1 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */ 2 // vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4: 3 #ident "$Id$" 4 /*====== 5 This file is part of PerconaFT. 6 7 8 Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved. 9 10 PerconaFT is free software: you can redistribute it and/or modify 11 it under the terms of the GNU General Public License, version 2, 12 as published by the Free Software Foundation. 13 14 PerconaFT is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. 21 22 ---------------------------------------- 23 24 PerconaFT is free software: you can redistribute it and/or modify 25 it under the terms of the GNU Affero General Public License, version 3, 26 as published by the Free Software Foundation. 27 28 PerconaFT is distributed in the hope that it will be useful, 29 but WITHOUT ANY WARRANTY; without even the implied warranty of 30 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 31 GNU Affero General Public License for more details. 32 33 You should have received a copy of the GNU Affero General Public License 34 along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. 35 36 ---------------------------------------- 37 38 Licensed under the Apache License, Version 2.0 (the "License"); 39 you may not use this file except in compliance with the License. 40 You may obtain a copy of the License at 41 42 http://www.apache.org/licenses/LICENSE-2.0 43 44 Unless required by applicable law or agreed to in writing, software 45 distributed under the License is distributed on an "AS IS" BASIS, 46 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 47 See the License for the specific language governing permissions and 48 limitations under the License. 49 ======= */ 50 51 #ident "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved." 52 53 #pragma once 54 55 #include "locktree/txnid_set.h" 56 #include "util/omt.h" 57 58 namespace toku { 59 60 // A wfg is a 'wait-for' graph. A directed edge in represents one 61 // txn waiting for another to finish before it can acquire a lock. 62 63 class wfg { 64 public: 65 // Create a lock request graph 66 void create(void); 67 68 // Destroy the internals of the lock request graph 69 void destroy(void); 70 71 // Add an edge (a_id, b_id) to the graph 72 void add_edge(TXNID a_txnid, TXNID b_txnid); 73 74 // Return true if a node with the given transaction id exists in the graph. 75 // Return false otherwise. 76 bool node_exists(TXNID txnid); 77 78 // Return true if there exists a cycle from a given transaction id in the graph. 79 // Return false otherwise. 80 bool cycle_exists_from_txnid(TXNID txnid); 81 82 // Apply a given function f to all of the nodes in the graph. The apply function 83 // returns when the function f is called for all of the nodes in the graph, or the 84 // function f returns non-zero. 85 void apply_nodes(int (*fn)(TXNID txnid, void *extra), void *extra); 86 87 // Apply a given function f to all of the edges whose origin is a given node id. 88 // The apply function returns when the function f is called for all edges in the 89 // graph rooted at node id, or the function f returns non-zero. 90 void apply_edges(TXNID txnid, 91 int (*fn)(TXNID txnid, TXNID edge_txnid, void *extra), void *extra); 92 93 private: 94 struct node { 95 // txnid for this node and the associated set of edges 96 TXNID txnid; 97 txnid_set edges; 98 bool visited; 99 100 static node *alloc(TXNID txnid); 101 102 static void free(node *n); 103 }; 104 ENSURE_POD(node); 105 106 toku::omt<node *> m_nodes; 107 108 node *find_node(TXNID txnid); 109 110 node *find_create_node(TXNID txnid); 111 112 bool cycle_exists_from_node(node *target, node *head); 113 114 static int find_by_txnid(node *const &node_a, const TXNID &txnid_b); 115 }; 116 ENSURE_POD(wfg); 117 118 } /* namespace toku */ 119