https://origsvn.digium.com/svn/asterisk/branches/1.4
........
r88805 | russell | 2007-11-05 16:07:54 -0600 (Mon, 05 Nov 2007) | 12 lines
After seeing crashes related to channel variables, I went looking around at the
ways that channel variables are handled. In general, they were not handled in
a thread-safe way. The channel _must_ be locked when reading or writing from/to
the channel variable list.
What I have done to improve this situation is to make pbx_builtin_setvar_helper()
and friends lock the channel when doing their thing. Asterisk API calls almost
all lock the channel for you as necessary, but this family of functions did not.
(closes issue #10923, reported by atis)
(closes issue #11159, reported by 850t)
........
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@88934
65c4cc65-6c06-0410-ace0-
fbb531ad65f3
-/*
- * Asterisk -- An open source telephony toolkit.
- *
- * Copyright (C) 1999 - 2007, Digium, Inc.
- *
- * Mark Spencer <markster@digium.com>
- *
- * See http://www.asterisk.org for more information about
- * the Asterisk project. Please do not directly contact
- * any of the maintainers of this project for assistance;
- * the project provides a web site, mailing lists and IRC
- * channels for your use.
- *
- * This program is free software, distributed under the terms of
- * the GNU General Public License Version 2. See the LICENSE file
- * at the top of the source tree.
- */
-
/* busy.h: Generated from frequencies 480 and 620
by gentone. 400 samples */
static short busy[400] = {
-/*
- * Asterisk -- An open source telephony toolkit.
- *
- * Copyright (C) 1999 - 2007, Digium, Inc.
- *
- * Mark Spencer <markster@digium.com>
- *
- * See http://www.asterisk.org for more information about
- * the Asterisk project. Please do not directly contact
- * any of the maintainers of this project for assistance;
- * the project provides a web site, mailing lists and IRC
- * channels for your use.
- *
- * This program is free software, distributed under the terms of
- * the GNU General Public License Version 2. See the LICENSE file
- * at the top of the source tree.
- */
-
/* ringtone.h: Generated from frequencies 440 and 480
by gentone. 200 samples */
static short ringtone[200] = {
struct ast_ignorepat *ip);
struct ast_sw *ast_walk_context_switches(struct ast_context *con, struct ast_sw *sw);
+/*!
+ * \note Will lock the channel.
+ */
int pbx_builtin_serialize_variables(struct ast_channel *chan, struct ast_str **buf);
+
+/*!
+ * \note Will lock the channel.
+ */
const char *pbx_builtin_getvar_helper(struct ast_channel *chan, const char *name);
+
+/*!
+ * \note Will lock the channel.
+ */
void pbx_builtin_pushvar_helper(struct ast_channel *chan, const char *name, const char *value);
+
+/*!
+ * \note Will lock the channel.
+ */
void pbx_builtin_setvar_helper(struct ast_channel *chan, const char *name, const char *value);
+
+/*!
+ * \note Will lock the channel.
+ */
void pbx_retrieve_variable(struct ast_channel *c, const char *var, char **ret, char *workspace, int workspacelen, struct varshead *headp);
void pbx_builtin_clear_globals(void);
+
+/*!
+ * \note Will lock the channel.
+ */
int pbx_builtin_setvar(struct ast_channel *chan, void *data);
+
int pbx_builtin_raise_exception(struct ast_channel *chan, void *data);
+
void pbx_substitute_variables_helper(struct ast_channel *c,const char *cp1,char *cp2,int count);
void pbx_substitute_variables_varshead(struct varshead *headp, const char *cp1, char *cp2, int count);
struct varshead *places[2] = { headp, &globals }; /* list of places where we may look */
if (c) {
+ ast_channel_lock(c);
places[0] = &c->varshead;
}
/*
if (need_substring)
*ret = substring(*ret, offset, length, workspace, workspacelen);
}
+
+ if (c)
+ ast_channel_unlock(c);
}
static void exception_store_free(void *data)
(*buf)->used = 0;
(*buf)->str[0] = '\0';
+ ast_channel_lock(chan);
+
AST_LIST_TRAVERSE(&chan->varshead, variables, entries) {
if ((var = ast_var_name(variables)) && (val = ast_var_value(variables))
/* && !ast_strlen_zero(var) && !ast_strlen_zero(val) */
break;
}
+ ast_channel_unlock(chan);
+
return total;
}
if (!name)
return NULL;
- if (chan)
+
+ if (chan) {
+ ast_channel_lock(chan);
places[0] = &chan->varshead;
+ }
for (i = 0; i < 2; i++) {
if (!places[i])
break;
}
+ if (chan)
+ ast_channel_unlock(chan);
+
return ret;
}
return;
}
- headp = (chan) ? &chan->varshead : &globals;
+ if (chan) {
+ ast_channel_lock(chan);
+ headp = &chan->varshead;
+ } else {
+ ast_rwlock_wrlock(&globalslock);
+ headp = &globals;
+ }
if (value) {
if (headp == &globals)
ast_verb(2, "Setting global variable '%s' to '%s'\n", name, value);
newvariable = ast_var_assign(name, value);
- if (headp == &globals)
- ast_rwlock_wrlock(&globalslock);
AST_LIST_INSERT_HEAD(headp, newvariable, entries);
- if (headp == &globals)
- ast_rwlock_unlock(&globalslock);
}
+
+ if (chan)
+ ast_channel_unlock(chan);
+ else
+ ast_rwlock_unlock(&globalslock);
}
void pbx_builtin_setvar_helper(struct ast_channel *chan, const char *name, const char *value)
struct varshead *headp;
const char *nametail = name;
- /* XXX may need locking on the channel ? */
if (name[strlen(name) - 1] == ')') {
char *function = ast_strdupa(name);
return;
}
- headp = (chan) ? &chan->varshead : &globals;
+ if (chan) {
+ ast_channel_lock(chan);
+ headp = &chan->varshead;
+ } else {
+ ast_rwlock_wrlock(&globalslock);
+ headp = &globals;
+ }
/* For comparison purposes, we have to strip leading underscores */
if (*nametail == '_') {
nametail++;
}
- if (headp == &globals)
- ast_rwlock_wrlock(&globalslock);
AST_LIST_TRAVERSE (headp, newvariable, entries) {
if (strcasecmp(ast_var_name(newvariable), nametail) == 0) {
/* there is already such a variable, delete it */
chan ? chan->uniqueid : "none");
}
- if (headp == &globals)
+ if (chan)
+ ast_channel_unlock(chan);
+ else
ast_rwlock_unlock(&globalslock);
}
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