git/lockfile.c

/*
 * Copyright (c) 2005, Junio C Hamano
 */

#include "git-compat-util.h"
#include "abspath.h"
#include "gettext.h"
#include "lockfile.h"

/*
 * path = absolute or relative path name
 *
 * Remove the last path name element from path (leaving the preceding
 * "/", if any).  If path is empty or the root directory ("/"), set
 * path to the empty string.
 */
static void trim_last_path_component(struct strbuf *path)
{ … }


/* We allow "recursive" symbolic links. Only within reason, though */
#define MAXDEPTH …

/*
 * path contains a path that might be a symlink.
 *
 * If path is a symlink, attempt to overwrite it with a path to the
 * real file or directory (which may or may not exist), following a
 * chain of symlinks if necessary.  Otherwise, leave path unmodified.
 *
 * This is a best-effort routine.  If an error occurs, path will
 * either be left unmodified or will name a different symlink in a
 * symlink chain that started with the original path.
 */
static void resolve_symlink(struct strbuf *path)
{ … }

/* Make sure errno contains a meaningful value on error */
static int lock_file(struct lock_file *lk, const char *path, int flags,
		     int mode)
{ … }

/*
 * Constants defining the gaps between attempts to lock a file. The
 * first backoff period is approximately INITIAL_BACKOFF_MS
 * milliseconds. The longest backoff period is approximately
 * (BACKOFF_MAX_MULTIPLIER * INITIAL_BACKOFF_MS) milliseconds.
 */
#define INITIAL_BACKOFF_MS …
#define BACKOFF_MAX_MULTIPLIER …

/*
 * Try locking path, retrying with quadratic backoff for at least
 * timeout_ms milliseconds. If timeout_ms is 0, try locking the file
 * exactly once. If timeout_ms is -1, try indefinitely.
 */
static int lock_file_timeout(struct lock_file *lk, const char *path,
			     int flags, long timeout_ms, int mode)
{ … }

void unable_to_lock_message(const char *path, int err, struct strbuf *buf)
{ … }

NORETURN void unable_to_lock_die(const char *path, int err)
{ … }

/* This should return a meaningful errno on failure */
int hold_lock_file_for_update_timeout_mode(struct lock_file *lk,
					   const char *path, int flags,
					   long timeout_ms, int mode)
{ … }

char *get_locked_file_path(struct lock_file *lk)
{ … }

int commit_lock_file(struct lock_file *lk)
{ … }