频繁点击一个按钮，程序崩溃，查看log部分详情如下：
04-11 11:10:40.371: W/dalvikvm(5507): ReferenceTable overflow (max=1024)
04-11 11:10:40.371: W/dalvikvm(5507): JNI pinned array reference table (0x6242b008) dump:
04-11 11:10:40.371: W/dalvikvm(5507): Last 10 entries (of 1024):
04-11 11:10:40.371: W/dalvikvm(5507): 1023: 0x42e97298 int[] (456 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1022: 0x41c16618 int[] (69 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1021: 0x42e5ef28 byte[] (1280 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1020: 0x4230da28 byte[] (119 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1019: 0x422a03f0 byte[] (14 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1018: 0x42efced0 byte[] (1920 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1017: 0x422bc570 byte[] (119 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1016: 0x41f52e68 byte[] (14 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1015: 0x423c41d0 byte[] (119 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1014: 0x422b8bf0 byte[] (14 elements)
04-11 11:10:40.371: W/dalvikvm(5507): Summary:
04-11 11:10:40.371: W/dalvikvm(5507): 20 of byte[] (12 elements) (20 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of byte[] (13 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 489 of byte[] (14 elements) (489 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of byte[] (68 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 3 of byte[] (69 elements) (3 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 486 of byte[] (119 elements) (486 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 10 of byte[] (148 elements) (10 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 10 of byte[] (152 elements) (10 unique instances)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of byte[] (1280 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of byte[] (1920 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of int[] (69 elements)
04-11 11:10:40.371: W/dalvikvm(5507): 1 of int[] (456 elements)
04-11 11:10:40.371: E/dalvikvm(5507): Failed adding to JNI pinned array ref table (1024 entries)
04-11 11:10:40.371: I/dalvikvm(5507): "main" prio=5 tid=1 RUNNABLE
主要问题是ReferenceTable overflow 。查看资料，发现是引用计数器溢出了，最大为1024.即java的内存管理机制是基于引用的，需要计数器来记录引用的次数。在overflow这句话下面dump出了最近的10个引用，Summary下面可以看出有哪些引用。可以发现其中有两组byte[]，每组的引用达到480多次。我恍然大悟，每点击一次按钮，引用一次，下次点击时上次的资源未被释放。于是一直累加直至计数器溢出。
检查代码发现：
int nArrLen_u = env->GetArrayLength(jbUrl);
if(nArrLen_u > 0){
pUrl = (char *)malloc(nArrLen_u + 1);
bzero(pUrl, (nArrLen_u + 1));
jU = env->GetByteArrayElements(jbUrl, NULL);
memcpy(pUrl, jU, nArrLen_u);
}
int nArrLen_x = env->GetArrayLength(jbXml);
if(nArrLen_x > 0){
pXmlBuf = (char *)malloc(nArrLen_x + 1);
bzero(pXmlBuf, (nArrLen_x + 1));
jX = env->GetByteArrayElements(jbXml, NULL);
memcpy(pXmlBuf, jX, nArrLen_x);
}
代码上可以看出我调用了两次 GetByteArrayElements 但是却没有释放掉。所以在最后添上释放语句就解决了~
if(nArrLen_u > 0){
env->ReleaseByteArrayElements(jbUrl,jU,0);
}
if(nArrLen_x > 0){
env->ReleaseByteArrayElements(jbXml,jX,0);
}参考Android NDK之JNI陷阱 在用到NewByteArray类似方法时一定要DeleteLocalRef()，使用GetByteArrayElements时 要用ReleaseByteArrayElements来进行释放。
问题就是答案！真正明白是什么问题之后，也就找到了答案。