migrate a bunch of globals to LiveData

[mobile-ledger.git] / app / src / main / java / net / ktnx / mobileledger / utils / Locker.java

diff --git a/app/src/main/java/net/ktnx/mobileledger/utils/Locker.java b/app/src/main/java/net/ktnx/mobileledger/utils/Locker.java
new file mode 100644 (file)
index 0000000..515b314
--- /dev/null
+++ b/app/src/main/java/net/ktnx/mobileledger/utils/Locker.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2019 Damyan Ivanov.
+ * This file is part of MoLe.
+ * MoLe is free software: you can distribute it and/or modify it
+ * under the term of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your opinion), any later version.
+ *
+ * MoLe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License terms for details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.ktnx.mobileledger.utils;
+
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+public class Locker {
+    private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+    public LockHolder lockForWriting() {
+        ReentrantReadWriteLock.WriteLock wLock = lock.writeLock();
+        wLock.lock();
+
+        ReentrantReadWriteLock.ReadLock rLock = lock.readLock();
+        rLock.lock();
+
+        return new LockHolder(rLock, wLock);
+    }
+    public LockHolder lockForReading() {
+        ReentrantReadWriteLock.ReadLock rLock = lock.readLock();
+        rLock.lock();
+        return new LockHolder(rLock);
+    }
+}