[PATCH v2] gc: reject if another gc is running, unless --force is given
- From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
- Date
- Aug 3, 2013, 06:21 UTC
- Message-ID
- <1375510890-4728-1-git-send-email-pclouds@gmail.com>
- In-Reply-To
- <1375503605-32480-1-git-send-email-pclouds@gmail.com>
This may happen when `git gc --auto` is run automatically, then the user, to avoid wait time, switches to a new terminal, keeps working and `git gc --auto` is started again because the first gc instance has not clean up the repository.
This patch tries to avoid multiple gc running, especially in --auto mode. In the worst case, gc may be delayed 12 hours if a daemon reuses the pid stored in gc-%s.pid.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> --- v2 deals with the stored pid taken by another process and takes shared repository into account (sort of, it only makes sure gc is not run multiple times on the same machine, not only one gc instance across multiple machines)
I changed mingw.h to add a stub uname() because I don't think MinGW port has that function, but that's totally untested.
Documentation/git-gc.txt | 6 +++++- builtin/gc.c | 35 +++++++++++++++++++++++++++++++++++ compat/mingw.h | 6 ++++++ git-compat-util.h | 1 + 4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt index 2402ed6..e158a3b 100644 --- a/Documentation/git-gc.txt +++ b/Documentation/git-gc.txt @@ -9,7 +9,7 @@ git-gc - Cleanup unnecessary files and optimize the local repository SYNOPSIS -------- [verse] -'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] +'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] DESCRIPTION ----------- @@ -72,6 +72,10 @@ automatic consolidation of packs. --quiet:: Suppress all progress reports. +--force:: + Force `git gc` to run even if there may be another `git gc` + instance running on this repository. + Configuration ------------- diff --git a/builtin/gc.c b/builtin/gc.c index 6be6c8d..8a7f24a 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -172,6 +172,10 @@ int cmd_gc(int argc, const char **argv, const char *prefix) int aggressive = 0; int auto_gc = 0; int quiet = 0; + int force = 0; + FILE *fp; + struct utsname utsname; + struct stat st; struct option builtin_gc_options[] = { OPT__QUIET(&quiet, N_("suppress progress reporting")), @@ -180,6 +184,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix) PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire }, OPT_BOOLEAN(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")), OPT_BOOLEAN(0, "auto", &auto_gc, N_("enable auto-gc mode")), + OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")), OPT_END() }; @@ -225,6 +230,34 @@ int cmd_gc(int argc, const char **argv, const char *prefix) } else add_repack_all_option(); + if (uname(&utsname)) + strcpy(utsname.nodename, "unknown"); + + if (!force && + (fp = fopen(git_path("gc-%s.pid", utsname.nodename), "r")) != NULL && + !fstat(fileno(fp), &st) && + /* + * 12 hour limit is very generous as gc should never take + * that long. On the other hand we don't really need a + * strict limit here, running gc --auto one day late is + * not a big problem. --force can be used in manual gc + * after the user verifies that no gc is running. + */ + time(NULL) - st.st_mtime <= 12 * 3600) { + uintmax_t pid; + if (fscanf(fp, "%"PRIuMAX, &pid) == 1 && !kill(pid, 0)) { + if (auto_gc) + return 0; /* be quiet on --auto */ + die(_("gc is already running")); + } + fclose(fp); + } + + if ((fp = fopen(git_path("gc-%s.pid", utsname.nodename), "w")) != NULL) { + fprintf(fp, "%"PRIuMAX"\n", (uintmax_t) getpid()); + fclose(fp); + } + if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD)) return error(FAILED_RUN, pack_refs_cmd.argv[0]); @@ -249,5 +282,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix) warning(_("There are too many unreachable loose objects; " "run 'git prune' to remove them.")); + unlink(git_path("gc-%s.pid", utsname.nodename)); + return 0; } diff --git a/compat/mingw.h b/compat/mingw.h index bd0a88b..2c25d2d 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -68,6 +68,10 @@ struct itimerval { }; #define ITIMER_REAL 0 +struct utsname { + char nodename[128]; +}; + /* * sanitize preprocessor namespace polluted by Windows headers defining * macros which collide with git local versions @@ -86,6 +90,8 @@ static inline int fchmod(int fildes, mode_t mode) { errno = ENOSYS; return -1; } static inline pid_t fork(void) { errno = ENOSYS; return -1; } +static inline int uname(struct utsname *buf) +{ errno = ENOSYS; return -1; } static inline unsigned int alarm(unsigned int seconds) { return 0; } static inline int fsync(int fd) diff --git a/git-compat-util.h b/git-compat-util.h index 115cb1d..c6a53cb 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -139,6 +139,7 @@ #include <sys/resource.h> #include <sys/socket.h> #include <sys/ioctl.h> +#include <sys/utsname.h> #include <termios.h> #ifndef NO_SYS_SELECT_H #include <sys/select.h>
-- 1.8.2.83.gc99314b