Mercurial > hg > graal-compiler
view src/share/vm/ci/ciObject.cpp @ 21576:9c2c8e4b5333
Merge with 4b3b38415adf974774952abb69b359053d6f0018
author | Michael Van De Vanter <michael.van.de.vanter@oracle.com> |
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date | Thu, 28 May 2015 10:16:13 -0700 |
parents | 52b4284cb496 |
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/* * Copyright (c) 1999, 2014, 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 * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "ci/ciObject.hpp" #include "ci/ciUtilities.hpp" #include "gc_interface/collectedHeap.inline.hpp" #include "oops/oop.inline2.hpp" // ciObject // // This class represents an oop in the HotSpot virtual machine. // Its subclasses are structured in a hierarchy which mirrors // an aggregate of the VM's oop and klass hierarchies (see // oopHierarchy.hpp). Each instance of ciObject holds a handle // to a corresponding oop on the VM side and provides routines // for accessing the information in its oop. By using the ciObject // hierarchy for accessing oops in the VM, the compiler ensures // that it is safe with respect to garbage collection; that is, // GC and compilation can proceed independently without // interference. // // Within the VM, the oop and klass hierarchies are separate. // The compiler interface does not preserve this separation -- // the distinction between `Klass*' and `Klass' are not // reflected in the interface and instead the Klass hierarchy // is directly modeled as the subclasses of ciKlass. // ------------------------------------------------------------------ // ciObject::ciObject ciObject::ciObject(oop o) { ASSERT_IN_VM; if (ciObjectFactory::is_initialized()) { _handle = JNIHandles::make_local(o); } else { _handle = JNIHandles::make_global(o); } _klass = NULL; init_flags_from(o); } // ------------------------------------------------------------------ // ciObject::ciObject // ciObject::ciObject(Handle h) { ASSERT_IN_VM; if (ciObjectFactory::is_initialized()) { _handle = JNIHandles::make_local(h()); } else { _handle = JNIHandles::make_global(h); } _klass = NULL; init_flags_from(h()); } // ------------------------------------------------------------------ // ciObject::ciObject // // Unloaded klass/method variant. `klass' is the klass of the unloaded // klass/method, if that makes sense. ciObject::ciObject(ciKlass* klass) { ASSERT_IN_VM; assert(klass != NULL, "must supply klass"); _handle = NULL; _klass = klass; } // ------------------------------------------------------------------ // ciObject::ciObject // // NULL variant. Used only by ciNullObject. ciObject::ciObject() { ASSERT_IN_VM; _handle = NULL; _klass = NULL; } // ------------------------------------------------------------------ // ciObject::klass // // Get the ciKlass of this ciObject. ciKlass* ciObject::klass() { if (_klass == NULL) { if (_handle == NULL) { // When both _klass and _handle are NULL, we are dealing // with the distinguished instance of ciNullObject. // No one should ask it for its klass. assert(is_null_object(), "must be null object"); ShouldNotReachHere(); return NULL; } GUARDED_VM_ENTRY( oop o = get_oop(); _klass = CURRENT_ENV->get_klass(o->klass()); ); } return _klass; } // ------------------------------------------------------------------ // ciObject::equals // // Are two ciObjects equal? bool ciObject::equals(ciObject* obj) { return (this == obj); } // ------------------------------------------------------------------ // ciObject::hash // // A hash value for the convenience of compilers. // // Implementation note: we use the address of the ciObject as the // basis for the hash. Use the _ident field, which is well-behaved. int ciObject::hash() { return ident() * 31; } // ------------------------------------------------------------------ // ciObject::constant_encoding // // The address which the compiler should embed into the // generated code to represent this oop. This address // is not the true address of the oop -- it will get patched // during nmethod creation. // // // // Implementation note: we use the handle as the encoding. The // nmethod constructor resolves the handle and patches in the oop. // // This method should be changed to return an generified address // to discourage use of the JNI handle. jobject ciObject::constant_encoding() { assert(is_null_object() || handle() != NULL, "cannot embed null pointer"); assert(can_be_constant(), "oop must be NULL or perm"); return handle(); } // ------------------------------------------------------------------ // ciObject::can_be_constant bool ciObject::can_be_constant() { if (ScavengeRootsInCode >= 1) return true; // now everybody can encode as a constant return handle() == NULL; } // ------------------------------------------------------------------ // ciObject::should_be_constant() bool ciObject::should_be_constant() { if (ScavengeRootsInCode >= 2) return true; // force everybody to be a constant if (is_null_object()) return true; ciEnv* env = CURRENT_ENV; // We want Strings and Classes to be embeddable by default since // they used to be in the perm world. Not all Strings used to be // embeddable but there's no easy way to distinguish the interned // from the regulars ones so just treat them all that way. if (klass() == env->String_klass() || klass() == env->Class_klass()) { return true; } if (EnableInvokeDynamic && (klass()->is_subclass_of(env->MethodHandle_klass()) || klass()->is_subclass_of(env->CallSite_klass()))) { assert(ScavengeRootsInCode >= 1, "must be"); // We want to treat these aggressively. return true; } return handle() == NULL; } // ------------------------------------------------------------------ // ciObject::should_be_constant() void ciObject::init_flags_from(oop x) { int flags = 0; if (x != NULL) { assert(Universe::heap()->is_in_reserved(x), "must be"); if (x->is_scavengable()) flags |= SCAVENGABLE_FLAG; } _ident |= flags; } // ------------------------------------------------------------------ // ciObject::print // // Print debugging output about this ciObject. // // Implementation note: dispatch to the virtual print_impl behavior // for this ciObject. void ciObject::print(outputStream* st) { st->print("<%s", type_string()); GUARDED_VM_ENTRY(print_impl(st);) st->print(" ident=%d %s address=" INTPTR_FORMAT ">", ident(), is_scavengable() ? "SCAVENGABLE" : "", p2i((address)this)); } // ------------------------------------------------------------------ // ciObject::print_oop // // Print debugging output about the oop this ciObject represents. void ciObject::print_oop(outputStream* st) { if (is_null_object()) { st->print_cr("NULL"); } else if (!is_loaded()) { st->print_cr("UNLOADED"); } else { GUARDED_VM_ENTRY(get_oop()->print_on(st);) } }