+/* function used to destroy the specified context */
+typedef void (*xbt_pfn_context_free_t) (xbt_context_t);
+
+/* function used to kill the specified context */
+typedef void (*xbt_pfn_context_kill_t) (xbt_context_t);
+
+/* function used to resume the specified context */
+typedef void (*xbt_pfn_context_schedule_t) (xbt_context_t);
+
+/* function used to yield the specified context */
+typedef void (*xbt_pfn_context_yield_t) (void);
+
+/* function used to start the specified context */
+typedef void (*xbt_pfn_context_start_t) (xbt_context_t);
+
+/* function used to stop the current context */
+typedef void (*xbt_pfn_context_stop_t) (int);
+