commit a20c3d04faa392d0689c3d206bcc44b38fe042fa
author Alice Wang <aliceywang@google.com> Fri Sep 16 12:33:52 2022 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Fri Sep 16 12:33:52 2022 +0000
tree 5cea46d27a23339107f58f2f66625ecad4085bc4
parent 56c37d6059cd911b8720b87f9bea122093d82546
parent 928893549a8519d5b73ec2759e1f8cfc54669b27

Merge "[apkverify] Point TODOs in comments to the correct bug ids"

javalib/src/android/system/virtualmachine/VirtualMachine.java

diff --git a/javalib/src/android/system/virtualmachine/VirtualMachine.java b/javalib/src/android/system/virtualmachine/VirtualMachine.java
index 828ac9f..ae84c08 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachine.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachine.java
@@ -45,11 +45,15 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.ref.WeakReference;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
+import java.util.WeakHashMap;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -65,6 +69,11 @@
  * @hide
  */
 public class VirtualMachine {
+    private static final Map<Context, Map<String, WeakReference<VirtualMachine>>> sInstances =
+            new WeakHashMap<>();
+
+    private static final Object sInstancesLock = new Object();
+
     /** Name of the directory under the files directory where all VMs created for the app exist. */
     private static final String VM_DIR = "vm";
 
@@ -159,6 +168,8 @@
 
     private final ExecutorService mExecutorService = Executors.newCachedThreadPool();
 
+    @NonNull private final Context mContext;
+
     static {
         System.loadLibrary("virtualmachine_jni");
     }
@@ -166,6 +177,7 @@
     private VirtualMachine(
             @NonNull Context context, @NonNull String name, @NonNull VirtualMachineConfig config)
             throws VirtualMachineException {
+        mContext = context;
         mPackageName = context.getPackageName();
         mName = name;
         mConfig = config;
@@ -231,6 +243,18 @@
             throw new VirtualMachineException("failed to create instance partition", e);
         }
 
+        synchronized (sInstancesLock) {
+            Map<String, WeakReference<VirtualMachine>> instancesMap;
+            if (sInstances.containsKey(context)) {
+                instancesMap = sInstances.get(context);
+            } else {
+                instancesMap = new HashMap<>();
+                sInstances.put(context, instancesMap);
+            }
+
+            instancesMap.put(name, new WeakReference<>(vm));
+        }
+
         return vm;
     }
 
@@ -249,7 +273,23 @@
             throw new VirtualMachineException(e);
         }
 
-        VirtualMachine vm = new VirtualMachine(context, name, config);
+        VirtualMachine vm;
+        synchronized (sInstancesLock) {
+            Map<String, WeakReference<VirtualMachine>> instancesMap;
+            if (sInstances.containsKey(context)) {
+                instancesMap = sInstances.get(context);
+            } else {
+                instancesMap = new HashMap<>();
+                sInstances.put(context, instancesMap);
+            }
+
+            if (instancesMap.containsKey(name)) {
+                vm = instancesMap.get(name).get();
+            } else {
+                vm = new VirtualMachine(context, name, config);
+                instancesMap.put(name, new WeakReference<>(vm));
+            }
+        }
 
         // If config file exists, but the instance image file doesn't, it means that the VM is
         // corrupted. That's different from the case that the VM doesn't exist. Throw an exception
@@ -544,6 +584,11 @@
         mInstanceFilePath.delete();
         mIdsigFilePath.delete();
         vmRootDir.delete();
+
+        synchronized (sInstancesLock) {
+            Map<String, WeakReference<VirtualMachine>> instancesMap = sInstances.get(mContext);
+            if (instancesMap != null) instancesMap.remove(mName);
+        }
     }
 
     /**

tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java

diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index 99afe98..c2060cb 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -504,4 +504,21 @@
         assertThat(bootResult.deathReason).isEqualTo(
                 VirtualMachineCallback.DEATH_REASON_MICRODROID_INVALID_PAYLOAD_CONFIG);
     }
+
+    @Test
+    public void sameInstancesShareTheSameVmObject()
+            throws VirtualMachineException, InterruptedException, IOException {
+        VirtualMachineConfig.Builder builder =
+                mInner.newVmConfigBuilder("assets/vm_config.json");
+        VirtualMachineConfig normalConfig = builder.debugLevel(DebugLevel.NONE).build();
+        VirtualMachine vm = mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
+        VirtualMachine vm2 = mInner.getVirtualMachineManager().get("test_vm");
+        assertThat(vm).isEqualTo(vm2);
+
+        VirtualMachine newVm = mInner.forceCreateNewVirtualMachine("test_vm", normalConfig);
+        VirtualMachine newVm2 = mInner.getVirtualMachineManager().get("test_vm");
+        assertThat(newVm).isEqualTo(newVm2);
+
+        assertThat(vm).isNotEqualTo(newVm);
+    }
 }