using static local variable instead of global variables for globalMutex

polyglot-compiler · Dec 18, 2019 · 4abbe18 · 4abbe18
1 parent 3ee3537
commit 4abbe18
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Showing 8 changed files with 28 additions and 19 deletions.
diff --git a/compiler/src/jlang/extension/JLangClassDeclExt.java b/compiler/src/jlang/extension/JLangClassDeclExt.java
@@ -19,6 +19,7 @@
 import java.util.stream.Stream;
 
 import static jlang.extension.JLangSynchronizedExt.buildMonitorFunc;
+import static jlang.extension.JLangSynchronizedExt.buildMonitorFuncWithGlobalMutex;
 import static jlang.util.Constants.REGISTER_CLASS_FUNC;
 import static jlang.util.Constants.RUNTIME_ARRAY;
 import static org.bytedeco.javacpp.LLVM.*;
@@ -192,9 +193,7 @@ public static void buildClassLoadingFunc(LLVMTranslator v, ClassType ct, ClassBo
 
         Runnable buildBody = () -> {
             // Synchronize the class loading function.
-            LLVMValueRef globalMutexPtr = v.utils.getGlobal(Constants.GLOBAL_MUTEX_OBJECT, v.utils.toLL(v.ts.Object()));
-            LLVMValueRef globalMutex = LLVMBuildLoad(v.builder, globalMutexPtr, "load.classLoad");
-            buildMonitorFunc(v, Constants.MONITOR_ENTER, globalMutex);
+            buildMonitorFuncWithGlobalMutex(v, Constants.MONITOR_ENTER);
 
             // Allocate and store a new java.lang.Class instance.
             // Note that we do not call any constructors for the allocated class objects.
@@ -252,7 +251,7 @@ public static void buildClassLoadingFunc(LLVMTranslator v, ClassType ct, ClassBo
                 }
             }
 
-            buildMonitorFunc(v, Constants.MONITOR_EXIT, globalMutex);
+            buildMonitorFuncWithGlobalMutex(v, Constants.MONITOR_EXIT);
 
             // Return the loaded class.
             LLVMBuildRet(v.builder, clazz);

diff --git a/compiler/src/jlang/extension/JLangSynchronizedExt.java b/compiler/src/jlang/extension/JLangSynchronizedExt.java
@@ -3,7 +3,9 @@
 package jlang.extension;
 
 import jlang.ast.JLangExt;
+import jlang.util.Constants;
 import jlang.visit.LLVMTranslator;
+import org.bytedeco.javacpp.LLVM.LLVMBasicBlockRef;
 import org.bytedeco.javacpp.LLVM.LLVMTypeRef;
 import org.bytedeco.javacpp.LLVM.LLVMValueRef;
 import polyglot.ast.Node;
@@ -24,6 +26,15 @@ public Node leaveTranslateLLVM(LLVMTranslator v) {
         return super.leaveTranslateLLVM(v);
     }
 
+    public static void buildMonitorFuncWithGlobalMutex(LLVMTranslator v, String op) {
+        LLVMTypeRef getGlobalMutexFuncType = v.utils.functionType(
+                v.utils.toLL(v.ts.Object())
+        );
+        LLVMValueRef getGlobalMutexFunc = v.utils.getFunction(Constants.GET_GLOBAL_MUTEX_OBJECT, getGlobalMutexFuncType);
+        LLVMValueRef globalMutex = v.utils.buildFunCall(getGlobalMutexFunc);
+        buildMonitorFunc(v, op, globalMutex);
+    }
+
     public static void buildMonitorFunc(LLVMTranslator v, String op, LLVMValueRef syncObj) {
         LLVMValueRef cast = LLVMBuildBitCast(v.builder, syncObj, v.utils.toLL(v.ts.Object()), "cast_l");
         LLVMTypeRef monitorFuncType = v.utils.functionType(

diff --git a/compiler/src/jlang/util/Constants.java b/compiler/src/jlang/util/Constants.java
@@ -35,7 +35,7 @@ public class Constants {
     public static final String RESUME_UNWIND_EXCEPTION = "_Unwind_Resume";
     public static final String MONITOR_ENTER = "jni_MonitorEnter";
     public static final String MONITOR_EXIT = "jni_MonitorExit";
-    public static final String GLOBAL_MUTEX_OBJECT = "Polyglot_native_GlobalMutexObject";
+    public static final String GET_GLOBAL_MUTEX_OBJECT = "getGlobalMutexObject";
 
     public static final Set<String> NON_INVOKE_FUNCTIONS = new HashSet<>(CollectionUtil.list(
             CALLOC, CREATE_EXCEPTION, EXTRACT_EXCEPTION

diff --git a/compiler/src/jlang/util/LLVMUtils.java b/compiler/src/jlang/util/LLVMUtils.java
@@ -22,6 +22,7 @@
 import java.util.stream.IntStream;
 
 import static jlang.extension.JLangSynchronizedExt.buildMonitorFunc;
+import static jlang.extension.JLangSynchronizedExt.buildMonitorFuncWithGlobalMutex;
 import static org.bytedeco.javacpp.LLVM.*;
 
 /**
@@ -805,9 +806,7 @@ public LLVMValueRef buildGlobalCStr(String str) {
     /** Emits a check to ensure that the given class has been loaded by the runtime. */
     public void buildClassLoadCheck(ClassType ct) {
         // Synchronize the class loading function.
-        LLVMValueRef globalMutexPtr = v.utils.getGlobal(Constants.GLOBAL_MUTEX_OBJECT, v.utils.toLL(v.ts.Object()));
-        LLVMValueRef globalMutex = LLVMBuildLoad(v.builder, globalMutexPtr, "load.classLoad");
-        buildMonitorFunc(v, Constants.MONITOR_ENTER, globalMutex);
+        buildMonitorFuncWithGlobalMutex(v, Constants.MONITOR_ENTER);
 
         LLVMBasicBlockRef loadClass = v.utils.buildBlock("load.class");
         LLVMBasicBlockRef end = v.utils.buildBlock("continue");
@@ -827,7 +826,7 @@ public void buildClassLoadCheck(ClassType ct) {
 
         LLVMPositionBuilderAtEnd(v.builder, end);
 
-        buildMonitorFunc(v, Constants.MONITOR_EXIT, globalMutex);
+        buildMonitorFuncWithGlobalMutex(v, Constants.MONITOR_EXIT);
     }
 
     /**

diff --git a/runtime/linux_version.map b/runtime/linux_version.map
@@ -19,6 +19,7 @@ SUNWprivate_1.1 {
 		__createInterfaceTables;
 		__java_personality_v0;
 		__GC_malloc;
+        getGlobalMutexObject;
         local:
 	        *;
 };

diff --git a/runtime/native/class.cpp b/runtime/native/class.cpp
@@ -690,12 +690,11 @@ jclass LoadJavaClassFromLib(const char *name) {
  * function will be invoked. The class name is in the format java.lang.Class
  */
 jclass FindClass(const char *name) {
-    Monitor::Instance().enter(nullptr);
+    ScopedLock scopedLock(Monitor::Instance().globalMutex());
     jclass clazz = GetJavaClassFromName(name);
     if (clazz == nullptr) {
         clazz = LoadJavaClassFromLib(name);
     }
-    Monitor::Instance().exit(nullptr);
     return clazz;
 }
 
@@ -704,11 +703,10 @@ jclass FindClass(const char *name) {
  * function will be invoked. The class name is in the format java/lang/Class
  */
 jclass FindClassFromPathName(const char *name) {
-    Monitor::Instance().enter(nullptr);
+    ScopedLock scopedLock(Monitor::Instance().globalMutex());
     jclass clazz = GetJavaClassFromPathName(name);
     if (clazz == nullptr) {
         clazz = LoadJavaClassFromLib(name);
     }
-    Monitor::Instance().exit(nullptr);
     return clazz;
 }
diff --git a/runtime/native/factory.cpp b/runtime/native/factory.cpp
@@ -4,6 +4,7 @@
 
 #include "class.h"
 #include "rep.h"
+#include "monitor.h"
 
 #include <jni.h>
 #include <string.h>
@@ -66,6 +67,8 @@ jstring CreateJavaString(jcharArray chars) {
 }
 
 jobject CreateJavaObject(jclass clazz) {
+    ScopedLock lock(Monitor::Instance().globalMutex());
+
     auto info = GetJavaClassInfo(clazz);
     // TODO set exception (class is interface or abstract)
     if (info == NULL || info->cdv == NULL) {
@@ -81,6 +84,8 @@ jobject CreateJavaObject(jclass clazz) {
 
 jobject CloneJavaObject(jobject obj) {
     // TODO set exception if class is not cloneable
+    ScopedLock lock(Monitor::Instance().globalMutex());
+
     auto objRep = Unwrap(obj);
     auto cdv = objRep->Cdv();
     auto cls = cdv->Class()->Wrap();

diff --git a/runtime/native/monitor.cpp b/runtime/native/monitor.cpp
@@ -48,18 +48,14 @@ static void initSyncVars(jobject obj) {
 // A fake object to hold the sync_var of class loading function.
 // The class loading code could utilize this global object to ensure that
 // every class is only initilized by one thread once.
-JObjectRep __Polyglot_native_GlobalMutexObject;
-
-static jobject getGlobalMutexObject() {
+extern "C" jobject getGlobalMutexObject() {
+    static JObjectRep __Polyglot_native_GlobalMutexObject;
     if (__Polyglot_native_GlobalMutexObject.SyncVars() == nullptr) {
         initSyncVars(__Polyglot_native_GlobalMutexObject.Wrap());
     }
     return __Polyglot_native_GlobalMutexObject.Wrap();
 }
 
-jobject Polyglot_native_GlobalMutexObject = getGlobalMutexObject();
-
-
 Monitor::Monitor() {
     if (pthread_mutex_init(&mutex, nullptr) != 0) {
         perror("mutex init failed");