Factor out inner-classes out of ChildProcessLauncher.

content/public/android/java/src/org/chromium/content/browser/ChildConnectionAllocator.java

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.content.browser;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.os.Bundle;
+import android.text.TextUtils;
+
+import org.chromium.base.Log;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.content.app.PrivilegedProcessService;
+import org.chromium.content.app.SandboxedProcessService;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.annotation.concurrent.GuardedBy;
+
+/**
+ * This class is responsible for allocating and managing connections to child
+ * process services. These connections are in a pool (the services are defined
+ * in the AndroidManifest.xml).
+ */
+public class ChildConnectionAllocator {
+    private static final String TAG = "ChildConnAllocator";
+
+    private static final String NUM_SANDBOXED_SERVICES_KEY =
+            "org.chromium.content.browser.NUM_SANDBOXED_SERVICES";
+    private static final String NUM_PRIVILEGED_SERVICES_KEY =
+            "org.chromium.content.browser.NUM_PRIVILEGED_SERVICES";
+    private static final String SANDBOXED_SERVICES_NAME_KEY =
+            "org.chromium.content.browser.SANDBOXED_SERVICES_NAME";
+
+    private static final Object sAllocatorLock = new Object();
+
+    // Map from package name to ChildConnectionAllocator.
+    @GuardedBy("sAllocatorLock")
+    private static Map<String, ChildConnectionAllocator> sSandboxedChildConnectionAllocatorMap;
+
+    // Allocator used for non-sandboxed services.
+    @GuardedBy("sAllocatorLock")
+    private static ChildConnectionAllocator sPrivilegedChildConnectionAllocator;
+
+    // Used by test to override the default sandboxed service settings.
+    private static int sSandboxedServicesCountForTesting = -1;
+    private static String sSandboxedServicesNameForTesting;
+
+    // Connections to services. Indices of the array correspond to the service numbers.
+    private final ChildProcessConnection[] mChildProcessConnections;
+
+    private final String mChildClassName;
+    private final boolean mInSandbox;
+
+    private final Object mConnectionLock = new Object();
+
+    // The list of free (not bound) service indices.
+    @GuardedBy("mConnectionLock")
+    private final ArrayList<Integer> mFreeConnectionIndices;
+
+    // Each Allocator keeps a queue for the pending spawn data. Once a connection is free, we
+    // dequeue the pending spawn data from the same allocator as the connection.
+    @GuardedBy("mConnectionLock")
+    private final Queue<ChildSpawnData> mPendingSpawnQueue = new LinkedList<>();
+
+    public static ChildConnectionAllocator getAllocator(
+            Context context, String packageName, boolean inSandbox) {
+        synchronized (sAllocatorLock) {
+            if (!inSandbox) {
+                if (sPrivilegedChildConnectionAllocator == null) {
+                    sPrivilegedChildConnectionAllocator = new ChildConnectionAllocator(false,
+                            getNumberOfServices(context, false, packageName),
+                            getClassNameOfService(context, false, packageName));
+                }
+                return sPrivilegedChildConnectionAllocator;
+            }
+
+            if (sSandboxedChildConnectionAllocatorMap == null) {
+                sSandboxedChildConnectionAllocatorMap =
+                        new ConcurrentHashMap<String, ChildConnectionAllocator>();
+            }
+            if (!sSandboxedChildConnectionAllocatorMap.containsKey(packageName)) {
+                Log.w(TAG,
+                        "Create a new ChildConnectionAllocator with package name = %s,"
+                                + " inSandbox = true",
+                        packageName);
+                sSandboxedChildConnectionAllocatorMap.put(packageName,
+                        new ChildConnectionAllocator(true,
+                                getNumberOfServices(context, true, packageName),
+                                getClassNameOfService(context, true, packageName)));
+            }
+            return sSandboxedChildConnectionAllocatorMap.get(packageName);
+            // TODO(pkotwicz|hanxi): Figure out when old allocators should be removed from
+            // {@code sSandboxedChildConnectionAllocatorMap}.
+        }
+    }
+
+    private static String getClassNameOfService(
+            Context context, boolean inSandbox, String packageName) {
+        if (!inSandbox) {
+            return PrivilegedProcessService.class.getName();
+        }
+
+        if (!TextUtils.isEmpty(sSandboxedServicesNameForTesting)) {
+            return sSandboxedServicesNameForTesting;
+        }
+
+        String serviceName = null;
+        try {
+            PackageManager packageManager = context.getPackageManager();
+            ApplicationInfo appInfo =
+                    packageManager.getApplicationInfo(packageName, PackageManager.GET_META_DATA);
+            if (appInfo.metaData != null) {
+                serviceName = appInfo.metaData.getString(SANDBOXED_SERVICES_NAME_KEY);
+            }
+        } catch (PackageManager.NameNotFoundException e) {
+            throw new RuntimeException("Could not get application info.");
+        }
+
+        if (serviceName != null) {
+            // Check that the service exists.
+            try {
+                PackageManager packageManager = context.getPackageManager();
+                // PackageManager#getServiceInfo() throws an exception if the service does not
+                // exist.
+                packageManager.getServiceInfo(new ComponentName(packageName, serviceName + "0"), 0);
+                return serviceName;
+            } catch (PackageManager.NameNotFoundException e) {
+                throw new RuntimeException(
+                        "Illegal meta data value: the child service doesn't exist");
+            }
+        }
+        return SandboxedProcessService.class.getName();
+    }
+
+    static int getNumberOfServices(Context context, boolean inSandbox, String packageName) {
+        int numServices = -1;
+        if (inSandbox && sSandboxedServicesCountForTesting != -1) {
+            numServices = sSandboxedServicesCountForTesting;
+        } else {
+            try {
+                PackageManager packageManager = context.getPackageManager();
+                ApplicationInfo appInfo = packageManager.getApplicationInfo(
+                        packageName, PackageManager.GET_META_DATA);
+                if (appInfo.metaData != null) {
+                    numServices = appInfo.metaData.getInt(
+                            inSandbox ? NUM_SANDBOXED_SERVICES_KEY : NUM_PRIVILEGED_SERVICES_KEY,
+                            -1);
+                }
+            } catch (PackageManager.NameNotFoundException e) {
+                throw new RuntimeException("Could not get application info");
+            }
+        }
+        if (numServices < 0) {
+            throw new RuntimeException("Illegal meta data value for number of child services");
+        }
+        return numServices;
+    }
+
+    @VisibleForTesting
+    public static void setSanboxServicesSettingsForTesting(int serviceCount, String serviceName) {
+        sSandboxedServicesCountForTesting = serviceCount;
+        sSandboxedServicesNameForTesting = serviceName;
+    }
+
+    private ChildConnectionAllocator(
+            boolean inSandbox, int numChildServices, String serviceClassName) {
+        mChildProcessConnections = new ChildProcessConnectionImpl[numChildServices];
+        mFreeConnectionIndices = new ArrayList<Integer>(numChildServices);
+        for (int i = 0; i < numChildServices; i++) {
+            mFreeConnectionIndices.add(i);
+        }
+        mChildClassName = serviceClassName;
+        mInSandbox = inSandbox;
+    }
+
+    // Allocates or enqueues. If there are no free slots, returns null and enqueues the spawn data.
+    public ChildProcessConnection allocate(ChildSpawnData spawnData,
+            ChildProcessConnection.DeathCallback deathCallback, Bundle childProcessCommonParameters,
+            boolean queueIfNoSlotAvailable) {
+        assert spawnData.isInSandbox() == mInSandbox;
+        synchronized (mConnectionLock) {
+            if (mFreeConnectionIndices.isEmpty()) {
+                Log.d(TAG, "Ran out of services to allocate.");
+                if (queueIfNoSlotAvailable) {
+                    mPendingSpawnQueue.add(spawnData);
+                }
+                return null;
+            }
+            int slot = mFreeConnectionIndices.remove(0);
+            assert mChildProcessConnections[slot] == null;
+            mChildProcessConnections[slot] = new ChildProcessConnectionImpl(spawnData.getContext(),
+                    slot, mInSandbox, deathCallback, mChildClassName, childProcessCommonParameters,
+                    spawnData.isAlwaysInForeground(), spawnData.getCreationParams());
+            Log.d(TAG, "Allocator allocated a connection, sandbox: %b, slot: %d", mInSandbox, slot);
+            return mChildProcessConnections[slot];
+        }
+    }
+
+    // Also return the first ChildSpawnData in the pending queue, if any.
+    public ChildSpawnData free(ChildProcessConnection connection) {
+        synchronized (mConnectionLock) {
+            int slot = connection.getServiceNumber();
+            if (mChildProcessConnections[slot] != connection) {
+                int occupier = mChildProcessConnections[slot] == null
+                        ? -1
+                        : mChildProcessConnections[slot].getServiceNumber();
+                Log.e(TAG,
+                        "Unable to find connection to free in slot: %d "
+                                + "already occupied by service: %d",
+                        slot, occupier);
+                assert false;
+            } else {
+                mChildProcessConnections[slot] = null;
+                assert !mFreeConnectionIndices.contains(slot);
+                mFreeConnectionIndices.add(slot);
+                Log.d(TAG, "Allocator freed a connection, sandbox: %b, slot: %d", mInSandbox, slot);
+            }
+            return mPendingSpawnQueue.poll();
+        }
+    }
+
+    public boolean isFreeConnectionAvailable() {
+        synchronized (mConnectionLock) {
+            return !mFreeConnectionIndices.isEmpty();
+        }
+    }
+
+    /** @return the count of connections managed by the allocator */
+    @VisibleForTesting
+    int allocatedConnectionsCountForTesting() {
+        synchronized (mConnectionLock) {
+            return mChildProcessConnections.length - mFreeConnectionIndices.size();
+        }
+    }
+
+    @VisibleForTesting
+    ChildProcessConnection[] connectionArrayForTesting() {
+        return mChildProcessConnections;
+    }
+
+    @VisibleForTesting
+    void enqueuePendingQueueForTesting(ChildSpawnData spawnData) {
+        synchronized (mConnectionLock) {
+            mPendingSpawnQueue.add(spawnData);
+        }
+    }
+
+    @VisibleForTesting
+    int pendingSpawnsCountForTesting() {
+        synchronized (mConnectionLock) {
+            return mPendingSpawnQueue.size();
+        }
+    }
+}