CRIU resets j.l.VirtualThread.ForkJoinPool.parallelism after restore

If there is no system property jdk.virtualThreadScheduler.parallelism
set at VM startup, j.l.VirtualThread.ForkJoinPool.parallelism value is
reset to match Runtime.getRuntime().availableProcessors() after CRIU
restore;
Added VM_VMHelpers methods
getStaticFieldObject/findinstanceFieldOffset/setObjectFieldI32;
Changed hashClassTableAt to peekClassHashTable;
Minor refactoring;
Added tests.

Signed-off-by: Jason Feng <[email protected]>

runtime/nls/j9vm/j9vm.nls

@@ -2151,4 +2151,27 @@ J9NLS_VM_ILLEGAL_THREAD_STATE_UPCALL=The JVM failed to proceed due to the wrong
 J9NLS_VM_ILLEGAL_THREAD_STATE_UPCALL.explanation=An error occurred when the JVM attempted to perform upcall in the trivial downcall
 J9NLS_VM_ILLEGAL_THREAD_STATE_UPCALL.system_action=The JVM will throw a IllegalThreadStateException.
 J9NLS_VM_ILLEGAL_THREAD_STATE_UPCALL.user_response=Ensure the specified linker options for downcall are valid.
+
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_FORKJOINPOOL_CNF=The JVM could not reset java.lang.VirtualThread.ForkJoinPool.parallelism due to java.util.concurrent.ForkJoinPool class not found
+# START NON-TRANSLATABLE
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_FORKJOINPOOL_CNF.sample_input_1=1
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_FORKJOINPOOL_CNF.explanation=CRIUSupport::checkpointJVM failed.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_FORKJOINPOOL_CNF.system_action=The JVM will throw a JVMRestoreException.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_FORKJOINPOOL_CNF.user_response=View CRIU documentation to determine how to resolve the exception.
+# END NON-TRANSLATABLE
+
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_DEFAULT_SCHEDULER_ADDRESS=The JVM could not reset java.lang.VirtualThread.ForkJoinPool.parallelism due to invalid DEFAULT_SCHEDULER address
+# START NON-TRANSLATABLE
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_DEFAULT_SCHEDULER_ADDRESS.sample_input_1=1
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_DEFAULT_SCHEDULER_ADDRESS.explanation=CRIUSupport::checkpointJVM failed.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_DEFAULT_SCHEDULER_ADDRESS.system_action=The JVM will throw a JVMRestoreException.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_DEFAULT_SCHEDULER_ADDRESS.user_response=View CRIU documentation to determine how to resolve the exception.
+# END NON-TRANSLATABLE
+
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_PARALLELISM_OFFSET=The JVM could not reset java.lang.VirtualThread.ForkJoinPool.parallelism due to invalid parallelism offset
+# START NON-TRANSLATABLE
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_PARALLELISM_OFFSET.sample_input_1=1
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_PARALLELISM_OFFSET.explanation=CRIUSupport::checkpointJVM failed.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_PARALLELISM_OFFSET.system_action=The JVM will throw a JVMRestoreException.
+J9NLS_VM_CRIU_RESTORE_RESET_VIRTUALTHREAD_FORKJOINPOOL_PARALLELISM_INVALID_PARALLELISM_OFFSET.user_response=View CRIU documentation to determine how to resolve the exception.
 # END NON-TRANSLATABLE

runtime/oti/VMHelpers.hpp

@@ -40,6 +40,7 @@
 #include "j9vmconstantpool.h"
 #include "j9modifiers_api.h"
 #include "j9cp.h"
+#include "vm_api.h"
 #include "ute.h"
 #include "AtomicSupport.hpp"
 #include "ObjectAllocationAPI.hpp"
@@ -2072,6 +2073,100 @@ class VM_VMHelpers
 		}
 	}
 #endif /* JAVA_SPEC_VERSION >= 20 */
+
+	/**
+	 * Get a static field object within a defining class.
+	 *
+	 * Current thread must have VM access.
+	 *
+	 * @param[in] currentThread the current J9VMThread
+	 * @param[in] definingClassName the defining class name
+	 * @param[in] fieldName the field name
+	 * @param[in] signature the field signature
+	 *
+	 * @return the field object if successs, otherwise NULL
+	 */
+	static VMINLINE j9object_t
+	getStaticFieldObject(J9VMThread *currentThread, const char *definingClassName, const char *fieldName, const char *signature)
+	{
+		J9JavaVM *vm = currentThread->javaVM;
+		j9object_t fieldObject = NULL;
+		J9InternalVMFunctions const *vmFuncs = vm->internalVMFunctions;
+		J9Class *definingClass = vmFuncs->peekClassHashTable(currentThread, vm->systemClassLoader, (U_8 *)definingClassName, strlen(definingClassName));
+		void *fieldAddress = vmFuncs->staticFieldAddress(currentThread, definingClass, (U_8*)fieldName, strlen(fieldName), (U_8*)signature, strlen(signature), NULL, NULL, 0, NULL);
+		if (NULL != fieldAddress) {
+			MM_ObjectAccessBarrierAPI objectAccessBarrier = MM_ObjectAccessBarrierAPI(currentThread);
+			fieldObject = objectAccessBarrier.inlineStaticReadObject(currentThread, definingClass, (j9object_t*)fieldAddress, FALSE);
+		}
+		return fieldObject;
+	}
+
+	/**
+	 * Find the offset of an instance field.
+	 *
+	 * @param[in] currentThread the current J9VMThread
+	 * @param[in] instanceType the instance class
+	 * @param[in] fieldName the field name
+	 * @param[in] fieldSig the field signature
+	 *
+	 * @return the offset
+	 */
+	static VMINLINE IDATA
+	findinstanceFieldOffset(J9VMThread *currentThread, J9Class *instanceType, const char *fieldName, const char *fieldSig)
+	{
+		J9JavaVM *vm = currentThread->javaVM;
+
+		IDATA offset = (UDATA)vm->internalVMFunctions->instanceFieldOffset(
+			currentThread, instanceType,
+			(U_8 *)fieldName, strlen(fieldName),
+			(U_8 *)fieldSig, strlen(fieldSig),
+			NULL, NULL, 0);
+
+		if (-1 != offset) {
+			offset += J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread);
+		}
+
+		return offset;
+	}
+
+#if defined(J9VM_OPT_CRIU_SUPPORT)
+	/**
+	 * Reset java.util.concurrent.ForkJoinPool.parallelism with a value supplied.
+	 *
+	 * Current thread must have VM access.
+	 *
+	 * @param[in] currentThread the current J9VMThread
+	 * @param[in] instanceObject a java.util.concurrent.ForkJoinPool instance object
+	 * @param[in] value the I_32 value to be set into the parallelism field
+	 *
+	 * @return true if the value has been set into the field within the instance object, false if not
+	 */
+	static VMINLINE bool
+	resetJUCForkJoinPoolParallelism(J9VMThread *currentThread, j9object_t instanceObject, I_32 value)
+	{
+		bool result = false;
+		J9JavaVM *vm = currentThread->javaVM;
+		IDATA fieldOffset = vm->checkpointState.jucForkJoinPoolParallelismOffset;
+
+		if (0 == fieldOffset) {
+#define JUC_FORKJOINPOOL "java/util/concurrent/ForkJoinPool"
+			J9Class *definingClass = vm->internalVMFunctions->peekClassHashTable(currentThread, vm->systemClassLoader, (U_8 *)JUC_FORKJOINPOOL, LITERAL_STRLEN(JUC_FORKJOINPOOL));
+#undef JUC_FORKJOINPOOL
+			if (NULL != definingClass) {
+				fieldOffset = findinstanceFieldOffset(currentThread, definingClass, "parallelism", "I");
+			} else {
+				fieldOffset = -1;
+			}
+		}
+		if (-1 != fieldOffset) {
+			MM_ObjectAccessBarrierAPI objectAccessBarrier = MM_ObjectAccessBarrierAPI(currentThread);
+			objectAccessBarrier.inlineMixedObjectStoreI32(currentThread, instanceObject, fieldOffset, value, false);
+			vm->checkpointState.jucForkJoinPoolParallelismOffset = fieldOffset;
+			result = true;
+		}
+		return result;
+	}
+#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
 };
 
 #endif /* VMHELPERS_HPP_ */

runtime/oti/j9nonbuilder.h

@@ -4202,6 +4202,9 @@ typedef struct J9DelayedLockingOpertionsRecord {
 
 typedef struct J9CRIUCheckpointState {
 	U_32 flags;
+#if JAVA_SPEC_VERSION >= 20
+	UDATA checkpointCPUCount;
+#endif /* JAVA_SPEC_VERSION >= 20 */
 	struct J9DelayedLockingOpertionsRecord *delayedLockingOperationsRoot;
 	struct J9Pool *hookRecords;
 	struct J9Pool *classIterationRestoreHookRecords;
@@ -4238,6 +4241,7 @@ typedef struct J9CRIUCheckpointState {
 	UDATA libCRIUHandle;
 	struct J9VMInitArgs *restoreArgsList;
 	char *restoreArgsChars;
+	IDATA jucForkJoinPoolParallelismOffset;
 } J9CRIUCheckpointState;
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
 

runtime/vm/CRIUHelpers.cpp

@@ -46,7 +46,6 @@ J9_DECLARE_CONSTANT_UTF8(j9InternalCheckpointHookAPI_name, "org/eclipse/openj9/c
 static void addInternalJVMCheckpointHook(J9VMThread *currentThread, BOOLEAN isRestore, J9Class *instanceType, BOOLEAN includeSubClass, hookFunc hookFunc);
 static void cleanupCriuHooks(J9VMThread *currentThread);
 static BOOLEAN fillinHookRecords(J9VMThread *currentThread, j9object_t object);
-static IDATA findinstanceFieldOffsetHelper(J9VMThread *currentThread, J9Class *instanceType, const char *fieldName, const char *fieldSig);
 static void initializeCriuHooks(J9VMThread *currentThread);
 static BOOLEAN juRandomReseed(J9VMThread *currentThread, void *userData, const char **nlsMsgFormat);
 static BOOLEAN criuRestoreInitializeTrace(J9VMThread *currentThread, void *userData, const char **nlsMsgFormat);
@@ -162,22 +161,6 @@ addInternalJVMCheckpointHook(J9VMThread *currentThread, BOOLEAN isRestore, J9Cla
 	}
 }
 
-static IDATA
-findinstanceFieldOffsetHelper(J9VMThread *currentThread, J9Class *instanceType, const char *fieldName, const char *fieldSig)
-{
-	IDATA offset = (UDATA)instanceFieldOffset(
-		currentThread, instanceType,
-		(U_8*)fieldName, strlen(fieldName),
-		(U_8*)fieldSig, strlen(fieldSig),
-		NULL, NULL, 0);
-
-	if (-1 != offset) {
-		offset += J9VMTHREAD_OBJECT_HEADER_SIZE(currentThread);
-	}
-
-	return offset;
-}
-
 /**
  * An internal JVM checkpoint hook is to re-seed java.util.Random.seed.value.
  *
@@ -197,13 +180,13 @@ juRandomReseed(J9VMThread *currentThread, void *userData, const char **nlsMsgFor
 	PORT_ACCESS_FROM_VMC(currentThread);
 
 	/* Assuming this hook record is to re-seed java.util.Random.seed.value. */
-	IDATA seedOffset = findinstanceFieldOffsetHelper(currentThread, hookRecord->instanceType, "seed", "Ljava/util/concurrent/atomic/AtomicLong;");
+	IDATA seedOffset = VM_VMHelpers::findinstanceFieldOffset(currentThread, hookRecord->instanceType, "seed", "Ljava/util/concurrent/atomic/AtomicLong;");
 	if (-1 != seedOffset) {
 #define JUCA_ATOMICLONG "java/util/concurrent/atomic/AtomicLong"
-		J9Class *jucaAtomicLongClass = hashClassTableAt(vm->systemClassLoader, (U_8 *)JUCA_ATOMICLONG, LITERAL_STRLEN(JUCA_ATOMICLONG));
+		J9Class *jucaAtomicLongClass = peekClassHashTable(currentThread, vm->systemClassLoader, (U_8 *)JUCA_ATOMICLONG, LITERAL_STRLEN(JUCA_ATOMICLONG));
 #undef JUCA_ATOMICLONG
 		if (NULL != jucaAtomicLongClass) {
-			IDATA valueOffset = findinstanceFieldOffsetHelper(currentThread, jucaAtomicLongClass, "value", "J");
+			IDATA valueOffset = VM_VMHelpers::findinstanceFieldOffset(currentThread, jucaAtomicLongClass, "value", "J");
 			if (-1 != valueOffset) {
 				PORT_ACCESS_FROM_JAVAVM(vm);
 				pool_state walkState = {0};
@@ -456,13 +439,31 @@ initializeCriuHooks(J9VMThread *currentThread)
 		}
 	}
 
+#if JAVA_SPEC_VERSION >= 20
+	{
+		J9VMSystemProperty *vtParallelism = NULL;
+		PORT_ACCESS_FROM_VMC(currentThread);
+		if (J9SYSPROP_ERROR_NONE != getSystemProperty(vm, "jdk.virtualThreadScheduler.parallelism", &vtParallelism)) {
+			/* This system property only affects j.l.VirtualThread.ForkJoinPool.parallelism at VM startup. */
+			UDATA cpuCount = j9sysinfo_get_number_CPUs_by_type(J9PORT_CPU_TARGET);
+			if (cpuCount < 1) {
+				cpuCount = 1;
+			}
+			vm->checkpointState.checkpointCPUCount = cpuCount;
+			Trc_VM_criu_initializeCriuHooks_checkpointCPUCount(currentThread, cpuCount);
+		}
+	}
+#endif /* JAVA_SPEC_VERSION >= 20 */
+
 	{
 		/* Add restore hook to re-seed java.uti.Random.seed.value */
 #define JAVA_UTIL_RANDOM "java/util/Random"
 		J9Class *juRandomClass = peekClassHashTable(currentThread, vm->systemClassLoader, (U_8 *)JAVA_UTIL_RANDOM, LITERAL_STRLEN(JAVA_UTIL_RANDOM));
 #undef JAVA_UTIL_RANDOM
 		if (NULL != juRandomClass) {
 			addInternalJVMCheckpointHook(currentThread, TRUE, juRandomClass, FALSE, juRandomReseed);
+		} else {
+			Trc_VM_criu_initializeCriuHooks_Random_CNF(currentThread);
 		}
 		addInternalJVMCheckpointHook(currentThread, TRUE, NULL, FALSE, criuRestoreInitializeTrace);
 		addInternalJVMCheckpointHook(currentThread, TRUE, NULL, FALSE, criuRestoreInitializeXrs);
@@ -495,8 +496,8 @@ fillinHookRecords(J9VMThread *currentThread, j9object_t object)
 	BOOLEAN result = TRUE;
 
 	J9InternalHookRecord *hookRecord = (J9InternalHookRecord*)pool_startDo(hookRecords, &walkState);
+	J9Class *clazz = J9OBJECT_CLAZZ_VM(vm, object);
 	while (NULL != hookRecord) {
-		J9Class *clazz = J9OBJECT_CLAZZ_VM(vm, object);
 		if ((clazz == hookRecord->instanceType)
 			|| (hookRecord->includeSubClass && isSameOrSuperClassOf(hookRecord->instanceType, clazz))
 		) {
@@ -602,6 +603,29 @@ runInternalJVMRestoreHooks(J9VMThread *currentThread, const char **nlsMsgFormat)
 		}
 	}
 
+#if JAVA_SPEC_VERSION >= 20
+	if (0 != vm->checkpointState.checkpointCPUCount) {
+		/* Only reset j.l.VirtualThread.ForkJoinPool.parallelism if jdk.virtualThreadScheduler.parallelism is not set. */
+		PORT_ACCESS_FROM_VMC(currentThread);
+		UDATA cpuCount = j9sysinfo_get_number_CPUs_by_type(J9PORT_CPU_TARGET);
+		if (cpuCount < 1) {
+			/* This matches ForkJoinPool default constructor with Runtime.getRuntime().availableProcessors(). */
+			cpuCount = 1;
+		}
+		if (cpuCount != vm->checkpointState.checkpointCPUCount) {
+			j9object_t fjpObject = VM_VMHelpers::getStaticFieldObject(currentThread, "java/lang/VirtualThread", "DEFAULT_SCHEDULER", "Ljava/util/concurrent/ForkJoinPool;");
+			if (NULL != fjpObject) {
+				result = VM_VMHelpers::resetJUCForkJoinPoolParallelism(currentThread, fjpObject, cpuCount);
+				Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_reset_parallelism(currentThread, fjpObject, cpuCount);
+			} else {
+				Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_DEFAULT_SCHEDULER_NULL(currentThread);
+			}
+		} else {
+			Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_same_cpucount(currentThread, cpuCount);
+		}
+	}
+#endif /* JAVA_SPEC_VERSION >= 20 */
+
 	/* Cleanup at restore. */
 	cleanupCriuHooks(currentThread);
 	Trc_VM_criu_runRestoreHooks_Exit(currentThread);

runtime/vm/j9vm.tdf

@@ -930,3 +930,9 @@ TraceExit=Trc_VM_criu_initHooks_Exit Overhead=1 Level=5 Template="initializeCriu
 TraceException=Trc_VM_criu_setSingleThreadModeJVMCRIUException_triggerOneOffJavaDump Overhead=1 Level=1 Template="setCRIUSingleThreadModeJVMCRIUException triggerOneOffDump() returns %d"
 
 TraceException=Trc_VM_checkVisibility_Failed Overhead=1 Level=1 Template="checkVisibility from %p (%.*s) to %p (%.*s) modifiers=%zx lookupOptions=%zx failed"
+
+TraceEvent=Trc_VM_criu_initializeCriuHooks_checkpointCPUCount Overhead=1 Level=3 Template="initializeCriuHooks() checkpoint CPU count (%zu)"
+TraceEvent=Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_same_cpucount Overhead=1 Level=5 Template="Reset j.l.VirtualThread.ForkJoinPool.parallelism: same cpu count (%zu) between C/R"
+TraceEvent=Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_reset_parallelism Overhead=1 Level=5 Template="Reset j.l.VirtualThread.ForkJoinPool.parallelism: fjpObject(0x%p) parallelism(%zu) after restore"
+TraceException=Trc_VM_criu_initializeCriuHooks_Random_CNF Overhead=1 Level=3 Template="initializeCriuHooks() j.u.Random class not found"
+TraceException=Trc_VM_criu_jlVirtualThreadForkJoinPoolResetParallelism_DEFAULT_SCHEDULER_NULL Overhead=1 Level=3 Template="Reset j.l.VirtualThread.ForkJoinPool.parallelism: DEFAULT_SCHEDULER is NULL"

test/functional/cmdLineTests/criu/build.xml

@@ -41,26 +41,41 @@
 	</target>
 
 	<target name="compile" depends="init" description="Using java ${JDK_VERSION} to compile the source ">
-		<property name="addExports" value="--add-exports java.base/openj9.internal.criu=ALL-UNNAMED --add-exports java.base/jdk.internal.misc=ALL-UNNAMED" />
-		<echo>===addExports:        ${addExports}</echo>
 		<echo>Ant version is ${ant.version}</echo>
 		<echo>============COMPILER SETTINGS============</echo>
 		<echo>===fork:                         yes</echo>
 		<echo>===executable:                   ${compiler.javac}</echo>
 		<echo>===debug:                        on</echo>
 		<echo>===destdir:                      ${DEST}</echo>
+		<if>
+			<not>
+				<matches string="${JDK_VERSION}" pattern="^(8|9|1[0-9])$$" />
+			</not>
+			<then>
+				<property name="enablePreview" value="--enable-preview -source ${JDK_VERSION}" />
+			</then>
+			<else>
+				<property name="enablePreview" value="" />
+				<property name="excludeTestMachineResourceChange" value="org/openj9/criu/TestMachineResourceChange.java" />
+			</else>
+		</if>
 		<if>
 			<equals arg1="${JDK_VERSION}" arg2="8" />
 			<then>
-				<property name="excludeFile" value="org/openj9/criu/JDK11UpTimeoutAdjustmentTest.java" />
+				<property name="excludeJDK11UpTimeoutAdjustmentTest" value="org/openj9/criu/JDK11UpTimeoutAdjustmentTest.java" />
 				<javac srcdir="${src}" destdir="${build}" debug="true" fork="true" executable="${compiler.javac}" includeAntRuntime="false" encoding="ISO-8859-1">
-					<exclude name="${excludeFile}" />
+					<exclude name="${excludeJDK11UpTimeoutAdjustmentTest}" />
+					<exclude name="${excludeTestMachineResourceChange}" />
 				</javac>
 			</then>
 			<else>
-				<property name="addExports" value="--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED --add-exports=java.base/openj9.internal.criu=ALL-UNNAMED" />
+				<property name="addExports" value="--add-exports java.base/openj9.internal.criu=ALL-UNNAMED --add-exports java.base/jdk.internal.misc=ALL-UNNAMED" />
+				<echo>===addExports:        ${addExports}</echo>
+				<echo>===enablePreview:     ${enablePreview}</echo>
 				<javac srcdir="${src}" destdir="${build}" debug="true" fork="true" executable="${compiler.javac}" includeAntRuntime="false" encoding="ISO-8859-1">
 					<compilerarg line="${addExports}" />
+					<compilerarg line="${enablePreview}" />
+					<exclude name="${excludeTestMachineResourceChange}" />
 				</javac>
 			</else>
 		</if>