The memory gain access to methods of Java’s sun.misc.Unsafe class would be deprecated for elimination in a future release of the platform, under a JEP(JDK Improvement Proposition)afoot in the OpenJDK neighborhood. Of the class’s 87 approaches, 79 would be removed.These unsupported approaches have had supported replacements because JDK 9, for accessing on-heap memory, and JDK 22, for accessing off-heap memory, the proposal states. Library designers are strongly motivated to migrate from sun.misc.Unsafe to these supported replacements. Goals of the proposition include getting ready for the removal of these memory access methods in a future Java release and helping designers understand when their applications count on them. It is not an objective of the proposal to remove the sun.misc.Unsafe class completely, as a little number of its techniques are not utilized for memory access and will stay undeprecated. The proposal does not point out a particular release of Java that would deprecate the approaches. The next variation of standard Java, JDK 22, due in March, already has its feature set frozen. However JDK 23, likely to be launched in September, could be a possible target. In the past, unsafe code was considered as needed for low-level programs. The sun.misc.Unsafe class was introduced in 2002 as a method for
Java classes in the JDK to carry out low-level operations. Its memory gain access to methods, as the name of the class suggests, are hazardous and can lead to undefined behavior, so they were not exposed as a standard API. They were presented with the assumption that they were exclusively for usage within the JDK, that callers within the JDK would perform exhaustive safety checks before
utilizing them, which safe basic APIs for the functionality would be added to the Java platform, the proposal says. But with no way in 2002 to prevent sun.misc.Unsafe from being utilized outside the JDK, its memory access methods became a”Swiss Army knife “for library developers who wanted more power and performance than basic APIs might supply. Regrettably, not all libraries perform safety checks before calling these techniques, therefore providing a danger of failures and crashes in applications.During the past a number of years, two standard APIs have actually been presented as replacements for the memory access approaches in sun.misc.Unsafe. These are java.lang.invoke from JDK 9 and java.lang.foreign from
JDK 22. Copyright © 2024 IDG Communications, Inc. Source
