java - Android JNI 中的 native 崩溃 SIGSEGV

Question

我在我的应用程序中随机收到 native 崩溃 信号 11 (SIGSEGV)，代码 1 (SEGV_MAPERR)。该应用程序循环处理文件并在 C++ 代码中分析它们并返回一个 float 数组。这是在处理文件时运行一段时间的 AsyncTask 中完成的。我在导致崩溃的代码中做错了什么？还是超能力的问题？谢谢你。

这是 AsyncTask 的 doInBackground 函数:

protected String doInBackground(Object... urls) {

            for (int i = 0; i < songFiles.size(); i++) {
                SongFile temp = songFiles.get(i);
                try {
                    float[] f = Analyser.getInfo(temp.getPath());
                        if (f != null && f.length > 1) {
                            ...save to DB
                        }
                    }

                } catch (Exception e) {
                }
            }
            return "";
        } 

Java和C++代码之间的函数:

extern "C" JNIEXPORT jfloatArray Java_com_superpowered_SuperpoweredPlayer_getInfo(JNIEnv *env, jobject instance,jstring filepath) {
    jfloatArray ret;
    char *Path= (char *) env->GetStringUTFChars(filepath, JNI_FALSE);

    ret = (jfloatArray)env->NewFloatArray(2);

    float *values = superpoweredPlayer->getKey(Path);

    env->SetFloatArrayRegion(ret, 0, 2, values);
    env->ReleaseStringUTFChars(filepath, Path);
    return ret;

}

C++函数getKey:

float *SuperpoweredPlayer::getKey(char *url) {

    SuperpoweredDecoder *decoder = new SuperpoweredDecoder();

    //decoder initialize from the URL input
    const char *openError = decoder->open(url, false, 0, 0);
    if (openError) {
        delete decoder;
        return NULL;
    };

    // Create the analyzer.
    SuperpoweredOfflineAnalyzer *analyzer = new SuperpoweredOfflineAnalyzer(decoder->samplerate, 0, decoder->durationSeconds);

    // Create a buffer for the 16-bit integer samples coming from the decoder.
    short int *intBuffer = (short int *)malloc(decoder->samplesPerFrame * 2 * sizeof(short int) + 16384);
    // Create a buffer for the 32-bit floating point samples required by the effect.
    float *floatBuffer = (float *)malloc(decoder->samplesPerFrame * 2 * sizeof(float) + 1024);

    // Processing.
    while (true) {

        // Decode one frame. samplesDecoded will be overwritten with the actual decoded number of samples.
        unsigned int samplesDecoded = decoder->samplesPerFrame;
        if (decoder->decode(intBuffer, &samplesDecoded) == SUPERPOWEREDDECODER_ERROR) break;
        if (samplesDecoded < 1) break;

        // Convert the decoded PCM samples from 16-bit integer to 32-bit floating point.
        SuperpoweredShortIntToFloat(intBuffer, floatBuffer, samplesDecoded);

        // Submit samples to the analyzer.
        analyzer->process(floatBuffer, samplesDecoded);

        // Update the progress indicator.
        // progress = (double)decoder->samplePosition / (double)decoder->durationSamples;
    };



    // Get the result.
    unsigned char *averageWaveform = NULL, *lowWaveform = NULL, *midWaveform = NULL, *highWaveform = NULL, *peakWaveform = NULL, *notes = NULL;
    int waveformSize, overviewSize, keyIndex;
    char *overviewWaveform = NULL;
    float loudpartsAverageDecibel, peakDecibel, bpm, averageDecibel, beatgridStartMs = 0;
    analyzer->getresults(&averageWaveform, &peakWaveform, &lowWaveform, &midWaveform, &highWaveform, &notes, &waveformSize, &overviewWaveform, &overviewSize, &averageDecibel, &loudpartsAverageDecibel, &peakDecibel, &bpm, &beatgridStartMs, &keyIndex);

    float *ret;
    ret=(float*)malloc(2*sizeof(float));
    ret[0] = bpm;
    ret[1] = keyIndex;

    // Cleanup.
    delete decoder;
    delete analyzer;
    free(intBuffer);
    free(floatBuffer);

    // Done with the result, free memory.
    if (averageWaveform) free(averageWaveform);
    if (lowWaveform) free(lowWaveform);
    if (midWaveform) free(midWaveform);
    if (highWaveform) free(highWaveform);
    if (peakWaveform) free(peakWaveform);
    if (notes) free(notes);
    if (overviewWaveform) free(overviewWaveform);

    return ret;

}

Answer 1

请仔细检查您是否正在释放所有内存，是否正在分配以及是否以相反的顺序释放内存/删除对象，例如如果您创建对象 A 然后 B，您应该删除 B 然后 A。

1. 内存泄漏:float* values 未在 Java_com_superpowered_SuperpoweredPlayer_getInfo() 中释放
2. 我会先释放在 analyzer->getresults() 中分配的内存，然后是 floatBuffer 和 intBuffer，然后是删除分析器，最后是解码器。

您确定使用 free() 释放在 analyzer->getresults() 中分配的内存是正确的(且安全的)吗，因为超能力中的 free 可能与代码中的 free 不同(如果两者都静态链接到标准C 库)？