android - 使用许多不同种类的表情符号和语言(除了 ascii，但仍然有效的修改后的 utf-8)时，调用 C++ JNI NewStringUTF 会使 android 应用程序崩溃

Question

我正在尝试解决 Android 5.x 上的 Cocos2d-x 键盘输入崩溃问题，当时我从键盘上发现的带有许多表情符号的文本创建 CCImage(虽然有些工作，但大多数不工作。)在 Android 4 上。 x 一些设备只显示损坏的文本/额外字符。崩溃的根源是 JNI 的 NewStringUTF() 调用。它根本不支持 Android 5/Lollipop 中的所有 2、3 和 4 字节 utf-8 字符。

此崩溃发生在 cocos2d-x v2.2.6(并在 3.x 上确认)使用 NDK 10e 和工具链 4.8(不确定是否有任何差异，我们在迁移到 Android 之前使用 9d Studio 和我确信我们遇到了这个问题，但 lollipop 的使用要少得多。)

如果您从不推送任何未修改的 utf-8 符号(即坚持使用 ascii)，您可能永远不会看到问题。

Log Cat:
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]     string: '👊👊'
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]     in call to NewStringUTF
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]     from void org.cocos2dx.lib.Cocos2dxHelper.nativeSetEditTextDialogResult(byte[])
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65] "GLThread 45716" prio=5 tid=14 Runnable
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   | group="main" sCount=0 dsCount=0 obj=0x12c0c6c0 self=0xf442bc00
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   | sysTid=10959 nice=0 cgrp=default sched=0/0 handle=0xf450c380
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   | state=R schedstat=( 0 0 0 ) utm=1164 stm=188 core=2 HZ=100
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   | stack=0xeed4e000-0xeed50000 stackSize=1036KB
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   | held mutexes= "mutator lock"(shared held)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #00 pc 00004e64  /system/lib/libbacktrace_libc++.so (UnwindCurrent::Unwind(unsigned int, ucontext*)+23)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #01 pc 00003665  /system/lib/libbacktrace_libc++.so (Backtrace::Unwind(unsigned int, ucontext*)+8)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #02 pc 00271461  /system/lib/libart.so (art::DumpNativeStack(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, int, char const*, art::mirror::ArtMethod*)+84)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #03 pc 002534d7  /system/lib/libart.so (art::Thread::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) const+158)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #04 pc 000b7f5b  /system/lib/libart.so (art::JniAbort(char const*, char const*)+610)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #05 pc 000b8681  /system/lib/libart.so (art::JniAbortF(char const*, char const*, ...)+68)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #06 pc 000bac4f  /system/lib/libart.so (art::ScopedCheck::Check(bool, char const*, ...) (.constprop.129)+922)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #07 pc 000c474d  /system/lib/libart.so (art::CheckJNI::NewStringUTF(_JNIEnv*, char const*)+44)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #08 pc 002a6324  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (_JNIEnv::NewStringUTF(char const*)+40)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #09 pc 0076eb6c  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::BitmapDC::getBitmapFromJavaShadowStroke(char const*, int, int, cocos2d::CCImage::ETextAlign, char const*, float, float, float, float, bool, float, float, float, float, bool, float, float, float, float)+312)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #10 pc 0076f12c  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::CCImage::initWithStringShadowStroke(char const*, int, int, cocos2d::CCImage::ETextAlign, char const*, int, float, float, float, bool, float, float, float, float, bool, float, float, float, float)+216)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #11 pc 007aeb14  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::CCTexture2D::initWithString(char const*, cocos2d::_ccFontDefinition*)+1188)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #12 pc 0072cd6c  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::CCLabelTTF::updateTexture()+120)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #13 pc 0072c804  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::CCLabelTTF::setString(char const*)+260)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #14 pc 00523140  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (cocos2d::extension::CCEditBoxImplAndroid::setText(char const*)+344)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #15 pc 00523474  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (???)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #16 pc 0076fb2c  /data/app/com.appsomniacs.da2.debug-1/lib/arm/libcocos2dcpp.so (Java_org_cocos2dx_lib_Cocos2dxHelper_nativeSetEditTextDialogResult+208)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   native: #17 pc 001dfeb1  /data/dalvik-cache/arm/data@app@com.appsomniacs.da2.debug-1@base.apk@classes.dex (Java_org_cocos2dx_lib_Cocos2dxHelper_nativeSetEditTextDialogResult___3B+100)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   at org.cocos2dx.lib.Cocos2dxHelper.nativeSetEditTextDialogResult(Native method)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   at org.cocos2dx.lib.Cocos2dxHelper.access$000(Cocos2dxHelper.java:41)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   at org.cocos2dx.lib.Cocos2dxHelper$1.run(Cocos2dxHelper.java:267)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1501)
    12-11 01:02:17.460 10451-10959/com.appsomniacs.da2.debug A/art: sart/runtime/check_jni.cc:65]   at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1278)

堆栈跟踪(来自不同的测试，但同样的崩溃)

    Build fingerprint: 'samsung/zerofltetmo/zerofltetmo:5.1.1/LMY47X/G920TUVU3DOJ7:user/release-keys'
            Revision: '11'
            ABI: 'arm'
            pid: 18460, tid: 18534, name: GLThread 28670  >>> com.appsomniacs.da2 <<<
            signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
                r0 00000000  r1 00004866  r2 00000006  r3 00000000
                r4 f33a4db8  r5 00000006  r6 00000000  r7 0000010c
                r8 88476100  r9 f442c800  sl 00000000  fp 12f61070
                ip 00004866  sp f33a4960  lr f6f01cf9  pc f6f25c30  cpsr 600b0010

            backtrace:
                #00 pc 0003bc30  /system/lib/libc.so (tgkill+12)
                #01 pc 00017cf5  /system/lib/libc.so (pthread_kill+52)
                #02 pc 00018907  /system/lib/libc.so (raise+10)
                #03 pc 000151a5  /system/lib/libc.so (__libc_android_abort+36)
                #04 pc 00012fec  /system/lib/libc.so (abort+4)
                #05 pc 0075a275  /data/app/com.appsomniacs.da2-2/lib/arm/libcocos2dcpp.so (__gnu_cxx::__verbose_terminate_handler()+220)
                #06 pc 0072a10b  /data/app/com.appsomniacs.da2-

2/lib/arm/libcocos2dcpp.so (__cxxabiv1::__terminate(void (*)())+2)
            #07 pc 0072a13b  /data/app/com.appsomniacs.da2-2/lib/arm/libcocos2dcpp.so (std::terminate()+10)
            #08 pc 0072a4ab  /data/app/com.appsomniacs.da2-2/lib/arm/libcocos2dcpp.so (__cxa_pure_virtual+14)
            #09 pc 0041ecc5  /data/app/com.appsomniacs.da2-2/lib/arm/libcocos2dcpp.so
            #10 pc 005977ab  /data/app/com.appsomniacs.da2-2/lib/arm/libcocos2dcpp.so (Java_org_cocos2dx_lib_Cocos2dxHelper_nativeSetEditTextDialogResult+110)
            #11 pc 001dfe39  /data/dalvik-cache/arm/data@app@com.appsomniacs.da2-2@base.apk@classes.dex

Answer 1

我们通过发送 jbyte 数组中的 std::string 的内容找到了解决方案，让 java 端成为 java 并返回我们可以在 C++ jni 端使用的 jstring。对我们来说，这些字符串来自用户键盘，我在一周内发生了 170k 次崩溃，说他们在角色名称中使用表情符号并疯狂聊天……并且命名他们的头像本身也导致了崩溃。因此，Android 5.x 用户加入的任何大厅都会导致他们崩溃，只要他们的客户端试图用有问题的角色呈现其他玩家的名字。在 Android 4.x 中，这不是问题，因为它只是打印了一些垃圾字符。

在你的c++端你可以做这样的事情来实现这个功能:

jstring JniHelper::getjString(const char *input) {
    JniMethodInfo minfo; // JniHelper

    bool hasMethod = JniHelper::getStaticMethodInfo (minfo, APPTAG_JNI_PACKAGE_NAME, "convertCStringToJniSafeString", "([B)Ljava/lang/String;");
    if (!hasMethod)
    {
        return minfo.env->NewStringUTF(""); // TODO Tune your response to fit your needs...
    }
    else
    {
        string nativeString = std::string(input); // has a bit of a code smell, there is probably a better way.
        // cite: http://stackoverflow.com/questions/27303316/c-stdstring-to-jstring-with-a-fixed-length
        jbyteArray array = minfo.env->NewByteArray(nativeString.length());
        minfo.env->SetByteArrayRegion(array,0,nativeString.length(),(jbyte*)nativeString.c_str());

        // cite: http://discuss.cocos2d-x.org/t/jni-return-string/9982/3
        jstring str = (jstring)minfo.env->CallStaticObjectMethod(minfo.classID, minfo.methodID, array);
        minfo.env->DeleteLocalRef(array);
        return str;
    }
}

在 java 端将其转换为 java 字符串并以相同的方法返回它:

public static String convertCStringToJniSafeString(byte[] input) {
    try {
        String nativeString = new String(input, "UTF-8"); // please debate what the safest charset should be?
        return nativeString;
    } catch (UnsupportedEncodingException e) {
        // TODO Simplistic Error handling, tune to your needs.
        Log.e(APPTAG, "Couldn't convert the jbyteArray to jstring");
        return ""; //JSTRING_CONVERT_FAIL
    }
}

在我们的例子中，我们想要一个 jstring(作为修改后的 UTF8 输入)提供给渲染端并存储以供稍后检索，返回一个空字符串只是我们在转换失败时提示我们的一个选择。

我希望这可以帮助某人找到一种方法……甚至是正确的方法……