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
20 namespace Commonlibrary::Concurrent::LocksModule {
21
CreateDeadlockWarningMessage(DeadlockInfo && deadlock)22 std::string CreateDeadlockWarningMessage(DeadlockInfo &&deadlock)
23 {
24 std::stringstream s;
25 auto vertexPrinter = [](tid_t tid) { return "TID " + std::to_string(tid); };
26 auto edgePrinter = [](const AsyncLockDependency *edata) {
27 if (edata == nullptr) {
28 return std::string(" <-- lock {NULL} -- WAITED BY ");
29 }
30 return " <-- lock {" + edata->name + "} -- WAITED BY ";
31 };
32 s << "!!! DEADLOCK WARNING !!!\n"
33 << LockGraph::CycleAsString(deadlock, "Possible deadlock: ", "\n", vertexPrinter, edgePrinter);
34 return s.str();
35 }
36
CreateFullLockInfosMessage(tid_t targetTid,std::vector<AsyncLockDependency> && dependencies,DeadlockInfo && deadlock)37 std::string CreateFullLockInfosMessage(tid_t targetTid, std::vector<AsyncLockDependency> &&dependencies,
38 DeadlockInfo &&deadlock)
39 {
40 std::stringstream s;
41 s << "\nThread's async locks information:\n";
42 for (auto &maybeHeld : dependencies) {
43 if ((maybeHeld.holderTid == targetTid) && (maybeHeld.waiterTid == INVALID_TID)) {
44 s << "HELD: lock {" + maybeHeld.name + "} , taken at:\n" + maybeHeld.creationStacktrace + "\n";
45 }
46 }
47 for (auto &maybeWaiting : dependencies) {
48 if (maybeWaiting.waiterTid == targetTid) {
49 s << "WAITING: lock {" + maybeWaiting.name + "} , taken at:\n" + maybeWaiting.creationStacktrace + "\n";
50 }
51 }
52 if (!deadlock.IsEmpty()) {
53 s << CreateDeadlockWarningMessage(std::move(deadlock));
54 } else {
55 s << "No deadlocks detected.\n";
56 }
57 return s.str();
58 }
59
CheckDeadlocks(const std::vector<AsyncLockDependency> & dependencies)60 DeadlockInfo CheckDeadlocks(const std::vector<AsyncLockDependency> &dependencies)
61 {
62 LockGraph::AdjacencyList adjlist;
63 for (auto &dep : dependencies) {
64 if (dep.waiterTid == INVALID_TID) {
65 // this is the "held only" edge, skip
66 continue;
67 }
68 adjlist.push_back(std::make_tuple(dep.waiterTid, dep.holderTid, &dep));
69 }
70 LockGraph g(std::move(adjlist));
71 return g.FindFirstCycle();
72 }
73
74 } // namespace Commonlibrary::Concurrent::LocksModule