JobSystemThreadPool: add the setNumThreads() method

stephengold · Jul 8, 2024 · 8d10ceb · 8d10ceb
1 parent a542e0b
commit 8d10ceb
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diff --git a/src/main/java/com/github/stephengold/joltjni/JobSystemThreadPool.java b/src/main/java/com/github/stephengold/joltjni/JobSystemThreadPool.java
@@ -60,6 +60,19 @@ public JobSystemThreadPool(int maxJobs, int maxBarriers, int numThreads) {
         setVirtualAddress(systemVa, true);
     }
     // *************************************************************************
+    // new methods exposed
+
+    /**
+     * Alter the number of worker threads. This is one less than the maximum
+     * number of jobs that can execute concurrently.
+     *
+     * @param numThreads the desired number of threads (&ge;0)
+     */
+    public void setNumThreads(int numThreads) {
+        long systemVa = va();
+        setNumThreads(systemVa, numThreads);
+    }
+    // *************************************************************************
     // JobSystem methods
 
     /**
@@ -82,4 +95,6 @@ native private static long createJobSystem(
             int maxJobs, int maxBarriers, int numThreads);
 
     native private static void free(long systemVa);
+
+    native private static void setNumThreads(long systemVa, int numThreads);
 }
diff --git a/src/main/native/glue/JobSystemThreadPool.cpp b/src/main/native/glue/JobSystemThreadPool.cpp
@@ -54,3 +54,15 @@ JNIEXPORT void JNICALL Java_com_github_stephengold_joltjni_JobSystemThreadPool_f
     delete pSystem;
 #endif
 }
+
+/*
+ * Class:     com_github_stephengold_joltjni_JobSystemThreadPool
+ * Method:    setNumThreads
+ * Signature: (JI)V
+ */
+JNIEXPORT void JNICALL Java_com_github_stephengold_joltjni_JobSystemThreadPool_setNumThreads
+  (JNIEnv *, jclass, jlong systemVa, jint numThreads) {
+    JobSystemThreadPool * const pSystem
+        = reinterpret_cast<JobSystemThreadPool *> (systemVa);
+    pSystem->SetNumThreads(numThreads);
+}