Implement error callback pop

Author: Matthew-Whitlock

include/fenix.h

@@ -69,7 +69,7 @@ extern "C" {
 #define FENIX_SUCCESS                         0
 #define FENIX_ERROR_UNINITIALIZED            -9
 #define FENIX_ERROR_NOCATEGORY              -10
-#define FENIX_ERROR_CALLBACK_NOT_REGISTERD  -11
+#define FENIX_ERROR_CALLBACK_NOT_REGISTERED -11
 #define FENIX_ERROR_GROUP_CREATE            -12
 #define FENIX_ERROR_MEMBER_CREATE           -13
 #define FENIX_ERROR_COMMIT_BARRIER         -133
@@ -142,6 +142,8 @@ int Fenix_Initialized(int *);
 int Fenix_Callback_register(void (*recover)(MPI_Comm, int, void *),
                             void *callback_data);
 
+int Fenix_Callback_pop();
+
 int Fenix_get_number_of_ranks_with_role(int, int *);
 
 int Fenix_get_role(MPI_Comm comm, int rank, int *role);

include/fenix_process_recovery.h

@@ -100,6 +100,8 @@ int __fenix_repair_ranks();
 
 int __fenix_callback_register(void (*recover)(MPI_Comm, int, void *), void *);
 
+int __fenix_callback_pop();
+
 void __fenix_callback_push(fenix_callback_list_t **, fenix_callback_func *);
 
 void __fenix_callback_invoke_all(int error);

src/fenix.c

@@ -67,6 +67,10 @@ int Fenix_Callback_register(void (*recover)(MPI_Comm, int, void *), void *callba
     return __fenix_callback_register(recover, callback_data);
 }
 
+int Fenix_Callback_pop() {
+    return __fenix_callback_pop();
+}
+
 int Fenix_Initialized(int *flag) {
     *flag = (fenix.fenix_init_flag) ? 1 : 0;
     return FENIX_SUCCESS;

src/fenix_callbacks.c

@@ -80,6 +80,19 @@ int __fenix_callback_register(void (*recover)(MPI_Comm, int, void *), void *call
     return error_code;
 }
 
+int __fenix_callback_pop(){
+   if(!fenix.fenix_init_flag) return FENIX_ERROR_UNINITIALIZED;
+   if(fenix.callback_list == NULL) return FENIX_ERROR_CALLBACK_NOT_REGISTERED;
+   
+   fenix_callback_list_t* old_head = fenix.callback_list;
+   fenix.callback_list = old_head->next;
+
+   free(old_head->callback);
+   free(old_head);
+
+   return FENIX_SUCCESS;
+}
+
 void __fenix_callback_invoke_all(int error)
 {
     fenix_callback_list_t *current = fenix.callback_list;