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8163880: Constant pool caching of fields inhibited/delayed unnecessarily

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Delay/inhibit constant pool caching of fields only if necessary

Reviewed-by: kvn
This commit is contained in:
Zoltan Majo 2016-08-29 07:32:37 +02:00
parent 2b1aa4e8ae
commit 97ed41a8e9
1 changed files with 21 additions and 9 deletions
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30
hotspot/src/share/vm/interpreter/interpreterRuntime.cpp
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@ -576,27 +576,39 @@ void InterpreterRuntime::resolve_get_put(JavaThread* thread, Bytecodes::Code byt
// compute auxiliary field attributes
TosState state = as_TosState(info.field_type());
// Put instructions on final fields are not resolved. This is required so we throw
// exceptions at the correct place (when the instruction is actually invoked).
// Resolution of put instructions on final fields is delayed. That is required so that
// exceptions are thrown at the correct place (when the instruction is actually invoked).
// If we do not resolve an instruction in the current pass, leaving the put_code
// set to zero will cause the next put instruction to the same field to reresolve.
// Resolution of put instructions to final instance fields with invalid updates (i.e.,
// to final instance fields with updates originating from a method different than <init>)
// is inhibited. A putfield instruction targeting an instance final field must throw
// an IllegalAccessError if the instruction is not in an instance
// initializer method <init>. If resolution were not inhibited, a putfield
// in an initializer method could be resolved in the initializer. Subsequent
// putfield instructions to the same field would then use cached information.
// As a result, those instructions would not pass through the VM. That is,
// checks in resolve_field_access() would not be executed for those instructions
// and the required IllegalAccessError would not be thrown.
//
// Also, we need to delay resolving getstatic and putstatic instructions until the
// class is initialized. This is required so that access to the static
// field will call the initialization function every time until the class
// is completely initialized ala. in 2.17.5 in JVM Specification.
InstanceKlass* klass = InstanceKlass::cast(info.field_holder());
bool uninitialized_static = ((bytecode == Bytecodes::_getstatic || bytecode == Bytecodes::_putstatic) &&
!klass->is_initialized());
Bytecodes::Code put_code = (Bytecodes::Code)0;
if (is_put && !info.access_flags().is_final() && !uninitialized_static) {
put_code = ((is_static) ? Bytecodes::_putstatic : Bytecodes::_putfield);
}
bool uninitialized_static = is_static && !klass->is_initialized();
bool has_initialized_final_update = info.field_holder()->major_version() >= 53 &&
info.has_initialized_final_update();
assert(!(has_initialized_final_update && !info.access_flags().is_final()), "Fields with initialized final updates must be final");
Bytecodes::Code get_code = (Bytecodes::Code)0;
Bytecodes::Code put_code = (Bytecodes::Code)0;
if (!uninitialized_static) {
get_code = ((is_static) ? Bytecodes::_getstatic : Bytecodes::_getfield);
if ((is_put && !has_initialized_final_update) || !info.access_flags().is_final()) {
put_code = ((is_static) ? Bytecodes::_putstatic : Bytecodes::_putfield);
}
}
cp_cache_entry->set_field(