+#if PSI_THREADED_PARSER
+# include <pthread.h>
+
+static pthread_mutex_t psi_string_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+zend_string *psi_string_init_interned(const char *buf, size_t len, int p)
+{
+ zend_string *str;
+
+ pthread_mutex_lock(&psi_string_mutex);
+ str = zend_string_init_interned(buf, len, p);
+ pthread_mutex_unlock(&psi_string_mutex);
+
+ return str;
+}
+
+zend_string *psi_new_interned_string(zend_string *str)
+{
+ zend_string *new_str;
+
+ pthread_mutex_lock(&psi_string_mutex);
+ new_str = zend_new_interned_string(str);
+ pthread_mutex_unlock(&psi_string_mutex);
+
+ return new_str;
+}
+
+#endif
+