界: Time and State

分布式计算是关于时间和状态的。也就是说，为了让多个组件相互通信，必须共享状态，所有这些都需要时间。

大多数程序员都会将其工作拟人化。他们会让一个控制线程以同样的方式（他们必须自己完成工作时采取的方式）执行整个程序。然而，现代计算机不同任务之间切换得非常快，在多核、多 CPU 或分布式系统中，两个事件可能完全同时发生。程序员预期的程序执行过程与实际情况之间存在差距，即存在缺陷。这些缺陷与线程、流程、时间和信息之间的意外交互有关。这些交互是通过共享状态发生的：信号量、变量、文件系统，以及总而言之，可以存储信息的任何内容。

Code Correctness: Call to sleep() in Lock

Abstract
调用 sleep() 同时保持锁定可能会导致性能下降以及死锁。
Explanation
如果多个线程尝试获取一个资源上的锁定，在调用 sleep() 的同时保持锁定可导致所有其他线程等待释放该资源，这就会造成性能下降和死锁。

例 1：下列代码调用 sleep() 同时还保持锁定。

ReentrantLock rl = new ReentrantLock();
...
rl.lock();
Thread.sleep(500);
...
rl.unlock();
References
[1] LCK09-J. Do not perform operations that can block while holding a lock CERT
[2] Standards Mapping - Common Weakness Enumeration CWE ID 557
[3] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000336, CCI-000366, CCI-001094
[4] Standards Mapping - NIST Special Publication 800-53 Revision 4 CM-4 Security Impact Analysis (P2), CM-6 Configuration Settings (P1), SC-5 Denial of Service Protection (P1)
[5] Standards Mapping - NIST Special Publication 800-53 Revision 5 CM-4 Impact Analyses, CM-6 Configuration Settings, SC-5 Denial of Service Protection
[6] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[7] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9
[8] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[9] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[10] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[11] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[12] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[13] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[14] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[15] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[16] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II, APSC-DV-002950 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002400 CAT II, APSC-DV-002950 CAT II
[30] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[31] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.controlflow.java.code_correctness_call_to_sleep_in_lock