Sébastien Blin | 1f91576 | 2020-08-03 13:27:42 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019-2020 by Savoir-faire Linux |
| 3 | * Author: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | // Based on: https://stackoverflow.com/a/28172162 |
| 19 | |
| 20 | #include "runguard.h" |
| 21 | #include <QCryptographicHash> |
| 22 | |
| 23 | namespace { |
| 24 | |
| 25 | QString |
| 26 | generateKeyHash(const QString &key, const QString &salt) |
| 27 | { |
| 28 | QByteArray data; |
| 29 | |
| 30 | data.append(key.toUtf8()); |
| 31 | data.append(salt.toUtf8()); |
| 32 | data = QCryptographicHash::hash(data, QCryptographicHash::Sha1).toHex(); |
| 33 | |
| 34 | return data; |
| 35 | } |
| 36 | |
| 37 | } // namespace |
| 38 | |
| 39 | RunGuard::RunGuard(const QString &key) |
| 40 | : key_(key) |
| 41 | , memLockKey_(generateKeyHash(key, "_memLockKey")) |
| 42 | , sharedmemKey_(generateKeyHash(key, "_sharedmemKey")) |
| 43 | , sharedMem_(sharedmemKey_) |
| 44 | , memLock_(memLockKey_, 1) |
| 45 | {} |
| 46 | |
| 47 | RunGuard::~RunGuard() |
| 48 | { |
| 49 | release(); |
| 50 | } |
| 51 | |
| 52 | void |
| 53 | RunGuard::tryRestorePrimaryInstance() |
| 54 | { |
| 55 | /* |
| 56 | * TODO: relaunch application |
| 57 | */ |
| 58 | } |
| 59 | |
| 60 | bool |
| 61 | RunGuard::isAnotherRunning() |
| 62 | { |
| 63 | if (sharedMem_.isAttached()) |
| 64 | return false; |
| 65 | |
| 66 | memLock_.acquire(); |
| 67 | const bool isRunning = sharedMem_.attach(); |
| 68 | if (isRunning) |
| 69 | sharedMem_.detach(); |
| 70 | memLock_.release(); |
| 71 | |
| 72 | return isRunning; |
| 73 | } |
| 74 | |
| 75 | bool |
| 76 | RunGuard::tryToRun() |
| 77 | { |
| 78 | #ifdef Q_OS_WIN |
| 79 | if (isAnotherRunning()) { |
| 80 | /* |
| 81 | * This is a secondary instance, |
| 82 | * connect to the primary instance to trigger a restore |
| 83 | * then fail. |
| 84 | */ |
| 85 | if (socket_ == nullptr) { |
| 86 | socket_ = new QLocalSocket(); |
| 87 | } |
| 88 | if (socket_->state() == QLocalSocket::UnconnectedState |
| 89 | || socket_->state() == QLocalSocket::ClosingState) { |
| 90 | socket_->connectToServer(key_); |
| 91 | } |
| 92 | if (socket_->state() == QLocalSocket::ConnectingState) { |
| 93 | socket_->waitForConnected(); |
| 94 | } |
| 95 | return false; |
| 96 | } |
| 97 | |
| 98 | memLock_.acquire(); |
| 99 | const bool result = sharedMem_.create(sizeof(quint64)); |
| 100 | memLock_.release(); |
| 101 | if (!result) { |
| 102 | release(); |
| 103 | return false; |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * This is the primary instance, |
| 108 | * listen for subsequent instances. |
| 109 | */ |
| 110 | QLocalServer::removeServer(key_); |
| 111 | server_ = new QLocalServer(); |
| 112 | server_->setSocketOptions(QLocalServer::UserAccessOption); |
| 113 | server_->listen(key_); |
| 114 | QObject::connect(server_, |
| 115 | &QLocalServer::newConnection, |
| 116 | this, |
| 117 | &RunGuard::tryRestorePrimaryInstance); |
| 118 | #endif |
| 119 | |
| 120 | return true; |
| 121 | } |
| 122 | |
| 123 | void |
| 124 | RunGuard::release() |
| 125 | { |
| 126 | memLock_.acquire(); |
| 127 | if (sharedMem_.isAttached()) |
| 128 | sharedMem_.detach(); |
| 129 | memLock_.release(); |
| 130 | } |