android: Java ChildProcessLauncherHelper instance

content/public/android/java/src/org/chromium/content/browser/ChildProcessLauncherHelper.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.Context;
+import android.os.ParcelFileDescriptor;
+
+import org.chromium.base.Log;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.process_launcher.FileDescriptorInfo;
+
+import java.io.IOException;
+
+/**
+ * This is the java counterpart to ChildProcessLauncherHelper. It is owned by native side and
+ * has an explicit destroy method.
+ * Each public or jni methods should have explicit documentation on what threads they are called.
+ */
+@JNINamespace("content::internal")
+class ChildProcessLauncherHelper {
+    private static final String TAG = "ChildProcLH";
+
+    // Note this is not the actual native pointer to ChildProcessLauncherHelper.

[Maria, 2017/03/27 19:22:51]

It might be nice to say what it IS in addition to what it isn't

+    private long mNativePointer;
+    private int mPid;
+
+    // Called on launcher thread.
+    @CalledByNative
+    private static FileDescriptorInfo makeFdInfo(
+            int id, int fd, boolean autoClose, long offset, long size) {
+        ParcelFileDescriptor pFd;
+        if (autoClose) {
+            // Adopt the FD, it will be closed when we close the ParcelFileDescriptor.
+            pFd = ParcelFileDescriptor.adoptFd(fd);
+        } else {
+            try {
+                pFd = ParcelFileDescriptor.fromFd(fd);
+            } catch (IOException e) {
+                Log.e(TAG, "Invalid FD provided for process connection, aborting connection.", e);
+                return null;
+            }
+        }
+        return new FileDescriptorInfo(id, pFd, offset, size);
+    }
+
+    // Called on launcher thread.
+    @CalledByNative
+    private static ChildProcessLauncherHelper create(long nativePointer, Context context,
+            int paramId, final String[] commandLine, int childProcessId,
+            FileDescriptorInfo[] filesToBeMapped) {
+        return new ChildProcessLauncherHelper(
+                nativePointer, context, paramId, commandLine, childProcessId, filesToBeMapped);
+    }
+
+    private ChildProcessLauncherHelper(long nativePointer, Context context, int paramId,
+            final String[] commandLine, int childProcessId, FileDescriptorInfo[] filesToBeMapped) {
+        mNativePointer = nativePointer;
+
+        ChildProcessLauncher.start(context, paramId, commandLine, childProcessId, filesToBeMapped,
+                new ChildProcessLauncher.LaunchCallback() {
+                    @Override
+                    public void onChildProcessStarted(int pid) {
+                        mPid = pid;
+                        if (mNativePointer != 0) {
+                            nativeOnChildProcessStarted(mNativePointer, pid);
+                        }
+                        mNativePointer = 0;
+                    }
+                });
+    }
+
+    // Called on client (UI or IO) thread.
+    @CalledByNative
+    private boolean isOomProtected() {
+        return ChildProcessLauncher.getBindingManager().isOomProtected(mPid);
+    }
+
+    // Called on launcher thread.
+    @CalledByNative
+    private void setInForeground(int pid, boolean inForeground) {
+        assert mPid == pid;
+        ChildProcessLauncher.getBindingManager().setInForeground(mPid, inForeground);
+    }
+
+    @CalledByNative
+    private static void stop(int pid) {
+        ChildProcessLauncher.stop(pid);
+    }
+
+    // Can be called on a number of threads, including launcher, and binder.
+    private static native void nativeOnChildProcessStarted(long ptr, int pid);
+}