[PATCH 05/16] libfshelp: add translator-list.c
Add functions that maintain a list of active translators.
* libfshelp/translator-list.c: New file.
* libfshelp/fshelp.h: Add function declarations.
* libfshelp/Makefile: Add translator-list.c, link against libihash.
---
libfshelp/Makefile | 3 +-
libfshelp/fshelp.h | 33 ++++++++-
libfshelp/translator-list.c | 169 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 203 insertions(+), 2 deletions(-)
create mode 100644 libfshelp/translator-list.c
diff --git a/libfshelp/Makefile b/libfshelp/Makefile
index 4de3837..6ba6a14 100644
--- a/libfshelp/Makefile
+++ b/libfshelp/Makefile
@@ -20,6 +20,7 @@ makemode := library
libname = libfshelp
SRCS = lock-acquire.c lock-init.c \
+ translator-list.c \
start-translator-long.c start-translator.c \
fetch-root.c transbox-init.c set-active.c fetch-control.c \
drop-transbox.c translated.c \
@@ -32,7 +33,7 @@ SRCS = lock-acquire.c lock-init.c \
touch.c
installhdrs = fshelp.h
-HURDLIBS = shouldbeinlibc iohelp ports
+HURDLIBS = shouldbeinlibc iohelp ports ihash
LDLIBS += -lpthread
OBJS = $(subst .c,.o,$(SRCS))
diff --git a/libfshelp/fshelp.h b/libfshelp/fshelp.h
index cf39fbc..43fbcd7 100644
--- a/libfshelp/fshelp.h
+++ b/libfshelp/fshelp.h
@@ -1,5 +1,6 @@
/* FS helper library definitions
- Copyright (C) 1994,95,96,97,98,99,2000,01,02 Free Software Foundation, Inc.
+ Copyright (C) 1994,95,96,97,98,99,2000,01,02,13
+ Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
@@ -32,6 +33,36 @@
#include <maptime.h>
+/* Keeping track of active translators */
+/* These routines keep a list of active translators. They are
+ self-contained and do not require multi threading or the ports
+ library. */
+
+/* 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 (const char *name, mach_port_t active);
+
+/* 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);
+
+/* This kind of function is used by fshelp_get_active_translators to
+ filter the list of translators to return. If a filter returns an
+ error for a given PATH, the translator bound to the PATH is not
+ included in the list. */
+typedef error_t (*fshelp_filter) (const char *path);
+
+/* 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);
+
+
/* Passive translator linkage */
/* These routines are self-contained and start passive translators,
returning the control port. They do not require multi threading
diff --git a/libfshelp/translator-list.c b/libfshelp/translator-list.c
new file mode 100644
index 0000000..a24d976
--- /dev/null
+++ b/libfshelp/translator-list.c
@@ -0,0 +1,169 @@
+/* A list of active translators.
+
+ Copyright (C) 2013 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 <mach.h>
+#include <mach/notify.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fshelp.h"
+
+struct translator
+{
+ 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)
+{
+ /* No need to deallocate port, we only keep the name of the
+ port, not a reference. */
+ free (element);
+}
+
+/* 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 (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->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)
+ /* 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;
+}
--
1.7.10.4
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