diff --git a/java/ql/integration-tests/java/query-suite/java-code-quality-extended.qls.expected b/java/ql/integration-tests/java/query-suite/java-code-quality-extended.qls.expected index d177c4ad6a5..5c82bd5e349 100644 --- a/java/ql/integration-tests/java/query-suite/java-code-quality-extended.qls.expected +++ b/java/ql/integration-tests/java/query-suite/java-code-quality-extended.qls.expected @@ -32,6 +32,7 @@ ql/java/ql/src/Likely Bugs/Concurrency/CallsToRunnableRun.ql ql/java/ql/src/Likely Bugs/Concurrency/DoubleCheckedLocking.ql ql/java/ql/src/Likely Bugs/Concurrency/DoubleCheckedLockingWithInitRace.ql ql/java/ql/src/Likely Bugs/Concurrency/NonSynchronizedOverride.ql +ql/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql ql/java/ql/src/Likely Bugs/Concurrency/SynchOnBoxedType.ql ql/java/ql/src/Likely Bugs/Concurrency/SynchSetUnsynchGet.ql ql/java/ql/src/Likely Bugs/Frameworks/JUnit/JUnit5MissingNestedAnnotation.ql diff --git a/java/ql/integration-tests/java/query-suite/java-code-quality.qls.expected b/java/ql/integration-tests/java/query-suite/java-code-quality.qls.expected index 05565601e40..e558cf3ffc4 100644 --- a/java/ql/integration-tests/java/query-suite/java-code-quality.qls.expected +++ b/java/ql/integration-tests/java/query-suite/java-code-quality.qls.expected @@ -30,6 +30,7 @@ ql/java/ql/src/Likely Bugs/Concurrency/CallsToRunnableRun.ql ql/java/ql/src/Likely Bugs/Concurrency/DoubleCheckedLocking.ql ql/java/ql/src/Likely Bugs/Concurrency/DoubleCheckedLockingWithInitRace.ql ql/java/ql/src/Likely Bugs/Concurrency/NonSynchronizedOverride.ql +ql/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql ql/java/ql/src/Likely Bugs/Concurrency/SynchOnBoxedType.ql ql/java/ql/src/Likely Bugs/Concurrency/SynchSetUnsynchGet.ql ql/java/ql/src/Likely Bugs/Frameworks/JUnit/JUnit5MissingNestedAnnotation.ql diff --git a/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.md b/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.md new file mode 100644 index 00000000000..424407f5cc6 --- /dev/null +++ b/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.md @@ -0,0 +1,24 @@ +## Overview + +According to the Java documentation on `ScheduledThreadPoolExecutor`, it is not a good idea to set `corePoolSize` to zero, since doing so indicates the executor to keep 0 threads in its pool and the executor will serve no purpose. + +## Recommendation + +Set the `ScheduledThreadPoolExecutor` to have 1 or more threads in its thread pool and use the class's other methods to create a thread execution schedule. + +## Example + +```java +public class Test { + void f() { + int i = 0; + ScheduledThreadPoolExecutor s = new ScheduledThreadPoolExecutor(1); // COMPLIANT + ScheduledThreadPoolExecutor s1 = new ScheduledThreadPoolExecutor(0); // NON_COMPLIANT + s.setCorePoolSize(0); // NON_COMPLIANT + s.setCorePoolSize(i); // NON_COMPLIANT + } +} +``` + +## References +- [ScheduledThreadPoolExecutor](https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/util/concurrent/ScheduledThreadPoolExecutor.html) diff --git a/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql b/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql new file mode 100644 index 00000000000..0b8acb5a088 --- /dev/null +++ b/java/ql/src/Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql @@ -0,0 +1,36 @@ +/** + * @id java/java-util-concurrent-scheduledthreadpoolexecutor + * @name Zero threads set for `java.util.concurrent.ScheduledThreadPoolExecutor` + * @description Setting `java.util.concurrent.ScheduledThreadPoolExecutor` to have 0 threads serves + * no purpose and may indicate programmer error. + * @kind problem + * @precision very-high + * @problem.severity recommendation + * @previous-id java/javautilconcurrentscheduledthreadpoolexecutor + * @tags quality + * reliability + * correctness + * concurrency + */ + +import java +import semmle.code.java.dataflow.DataFlow + +/** + * A `Call` that has the ability to set or modify the `corePoolSize` of the `java.util.concurrent.ScheduledThreadPoolExecutor` type. + */ +class Sink extends Call { + Sink() { + this.getCallee() + .hasQualifiedName("java.util.concurrent", "ThreadPoolExecutor", "setCorePoolSize") or + this.getCallee() + .hasQualifiedName("java.util.concurrent", "ScheduledThreadPoolExecutor", + "ScheduledThreadPoolExecutor") + } +} + +from IntegerLiteral zero, Sink set +where + DataFlow::localFlow(DataFlow::exprNode(zero), DataFlow::exprNode(set.getArgument(0))) and + zero.getIntValue() = 0 +select set, "ScheduledThreadPoolExecutor.corePoolSize is set to have 0 threads." diff --git a/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.expected b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.expected new file mode 100644 index 00000000000..038f2d1d998 --- /dev/null +++ b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.expected @@ -0,0 +1,3 @@ +| Test.java:7:42:7:75 | new ScheduledThreadPoolExecutor(...) | ScheduledThreadPoolExecutor.corePoolSize is set to have 0 threads. | +| Test.java:8:9:8:28 | setCorePoolSize(...) | ScheduledThreadPoolExecutor.corePoolSize is set to have 0 threads. | +| Test.java:9:9:9:28 | setCorePoolSize(...) | ScheduledThreadPoolExecutor.corePoolSize is set to have 0 threads. | diff --git a/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.qlref b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.qlref new file mode 100644 index 00000000000..e0089e4cf02 --- /dev/null +++ b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/ScheduledThreadPoolExecutorZeroThread.qlref @@ -0,0 +1,2 @@ +query: Likely Bugs/Concurrency/ScheduledThreadPoolExecutorZeroThread.ql +postprocess: utils/test/InlineExpectationsTestQuery.ql diff --git a/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/Test.java b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/Test.java new file mode 100644 index 00000000000..d02e6a3403e --- /dev/null +++ b/java/ql/test/query-tests/ScheduledThreadPoolExecutorZeroThread/Test.java @@ -0,0 +1,11 @@ +import java.util.concurrent.ScheduledThreadPoolExecutor; + +public class Test { + void f() { + int i = 0; + ScheduledThreadPoolExecutor s = new ScheduledThreadPoolExecutor(1); // Compliant + ScheduledThreadPoolExecutor s1 = new ScheduledThreadPoolExecutor(0); // $ Alert + s.setCorePoolSize(0); // $ Alert + s.setCorePoolSize(i); // $ Alert + } +}