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CRIU DebugOnRestore mode is disabled when debug events are hooked
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isDebugOnRestoreEnabled() returns false if some debug-specific
flags/events are enabled/hooked, this matches J9::Options::isFSDNeeded()
in compiler/control/J9Options.cpp;
DebugOnRestore mode is enabled when CRIU is enabled, -XX:+DebugOnRestore
is specified, JDWP is not enabled, and no debug-specific flags/events
are enabled/hooked;
When DebugOnRestore mode is enabled, debug related events
and hooks can't be enabled or hooked pre-checkpoint,
isDebugAgentDisabled() returns TRUE in this case, otherwise FALSE.

Signed-off-by: Jason Feng <[email protected]>
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@JasonFengJ9
JasonFengJ9 committed Jan 21, 2025
1 parent cccf21d commit a048979
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Showing 7 changed files with 178 additions and 68 deletions.
26 changes: 17 additions & 9 deletions runtime/jvmti/jvmtiCapability.c
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Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,8 @@ jvmtiGetPotentialCapabilities(jvmtiEnv* env, jvmtiCapabilities* capabilities_ptr
J9JavaVM * vm = j9env->vm;
J9JVMTIData * jvmtiData = J9JVMTI_DATA_FROM_VM(vm);
jvmtiCapabilities rv_capabilities;
J9HookInterface ** vmHook = vm->internalVMFunctions->getVMHookInterface(vm);
J9InternalVMFunctions *vmFuncs = vm->internalVMFunctions;
J9HookInterface **vmHook = vmFuncs->getVMHookInterface(vm);
jvmtiError rc;

Trc_JVMTI_jvmtiGetPotentialCapabilities_Entry(env);
Expand Down Expand Up @@ -206,8 +207,13 @@ jvmtiGetPotentialCapabilities(jvmtiEnv* env, jvmtiCapabilities* capabilities_ptr
}

if ((*vmHook)->J9HookIsEnabled(vmHook, J9HOOK_VM_POP_FRAMES_INTERRUPT)) {
rv_capabilities.can_pop_frame = 1;
rv_capabilities.can_force_early_return = 1;
#if defined(J9VM_OPT_CRIU_SUPPORT)
if (!vmFuncs->isDebugAgentDisabled(vm))
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
{
rv_capabilities.can_pop_frame = 1;
rv_capabilities.can_force_early_return = 1;
}
}

if ((*vmHook)->J9HookIsEnabled(vmHook, J9HOOK_VM_REQUIRED_DEBUG_ATTRIBUTES) ||
Expand All @@ -231,7 +237,12 @@ jvmtiGetPotentialCapabilities(jvmtiEnv* env, jvmtiCapabilities* capabilities_ptr
if ((*vmHook)->J9HookIsEnabled(vmHook, J9HOOK_VM_REQUIRED_DEBUG_ATTRIBUTES) ||
(vm->requiredDebugAttributes & J9VM_DEBUG_ATTRIBUTE_CAN_ACCESS_LOCALS)
) {
rv_capabilities.can_access_local_variables = 1;
#if defined(J9VM_OPT_CRIU_SUPPORT)
if (!vmFuncs->isDebugAgentDisabled(vm))
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
{
rv_capabilities.can_access_local_variables = 1;
}
}

rv_capabilities.can_tag_objects = 1;
Expand Down Expand Up @@ -548,16 +559,13 @@ mapCapabilitiesToEvents(J9JVMTIEnv * j9env, jvmtiCapabilities * capabilities, J9

#if defined(J9VM_OPT_CRIU_SUPPORT)
J9JavaVM *vm = j9env->vm;
J9InternalVMFunctions *vmFuncs = vm->internalVMFunctions;
BOOLEAN skipHookReserve = vmFuncs->isCheckpointAllowed(vm)
&& vmFuncs->isDebugOnRestoreEnabled(vm);
/* Skip J9HookReserve for the events required by JDWP agent pre-checkpoint when DebugOnRestore is enabled,
/* Skip J9HookReserve for the events required by JDWP agent pre-checkpoint when isDebugAgentDisabled() returns TRUE,
* these events will be registered post-restore if a JDWP agent is specified in the restore option file,
* otherwise they are going to be unregistered by J9HookUnregister() which only clears J9HOOK_FLAG_HOOKED,
* but not J9HOOK_FLAG_RESERVED.
* J9HookUnreserve() might clear the flag set by other callers.
*/
if (!skipHookReserve)
if (!vm->internalVMFunctions->isDebugAgentDisabled(vm))
#endif /* defined(J9VM_OPT_CRIU_SUPPORT)*/
{
if (capabilities->can_generate_single_step_events) {
Expand Down
71 changes: 27 additions & 44 deletions runtime/jvmti/jvmtiHook.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,8 +155,6 @@ static BOOLEAN shouldPostEvent(J9VMThread *currentThread, J9Method *method);
#if defined(J9VM_OPT_CRIU_SUPPORT)
static void jvmtiHookVMCheckpoint(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
static void jvmtiHookVMRestore(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
static void jvmtiHookVMRestoreCRIUInit(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
static void jvmtiHookVMRestoreStartAgent(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
static void hookDisableHelper(J9JavaVM *vm, J9HookInterface **vmHook, UDATA eventNum, J9HookFunction function, BOOLEAN unreserve, void *userData);

static void
Expand Down Expand Up @@ -557,37 +555,6 @@ jvmtiHookVMCheckpoint(J9HookInterface **hook, UDATA eventNum, void *eventData, v
TRACE_JVMTI_EVENT_RETURN(jvmtiHookVMCheckpoint);
}

static void
jvmtiHookVMRestoreCRIUInit(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData)
{
Trc_JVMTI_jvmtiHookVMRestoreCRIUInit_Entry();
criuRestoreInitializeLib(((J9RestoreEvent *)eventData)->currentThread->javaVM, (J9JVMTIEnv *)userData);
TRACE_JVMTI_EVENT_RETURN(jvmtiHookVMRestoreCRIUInit);
}

static void
jvmtiHookVMRestoreStartAgent(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData)
{
J9VMThread *currentThread = ((J9RestoreEvent *)eventData)->currentThread;
J9JavaVM *vm = currentThread->javaVM;
J9InternalVMFunctions const * const vmFuncs = vm->internalVMFunctions;

Trc_JVMTI_jvmtiHookVMRestoreStartAgent_Entry();
vmFuncs->internalExitVMToJNI(currentThread);
if (J9_ARE_ANY_BITS_SET(vm->checkpointState.flags, J9VM_CRIU_IS_JDWP_ENABLED)) {
criuRestoreStartAgent(vm);
} else {
/* Last part of cleanup if there was no JDWP agent specified.
* This releases VM access hence can't be invoked within criuDisableHooks() from
* J9HOOK_VM_PREPARING_FOR_RESTORE.
*/
jvmtiEnv *jvmti_env = vm->checkpointState.jvmtienv;
(*jvmti_env)->DisposeEnvironment(jvmti_env);
}
vmFuncs->internalEnterVMFromJNI(currentThread);
TRACE_JVMTI_EVENT_RETURN(jvmtiHookVMRestoreStartAgent);
}

static void
jvmtiHookVMRestore(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData)
{
Expand Down Expand Up @@ -1075,6 +1042,21 @@ jvmtiHookClassLoad(J9HookInterface** hook, UDATA eventNum, void* eventData, void
UDATA
isEventHookable(J9JVMTIEnv * j9env, jvmtiEvent event)
{
#if defined(J9VM_OPT_CRIU_SUPPORT)
J9JavaVM *vm = j9env->vm;
if (vm->internalVMFunctions->isDebugAgentDisabled(vm)) {
switch(event) {
case JVMTI_EVENT_FRAME_POP: /* fall through */
case JVMTI_EVENT_FIELD_ACCESS: /* fall through */
case JVMTI_EVENT_FIELD_MODIFICATION: /* fall through */
case JVMTI_EVENT_SINGLE_STEP: /* fall through */
case JVMTI_EVENT_BREAKPOINT:
return FALSE;
default:
break;
}
}
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
return processEvent(j9env, event, hookIsDisabled) == 0;
}

Expand Down Expand Up @@ -1136,6 +1118,18 @@ hookNonEventCapabilities(J9JVMTIEnv * j9env, jvmtiCapabilities * capabilities)
J9JVMTIHookInterfaceWithID * gcOmrHook = &j9env->gcOmrHook;
J9JVMTIData * jvmtiData = J9JVMTI_DATA_FROM_VM(vm);

#if defined(J9VM_OPT_CRIU_SUPPORT)
if (vm->internalVMFunctions->isDebugAgentDisabled(vm)) {
if (capabilities->can_pop_frame
|| capabilities->can_force_early_return
|| capabilities->can_access_local_variables
|| capabilities->can_generate_breakpoint_events
) {
return 1;
}
}
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

if (capabilities->can_generate_breakpoint_events) {
if (hookRegister(vmHook, J9HOOK_VM_BREAKPOINT, jvmtiHookBreakpoint, OMR_GET_CALLSITE(), j9env)) {
return 1;
Expand Down Expand Up @@ -2046,17 +2040,6 @@ hookGlobalEvents(J9JVMTIData * jvmtiData)
return 1;
}

#if defined(J9VM_OPT_CRIU_SUPPORT)
if (vm->internalVMFunctions->isDebugOnRestoreEnabled(vm)) {
if ((*vmHook)->J9HookRegisterWithCallSite(vmHook, J9HOOK_TAG_AGENT_ID | J9HOOK_VM_PREPARING_FOR_RESTORE, jvmtiHookVMRestoreCRIUInit, OMR_GET_CALLSITE(), jvmtiData, J9HOOK_AGENTID_FIRST)) {
return 1;
}
if ((*vmHook)->J9HookRegisterWithCallSite(vmHook, J9HOOK_TAG_AGENT_ID | J9HOOK_VM_CRIU_RESTORE, jvmtiHookVMRestoreStartAgent, OMR_GET_CALLSITE(), jvmtiData, J9HOOK_AGENTID_FIRST)) {
return 1;
}
}
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

if ((*vmHook)->J9HookRegisterWithCallSite(vmHook, J9HOOK_TAG_AGENT_ID | J9HOOK_VM_SHUTTING_DOWN, jvmtiHookVMShutdownLast, OMR_GET_CALLSITE(), jvmtiData, J9HOOK_AGENTID_LAST)) {
return 1;
}
Expand Down
98 changes: 90 additions & 8 deletions runtime/jvmti/jvmtiStartup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,10 @@ I_32 JNICALL loadAgentLibraryOnAttach(struct J9JavaVM *vm, const char *library,
static BOOLEAN isAgentLibraryLoaded(J9JavaVM *vm, const char *library, BOOLEAN decorate);
static jint createAgentLibraryWithOption(J9JavaVM *vm, J9VMInitArgs *argsList, IDATA agentIndex, J9JVMTIAgentLibrary **agentLibrary, CreateAgentOption createAgentOption, BOOLEAN *isJDWPagent);
static BOOLEAN processAgentLibraryFromArgsList(J9JavaVM *vm, J9VMInitArgs *argsList, BOOLEAN loadLibrary, CreateAgentOption createAgentOption);
#if defined(J9VM_OPT_CRIU_SUPPORT)
static void jvmtiHookVMRestoreCRIUInit(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
static void jvmtiHookVMRestoreStartAgent(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData);
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

#define INSTRUMENT_LIBRARY "instrument"

Expand Down Expand Up @@ -267,6 +271,53 @@ processAgentLibraryFromArgsList(J9JavaVM *vm, J9VMInitArgs *argsList, BOOLEAN lo
}

#if defined(J9VM_OPT_CRIU_SUPPORT)
/**
* A hook method to invoke criuRestoreInitializeLib().
*
* @param[in] hook the VM hook interface, not used
* @param[in] eventNum the event number, not used
* @param[in] eventData the event data, not used
* @param[in] userData the registered user data
*/
static void
jvmtiHookVMRestoreCRIUInit(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData)
{
Trc_JVMTI_jvmtiHookVMRestoreCRIUInit_Entry();
criuRestoreInitializeLib(((J9RestoreEvent *)eventData)->currentThread->javaVM, (J9JVMTIEnv *)userData);
Trc_JVMTI_jvmtiHookVMRestoreCRIUInit_Exit();
}

/**
* A hook method to start agents or cleanup post-restore.
*
* @param[in] hook the VM hook interface, not used
* @param[in] eventNum the event number, not used
* @param[in] eventData the event data
* @param[in] userData the registered user data, not used
*/
static void
jvmtiHookVMRestoreStartAgent(J9HookInterface **hook, UDATA eventNum, void *eventData, void *userData)
{
J9VMThread *currentThread = ((J9RestoreEvent *)eventData)->currentThread;
J9JavaVM *vm = currentThread->javaVM;
J9InternalVMFunctions const * const vmFuncs = vm->internalVMFunctions;

Trc_JVMTI_jvmtiHookVMRestoreStartAgent_Entry();
vmFuncs->internalExitVMToJNI(currentThread);
if (J9_ARE_ANY_BITS_SET(vm->checkpointState.flags, J9VM_CRIU_IS_JDWP_ENABLED)) {
criuRestoreStartAgent(vm);
} else {
/* Last part of cleanup if there was no JDWP agent specified.
* This releases VM access hence can't be invoked within criuDisableHooks() from
* J9HOOK_VM_PREPARING_FOR_RESTORE.
*/
jvmtiEnv *jvmti_env = vm->checkpointState.jvmtienv;
(*jvmti_env)->DisposeEnvironment(jvmti_env);
}
vmFuncs->internalEnterVMFromJNI(currentThread);
Trc_JVMTI_jvmtiHookVMRestoreStartAgent_Exit();
}

/**
* Add JVMTI capabilities before checkpoint.
* This is required for debugger support when JIT is enabled.
Expand Down Expand Up @@ -418,14 +469,45 @@ IDATA J9VMDllMain(J9JavaVM *vm, IDATA stage, void *reserved)
hshelpUTRegister(vm);

#if defined(J9VM_OPT_CRIU_SUPPORT)
/*
* Adding capabilities is required before checkpoint if JIT is enabled.
* Following code can be removed when JIT allows capabilities to be added after restore.
*/
if (vm->internalVMFunctions->isDebugOnRestoreEnabled(vm)) {
Trc_JVMTI_criuAddCapabilities_invoked();
/* ignore the failure, it won't cause a problem if JDWP is not enabled later */
criuAddCapabilities(vm, NULL != vm->jitConfig);
{
/* The isDebugEventOrFlagEnabled calculation matches a part of J9::Options::isFSDNeeded()
* in compiler/control/J9Options.cpp.
*/
BOOLEAN isDebugEventOrFlagEnabled = J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_BREAKPOINT)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_FRAME_POP)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_FRAME_POPPED)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_GET_FIELD)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_PUT_FIELD)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_GET_STATIC_FIELD)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_PUT_STATIC_FIELD)
#if defined (J9VM_INTERP_HOT_CODE_REPLACEMENT)
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_POP_FRAMES_INTERRUPT)
#endif
#if defined(J9VM_JIT_FULL_SPEED_DEBUG)
|| (vm->requiredDebugAttributes & J9VM_DEBUG_ATTRIBUTE_CAN_ACCESS_LOCALS)
#endif
|| J9_EVENT_IS_HOOKED_OR_RESERVED(vm->hookInterface, J9HOOK_VM_SINGLE_STEP);
J9InternalVMFunctions *vmFuncs = vm->internalVMFunctions;
BOOLEAN isDebugOnRestoreEnabled = !isDebugEventOrFlagEnabled
&& J9_ARE_ALL_BITS_SET(vm->checkpointState.flags, J9VM_CRIU_SUPPORT_DEBUG_ON_RESTORE)
&& vmFuncs->isCRaCorCRIUSupportEnabled(vm);

if (isDebugOnRestoreEnabled) {
J9HookInterface ** vmHook = vmFuncs->getVMHookInterface(vm);
if ((*vmHook)->J9HookRegisterWithCallSite(vmHook, J9HOOK_TAG_AGENT_ID | J9HOOK_VM_PREPARING_FOR_RESTORE, jvmtiHookVMRestoreCRIUInit, OMR_GET_CALLSITE(), jvmtiData, J9HOOK_AGENTID_FIRST)) {
goto _error;
}
if ((*vmHook)->J9HookRegisterWithCallSite(vmHook, J9HOOK_TAG_AGENT_ID | J9HOOK_VM_CRIU_RESTORE, jvmtiHookVMRestoreStartAgent, OMR_GET_CALLSITE(), jvmtiData, J9HOOK_AGENTID_FIRST)) {
goto _error;
}
/* Adding capabilities is required before checkpoint if JIT is enabled.
* Following code can be removed when JIT allows capabilities to be added after restore.
*/
Trc_JVMTI_criuAddCapabilities_invoked();
/* ignore the failure, it won't cause a problem if JDWP is not enabled later */
criuAddCapabilities(vm, NULL != vm->jitConfig);
vm->checkpointState.isDebugOnRestoreEnabled = isDebugOnRestoreEnabled;
}
}
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

Expand Down
2 changes: 2 additions & 0 deletions runtime/oti/j9nonbuilder.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4456,6 +4456,7 @@ typedef struct J9CRIUCheckpointState {
UDATA javaDebugThreadCount;
jvmtiEnv *jvmtienv;
jvmtiCapabilities requiredCapabilities;
BOOLEAN isDebugOnRestoreEnabled;
} J9CRIUCheckpointState;
#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

Expand Down Expand Up @@ -5247,6 +5248,7 @@ typedef struct J9InternalVMFunctions {
BOOLEAN (*isNonPortableRestoreMode)(struct J9VMThread *currentThread);
BOOLEAN (*isJVMInPortableRestoreMode)(struct J9VMThread *currentThread);
BOOLEAN (*isDebugOnRestoreEnabled)(struct J9JavaVM *vm);
BOOLEAN (*isDebugAgentDisabled)(struct J9JavaVM *vm);
void (*setRequiredGhostFileLimit)(struct J9VMThread *currentThread, U_32 ghostFileLimit);
BOOLEAN (*runInternalJVMCheckpointHooks)(struct J9VMThread *currentThread, const char **nlsMsgFormat);
BOOLEAN (*runInternalJVMRestoreHooks)(struct J9VMThread *currentThread, const char **nlsMsgFormat);
Expand Down
38 changes: 34 additions & 4 deletions runtime/oti/vm_api.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -583,17 +583,47 @@ BOOLEAN
isJVMInPortableRestoreMode(J9VMThread *currentThread);

/**
* @brief Queries if debug on restore (specified via
* -XX:+DebugOnRestore) is supported. If so, the JVM
* will run in FSD mode pre-checkpoint and will transition out
* FSD mode on restore (unless debug is specified post restore).
* @brief This is a helper to query if debug on restore mode is enabled.
*
* A few use scenarios:
* 1. If CRIU is not enabled, FSD is disabled by default unless JDWP or some
* debug-specific flags/events are enabled/hooked, there is no notion of
* DebugOnRestore;
* 2. If CRIU is enabled (via -XX:+EnableCRIUSupport) but -XX:+DebugOnRestore
* is not specified, this is the same as use case #1;
* 3. If CRIU is enabled and -XX:+DebugOnRestore is specified,
* 3.1 If JDWP or some debug-specific flags/events are enabled/hooked, FSD
* mode is enabled, and JIT doesn't do any pre-emptive recompilation
* and debugging is enabled.
* 3.2 Otherwise FSD code is generated but FSD mode is not enabled,
* 3.2.1 If FSD is enabled via the post-restore option file, JIT will
* transmit to the interpreter as soon as possible, or VM triggers
* a transition via the FSD code generated pre-checkpoint;
* 3.2.2 Otherwise JIT throws all FSD code and uses the pre-emptively
* recompiled code in default mode.
*
* This helper method returns TRUE if CRIU is enabled, -XX:+DebugOnRestore is
* specified, JDWP is not enabled, and no debug-specific flags/events are
* enabled/hooked. JIT generates FSD code but FSD mode is not enabled.
* Otherwise, this returns FALSE, JIT checks if debug related flags/events are
* enabled/hooked and determines if FSD mode is to be enabled.
*
* @param vm javaVM token
* @return TRUE if enabled, FALSE otherwise
*/
BOOLEAN
isDebugOnRestoreEnabled(J9JavaVM *vm);

/**
* @brief This is a helper to query if the debug agent is disabled.
*
* @param vm javaVM token
* @return TRUE if isDebugOnRestoreEnabled() and isCheckpointAllowed() return TRUE,
* FALSE otherwise
*/
BOOLEAN
isDebugAgentDisabled(J9JavaVM *vm);

/**
* @brief Sets the maximum size for the CRIU ghost files.
* If the new limit is smaller or equal to the previous limit,
Expand Down
10 changes: 7 additions & 3 deletions runtime/vm/CRIUHelpers.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -178,9 +178,13 @@ isJVMInPortableRestoreMode(J9VMThread *currentThread)
BOOLEAN
isDebugOnRestoreEnabled(J9JavaVM *vm)
{
return J9_ARE_NO_BITS_SET(vm->checkpointState.flags, J9VM_CRIU_IS_JDWP_ENABLED)
&& J9_ARE_ALL_BITS_SET(vm->checkpointState.flags, J9VM_CRIU_SUPPORT_DEBUG_ON_RESTORE)
&& isCRaCorCRIUSupportEnabled(vm);
return vm->checkpointState.isDebugOnRestoreEnabled;
}

BOOLEAN
isDebugAgentDisabled(J9JavaVM *vm)
{
return isCheckpointAllowed(vm) && vm->checkpointState.isDebugOnRestoreEnabled;
}

void
Expand Down
1 change: 1 addition & 0 deletions runtime/vm/intfunc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -423,6 +423,7 @@ J9InternalVMFunctions J9InternalFunctions = {
isNonPortableRestoreMode,
isJVMInPortableRestoreMode,
isDebugOnRestoreEnabled,
isDebugAgentDisabled,
setRequiredGhostFileLimit,
runInternalJVMCheckpointHooks,
runInternalJVMRestoreHooks,
Expand Down

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