Add cancel backup capability.
This will stop the iteration of the partition objects, kill the
current twrpTar thread and remove the backup directory.
Implement TWAtomicInt class to give us a wrapper that automatically
uses mutexes before the read and write to help ensure that the
reads and writes will be atomic based on documentation.
Change-Id: I645b22bc980a292e9c7202acb24ffd22ebe68c63
diff --git a/tw_atomic.cpp b/tw_atomic.cpp
new file mode 100644
index 0000000..31cdd85
--- /dev/null
+++ b/tw_atomic.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 The Team Win Recovery Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <pthread.h>
+#include <stdio.h>
+#include "tw_atomic.hpp"
+
+/*
+ * According to this documentation:
+ * https://developer.android.com/training/articles/smp.html
+ * it is recommended to use mutexes instead of atomics. This class
+ * provides us with a wrapper to make "atomic" variables easy to use.
+ */
+
+TWAtomicInt::TWAtomicInt(int initial_value /* = 0 */) {
+ if (pthread_mutex_init(&mutex_lock, NULL) != 0) {
+ // This should hopefully never happen. If it does, the
+ // operations will not be atomic, but we will allow things to
+ // continue anyway after logging the issue and just hope for
+ // the best.
+ printf("TWAtomic error initializing mutex.\n");
+ use_mutex = false;
+ } else {
+ use_mutex = true;
+ }
+ value = initial_value;
+}
+
+TWAtomicInt::~TWAtomicInt() {
+ if (use_mutex)
+ pthread_mutex_destroy(&mutex_lock);
+}
+
+void TWAtomicInt::set_value(int new_value) {
+ if (use_mutex) {
+ pthread_mutex_lock(&mutex_lock);
+ value = new_value;
+ pthread_mutex_unlock(&mutex_lock);
+ } else {
+ value = new_value;
+ }
+}
+
+int TWAtomicInt::get_value(void) {
+ int ret_val;
+
+ if (use_mutex) {
+ pthread_mutex_lock(&mutex_lock);
+ ret_val = value;
+ pthread_mutex_unlock(&mutex_lock);
+ } else {
+ ret_val = value;
+ }
+ return ret_val;
+}