0ctf2018 blackhole writeup 题目链接 https://github.com/eternalsakura/ctf_pwn/blob/master/0ctf2018/blackhole.tar.gz
BlackHole开发很久了,目前稳定性、性能都还可以了,但是作为一个Java程序,内存开销一直是硬伤,动不动100M内存下去了,对于单机用户实在是不太友好。 怎么办?优化先从分析开始!
)); } } /** * 在for循环中遍历key */ @Benchmark public static StringBuffer forEachKey(Blackhole blackhole...blackhole) { for (Integer key : map.values()) { blackhole.consume(add(key,key)); } }.../** * Iterator遍历; */ @Benchmark public static void forEachIterator(Blackhole blackhole) { Iterator...blackhole) { map.forEach((key, value) -> { blackhole.consume(add(key,value)); }); }...(add(key,value)); }); } @Benchmark public static void forEachStreamparallel(Blackhole blackhole)
blackhole) { String str = ""; for (int i = 0; i < STRING_ELEMENT_COUNT; i++) {...str += i; } blackhole.consume(str); } @Benchmark public void testStringBuilder...(Blackhole blackhole) { StringBuilder str = new StringBuilder(""); for (int i = 0; i...< STRING_ELEMENT_COUNT; i++) { str.append(i); } blackhole.consume(str);...} @Benchmark public void testStringBuffer(Blackhole blackhole) { StringBuffer str =
我写了个简单的demo作为表访问方法blackhole_am。作为一个新插件的一个demo,操作函数都是空函数。创建表访问方式需要CREATE ACCESS METHOD。...=# CREATE EXTENSION blackhole_am; CREATE EXTENSION =# \dx+ blackhole_am Objects in extension "blackhole_am..." Object description ----------------------------------------- access method blackhole_am...using: =# CREATE TABLE blackhole_tab (id int) USING blackhole_am; CREATE TABLE =# INSERT INTO blackhole_tab...://paquier.xyz/postgresql-2/postgres-12-table-am-blackhole/
更新:安装hijack吧,这个效率更高,支持多个软件混合录制声音 https://rogueamoeba.com/audiohijack/ 首先安装BlackHole https://github.com.../ExistentialAudio/BlackHole 其次根据这个教程在MIDI里面设置多输出设备 https://github.com/ExistentialAudio/BlackHole/wiki.../Multi-Output-Device 在多输出设备里面排序使得内建输出排第一个,同时给内建输出和BlackHole都打上勾 选择将此设备用于声音输出 之后录制的时候选BlackHole...即可 右键quicktime设置录屏 麦克风选择blackHole即可 发布者:全栈程序员栈长,转载请注明出处:https://javaforall.cn/143830.html原文链接
blackhole) { for (Map.Entry entry : map.entrySet()) { Integer...blackhole) { for (Integer key : map.values()) { blackhole.consume(add(key,key));...blackhole) { Iterator> entries = map.entrySet().iterator();...blackhole) { map.forEach((key, value) -> { blackhole.consume(add(key,value));...}); } @Benchmark public static void forEachStreamparallel(Blackhole blackhole) {
@Param(value = {"10", "50", "100"}) private int length; /** * 循环体外创建对象 * @param blackhole...*/ @Benchmark public void outsideLoop(Blackhole blackhole) { Object object = null...(object); } } /** * 循环体内创建对象 * @param blackhole */ @Benchmark...public void insideLoop(Blackhole blackhole) { for (int i = 0; i < length; i++) {...Object object = new Object(); blackhole.consume(object); } } } 测试结果如下: Benchmark
本文将为您详细介绍如何使用 datagen 和 blackhole 连接器随机产生数据和存储数据,来实现一个最简单的 Flink 任务。.../ CREATE TABLE blackhole_sink ( user_id INT, item_id INT, behavior VARCHAR ) WITH ('connector'...= 'blackhole'); 3....编写业务 SQL INSERT INTO blackhole_sink ( SELECT user_id, item_id, behavior FROM random_source...Sink 到 Blackhole 的数据会被丢弃,用户无法查询到其中的数据,此连接器一般用于于性能测试。
本文将为您详细介绍如何使用 datagen 和 blackhole 连接器随机产生和存储数据。...创建 Sink -- 输入到 Blackhole Sink 的数据, 会被全部丢弃。Blackhole Sink 适合做性能测试。...-- 参见 https://ci.apache.org/projects/flink/flink-docs-release-1.13/zh/docs/connectors/table/blackhole...) WITH ('connector' = 'blackhole'); 3....Sink 到 Blackhole 的数据会被丢弃,用户无法查询到其中的数据,此连接器一般用于于性能测试。
void addLinkedByFirst(Blackhole blackhole) { for (int i = 0; i < +operationSize; i++) {...linkedList.add(i, i); } // 为了避免 JIT 忽略未被使用的结果计算 blackhole.consume(linkedList)...(arrayList); } @Benchmark public void addLinkedByMiddle(Blackhole blackhole) { int...(arrayList); } @Benchmark public void addLinkedByEnd(Blackhole blackhole) { int...(arrayList); } @Benchmark public void addLinked(Blackhole blackhole) { // 中间删除链表
.*; import org.openjdk.jmh.infra.Blackhole; import org.openjdk.jmh.results.format.ResultFormatType; import...Runner(opt).run(); } @Benchmark // 测试StringBuffer 添加操作 public void testStringBufferAdd(Blackhole...blackhole) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < length; i++)...{ sb.append(i); } blackhole.consume(sb.toString()); } @Benchmark...// 测试SptingBuilder 添加操作 public void testStringBuilderAdd(Blackhole blackhole) { StringBuilder
"ipList": ip, } r = requests.get(url=Url, params=Data, headers=headers, verify=False) BlackHole_data...= r.json()['result']['data'] if len(BlackHole_data) > 0: print("BlackHole IP:===========...====\n") print(BlackHole_data) else: print ("no BlackHole") if __name__ == '__
.*; import org.openjdk.jmh.infra.Blackhole; import org.openjdk.jmh.results.format.ResultFormatType...snow() { snowflakeUtils.nextId(); } @Benchmark public void exclusive(Blackhole...blackhole) { Integer i = exclusive.get(); i++; blackhole.consume(i + "..."); } @Benchmark public void share(Blackhole blackhole) { blackhole.consume
两个EXP被黑客用来传播恶意软件,国外著名的黑名工具包BlackHole Exploit Kit和Cool Exploit Kit已经更新了该EXP。...BlackHole作者Paunch昨天在网络公布,称在BlackHole添加该JAVA 0day是送给软件用户的新年福利,经AlienVault Labs确认,BlackHole工具中使用的EXP证实为
} blackhole.consume(a); } @Benchmark public void testStringBuilderAdd(Blackhole...blackhole) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++...) { sb.append(i); } blackhole.consume(sb.toString()); } public...注意事项 1、代码死码消除 @Benchmark public void testStringAdd(Blackhole blackhole) { String a = ""; for...JMH 提供了两种方式避免这种问题,一种是将这个变量作为方法返回值 return a,一种是通过 Blackhole 的 consume 来避免 JIT 的优化消除。
testRandomIntWithBound(Blackhole blackhole) throws Exception { //注意不取 2^n 这种数字,因为这种数字一般不会作为实际应用的范围...(Blackhole blackhole) throws Exception { blackhole.consume(splittableRandom.get().nextInt()); }...@Benchmark public void testSplittableRandomIntWithBound(Blackhole blackhole) throws Exception { //...(Blackhole blackhole) throws Exception { //注意不取 2^n 这种数字,因为这种数字一般不会作为实际应用的范围,但是底层针对这种数字有优化 blackhole.consume...(Blackhole blackhole) { //注意不取 2^n 这种数字,因为这种数字一般不会作为实际应用的范围,但是底层针对这种数字有优化 blackhole.consume(drbg.get
blackhole) throws Exception { for (int i = 0; i < a.length; i++) { c[i] = (a[i] * a[i] + b[i] *...b[i]) * -1.0f; } } @Benchmark public void testVector(Blackhole blackhole) { int i = 0; //高于数组长度的...blackhole) throws Exception { blackhole.consume(randomGenerator.get().nextInt()); } @Benchmark...public void testRandomIntWithBound(Blackhole blackhole) throws Exception { //注意不取 2^n 这种数字,因为这种数字一般不会作为实际应用的范围...,但是底层针对这种数字有优化 blackhole.consume(randomGenerator.get().nextInt(1, 100)); } public static void main
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