From 4e837093157939ec53ec2865aefa9cb21c7e27cb Mon Sep 17 00:00:00 2001
From: Alessandro Pignotti <a.pignotti@sssup.it>
Date: Fri, 5 Oct 2012 16:49:36 -0700
Subject: [PATCH] Improve thread safety of localization

---
 src/xlibi18n/lcWrap.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/xlibi18n/lcWrap.c b/src/xlibi18n/lcWrap.c
index c3f5ca5..6809da2 100644
--- a/src/xlibi18n/lcWrap.c
+++ b/src/xlibi18n/lcWrap.c
@@ -57,6 +57,7 @@ from The Open Group.
 #include <config.h>
 #endif
 #include <stdlib.h>
+#include <pthread.h>
 #include "Xlibint.h"
 #include "Xlcint.h"
 #include <X11/Xlocale.h>
@@ -173,6 +174,7 @@ typedef struct _XLCdListRec {
 } XLCdListRec, *XLCdList;
 
 static XLCdList lcd_list = NULL;
+static pthread_mutex_t lcd_list_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 typedef struct _XlcLoaderListRec {
     struct _XlcLoaderListRec *next;
@@ -180,6 +182,8 @@ typedef struct _XlcLoaderListRec {
 } XlcLoaderListRec, *XlcLoaderList;
 
 static XlcLoaderList loader_list = NULL;
+static pthread_mutex_t loader_list_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t opencloseLC_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 void
 _XlcRemoveLoader(
@@ -187,13 +191,18 @@ _XlcRemoveLoader(
 {
     XlcLoaderList loader, prev;
 
+    pthread_mutex_lock(&loader_list_mutex);
     if (loader_list == NULL)
+    {
+        pthread_mutex_unlock(&loader_list_mutex);
 	return;
+    }
 
     prev = loader = loader_list;
     if (loader->proc == proc) {
 	loader_list = loader->next;
 	Xfree(loader);
+        pthread_mutex_unlock(&loader_list_mutex);
 	return;
     }
 
@@ -201,11 +210,13 @@ _XlcRemoveLoader(
 	if (loader->proc == proc) {
 	    prev->next = loader->next;
 	    Xfree(loader);
+            pthread_mutex_unlock(&loader_list_mutex);
 	    return;
 	}
 	prev = loader;
     }
 
+    pthread_mutex_unlock(&loader_list_mutex);
     return;
 }
 
@@ -224,6 +235,7 @@ _XlcAddLoader(
 
     loader->proc = proc;
 
+    pthread_mutex_lock(&loader_list_mutex);
     if (loader_list == NULL)
 	position = XlcHead;
 
@@ -238,6 +250,7 @@ _XlcAddLoader(
 	loader->next = NULL;
 	last->next = loader;
     }
+    pthread_mutex_unlock(&loader_list_mutex);
 
     return True;
 }
@@ -276,17 +289,23 @@ _XOpenLC(
     /*
      * search for needed lcd, if found return it
      */
+    pthread_mutex_lock(&lcd_list_mutex);
     for (cur = lcd_list; cur; cur = cur->next) {
 	if (!strcmp (cur->lcd->core->name, name)) {
 	    lcd = cur->lcd;
 	    cur->ref_count++;
+            pthread_mutex_unlock(&lcd_list_mutex);
 	    goto found;
 	}
     }
+    pthread_mutex_unlock(&lcd_list_mutex);
 
+    pthread_mutex_lock(&opencloseLC_mutex);
     if (!loader_list)
 	_XlcInitLoader();
+    pthread_mutex_unlock(&opencloseLC_mutex);
 
+    pthread_mutex_lock(&loader_list_mutex);
     /*
      * not there, so try to get and add to list
      */
@@ -297,16 +316,20 @@ _XOpenLC(
 	    if (cur) {
 		cur->lcd = lcd;
 		cur->ref_count = 1;
+                pthread_mutex_lock(&lcd_list_mutex);
 		cur->next = lcd_list;
 		lcd_list = cur;
+                pthread_mutex_unlock(&lcd_list_mutex);
 	    } else {
 		(*lcd->methods->close)(lcd);
 		lcd = (XLCd) NULL;
 	    }
+            pthread_mutex_unlock(&loader_list_mutex);
 	    goto found;
 	}
     }
 
+    pthread_mutex_unlock(&loader_list_mutex);
     lcd = NULL;
 
 found:
@@ -325,6 +348,7 @@ _XCloseLC(
 {
     XLCdList cur, *prev;
 
+    pthread_mutex_lock(&lcd_list_mutex);
     for (prev = &lcd_list; (cur = *prev); prev = &cur->next) {
 	if (cur->lcd == lcd) {
 	    if (--cur->ref_count < 1) {
@@ -335,11 +359,14 @@ _XCloseLC(
 	    break;
 	}
     }
+    pthread_mutex_unlock(&lcd_list_mutex);
 
+    pthread_mutex_lock(&opencloseLC_mutex);
     if(loader_list) {
 	_XlcDeInitLoader();
 	loader_list = NULL;
     }
+    pthread_mutex_unlock(&opencloseLC_mutex);
 }
 
 /*
-- 
1.7.9.5