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: Erroneous Synchronization
Abstract
如果线程向其他线程发出信号后并未解除锁定 mutex,则其他线程将保持锁定并继续等待 mutex。
Explanation
在线程向其他等待 mutex 的线程发出信号后,它必须调用
例 1:以下代码通过调用
pthread_mutex_unlock()
来解除锁定 mutex,然后其他线程才能开始运行。如果发出信号的线程无法解除锁定 mutex,则在第二个线程中调用 pthread_cond_wait()
函数时不会返回任何值,该线程也将无法执行。 例 1:以下代码通过调用
pthread_cond_signal()
向其他等待 mutex 的线程发出信号,但无法解除锁定 mutex,而其他线程会继续等待 mutex。
...
pthread_mutex_lock(&count_mutex);
// Signal waiting thread
pthread_cond_signal(&count_threshold_cv);
...
References
[1] Standards Mapping - CIS Azure Kubernetes Service Benchmark 1.0
[2] Standards Mapping - CIS Amazon Elastic Kubernetes Service Benchmark 2.0
[3] Standards Mapping - CIS Amazon Web Services Foundations Benchmark 1
[4] Standards Mapping - CIS Google Kubernetes Engine Benchmark normal
[5] Standards Mapping - Common Weakness Enumeration CWE ID 373
[6] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-000336, CCI-000366, CCI-001094
[7] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 1.3
[8] 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)
[9] Standards Mapping - NIST Special Publication 800-53 Revision 5 CM-4 Impact Analyses, CM-6 Configuration Settings, SC-5 Denial of Service Protection
[10] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service
[11] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9
[12] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II
[13] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II
[14] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II
[15] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II
[16] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II
[17] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II
[18] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II
[19] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II
[20] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II
[21] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II
[22] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II
[23] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II
[24] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II
[25] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II
[26] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II
[27] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II
[28] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II
[29] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II
[30] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II
[31] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II
[32] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II, APSC-DV-002950 CAT II
[33] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)
[34] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service
desc.structural.cpp.code_correctness_erroneous_synchronization