Call to Thread run() instead of start()

The program calls a thread's run() method instead of calling start(), which causes the code to run in the thread of the caller instead of the callee.


Description

In most cases a direct call to a Thread object's run() method is a bug. The programmer intended to begin a new thread of control, but accidentally called run() instead of start(), so the run() method will execute in the caller's thread of control.

Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

The following excerpt from a Java program mistakenly calls run() instead of start().

Thread thr = new Thread() {
  public void run() {
    ...
  }
};

thr.run();

See Also

SEI CERT Oracle Secure Coding Standard for Java - Guidelines 10. Thread APIs (THI)

Weaknesses in this category are related to the rules and recommendations in the Thread APIs (THI) section of the SEI CERT Oracle Secure Coding Standard for Java.

SFP Secondary Cluster: Use of an Improper API

This category identifies Software Fault Patterns (SFPs) within the Use of an Improper API cluster (SFP3).

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.

Weaknesses in Software Written in Java

This view (slice) covers issues that are found in Java programs that are not common to all languages.


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