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8382584: [lworld] Mandatory pre-loading still present in systemDictionary.cpp #2409

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8382584: [lworld] Mandatory pre-loading still present in systemDictionary.cpp #2409

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b24ca87
removed forced loading for nullrestricted
caspernorrbin May 7, 2026
4c706f8
re-add failed marker
caspernorrbin May 13, 2026
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47 changes: 2 additions & 45 deletions src/hotspot/share/classfile/systemDictionary.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1106,43 +1106,7 @@ bool SystemDictionary::check_shared_class_super_types(InstanceKlass* ik, Handle
return true;
}

// Pre-load class referred to in non-static null-free instance field. These fields trigger MANDATORY loading.
// Some pre-loading does not fail fatally
bool SystemDictionary::preload_from_null_free_field(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS) {
TempNewSymbol name = Signature::strip_envelope(sig);
log_info(class, preload)("Preloading of class %s during loading of shared class %s. "
"Cause: a null-free non-static field is declared with this type",
name->as_C_string(), ik->name()->as_C_string());
InstanceKlass* real_k = SystemDictionary::resolve_with_circularity_detection(ik->name(), name,
class_loader, false, CHECK_false);
if (HAS_PENDING_EXCEPTION) {
log_info(class, preload)("Preloading of class %s during loading of class %s "
"(cause: null-free non-static field) failed: %s",
name->as_C_string(), ik->name()->as_C_string(),
PENDING_EXCEPTION->klass()->name()->as_C_string());
return false; // Exception is still pending
}

InstanceKlass* k = ik->get_inline_type_field_klass_or_null(field_index);
if (real_k != k) {
// oops, the app has substituted a different version of k! Does not fail fatally
log_info(class, preload)("Preloading of class %s during loading of shared class %s "
"(cause: null-free non-static field) failed : "
"app substituted a different version",
name->as_C_string(), ik->name()->as_C_string());
return false;
}
log_info(class, preload)("Preloading of class %s during loading of shared class %s "
"(cause: null-free non-static field) succeeded",
name->as_C_string(), ik->name()->as_C_string());

assert(real_k != nullptr, "Sanity check");
InstanceKlass::check_can_be_annotated_with_NullRestricted(real_k, ik->name(), CHECK_false);

return true;
}

// Tries to pre-load classes referred to in non-static nullable instance fields if they are found in the
// Tries to pre-load classes referred to in non-static instance fields if they are found in the
// loadable descriptors attribute. If loading fails, we can fail silently.
void SystemDictionary::try_preload_from_loadable_descriptors(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS) {
TempNewSymbol name = Signature::strip_envelope(sig);
Expand Down Expand Up @@ -1203,14 +1167,7 @@ InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik,
Symbol* sig = fs.signature();
int field_index = fs.index();

if (fs.is_null_free_inline_type()) {
// A false return means that the class didn't load for other reasons than an exception.
bool check = preload_from_null_free_field(ik, class_loader, sig, field_index, CHECK_NULL);
if (!check) {
ik->set_shared_loading_failed();
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@liach liach May 7, 2026

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Can we safely drop this failure marking?

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@coleenp coleenp May 8, 2026

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It's used for regular shared class loading so I don't think we can drop this shared_loading_failed marker.

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@caspernorrbin caspernorrbin May 13, 2026

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Didn't realise that one was needed. I've re-added it, along with an edit to try_preload_from_loadable_descriptors so we can see if we failed or not. It now also has a new parameter that decides if failing means we call shared_loading_failed .

return nullptr;
}
} else if (Signature::has_envelope(sig)) {
if (Signature::has_envelope(sig)) {
// Pending exceptions are cleared so we can fail silently
try_preload_from_loadable_descriptors(ik, class_loader, sig, field_index, CHECK_NULL);
}
Expand Down
3 changes: 1 addition & 2 deletions src/hotspot/share/classfile/systemDictionary.hpp
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -331,7 +331,6 @@ class SystemDictionary : AllStatic {

static bool add_loader_constraint(Symbol* name, Klass* klass_being_linked, Handle loader1,
Handle loader2);
static bool preload_from_null_free_field(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS);
static void try_preload_from_loadable_descriptors(InstanceKlass* ik, Handle class_loader, Symbol* sig, int field_index, TRAPS);
static InstanceKlass* load_shared_class(InstanceKlass* ik,
Handle class_loader,
Expand Down