1 /*
2 * Copyright (c) 2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include <sstream>
17
18 #include "deadlock_helpers.h"
19 #include "common.h"
20 #include "graph.h"
21
22 namespace Commonlibrary::Concurrent::LocksModule {
23
CreateDeadlockWarningMessage(DeadlockInfo && deadlock)24 std::string CreateDeadlockWarningMessage(DeadlockInfo &&deadlock)
25 {
26 std::stringstream s;
27 auto vertexPrinter = [](tid_t tid) { return "TID " + std::to_string(tid); };
28 auto edgePrinter = [](const AsyncLockDependency *edata) { return " <-- lock {" + edata->name + "} -- WAITED BY "; };
29 s << "!!! DEADLOCK WARNING !!!\n"
30 << LockGraph::CycleAsString(deadlock, "Possible deadlock: ", "\n", vertexPrinter, edgePrinter);
31 return s.str();
32 }
33
CreateFullLockInfosMessage(tid_t targetTid,std::vector<AsyncLockDependency> && dependencies,DeadlockInfo && deadlock)34 std::string CreateFullLockInfosMessage(tid_t targetTid, std::vector<AsyncLockDependency> &&dependencies,
35 DeadlockInfo &&deadlock)
36 {
37 std::stringstream s;
38 s << "\nThread's async locks information:\n";
39 for (auto &maybeHeld : dependencies) {
40 if ((maybeHeld.holderTid == targetTid) && (maybeHeld.waiterTid == INVALID_TID)) {
41 s << "HELD: lock {" + maybeHeld.name + "} , taken at:\n" + maybeHeld.creationStacktrace + "\n";
42 }
43 }
44 for (auto &maybeWaiting : dependencies) {
45 if (maybeWaiting.waiterTid == targetTid) {
46 s << "WAITING: lock {" + maybeWaiting.name + "} , taken at:\n" + maybeWaiting.creationStacktrace + "\n";
47 }
48 }
49 if (!deadlock.IsEmpty()) {
50 s << CreateDeadlockWarningMessage(std::move(deadlock));
51 } else {
52 s << "No deadlocks detected.\n";
53 }
54 return s.str();
55 }
56
CheckDeadlocks(const std::vector<AsyncLockDependency> & dependencies)57 DeadlockInfo CheckDeadlocks(const std::vector<AsyncLockDependency> &dependencies)
58 {
59 LockGraph::AdjacencyList adjlist;
60 for (auto &dep : dependencies) {
61 if (dep.waiterTid == INVALID_TID) {
62 // this is the "held only" edge, skip
63 continue;
64 }
65 adjlist.push_back(std::make_tuple(dep.waiterTid, dep.holderTid, &dep));
66 }
67 LockGraph g(std::move(adjlist));
68 return g.FindFirstCycle();
69 }
70
71 } // namespace Commonlibrary::Concurrent::LocksModule