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peter-lawreypeter-lawrey
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Add test for dumping the lock state
1 parent 25cbc4a commit 368dd31

7 files changed

Lines changed: 344 additions & 72 deletions

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‎pom.xml‎

Lines changed: 26 additions & 42 deletions
Original file line numberDiff line numberDiff line change
@@ -12,53 +12,37 @@
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<properties>
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<native.source.dir>src/main/c</native.source.dir>
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</properties>
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<dependencies>
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<dependency>
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<groupId>junit</groupId>
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<artifactId>junit</artifactId>
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<version>4.8.2</version>
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<scope>test</scope>
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</dependency>
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</dependencies>
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<build>
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<plugins>
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<plugin>
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<groupId>org.codehaus.mojo</groupId>
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<artifactId>native-maven-plugin</artifactId>
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<version>1.0-alpha-7</version>
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<extensions>true</extensions>
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<configuration>
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<javahClassNames>
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<javahClassName>vanilla.java.affinity.AffinitySupport</javahClassName>
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</javahClassNames>
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<javahSearchJNIFromDependencies>true</javahSearchJNIFromDependencies>
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<compilerStartOptions>
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<compilerStartOption>${commonCompilerOptions}</compilerStartOption>
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</compilerStartOptions>
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<sources>
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<source>
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<directory>${native.source.dir}</directory>
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<fileNames>
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<fileName>affinitysupport.c</fileName>
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</fileNames>
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</source>
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<source>
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<directory>${native.source.dir}/include</directory>
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</source>
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<source>
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<directory>target/native/javah</directory>
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</source>
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<source>
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<directory>/opt/java/openjdk/include/</directory>
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</source>
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<source>
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<directory>/opt/java/openjdk/include/linux/</directory>
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</source>
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</sources>
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<linkerStartOptions>
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<linkerStartOption>-shared</linkerStartOption>
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</linkerStartOptions>
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</configuration>
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<artifactId>exec-maven-plugin</artifactId>
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<version>1.2.1</version>
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<executions>
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<execution>
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<!-- this execution happens just after compiling the java classes, and builds the native code. -->
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<id>build-native</id>
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<phase>process-classes</phase>
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<goals>
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<goal>exec</goal>
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</goals>
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<configuration>
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<executable>src/main/c/Makefile</executable>
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<workingDirectory>src/main/c</workingDirectory>
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</configuration>
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</execution>
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</executions>
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</plugin>
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</plugins>
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</build>
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</project>

‎src/main/c/Makefile‎

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#!/usr/bin/make -f
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#
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# Makefile for C code
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#
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# C sources to compile
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TARGET_DIR := ../../../target/classes
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TARGET := $(TARGET_DIR)/libaffinity.so
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WORKING_DIR := $(TARGET_DIR)/../jni
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JAVA_BUILD_DIR := $(TARGET_DIR)
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JAVA_HOME ?= /usr/java/default
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JVM_SHARED_LIB := $(JAVA_HOME)/jre/lib/amd64/server
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INCLUDES := -I $(JAVA_HOME)/include -I $(JAVA_HOME)/include/linux -I $(WORKING_DIR)
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# classpath for javah
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ifdef CLASSPATH
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JAVAH_CLASSPATH = $(JAVA_BUILD_DIR):$(CLASSPATH)
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else
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JAVAH_CLASSPATH = $(JAVA_BUILD_DIR)
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endif
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all: $(TARGET)
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$(TARGET): vanilla_java_affinity_AffinitySupport.c $(WORKING_DIR)/vanilla_java_affinity_AffinitySupport.h
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gcc -O2 -shared -fPIC -L$(JVM_SHARED_LIB) -ljvm -lrt $(INCLUDES) vanilla_java_affinity_AffinitySupport.c -o $(TARGET)
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$(WORKING_DIR)/vanilla_java_affinity_AffinitySupport.h: $(TARGET_DIR)/vanilla/java/affinity/AffinitySupport.class
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mkdir -p $(TARGET_DIR)/jni
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javah -force -classpath $(JAVAH_CLASSPATH) -d $(WORKING_DIR) vanilla.java.affinity.AffinitySupport
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‎src/main/c/affinitysupport.c‎

Lines changed: 0 additions & 30 deletions
This file was deleted.

‎src/main/c/vanilla_java_affinity_AffinitySupport.c‎

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#define _GNU_SOURCE
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#include <jni.h>
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#include <sched.h>
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#include "vanilla_java_affinity_AffinitySupport.h"
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/*
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* Class: vanilla_java_affinity_AffinitySupport
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* Method: getAffinity
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* Signature: ()J
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*/
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JNIEXPORT jlong JNICALL Java_vanilla_java_affinity_AffinitySupport_getAffinity
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(JNIEnv *env, jclass c) {
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cpu_set_t mask;
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int ret = sched_getaffinity(0, sizeof(mask), &mask);
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if (ret < 0) return ~0LL;
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long long mask2 = 0, i;
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for(i=0;i<sizeof(mask2)*8;i++)
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if (CPU_ISSET(i, &mask))
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mask2 |= 1L << i;
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return (jlong) mask2;
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}
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/*
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* Class: vanilla_java_affinity_AffinitySupport
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* Method: setAffinity
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* Signature: (J)V
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*/
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JNIEXPORT void JNICALL Java_vanilla_java_affinity_AffinitySupport_setAffinity
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(JNIEnv *env, jclass c, jlong affinity) {
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int i;
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cpu_set_t mask;
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CPU_ZERO(&mask);
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for(i=0;i<sizeof(affinity)*8;i++)
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if ((affinity >> i) & 1)
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CPU_SET(i, &mask);
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sched_setaffinity(0, sizeof(mask), &mask);
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}
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#if defined(__i386__)
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static __inline__ unsigned long long rdtsc(void) {
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unsigned long long int x;
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__asm__ volatile (".byte 0x0f, 0x31" : "=A" (x));
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return x;
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}
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#elif defined(__x86_64__)
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static __inline__ unsigned long long rdtsc(void) {
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unsigned hi, lo;
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__asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
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return ( (unsigned long long)lo)|( ((unsigned long long)hi)<<32 );
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}
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#elif defined(__MIPS_32__)
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#define rdtsc(dest) \
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_ _asm_ _ _ _volatile_ _("mfc0 %0,$9; nop" : "=r" (dest))
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#elif defined(__MIPS_SGI__)
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#include <time.h>
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static __inline__ unsigned long long rdtsc (void) {
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struct timespec tp;
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clock_gettime (CLOCK_SGI_CYCLE, &tp);
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return (unsigned long long)(tp.tv_sec * (unsigned long long)1000000000) + (unsigned long long)tp.tv_nsec;
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}
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#endif
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/*
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* Class: vanilla_java_affinity_AffinitySupport
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* Method: rdtsc
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* Signature: ()J
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*/
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JNIEXPORT jlong JNICALL Java_vanilla_java_affinity_AffinitySupport_rdtsc
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(JNIEnv *env, jclass c) {
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return (jlong) rdtsc();
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}

‎src/main/java/vanilla/java/affinity/AffinityLock.java‎

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package vanilla.java.affinity;
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/**
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* @author peter.lawrey
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*/
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public class AffinityLock {
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public static final int PROCESSORS = Runtime.getRuntime().availableProcessors();
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public static final long BASE_AFFINITY = AffinitySupport.LOADED ? AffinitySupport.getAffinity() : -1L;
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public static final long RESERVED_AFFINITY = getReservedAffinity0();
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private static final AffinityLock[] LOCKS = new AffinityLock[PROCESSORS];
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private static final AffinityLock NONE = new AffinityLock(-1, false, false);
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private final int id;
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private final boolean base;
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private final boolean reserved;
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Thread assignedThread;
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AffinityLock(int id, boolean base, boolean reserved) {
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this.id = id;
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this.base = base;
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this.reserved = reserved;
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}
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static {
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for (int i = 0; i < PROCESSORS; i++)
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LOCKS[i] = new AffinityLock(i, ((BASE_AFFINITY >> i) & 1) != 0, ((RESERVED_AFFINITY >> i) & 1) != 0);
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}
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private static long getReservedAffinity0() {
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String reservedAffinity = System.getProperty("affinity.reserved");
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if (reservedAffinity == null)
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return ((1 << PROCESSORS) - 1) ^ BASE_AFFINITY;
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return Long.parseLong(reservedAffinity, 16);
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}
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public static AffinityLock acquireLock() {
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Thread t = Thread.currentThread();
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synchronized (AffinityLock.class) {
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for (int i = PROCESSORS - 1; i > 0; i++) {
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AffinityLock al = LOCKS[i];
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if (!al.reserved) continue;
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if (al.assignedThread != null) {
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if (al.assignedThread.isAlive()) continue;
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System.err.println("Lock assigned to " + al.assignedThread + " but this thread is dead.");
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}
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al.assignedThread = t;
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System.out.println("Assigning cpu " + al.id + " to " + al.assignedThread);
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return al;
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}
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}
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System.out.println("No reservable CPU for " + t);
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return AffinityLock.NONE;
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}
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public void release() {
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if (this == NONE) return;
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Thread t = Thread.currentThread();
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synchronized (AffinityLock.class) {
60+
if (assignedThread != t)
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throw new IllegalStateException("Cannot release lock " + id + " assigned to " + assignedThread);
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System.out.println("Releasing cpu " + id + " from " + t);
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assignedThread = null;
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}
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}
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public static String dumpLocks() {
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return dumpLocks0(LOCKS);
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}
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static String dumpLocks0(AffinityLock[] locks) {
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StringBuilder sb = new StringBuilder();
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for (int i = 0; i < locks.length; i++) {
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AffinityLock al = locks[i];
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sb.append(i).append(": ");
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if (al.assignedThread != null)
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sb.append(al.assignedThread).append(" alive=").append(al.assignedThread.isAlive());
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else if (al.reserved)
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sb.append("Reserved for this application");
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else if (al.base)
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sb.append("General use CPU");
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else
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sb.append("CPU not available");
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sb.append('\n');
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}
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return sb.toString();
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}
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}

‎src/main/java/vanilla/java/affinity/AffinitySupport.java‎

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package vanilla.java.affinity;
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public class AffinitySupport {
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public static final boolean LOADED;
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private static final int FACTOR_BITS = 10;
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private static long RDTSC_FACTOR = 1 << FACTOR_BITS;
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private static long CPU_FREQUENCY = 1000;
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private static final long START;
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static {
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boolean loaded;
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long start;
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try {
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System.loadLibrary("affinity");
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estimateFrequency(50);
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estimateFrequency(200);
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System.out.println("Estimated clock frequency was " + CPU_FREQUENCY + " MHz");
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start = rdtsc();
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loaded = true;
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} catch (UnsatisfiedLinkError ule) {
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System.err.println("Unable to find libaffinity in " + System.getProperty("java.library.path"));
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start = 0;
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loaded = false;
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}
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LOADED = loaded;
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START = start;
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}
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private static void estimateFrequency(int factor) {
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long now, start = System.nanoTime();
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while ((now = System.nanoTime()) == start) ;
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long start0 = rdtsc();
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long end = start + factor * 1000000;
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while ((now = System.nanoTime()) < end) ;
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long end0 = rdtsc();
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end = now;
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RDTSC_FACTOR = (end - start) << FACTOR_BITS / (end0 - start0);
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CPU_FREQUENCY = (end0 - start0) * 1000 / (end - start) + 1;
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}
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public native static long getAffinity();
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public native static void setAffinity(long affinity);
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public native static long rdtsc();
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public long nanoTime() {
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return LOADED ? tscToNano(rdtsc() - START) : System.nanoTime();
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}
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public long tscToNano(long tsc) {
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return tsc * RDTSC_FACTOR >> 10;
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}
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}

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