refactor: extract get_server_context helper to eliminate JNI boilerplate#75
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bernardladenthin merged 4 commits intomasterfrom Apr 5, 2026
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Move jllama_context struct to a new jni_helpers.hpp header and introduce get_server_context_impl() — a dependency-injectable helper that validates the Java-side model handle and returns the native server_context pointer. A thin get_server_context() wrapper in jllama.cpp binds the module-level globals so all call sites become a clean two-liner. Replaces 19 repetitive 2-5 line blocks (reinterpret_cast + optional null check + ThrowNew) with the helper across all JNIEXPORT functions. As a side-effect, nine functions that previously had no null-check guard now throw "Model is not loaded" instead of crashing on a stale handle. Add src/test/cpp/test_jni_helpers.cpp: four unit tests exercising get_server_context_impl() via a mock JNINativeInterface_ table — no JVM required. Wire the new test file and the JNI include path into the BUILD_TESTING CMake target. https://claude.ai/code/session_01UzZRdmP6koZtJpHgYns6rR
The wrapper referenced f_model_pointer and c_llama_error which are declared later in the anonymous namespace, causing a build error. Moved the wrapper to after all globals, just before parse_jstring(). https://claude.ai/code/session_01UzZRdmP6koZtJpHgYns6rR
AVX-512 is only available on newer Intel CPUs (e.g. Intel Xeon Platinum 8370C). The AMD EPYC 7763 used by GitHub Actions runners does not support it. When a libjllama.so compiled with AVX-512 instructions is loaded on such a machine the JVM crashes immediately with SIGILL. Set GGML_AVX512=OFF unconditionally so the distributed library runs on any x86-64 CPU with at least AVX2 (available since ~2013). https://claude.ai/code/session_01UzZRdmP6koZtJpHgYns6rR
Document four concrete reasons why AVX-512 is disabled for all builds: 1. CPUs without AVX-512 support crash with SIGILL (AMD EPYC 7763 vs Intel Xeon Platinum 8370C is the exact CI scenario that triggered this) 2. Intel disabled AVX-512 on all Alder Lake / Raptor Lake desktop CPUs due to the P-core / E-core scheduler incompatibility 3. Clock throttling on Skylake-X server chips and AMD Ryzen 9000 (Zen 5) makes AVX-512 actively harmful for throughput-sensitive workloads 4. High power draw can destabilize systems near voltage limits https://claude.ai/code/session_01UzZRdmP6koZtJpHgYns6rR
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Move jllama_context struct to a new jni_helpers.hpp header and introduce get_server_context_impl() — a dependency-injectable helper that validates the Java-side model handle and returns the native server_context pointer. A thin get_server_context() wrapper in jllama.cpp binds the module-level globals so all call sites become a clean two-liner.
Replaces 19 repetitive 2-5 line blocks (reinterpret_cast + optional null check + ThrowNew) with the helper across all JNIEXPORT functions. As a side-effect, nine functions that previously had no null-check guard now throw "Model is not loaded" instead of crashing on a stale handle.
Add src/test/cpp/test_jni_helpers.cpp: four unit tests exercising get_server_context_impl() via a mock JNINativeInterface_ table — no JVM required. Wire the new test file and the JNI include path into the BUILD_TESTING CMake target.
https://claude.ai/code/session_01UzZRdmP6koZtJpHgYns6rR