Use ThreadLocal caching for ExtendedRandom PRNG contexts - #1508
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Add ThreadLocal caching for native PRNG contexts used by ExtendedRandom. Each thread creates and reuses a PRNG context for supported DRBG algorithms. This avoids repeated EXTRAND_create calls when instances are created frequently. Benefits: - Reduce native allocation overhead - Reuse PRNG contexts per thread - Improve performance in RNG-heavy workloads Signed-off-by: Tao Liu <tao.liu@ibm.com>
ThreadLocal can cause native TCB context issues on z/OS. This change bypasses ThreadLocal on z/OS by creating instance-specific PRNG contexts, while other platforms continue using ThreadLocal for performance. Signed-off-by: Tao Liu <tao.liu@ibm.com>
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Avoid storing ThreadLocal-owned native PRNG context IDs in ockPRNGContextId. The native context is owned by the ThreadLocal PRNGContextPointer, so copying its raw context ID into the ExtendedRandom instance can leave a stale pointer if the creating thread exits and the ThreadLocal value is cleaned. Resolve the ThreadLocal PRNGContextPointer in nextBytes() instead, so each call uses the current thread's live context and keeps the PRNGContextPointer strongly reachable during the native call. Keep ockPRNGContextId only for instance-owned contexts, such as z/OS or after setSeed().
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Add ThreadLocal caching for native PRNG contexts used by ExtendedRandom. Each thread creates and reuses a PRNG context for supported DRBG algorithms.
This avoids repeated EXTRAND_create calls when instances are created frequently.
Benefits:
This PR is back-ported from PR #1255