在调用java.com回调()时，应用程序崩溃。由于detatchThread，得到运行时错误。

Question

我试图从native-lib.cpp类的callback()方法中创建一个回调来调用java中的一些方法。但为此，我还需要一个env变量。我试图在native-lib.cpp中创建同样的方法，但是得到了这个错误。 我想是因为线程被分离的问题。谁能澄清一下这个问题。我对回调的创建概念很陌生。谁能指出具体的问题。在我看来，detachThread有些问题。谁能澄清一下这个问题。先谢谢你了。

这是native-lib.cpp。

#include <jni.h>
#include <string>
#include "Numbers.h"

#include <android/log.h>

#define  LOG_TAG    "logs"

#define  LOGD(...)  __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)


typedef struct number_ctx{
    JavaVM  *javaVM;
    jclass   mathsClass;
    jobject  mathsObj;
    jclass   mainActivityClass;
    jobject  mainActivityObj;
    pthread_mutex_t  lock;
} NumbersCtx;
NumbersCtx g_ctx;


JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved) {
    JNIEnv* env;
    memset(&g_ctx, 0, sizeof(g_ctx));

    g_ctx.javaVM = vm;

    if (vm ->GetEnv((void **)&env, JNI_VERSION_1_6) != JNI_OK) {
        return JNI_ERR; // JNI version not supported.
    }

    jclass  clz = env->FindClass(
            "com/example/maths/Maths1");

    g_ctx.mathsClass = static_cast<jclass>(env->NewGlobalRef(clz));

    clz = env->FindClass(
            "com/example/maths/MainActivity");

    g_ctx.mainActivityClass = static_cast<jclass>(env->NewGlobalRef(clz));

    g_ctx.mathsObj = NULL;
    g_ctx.mainActivityObj = NULL;

    env->DeleteLocalRef(clz);

    return  JNI_VERSION_1_6;
}

void callback() {

    JNIEnv* env;

    LOGD("Starting finally ");

    if (g_ctx.javaVM ->GetEnv((void **)&env, JNI_VERSION_1_6) != JNI_OK) {
        LOGD("JNI Error is %d" , JNI_ERR); // JNI version not supported.
    }

    LOGD("Env variable received successfully");

    int status = g_ctx.javaVM->AttachCurrentThread(&env, NULL);

    if(status != JNI_OK) {
        LOGD("Failed to attach the thread");
    } else {

        LOGD("Thread attached successfully");

        jmethodID testMessage = env->GetMethodID(g_ctx.mathsClass, "printMessage",
                                                 "()V");
        // Call the method on the object
        env->CallVoidMethod(g_ctx.mathsObj, testMessage);

        if (env->ExceptionCheck()) {
            env->ExceptionDescribe();
        }

        LOGD("Void Method called Successfully");

        g_ctx.javaVM->DetachCurrentThread();

        LOGD("Thread detached successfully");
    }

    LOGD("This callback is called finally");
}

jfieldID getPtrFieldId(JNIEnv * env, jobject obj)
{
    static jfieldID ptrFieldId = 0;

    if (!ptrFieldId)
    {
        jclass c = env->GetObjectClass(obj);
        ptrFieldId = env->GetFieldID(c, "numberptr", "J");
        env->DeleteLocalRef(c);
    }

    return ptrFieldId;
}


extern "C"
JNIEXPORT void JNICALL
Java_com_example_maths_Maths1_createNumberInstance(JNIEnv *env, jobject thiz, jint a, jint b) {
    // TODO: implement createNumberInstance()

    g_ctx.mathsObj = env->NewGlobalRef(thiz);
    Numbers* num = new Numbers(a, b);
    callback();
    env->SetLongField(thiz, getPtrFieldId(env, thiz), (jlong) num);

}

这是我得到的错误信息

2020-06-02 19:25:39.101 15965-15965/com.example.maths A/m.example.math: runtime.cc:2067] Thread[1,tid=15965,Native,Thread*=0xec991800,peer=0x71b391f0,"main"] attempting to detach while still running code
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] Runtime aborting...
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] Dumping all threads without mutator lock held
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] All threads:
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] DALVIK THREADS (17):
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] "main" prio=10 tid=1 Runnable
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | group="" sCount=0 dsCount=0 flags=0 obj=0x71b391f0 self=0xec991800
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | sysTid=15965 nice=-10 cgrp=default sched=0/0 handle=0xece36dc8
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | state=R schedstat=( 466154407 353144186 350 ) utm=12 stm=34 core=0 HZ=100
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | stack=0xff27a000-0xff27c000 stackSize=8192KB
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | held mutexes= "abort lock" "mutator lock"(shared held)
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #00 pc 00493b43  /apex/com.android.runtime/lib/libart.so (art::DumpNativeStack(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, int, BacktraceMap*, char const*, art::ArtMethod*, void*, bool)+115)
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #01 pc 005b1fd2  /apex/com.android.runtime/lib/libart.so (art::Thread::DumpStack(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, bool, BacktraceMap*, bool) const+994)
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #02 pc 005ace61  /apex/com.android.runtime/lib/libart.so (art::Thread::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, bool, BacktraceMap*, bool) const+65)
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #03 pc 005d2cd1  /apex/com.android.runtime/lib/libart.so (art::DumpCheckpoint::Run(art::Thread*)+929)
2020-06-02 19:25:39.497 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #04 pc 005cac06  /apex/com.android.runtime/lib/libart.so (art::ThreadList::RunCheckpoint(art::Closure*, art::Closure*)+486)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #05 pc 005c9e6c  /apex/com.android.runtime/lib/libart.so (art::ThreadList::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, bool)+2268)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #06 pc 005796f0  /apex/com.android.runtime/lib/libart.so (art::AbortState::DumpAllThreads(std::__1::basic_ostream<char, std::__1::char_traits<char>>&, art::Thread*) const+448)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #07 pc 00564d30  /apex/com.android.runtime/lib/libart.so (art::Runtime::Abort(char const*)+1536)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #08 pc 000249b3  /apex/com.android.runtime/lib/libartbase.so (_ZNSt3__110__function6__funcIPFvPKcENS_9allocatorIS5_EES4_EclEOS3_+35)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #09 pc 0000bac7  /system/lib/libbase.so (android::base::LogMessage::~LogMessage()+727)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #10 pc 005645de  /apex/com.android.runtime/lib/libart.so (art::Runtime::DetachCurrentThread()+414)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #11 pc 003ecc83  /apex/com.android.runtime/lib/libart.so (art::JII::DetachCurrentThread(_JavaVM*)+67)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #12 pc 003e3445  /apex/com.android.runtime/lib/libart.so (art::(anonymous namespace)::CheckJII::DetachCurrentThread(_JavaVM*)+117)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #13 pc 00009d6a  /data/app/com.example.maths-alZFaEzd-BAd84VC19Fvrg==/lib/x86/libnative-lib.so (_JavaVM::DetachCurrentThread()+42)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #14 pc 00009a8a  /data/app/com.example.maths-alZFaEzd-BAd84VC19Fvrg==/lib/x86/libnative-lib.so (callback()+554)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #15 pc 0000a24c  /data/app/com.example.maths-alZFaEzd-BAd84VC19Fvrg==/lib/x86/libnative-lib.so (Java_com_example_maths_Maths1_createNumberInstance+172)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #16 pc 00144f67  /apex/com.android.runtime/lib/libart.so (art_quick_generic_jni_trampoline+71)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #17 pc 0013e7d2  /apex/com.android.runtime/lib/libart.so (art_quick_invoke_stub+338)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #18 pc 00149a69  /apex/com.android.runtime/lib/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+281)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #19 pc 00332502  /apex/com.android.runtime/lib/libart.so (art::interpreter::ArtInterpreterToCompiledCodeBridge(art::Thread*, art::ArtMethod*, art::ShadowFrame*, unsigned short, art::JValue*)+386)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #20 pc 0032c19c  /apex/com.android.runtime/lib/libart.so (bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&, art::Instruction const*, unsigned short, art::JValue*)+988)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #21 pc 006818dd  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+989)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #22 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #23 pc 0011dc02  [anon:dalvik-classes.dex extracted in memory from /data/app/com.example.maths-alZFaEzd-BAd84VC19Fvrg==/base.apk] (com.example.maths.Maths1.<init>+26)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #24 pc 0068461c  /apex/com.android.runtime/lib/libart.so (MterpInvokeDirect+1324)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #25 pc 00138921  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_direct+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #26 pc 0011db02  [anon:dalvik-classes.dex extracted in memory from /data/app/com.example.maths-alZFaEzd-BAd84VC19Fvrg==/base.apk] (com.example.maths.MainActivity.onCreate+26)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #27 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #28 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #29 pc 0019175e  /system/framework/framework.jar (android.app.Activity.performCreate+30)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #30 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #31 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #32 pc 00191726  /system/framework/framework.jar (android.app.Activity.performCreate+2)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #33 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #34 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #35 pc 001eefda  /system/framework/framework.jar (android.app.Instrumentation.callActivityOnCreate+6)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #36 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #37 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #38 pc 00180bb8  /system/framework/framework.jar (android.app.ActivityThread.performLaunchActivity+752)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #39 pc 0068461c  /apex/com.android.runtime/lib/libart.so (MterpInvokeDirect+1324)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #40 pc 00138921  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_direct+33)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #41 pc 00180836  /system/framework/framework.jar (android.app.ActivityThread.handleLaunchActivity+94)
2020-06-02 19:25:39.498 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #42 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #43 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #44 pc 0025e28e  /system/framework/framework.jar (android.app.servertransaction.LaunchActivityItem.execute+126)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #45 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #46 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #47 pc 002607da  /system/framework/framework.jar (android.app.servertransaction.TransactionExecutor.executeCallbacks+154)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #48 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #49 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #50 pc 00260716  /system/framework/framework.jar (android.app.servertransaction.TransactionExecutor.execute+146)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #51 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #52 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #53 pc 0017fb6e  /system/framework/framework.jar (android.app.ActivityThread$H.handleMessage+78)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #54 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #55 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #56 pc 002f5846  /system/framework/framework.jar (android.os.Handler.dispatchMessage+38)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #57 pc 00681b4c  /apex/com.android.runtime/lib/libart.so (MterpInvokeVirtual+1612)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #58 pc 00138821  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_virtual+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #59 pc 00319ee6  /system/framework/framework.jar (android.os.Looper.loop+466)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #60 pc 00684fdc  /apex/com.android.runtime/lib/libart.so (MterpInvokeStatic+1260)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #61 pc 001389a1  /apex/com.android.runtime/lib/libart.so (mterp_op_invoke_static+33)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #62 pc 00189466  /system/framework/framework.jar (android.app.ActivityThread.main+194)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #63 pc 002f8e0a  /apex/com.android.runtime/lib/libart.so (_ZN3art11interpreterL7ExecuteEPNS_6ThreadERKNS_20CodeItemDataAccessorERNS_11ShadowFrameENS_6JValueEbb.llvm.1175793267244191248+298)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #64 pc 002ffcc5  /apex/com.android.runtime/lib/libart.so (art::interpreter::EnterInterpreterFromEntryPoint(art::Thread*, art::CodeItemDataAccessor const&, art::ShadowFrame*)+181)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #65 pc 0066fc49  /apex/com.android.runtime/lib/libart.so (artQuickToInterpreterBridge+1209)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #66 pc 0014503d  /apex/com.android.runtime/lib/libart.so (art_quick_to_interpreter_bridge+77)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #67 pc 0013e9a2  /apex/com.android.runtime/lib/libart.so (art_quick_invoke_static_stub+418)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #68 pc 00149a7a  /apex/com.android.runtime/lib/libart.so (art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)+298)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #69 pc 0055a563  /apex/com.android.runtime/lib/libart.so (art::(anonymous namespace)::InvokeWithArgArray(art::ScopedObjectAccessAlreadyRunnable const&, art::ArtMethod*, art::(anonymous namespace)::ArgArray*, art::JValue*, char const*)+99)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #70 pc 0055c37f  /apex/com.android.runtime/lib/libart.so (art::InvokeMethod(art::ScopedObjectAccessAlreadyRunnable const&, _jobject*, _jobject*, _jobject*, unsigned int)+1327)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #71 pc 004c91a3  /apex/com.android.runtime/lib/libart.so (art::Method_invoke(_JNIEnv*, _jobject*, _jobject*, _jobjectArray*)+83)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   at com.example.maths.Maths1.createNumberInstance(Native method)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   at com.example.maths.Maths1.<init>(Maths1.java:16)
2020-06-02 19:25:39.499 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   at com.example.maths.MainActivity.onCreate(MainActivity.java:21)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] 
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] "Runtime worker thread 0" prio=10 tid=2 Native (still starting up)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | group="" sCount=1 dsCount=0 flags=1 obj=0x0 self=0xd9500000
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | sysTid=15991 nice=0 cgrp=default sched=0/0 handle=0xec77fd90
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | state=S schedstat=( 1604515 798906 8 ) utm=0 stm=0 core=1 HZ=100
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | stack=0xec771000-0xec773000 stackSize=63KB
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | held mutexes=
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   kernel: (couldn't read /proc/self/task/15991/stack)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #00 pc 00000b77  [vdso] (__kernel_vsyscall+7)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #01 pc 00092328  /apex/com.android.runtime/lib/bionic/libc.so (syscall+40)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #02 pc 00150802  /apex/com.android.runtime/lib/libart.so (art::ConditionVariable::WaitHoldingLocks(art::Thread*)+114)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #03 pc 00150783  /apex/com.android.runtime/lib/libart.so (art::ConditionVariable::Wait(art::Thread*)+35)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #04 pc 005d4b15  /apex/com.android.runtime/lib/libart.so (art::ThreadPool::GetTask(art::Thread*)+261)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #05 pc 005d3c43  /apex/com.android.runtime/lib/libart.so (art::ThreadPoolWorker::Run()+83)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #06 pc 005d370f  /apex/com.android.runtime/lib/libart.so (art::ThreadPoolWorker::Callback(void*)+239)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #07 pc 0011a8e5  /apex/com.android.runtime/lib/bionic/libc.so (__pthread_start(void*)+53)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #08 pc 000af6a7  /apex/com.android.runtime/lib/bionic/libc.so (__start_thread+71)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   (no managed stack frames)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] 
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] "Jit thread pool worker thread 0" prio=10 tid=3 Native
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | group="" sCount=1 dsCount=0 flags=1 obj=0x159c0030 self=0xec98ee00
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | sysTid=15990 nice=0 cgrp=default sched=0/0 handle=0xd9404d90
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | state=S schedstat=( 4160010 1789692 15 ) utm=0 stm=0 core=1 HZ=100
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | stack=0xd9306000-0xd9308000 stackSize=1023KB
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | held mutexes=
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   kernel: (couldn't read /proc/self/task/15990/stack)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #00 pc 00000b77  [vdso] (__kernel_vsyscall+7)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #01 pc 00092328  /apex/com.android.runtime/lib/bionic/libc.so (syscall+40)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #02 pc 00150802  /apex/com.android.runtime/lib/libart.so (art::ConditionVariable::WaitHoldingLocks(art::Thread*)+114)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #03 pc 00150783  /apex/com.android.runtime/lib/libart.so (art::ConditionVariable::Wait(art::Thread*)+35)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #04 pc 005d4b15  /apex/com.android.runtime/lib/libart.so (art::ThreadPool::GetTask(art::Thread*)+261)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #05 pc 005d3c75  /apex/com.android.runtime/lib/libart.so (art::ThreadPoolWorker::Run()+133)
2020-06-02 19:25:39.500 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #06 pc 005d370f  /apex/com.android.runtime/lib/libart.so (art::ThreadPoolWorker::Callback(void*)+239)
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #07 pc 0011a8e5  /apex/com.android.runtime/lib/bionic/libc.so (__pthread_start(void*)+53)
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   native: #08 pc 000af6a7  /apex/com.android.runtime/lib/bionic/libc.so (__start_thread+71)
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   (no managed stack frames)
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] 
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630] "Runtime worker thread 1" prio=10 tid=4 Native (still starting up)
2020-06-02 19:25:39.501 15965-15965/com.example.maths A/m.example.math: runtime.cc:630]   | group="" sCount=1 dsCount=0 flags=1 obj=0x0 self=0xd9508c00

Answer 1

我想在native-lib.cpp中创建同样的变量 GetEnv 返回 JNI_OK当前线程已经连接 你不应该试图拆开它.

这就是为什么Android会对你大喊大叫的原因：你在试图分离主线！你应该只在它返回的情况下尝试附加（然后再分离）。

你应该只尝试附加（然后再分离），如果它返回了 JNI_EDETACHED.