我在托管代码中创建了一个缓冲区:

var nativeBuffer = ShortArray(bufferSize)

这是Kotlin代码,但是根据stdlib documentation,此语法实际上是返回short []的包装器。

然后,我想使用JNI从C++写入此缓冲区:
JNIEXPORT void JNICALL Java_package_class_name_readNext
    (JNIEnv * env, jclass clazz, jshortArray javaArray)
{
    jboolean * isCopy;
    short * targetArray = env->GetShortArrayElements(javaArray, isCopy);

    // Do stuff to targetArray
}

问题在于GetShortArrayElements调用始终会导致崩溃,并带有以下逻辑删除:
11-07 21:23:53.610 86-86/? I/DEBUG: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
11-07 21:23:53.610 86-86/? I/DEBUG: Build fingerprint: 'generic/vbox86p/vbox86p:5.1/LMY47D/buildbot06092001:userdebug/test-keys'
11-07 21:23:53.610 86-86/? I/DEBUG: Revision: '0'
11-07 21:23:53.610 86-86/? I/DEBUG: ABI: 'x86'
11-07 21:23:53.610 86-86/? I/DEBUG: pid: 28339, tid: 28477, name: Thread-282  >>> <package-name> <<<
11-07 21:23:53.610 86-86/? I/DEBUG: signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xb3bcfacb
11-07 21:23:53.613 86-86/? I/DEBUG:     eax b3bcfacb  ebx b3ffcaa4  ecx a2497000  edx b426e480
11-07 21:23:53.613 86-86/? I/DEBUG:     esi a2497000  edi b3fff440
11-07 21:23:53.613 86-86/? I/DEBUG:     xcs 00000073  xds 0000007b  xes 0000007b  xfs 000000e7  xss 0000007b
11-07 21:23:53.613 86-86/? I/DEBUG:     eip b3dcd69c  ebp 9f5a2968  esp 9f5a2880  flags 00210282
11-07 21:23:53.613 86-86/? I/DEBUG:     #00 pc 002e069c  /system/lib/libart.so (short* art::JNI::GetPrimitiveArray<_jshortArray*, short, art::mirror::PrimitiveArray<short> >(_JNIEnv*, _jshortArray*, unsigned char*)+572)
11-07 21:23:53.613 86-86/? I/DEBUG:     #01 pc 0010cdad  /system/lib/libart.so (art::CheckJNI::GetShortArrayElements(_JNIEnv*, _jshortArray*, unsigned char*)+125)
javaArray不为空(通常为-1621480864之类的地址),并且nativeBuffer是静态变量,因此不太可能被GC处理。该行为发生在Genymotion实例(x86)和ARM设备上,但我仅针对Android 5.0+进行了测试。我还能错过什么?

最佳答案

糟糕,您没有正确使用isCopy参数。它应该是:

jboolean isCopy;
jshort* targetArray = env->GetShortArrayElements(javaArray, &isCopy);

也就是说,isCopy是一个“输出参数”(使用C#语言)。

如果您不在乎targetArray是否别名为javaArray,也可以改为传递nullptr,如下所示:
jshort* targetArray = env->GetShortArrayElements(javaArray, nullptr);

10-08 00:16