--- .sync/CacheContent_005.php	2004-06-14 15:37:29.381041184 -0300
+++ CacheContent.php	2004-06-14 15:36:49.514101880 -0300
@@ -29,9 +29,16 @@
 	function CacheContent($name,$exclude=array(),$set_no_cache=false) {
 		if (substr(APP_CACHE_DIR,-1)=='/') $this->cachefile=APP_CACHE_DIR.md5($name);
 		else $this->cachefile=APP_CACHE_DIR.'/'.md5($name);
+
+		$this->lockfile = $this->cachefile.'.lock';
 		
 		if (isset($_GET['clearcache']) && file_exists($this->cachefile)) {
-			unlink($this->cachefile);
+			$lp = fopen($this->lockfile, 'w');
+			if (flock($lp, LOCK_EX)) {
+				unlink($this->cachefile);
+				flock($lp, LOCK_UN);
+			}
+			fclose($lp);
 		}
 		
 		$cache=true;
@@ -45,8 +52,20 @@
 	
 	function begin() {
 		if ($this->cache && file_exists($this->cachefile)) {
-			readfile($this->cachefile);
-			return false;
+			$success = false;
+			$lp = fopen($this->lockfile, 'w');
+			if (flock($lp, LOCK_SH)) {
+				readfile($this->cachefile);
+				flock($lp, LOCK_UN);
+				$success = true;
+			}
+			fclose($lp);
+			if ($success) {
+				return false;
+			} else {
+				ob_start();
+				return true;
+			}
 		} else {
 			ob_start();
 			return true;
@@ -55,12 +74,17 @@
 	
 	function end() {
 		if ($this->cache) {
-			$var=ob_get_contents();
-			$fp=fopen($this->cachefile,'w');
-			chmod($this->cachefile,0660);
-			fwrite($fp,$var);
-			fclose($fp);
-			
+			$var = ob_get_contents();
+			$lp = fopen($this->lockfile, 'w');
+			if (flock($lp, LOCK_EX)) {
+				$fp = fopen($this->cachefile, 'w');
+				fwrite($fp, $var);
+				fclose($fp);
+				chmod($this->cachefile, 0660);
+				flock($lp, LOCK_UN);
+			}	
+			fclose($lp);
+			chmod($this->lockfile, 0660);
 			ob_end_flush();
 		}
 	}