diff options
Diffstat (limited to 'libfshelp/translator-list.c')
| -rw-r--r-- | libfshelp/translator-list.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/libfshelp/translator-list.c b/libfshelp/translator-list.c new file mode 100644 index 00000000..3ece7112 --- /dev/null +++ b/libfshelp/translator-list.c @@ -0,0 +1,202 @@ +/* A list of active translators. + + Copyright (C) 2013,14 Free Software Foundation, Inc. + + Written by Justus Winter <4winter@informatik.uni-hamburg.de> + + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with the GNU Hurd. If not, see <http://www.gnu.org/licenses/>. */ + +#include <argz.h> +#include <hurd/fsys.h> +#include <hurd/ihash.h> +#include <hurd/ports.h> +#include <mach.h> +#include <mach/notify.h> +#include <pthread.h> +#include <stdlib.h> +#include <string.h> +#include <libgen.h> + +#include "fshelp.h" + +struct translator +{ + struct port_info *pi; + char *name; + mach_port_t active; +}; + +/* The list of active translators. */ +static struct hurd_ihash translator_ihash + = HURD_IHASH_INITIALIZER (HURD_IHASH_NO_LOCP); + +/* The lock protecting the translator_ihash. */ +static pthread_mutex_t translator_ihash_lock = PTHREAD_MUTEX_INITIALIZER; + +static void +translator_ihash_cleanup (void *element, void *arg) +{ + struct translator *translator = element; + + if (translator->pi) + ports_port_deref (translator->pi); + /* No need to deallocate translator->active, we only keep the name of + the port, not a reference. */ + free (translator->name); + free (translator); +} + +/* Record an active translator being bound to the given file name + NAME. ACTIVE is the control port of the translator. */ +error_t +fshelp_set_active_translator (struct port_info *pi, + const char *name, + mach_port_t active) +{ + error_t err = 0; + pthread_mutex_lock (&translator_ihash_lock); + + if (! translator_ihash.cleanup) + hurd_ihash_set_cleanup (&translator_ihash, translator_ihash_cleanup, NULL); + + struct translator *t = NULL; + HURD_IHASH_ITERATE (&translator_ihash, value) + { + t = value; + if (strcmp (name, t->name) == 0) + goto update; /* Entry exists. */ + } + + t = malloc (sizeof (struct translator)); + if (! t) + return ENOMEM; + + t->active = MACH_PORT_NULL; + t->pi = NULL; + t->name = strdup (name); + if (! t->name) + { + err = errno; + free (t); + goto out; + } + + err = hurd_ihash_add (&translator_ihash, (hurd_ihash_key_t) t, t); + if (err) + goto out; + + update: + if (active) + { + if (t->pi != pi) + { + mach_port_t old; + err = mach_port_request_notification (mach_task_self (), active, + MACH_NOTIFY_DEAD_NAME, 0, + pi->port_right, + MACH_MSG_TYPE_MAKE_SEND_ONCE, + &old); + if (err) + return err; + if (old != MACH_PORT_NULL) + mach_port_deallocate (mach_task_self (), old); + + if (t->pi) + ports_port_deref (t->pi); + + ports_port_ref (pi); + t->pi = pi; + } + + /* No need to increment the reference count, we only keep the + name, not a reference. */ + t->active = active; + } + else + hurd_ihash_remove (&translator_ihash, (hurd_ihash_key_t) t); + + out: + pthread_mutex_unlock (&translator_ihash_lock); + return err; +} + +/* Remove the active translator specified by its control port ACTIVE. + If there is no active translator with the given control port, this + does nothing. */ +error_t +fshelp_remove_active_translator (mach_port_t active) +{ + error_t err = 0; + pthread_mutex_lock (&translator_ihash_lock); + + struct translator *t = NULL; + HURD_IHASH_ITERATE (&translator_ihash, value) + { + struct translator *v = value; + if (active == v->active) + { + t = v; + break; + } + } + + if (t) + hurd_ihash_remove (&translator_ihash, (hurd_ihash_key_t) t); + + pthread_mutex_unlock (&translator_ihash_lock); + return err; +} + +/* Records the list of active translators into the argz vector + specified by TRANSLATORS filtered by FILTER. */ +error_t +fshelp_get_active_translators (char **translators, + size_t *translators_len, + fshelp_filter filter) +{ + error_t err = 0; + pthread_mutex_lock (&translator_ihash_lock); + + HURD_IHASH_ITERATE (&translator_ihash, value) + { + struct translator *t = value; + if (filter) + { + char *dir = strdup (t->name); + if (! dir) + { + err = ENOMEM; + break; + } + + err = filter (dirname (dir)); + free (dir); + if (err) + { + err = 0; + continue; /* Skip this entry. */ + } + } + + err = argz_add (translators, translators_len, + t->name); + if (err) + break; + } + + pthread_mutex_unlock (&translator_ihash_lock); + return err; +} |