versions to be compatible. However, if the same user runs -+`git maintenance start` with multiple Git executables, then only the -+latest executable will be used. ++The `crontab` entry specifies the full path of the `git` executable to ++ensure that the executed `git` command is the same one with which ++`git maintenance start` was issued independent of `PATH`. If the same user ++runs `git maintenance start` with multiple Git executables, then only the ++latest executable is used. + +These commands use `git for-each-repo --config=maintenance.repo` to run +`git maintenance run --schedule=<frequency>` on each repository listed in +the multi-valued `maintenance.repo` config option. These are typically -+loaded from the user-specific global config located at `~/.gitconfig`. -+The `git maintenance` process then determines which maintenance tasks -+are configured to run on each repository with each `<frequency>` using -+the `maintenance.<task>.schedule` config options. These values are loaded -+from the global or repository config values. ++loaded from the user-specific global config. The `git maintenance` process ++then determines which maintenance tasks are configured to run on each ++repository with each `<frequency>` using the `maintenance.<task>.schedule` ++config options. These values are loaded from the global or repository ++config values. + +If the config values are insufficient to achieve your desired background +maintenance schedule, then you can create your own schedule. If you run +`crontab -e`, then an editor will load with your user-specific `cron` +schedule. In that editor, you can add your own schedule lines. You could +start by adapting the default schedule listed earlier, or you could read -+https://man7.org/linux/man-pages/man5/crontab.5.html[the `crontab` documentation] -+for advanced scheduling techniques. Please do use the full path and -+`--exec-path` techniques from the default schedule to ensure you are -+executing the correct binaries in your schedule. ++the crontab(5) documentation for advanced scheduling techniques. Please ++do use the full path and `--exec-path` techniques from the default ++schedule to ensure you are executing the correct binaries in your ++schedule. + GIT 3: ed0a0011fb ! 3: cd015a5cbd maintenance: use launchctl on macOS @@ Commit message subcommand will succeed, if such a task already exists. The need for a user id requires us to run 'id -u' which works on - POSIX systems but not Windows. The test therefore has a prerequisite - that we are not on Windows. The cross-platform logic still allows us to - test the macOS logic on a Linux machine. + POSIX systems but not Windows. Further, the need for fully-qualitifed + path names including $HOME behaves differently in the Git internals and + the external test suite. The $HOME variable starts with "C:\..." instead + of the "/c/..." that is provided by Git in these subcommands. The test + therefore has a prerequisite that we are not on Windows. The cross- + platform logic still allows us to test the macOS logic on a Linux + machine. We can verify the commands that were run by 'git maintenance start' and 'git maintenance stop' by injecting a script that writes the @@ Commit message Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> ## Documentation/git-maintenance.txt ## -@@ Documentation/git-maintenance.txt: for advanced scheduling techniques. Please do use the full path and - executing the correct binaries in your schedule. +@@ Documentation/git-maintenance.txt: schedule to ensure you are executing the correct binaries in your + schedule. +BACKGROUND MAINTENANCE ON MACOS SYSTEMS 4: b8d86fb983 ! 4: ac9a28bea3 maintenance: use Windows scheduled tasks @@ Commit message Since the GIT_TEST_MAINT_SCHEDULER environment variable allows us to specify 'schtasks' as the scheduler, we can test the Windows-specific - logic on a macOS platform. Thus, add a check that the XML file written + logic on other platforms. Thus, add a check that the XML file written by Git is valid when xmllint exists on the system. + Since we use a temporary file for the XML files sent to 'schtasks', we + must copy the file to a predictable filename. Use the number of lines in + the 'args' file to provide a filename for xmllint. Instead of an exact + match on the 'args' file, we 'grep' for the arguments other than the + filename. + There is a deficiency in the current design. Windows has two kinds of applications: GUI applications that start by "winmain()" and console applications that start by "main()". Console applications are attached @@ builtin/gc.c: static int launchctl_update_schedule(int run_maintenance, int fd, + int result; + struct child_process child = CHILD_PROCESS_INIT; + const char *xml; -+ char *xmlpath; + struct tempfile *tfile; + const char *frequency = get_frequency(schedule); + char *name = schtasks_task_name(frequency); + -+ xmlpath = xstrfmt("%s/schedule-%s.xml", -+ the_repository->objects->odb->path, -+ frequency); -+ tfile = create_tempfile(xmlpath); ++ tfile = xmks_tempfile("schedule_XXXXXX"); + if (!tfile || !fdopen_tempfile(tfile, "w")) -+ die(_("failed to create '%s'"), xmlpath); ++ die(_("failed to create temp xml file")); + + xml = "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>\n" + "<Task version=\"1.4\" xmlns=\"http://schemas.microsoft.com/windows/2004/02/mit/task\";>\n" @@ builtin/gc.c: static int launchctl_update_schedule(int run_maintenance, int fd, + "</Task>\n"; + fprintf(tfile->fp, xml, exec_path, exec_path, frequency); + strvec_split(&child.args, cmd); -+ strvec_pushl(&child.args, "/create", "/tn", name, "/f", "/xml", xmlpath, NULL); ++ strvec_pushl(&child.args, "/create", "/tn", name, "/f", "/xml", tfile->filename.buf, NULL); + close_tempfile_gently(tfile); + + child.no_stdout = 1; @@ builtin/gc.c: static int launchctl_update_schedule(int run_maintenance, int fd, + result = finish_command(&child); + + delete_tempfile(&tfile); -+ free(xmlpath); + free(name); + return result; +} @@ t/t7900-maintenance.sh: test_expect_success !MINGW 'start and stop macOS mainten + *) shift ;; + esac + done -+ test -z "$xmlfile" || cp "$xmlfile" . ++ lines=$(wc -l args | awk "{print \$1;}") ++ test -z "$xmlfile" || cp "$xmlfile" "schedule-$lines.xml" + EOF + + rm -f args && @@ t/t7900-maintenance.sh: test_expect_success !MINGW 'start and stop macOS mainten + # start registers the repo + git config --get --global maintenance.repo "$(pwd)" && + -+ printf "/create /tn Git Maintenance (%s) /f /xml .git/objects/schedule-%s.xml\n" \ -+ hourly hourly daily daily weekly weekly >expect && -+ test_cmp expect args && -+ + for frequency in hourly daily weekly + do -+ test_xmllint "schedule-$frequency.xml" ++ grep "/create /tn Git Maintenance ($frequency) /f /xml" args \ ++ || return 1 ++ done && ++ ++ for i in 1 2 3 ++ do ++ test_xmllint "schedule-$i.xml" && ++ grep "encoding=.US-ASCII." "schedule-$i.xml" || return 1 + done && + + rm -f args && -- gitgitgadget
