From 937aeb1904eb5cbe7a8c1c686877c7a9e1196ca6 Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Wed, 13 Dec 2023 10:08:12 +0100 Subject: common: Add an info callback to dotlock. * common/dotlock.h (enum dotlock_reasons): New. (DOTLOCK_PREPARE_CREATE): New flag. * common/dotlock.c (struct dotlock_handle): Add info_cb and info_cb_value. (dotlock_create): Support the new flag. (dotlock_finish_create): New. (read_lockfile): Silence in case of ENOENT. (dotlock_set_info_cb): New. Use callback after all error and info messages. (dotlock_take_unix, dotlock_take_w32): Allow termination by callback. --- common/dotlock.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++---- common/dotlock.h | 20 +++++++ common/t-dotlock.c | 36 +++++++++++- 3 files changed, 203 insertions(+), 11 deletions(-) (limited to 'common') diff --git a/common/dotlock.c b/common/dotlock.c index d1058845e..261e2cce7 100644 --- a/common/dotlock.c +++ b/common/dotlock.c @@ -396,6 +396,13 @@ struct dotlock_handle int extra_fd; /* A place for the caller to store an FD. */ + /* An optional info callback - see dotlock_set_info_cb. */ + int (*info_cb)(dotlock_t, void *, + enum dotlock_reasons reason, + const char *,...); + void *info_cb_value; + + #ifdef HAVE_DOSISH_SYSTEM HANDLE lockhd; /* The W32 handle of the lock file. */ #else /*!HAVE_DOSISH_SYSTEM */ @@ -545,8 +552,15 @@ read_lockfile (dotlock_t h, int *same_node, int *r_fd) if ( (fd = open (h->lockname, O_RDONLY)) == -1 ) { int e = errno; - my_info_2 ("error opening lockfile '%s': %s\n", - h->lockname, strerror(errno) ); + if (errno != ENOENT) + { + my_info_2 ("error opening lockfile '%s': %s\n", + h->lockname, strerror(errno) ); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "error opening lockfile '%s': %s\n", + h->lockname, strerror (errno) ); + } if (buffer != buffer_space) xfree (buffer); my_set_errno (e); /* Need to return ERRNO here. */ @@ -564,6 +578,10 @@ read_lockfile (dotlock_t h, int *same_node, int *r_fd) { int e = errno; my_info_1 ("error reading lockfile '%s'\n", h->lockname ); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "error reading lockfile '%s': %s\n", + h->lockname, strerror (errno) ); close (fd); if (buffer != buffer_space) xfree (buffer); @@ -583,6 +601,9 @@ read_lockfile (dotlock_t h, int *same_node, int *r_fd) if (nread < 11) { my_info_1 ("invalid size of lockfile '%s'\n", h->lockname); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_INV_FILE, + "invalid size of lockfile '%s'\n", h->lockname); if (buffer != buffer_space) xfree (buffer); my_set_errno (EINVAL); @@ -594,6 +615,9 @@ read_lockfile (dotlock_t h, int *same_node, int *r_fd) || !pid ) { my_error_2 ("invalid pid %d in lockfile '%s'\n", pid, h->lockname); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_INV_FILE, + "invalid pid %d in lockfile '%s'\n", pid, h->lockname); if (buffer != buffer_space) xfree (buffer); my_set_errno (EINVAL); @@ -722,6 +746,10 @@ dotlock_create_unix (dotlock_t h, const char *file_to_lock) UNLOCK_all_lockfiles (); my_error_2 (_("failed to create temporary file '%s': %s\n"), h->tname, strerror (errno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_WAITING, + _("failed to create temporary file '%s': %s\n"), + h->tname, strerror (errno)); xfree (h->tname); xfree (h); my_set_errno (saveerrno); @@ -755,6 +783,10 @@ dotlock_create_unix (dotlock_t h, const char *file_to_lock) int saveerrno = errno; my_error_2 ("can't check whether hardlinks are supported for '%s': %s\n" , h->tname, strerror (saveerrno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_CONFIG_TEST, + "can't check whether hardlinks are supported for '%s': %s\n" + , h->tname, strerror (saveerrno)); my_set_errno (saveerrno); } goto write_failed; @@ -783,6 +815,11 @@ dotlock_create_unix (dotlock_t h, const char *file_to_lock) all_lockfiles = h->next; UNLOCK_all_lockfiles (); my_error_2 (_("error writing to '%s': %s\n"), h->tname, strerror (errno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + _("error writing to '%s': %s\n"), + h->tname, strerror (errno)); + if ( fd != -1 ) close (fd); unlink (h->tname); @@ -849,6 +886,10 @@ dotlock_create_w32 (dotlock_t h, const char *file_to_lock) all_lockfiles = h->next; UNLOCK_all_lockfiles (); my_error_2 (_("can't create '%s': %s\n"), h->lockname, w32_strerror (-1)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + _("can't create '%s': %s\n"), + h->lockname, w32_strerror (-1)); xfree (h->lockname); xfree (h); my_set_errno (saveerrno); @@ -873,7 +914,10 @@ dotlock_create_w32 (dotlock_t h, const char *file_to_lock) POSIX systems a temporary file ".#lk..pid[.threadid] is used. - FLAGS must be 0. + The only defined FLAG bit is DOTLOCK_PREPARE_CREATE, which only + allocates the handle and requires a further call to + dotlock_finish_create. This can be used to set a callback between + these calls. The function returns an new handle which needs to be released using destroy_dotlock but gets also released at the termination of the @@ -895,7 +939,7 @@ dotlock_create (const char *file_to_lock, unsigned int flags) if ( !file_to_lock ) return NULL; /* Only initialization was requested. */ - if (flags) + if ((flags & ~DOTLOCK_PREPARE_CREATE)) { my_set_errno (EINVAL); return NULL; @@ -916,6 +960,24 @@ dotlock_create (const char *file_to_lock, unsigned int flags) return h; } + if ((flags & DOTLOCK_PREPARE_CREATE)) + return h; + else + return dotlock_finish_create (h, file_to_lock); +} + + +/* This function may be used along with dotlock_create (file_name, + * DOTLOCK_PREPARE_CREATE) to finish the creation call. The given + * filename shall be the same as passed to dotlock_create. On success + * the same handle H is returned, on error NULL is returned and H is + * released. */ +dotlock_t +dotlock_finish_create (dotlock_t h, const char *file_to_lock) +{ + if (!h || !file_to_lock) + return NULL; + #ifdef HAVE_DOSISH_SYSTEM return dotlock_create_w32 (h, file_to_lock); #else /*!HAVE_DOSISH_SYSTEM */ @@ -942,6 +1004,24 @@ dotlock_get_fd (dotlock_t h) } +/* Set a callback function for info diagnostics. The callback + * function CB is called with the handle, the opaque value OPAQUE, a + * reason code, and a format string with its arguments. The callback + * shall return 0 to continue operation or true in which case the + * current function will be terminated with an error. */ +void +dotlock_set_info_cb (dotlock_t h, + int (*cb)(dotlock_t, void *, + enum dotlock_reasons reason, + const char *,...), + void *opaque) +{ + h->info_cb = cb; + h->info_cb_value = opaque; +} + + + #ifdef HAVE_POSIX_SYSTEM /* Unix specific code of destroy_dotlock. */ @@ -1090,6 +1170,10 @@ dotlock_take_unix (dotlock_t h, long timeout) saveerrno = errno; my_error_2 ("lock not made: open(O_EXCL) of '%s' failed: %s\n", h->lockname, strerror (saveerrno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "lock not made: open(O_EXCL) of '%s' failed: %s\n", + h->lockname, strerror (saveerrno)); my_set_errno (saveerrno); return -1; } @@ -1111,6 +1195,10 @@ dotlock_take_unix (dotlock_t h, long timeout) saveerrno = errno; my_error_2 ("lock not made: writing to '%s' failed: %s\n", h->lockname, strerror (errno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "lock not made: writing to '%s' failed: %s\n", + h->lockname, strerror (errno)); close (fd); unlink (h->lockname); my_set_errno (saveerrno); @@ -1129,6 +1217,10 @@ dotlock_take_unix (dotlock_t h, long timeout) saveerrno = errno; my_error_1 ("lock not made: Oops: stat of tmp file failed: %s\n", strerror (errno)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "lock not made: Oops: stat of tmp file failed: %s\n", + strerror (errno)); /* In theory this might be a severe error: It is possible that link succeeded but stat failed due to changed permissions. We can't do anything about it, though. */ @@ -1150,6 +1242,9 @@ dotlock_take_unix (dotlock_t h, long timeout) { saveerrno = errno; my_info_0 ("cannot read lockfile\n"); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "cannot read lockfile\n"); my_set_errno (saveerrno); return -1; } @@ -1158,8 +1253,8 @@ dotlock_take_unix (dotlock_t h, long timeout) } else if ( (pid == getpid() && same_node) || (same_node && kill (pid, 0) && errno == ESRCH) ) - /* Stale lockfile is detected. */ { + /* Stale lockfile is detected. */ struct stat sb; /* Check if it's unlocked during examining the lockfile. */ @@ -1202,6 +1297,9 @@ dotlock_take_unix (dotlock_t h, long timeout) unlink (h->lockname); my_info_1 (_("removing stale lockfile (created by %d)\n"), pid); close (fd); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_STALE_REMOVED, + _("removing stale lockfile (created by %d)\n"), pid); goto again; } @@ -1228,6 +1326,15 @@ dotlock_take_unix (dotlock_t h, long timeout) sumtime = 0; my_info_3 (_("waiting for lock (held by %d%s) %s...\n"), pid, maybe_dead, maybe_deadlock(h)? _("(deadlock?) "):""); + if (h->info_cb + && h->info_cb (h, h->info_cb_value, DOTLOCK_WAITING, + _("waiting for lock (held by %d%s) %s...\n"), + pid, maybe_dead, + maybe_deadlock(h)? _("(deadlock?) "):"")) + { + my_set_errno (ECANCELED); + return -1; + } } tv.tv_sec = wtimereal / 1000; @@ -1268,7 +1375,11 @@ dotlock_take_w32 (dotlock_t h, long timeout) { my_error_2 (_("lock '%s' not made: %s\n"), h->lockname, w32_strerror (w32err)); - my_set_errno (map_w32_to_errno (w32err)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + _("lock '%s' not made: %s\n"), + h->lockname, w32_strerror (w32err)); + _set_errno (map_w32_to_errno (w32err)); return -1; } @@ -1281,7 +1392,16 @@ dotlock_take_w32 (dotlock_t h, long timeout) timedout = 1; /* remember. */ if (wtime >= 800) - my_info_1 (_("waiting for lock %s...\n"), h->lockname); + { + my_info_1 (_("waiting for lock %s...\n"), h->lockname); + if (h->info_cb + && h->info_cb (h, h->info_cb_value, DOTLOCK_WAITING, + _("waiting for lock %s...\n"), h->lockname)) + { + my_set_errno (ECANCELED); + return -1; + } + } Sleep (wtimereal); goto again; @@ -1334,12 +1454,18 @@ dotlock_release_unix (dotlock_t h) { saveerrno = errno; my_error_0 ("release_dotlock: lockfile error\n"); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "release_dotlock: lockfile error\n"); my_set_errno (saveerrno); return -1; } if ( pid != getpid() || !same_node ) { my_error_1 ("release_dotlock: not our lock (pid=%d)\n", pid); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_CONFLICT, + "release_dotlock: not our lock (pid=%d)\n", pid); my_set_errno (EACCES); return -1; } @@ -1349,6 +1475,10 @@ dotlock_release_unix (dotlock_t h) saveerrno = errno; my_error_1 ("release_dotlock: error removing lockfile '%s'\n", h->lockname); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "release_dotlock: error removing lockfile '%s'\n", + h->lockname); my_set_errno (saveerrno); return -1; } @@ -1369,10 +1499,15 @@ dotlock_release_w32 (dotlock_t h) memset (&ovl, 0, sizeof ovl); if (!UnlockFileEx (h->lockhd, 0, 1, 0, &ovl)) { - int saveerrno = map_w32_to_errno (GetLastError ()); + int ec = (int)GetLastError (); + my_error_2 ("release_dotlock: error removing lockfile '%s': %s\n", - h->lockname, w32_strerror (-1)); - my_set_errno (saveerrno); + h->lockname, w32_strerror (ec)); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_FILE_ERROR, + "release_dotlock: error removing lockfile '%s': %s\n", + h->lockname, w32_strerror (ec)); + my_set_errno (map_w32_to_errno (ec)); return -1; } @@ -1403,6 +1538,9 @@ dotlock_release (dotlock_t h) if ( !h->locked ) { my_debug_1 ("Oops, '%s' is not locked\n", h->lockname); + if (h->info_cb) + h->info_cb (h, h->info_cb_value, DOTLOCK_NOT_LOCKED, + "Oops, '%s' is not locked\n", h->lockname); return 0; } diff --git a/common/dotlock.h b/common/dotlock.h index 03131bb0c..915279176 100644 --- a/common/dotlock.h +++ b/common/dotlock.h @@ -97,12 +97,32 @@ extern "C" struct dotlock_handle; typedef struct dotlock_handle *dotlock_t; +enum dotlock_reasons + { + DOTLOCK_CONFIG_TEST, /* Can't check system - function terminates. */ + DOTLOCK_FILE_ERROR, /* General file error - function terminates. */ + DOTLOCK_INV_FILE, /* Invalid file - function terminates. */ + DOTLOCK_CONFLICT, /* Something is wrong - function terminates. */ + DOTLOCK_NOT_LOCKED, /* Not locked - No action required. */ + DOTLOCK_STALE_REMOVED, /* Stale lock file was removed - retrying. */ + DOTLOCK_WAITING /* Waiting for the lock - may be terminated. */ + }; + +#define DOTLOCK_PREPARE_CREATE (1<<5) /* Require dotlock_finish_create. */ + void dotlock_disable (void); dotlock_t dotlock_create (const char *file_to_lock, unsigned int flags); +dotlock_t dotlock_finish_create (dotlock_t h, const char *file_to_lock); void dotlock_set_fd (dotlock_t h, int fd); int dotlock_get_fd (dotlock_t h); +void dotlock_set_info_cb (dotlock_t h, + int (*cb)(dotlock_t, void *, + enum dotlock_reasons reason, + const char *,...), + void *opaque); void dotlock_destroy (dotlock_t h); int dotlock_take (dotlock_t h, long timeout); +int dotlock_is_locked (dotlock_t h); int dotlock_release (dotlock_t h); void dotlock_remove_lockfiles (void); diff --git a/common/t-dotlock.c b/common/t-dotlock.c index 994ef1be3..87e62bb33 100644 --- a/common/t-dotlock.c +++ b/common/t-dotlock.c @@ -52,6 +52,7 @@ #ifdef HAVE_W32_SYSTEM #define DIM(v) (sizeof(v)/sizeof((v)[0])) + const char * w32_strerror (int ec) { @@ -174,6 +175,11 @@ strconcat (const char *s1, ...) #define PGM "t-dotlock" +static int opt_silent; + + + + #ifndef HAVE_W32_SYSTEM static volatile int ctrl_c_pending_flag; static void @@ -217,6 +223,9 @@ inf (const char *format, ...) { va_list arg_ptr; + if (opt_silent) + return; + va_start (arg_ptr, format); fprintf (stderr, PGM "[%lu]: ", (unsigned long)getpid ()); vfprintf (stderr, format, arg_ptr); @@ -225,15 +234,35 @@ inf (const char *format, ...) } +static int +lock_info_cb (dotlock_t h, void *opaque, enum dotlock_reasons reason, + const char *format, ...) +{ + va_list arg_ptr; + + va_start (arg_ptr, format); + fprintf (stderr, PGM "[%lu]: info_cb: reason %d, ", + (unsigned long)getpid (), (int)reason); + vfprintf (stderr, format, arg_ptr); + va_end (arg_ptr); + return 0; +} + + static void lock_and_unlock (const char *fname) { dotlock_t h; unsigned long usec; - h = dotlock_create (fname, 0); + h = dotlock_create (fname, DOTLOCK_PREPARE_CREATE); if (!h) die ("error creating lock file for '%s': %s", fname, strerror (errno)); + dotlock_set_info_cb (h, lock_info_cb, NULL); + h = dotlock_finish_create (h, fname); + if (!h) + die ("error finishing lock file creation for '%s': %s", + fname, strerror (errno)); inf ("lock created"); do @@ -270,6 +299,11 @@ main (int argc, char **argv) ctrl_c_pending_flag = 1; argc--; } + if (argc > 1 && !strcmp (argv[1], "--silent")) + { + opt_silent = 1; + argc--; + } if (argc > 1) fname = argv[argc-1]; -- cgit v1.2.3