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
22namespace Commonlibrary::Concurrent::LocksModule {
23
24std::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
34std::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
57DeadlockInfo 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