diff options
Diffstat (limited to 'lockfile.h')
| -rw-r--r-- | lockfile.h | 73 |
1 files changed, 48 insertions, 25 deletions
diff --git a/lockfile.h b/lockfile.h index a204ab6f60..8131fa31b4 100644 --- a/lockfile.h +++ b/lockfile.h @@ -29,6 +29,8 @@ * the file or the new contents of the file (assuming that the * filesystem implements `rename(2)` atomically). * + * Most of the heavy lifting is done by the tempfile module (see + * "tempfile.h"). * * Calling sequence * ---------------- @@ -74,19 +76,19 @@ * `hold_lock_file_for_update()` or `hold_lock_file_for_append()`. * * If the program exits before `commit_lock_file()`, - * `commit_lock_file_to()`, or `rollback_lock_file()` is called, an - * `atexit(3)` handler will close and remove the lockfile, thereby - * rolling back any uncommitted changes. + * `commit_lock_file_to()`, or `rollback_lock_file()` is called, the + * tempfile module will close and remove the lockfile, thereby rolling + * back any uncommitted changes. * * If you need to close the file descriptor you obtained from a * `hold_lock_file_for_*()` function yourself, do so by calling - * `close_lock_file()`. You should never call `close(2)` or - * `fclose(3)` yourself, otherwise the `struct lock_file` structure - * would still think that the file descriptor needs to be closed, and - * a commit or rollback would result in duplicate calls to `close(2)`. - * Worse yet, if you close and then later open another file descriptor - * for a completely different purpose, then a commit or rollback might - * close that unrelated file descriptor. + * `close_lock_file()`. See "tempfile.h" for more information. + * + * + * Under the covers, a lockfile is just a tempfile with a few helper + * functions. In particular, the state diagram and the cleanup + * machinery are all implemented in the tempfile module. + * * * Error handling * -------------- @@ -103,14 +105,10 @@ * -1. */ +#include "tempfile.h" + struct lock_file { - struct lock_file *volatile next; - volatile sig_atomic_t active; - volatile int fd; - FILE *volatile fp; - volatile pid_t owner; - char on_list; - struct strbuf filename; + struct tempfile tempfile; }; /* String appended to a filename to derive the lockfile name: */ @@ -201,16 +199,29 @@ extern NORETURN void unable_to_lock_die(const char *path, int err); * error. The stream is closed automatically when `close_lock_file()` * is called or when the file is committed or rolled back. */ -extern FILE *fdopen_lock_file(struct lock_file *lk, const char *mode); +static inline FILE *fdopen_lock_file(struct lock_file *lk, const char *mode) +{ + return fdopen_tempfile(&lk->tempfile, mode); +} /* * Return the path of the lockfile. The return value is a pointer to a * field within the lock_file object and should not be freed. */ -extern const char *get_lock_file_path(struct lock_file *lk); +static inline const char *get_lock_file_path(struct lock_file *lk) +{ + return get_tempfile_path(&lk->tempfile); +} -extern int get_lock_file_fd(struct lock_file *lk); -extern FILE *get_lock_file_fp(struct lock_file *lk); +static inline int get_lock_file_fd(struct lock_file *lk) +{ + return get_tempfile_fd(&lk->tempfile); +} + +static inline FILE *get_lock_file_fp(struct lock_file *lk) +{ + return get_tempfile_fp(&lk->tempfile); +} /* * Return the path of the file that is locked by the specified @@ -227,7 +238,10 @@ extern char *get_locked_file_path(struct lock_file *lk); * or `rollback_lock_file()` should eventually be called if * `close_lock_file()` succeeds. */ -extern int close_lock_file(struct lock_file *lk); +static inline int close_lock_file(struct lock_file *lk) +{ + return close_tempfile(&lk->tempfile); +} /* * Re-open a lockfile that has been closed using `close_lock_file()` @@ -248,7 +262,10 @@ extern int close_lock_file(struct lock_file *lk); * * * `commit_lock_file()` to make the final version permanent. */ -extern int reopen_lock_file(struct lock_file *lk); +static inline int reopen_lock_file(struct lock_file *lk) +{ + return reopen_tempfile(&lk->tempfile); +} /* * Commit the change represented by `lk`: close the file descriptor @@ -265,7 +282,10 @@ extern int commit_lock_file(struct lock_file *lk); * Like `commit_lock_file()`, but rename the lockfile to the provided * `path`. `path` must be on the same filesystem as the lock file. */ -extern int commit_lock_file_to(struct lock_file *lk, const char *path); +static inline int commit_lock_file_to(struct lock_file *lk, const char *path) +{ + return rename_tempfile(&lk->tempfile, path); +} /* * Roll back `lk`: close the file descriptor and/or file pointer and @@ -273,6 +293,9 @@ extern int commit_lock_file_to(struct lock_file *lk, const char *path); * for a `lock_file` object that has already been committed or rolled * back. */ -extern void rollback_lock_file(struct lock_file *lk); +static inline void rollback_lock_file(struct lock_file *lk) +{ + delete_tempfile(&lk->tempfile); +} #endif /* LOCKFILE_H */ |