When dealing with NullPointerExceptions in Java, developers may encounter situations where the stack trace is absent altogether, rendering it difficult to trace the source of the exception.
Typically, when a NullPointerException is thrown, its stack trace provides valuable information about the offending code path. However, certain optimizations performed by the HotSpot JVM can suppress these stack traces.
To retrieve the stack traces, the following option must be passed to the JVM:
-XX:-OmitStackTraceInFastThrow
This option instructs the JVM to refrain from optimizing the handling of NullPointerExceptions, ensuring that stack traces are printed for each occurrence of the exception.
The HotSpot JVM employs an optimization technique that caches stack traces for frequently occurring exceptions, particularly NullPointerExceptions. This optimization aims to enhance performance and prevent excessive logging of identical stack traces.
In the HotSpot JVM, this optimization is implemented in the file graphKit.cpp. It involves a global variable named OmitStackTraceInFastThrow, which controls the suppression of stack traces.
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