Home | History | Annotate | Download | only in webview_zygote 
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 #define LOG_TAG "WebViewZygote"
     19 
     20 #include <sys/prctl.h>
     21 
     22 #include <android_runtime/AndroidRuntime.h>
     23 #include <binder/IPCThreadState.h>
     24 #include <binder/ProcessState.h>
     25 #include <utils/Log.h>
     26 #include <utils/String8.h>
     27 #include <utils/Vector.h>
     28 
     29 namespace android {
     30 
     31 class WebViewRuntime : public AndroidRuntime {
     32 public:
     33     WebViewRuntime(char* argBlockStart, size_t argBlockSize)
     34         : AndroidRuntime(argBlockStart, argBlockSize) {}
     35 
     36     ~WebViewRuntime() override {}
     37 
     38     void onStarted() override {
     39         // Nothing to do since this is a zygote server.
     40     }
     41 
     42     void onVmCreated(JNIEnv*) override {
     43         // Nothing to do when the VM is created in the zygote.
     44     }
     45 
     46     void onZygoteInit() override {
     47         // Called after a new process is forked.
     48         sp<ProcessState> proc = ProcessState::self();
     49         proc->startThreadPool();
     50     }
     51 
     52     void onExit(int code) override {
     53         IPCThreadState::self()->stopProcess();
     54         AndroidRuntime::onExit(code);
     55     }
     56 };
     57 
     58 }  // namespace android
     59 
     60 int main(int argc, char* const argv[]) {
     61     if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
     62         LOG_ALWAYS_FATAL("PR_SET_NO_NEW_PRIVS failed: %s", strerror(errno));
     63         return 12;
     64     }
     65 
     66     size_t argBlockSize = 0;
     67     for (int i = 0; i < argc; ++i) {
     68         argBlockSize += strlen(argv[i]) + 1;
     69     }
     70 
     71     android::WebViewRuntime runtime(argv[0], argBlockSize);
     72     runtime.addOption("-Xzygote");
     73 
     74     android::Vector<android::String8> args;
     75     runtime.start("com.android.internal.os.WebViewZygoteInit", args, /*zygote=*/ true);
     76 }
     77