src/share/vm/code/dependencies.hpp

Mon, 29 Aug 2011 05:07:35 -0700

author
twisti
date
Mon, 29 Aug 2011 05:07:35 -0700
changeset 3094
b27c72d69fd1
parent 3050
fdb992d83a87
child 4037
da91efe96a93
permissions
-rw-r--r--

7083184: JSR 292: don't store context class argument with call site dependencies
Reviewed-by: jrose, never

duke@435 1 /*
twisti@3050 2 * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #ifndef SHARE_VM_CODE_DEPENDENCIES_HPP
stefank@2314 26 #define SHARE_VM_CODE_DEPENDENCIES_HPP
stefank@2314 27
twisti@3050 28 #include "ci/ciCallSite.hpp"
stefank@2314 29 #include "ci/ciKlass.hpp"
twisti@3050 30 #include "ci/ciMethodHandle.hpp"
twisti@3050 31 #include "classfile/systemDictionary.hpp"
stefank@2314 32 #include "code/compressedStream.hpp"
stefank@2314 33 #include "code/nmethod.hpp"
stefank@2314 34 #include "utilities/growableArray.hpp"
stefank@2314 35
duke@435 36 //** Dependencies represent assertions (approximate invariants) within
twisti@3050 37 // the runtime system, e.g. class hierarchy changes. An example is an
twisti@3050 38 // assertion that a given method is not overridden; another example is
twisti@3050 39 // that a type has only one concrete subtype. Compiled code which
twisti@3050 40 // relies on such assertions must be discarded if they are overturned
twisti@3050 41 // by changes in the runtime system. We can think of these assertions
twisti@3050 42 // as approximate invariants, because we expect them to be overturned
duke@435 43 // very infrequently. We are willing to perform expensive recovery
duke@435 44 // operations when they are overturned. The benefit, of course, is
duke@435 45 // performing optimistic optimizations (!) on the object code.
duke@435 46 //
duke@435 47 // Changes in the class hierarchy due to dynamic linking or
duke@435 48 // class evolution can violate dependencies. There is enough
duke@435 49 // indexing between classes and nmethods to make dependency
duke@435 50 // checking reasonably efficient.
duke@435 51
duke@435 52 class ciEnv;
duke@435 53 class nmethod;
duke@435 54 class OopRecorder;
duke@435 55 class xmlStream;
duke@435 56 class CompileLog;
duke@435 57 class DepChange;
twisti@3050 58 class KlassDepChange;
twisti@3050 59 class CallSiteDepChange;
duke@435 60 class No_Safepoint_Verifier;
duke@435 61
duke@435 62 class Dependencies: public ResourceObj {
duke@435 63 public:
duke@435 64 // Note: In the comments on dependency types, most uses of the terms
duke@435 65 // subtype and supertype are used in a "non-strict" or "inclusive"
duke@435 66 // sense, and are starred to remind the reader of this fact.
duke@435 67 // Strict uses of the terms use the word "proper".
duke@435 68 //
duke@435 69 // Specifically, every class is its own subtype* and supertype*.
duke@435 70 // (This trick is easier than continually saying things like "Y is a
duke@435 71 // subtype of X or X itself".)
duke@435 72 //
duke@435 73 // Sometimes we write X > Y to mean X is a proper supertype of Y.
duke@435 74 // The notation X > {Y, Z} means X has proper subtypes Y, Z.
duke@435 75 // The notation X.m > Y means that Y inherits m from X, while
duke@435 76 // X.m > Y.m means Y overrides X.m. A star denotes abstractness,
duke@435 77 // as *I > A, meaning (abstract) interface I is a super type of A,
duke@435 78 // or A.*m > B.m, meaning B.m implements abstract method A.m.
duke@435 79 //
duke@435 80 // In this module, the terms "subtype" and "supertype" refer to
duke@435 81 // Java-level reference type conversions, as detected by
duke@435 82 // "instanceof" and performed by "checkcast" operations. The method
duke@435 83 // Klass::is_subtype_of tests these relations. Note that "subtype"
duke@435 84 // is richer than "subclass" (as tested by Klass::is_subclass_of),
duke@435 85 // since it takes account of relations involving interface and array
duke@435 86 // types.
duke@435 87 //
duke@435 88 // To avoid needless complexity, dependencies involving array types
duke@435 89 // are not accepted. If you need to make an assertion about an
duke@435 90 // array type, make the assertion about its corresponding element
duke@435 91 // types. Any assertion that might change about an array type can
duke@435 92 // be converted to an assertion about its element type.
duke@435 93 //
duke@435 94 // Most dependencies are evaluated over a "context type" CX, which
duke@435 95 // stands for the set Subtypes(CX) of every Java type that is a subtype*
duke@435 96 // of CX. When the system loads a new class or interface N, it is
duke@435 97 // responsible for re-evaluating changed dependencies whose context
duke@435 98 // type now includes N, that is, all super types of N.
duke@435 99 //
duke@435 100 enum DepType {
duke@435 101 end_marker = 0,
duke@435 102
duke@435 103 // An 'evol' dependency simply notes that the contents of the
duke@435 104 // method were used. If it evolves (is replaced), the nmethod
duke@435 105 // must be recompiled. No other dependencies are implied.
duke@435 106 evol_method,
duke@435 107 FIRST_TYPE = evol_method,
duke@435 108
duke@435 109 // A context type CX is a leaf it if has no proper subtype.
duke@435 110 leaf_type,
duke@435 111
duke@435 112 // An abstract class CX has exactly one concrete subtype CC.
duke@435 113 abstract_with_unique_concrete_subtype,
duke@435 114
duke@435 115 // The type CX is purely abstract, with no concrete subtype* at all.
duke@435 116 abstract_with_no_concrete_subtype,
duke@435 117
duke@435 118 // The concrete CX is free of concrete proper subtypes.
duke@435 119 concrete_with_no_concrete_subtype,
duke@435 120
duke@435 121 // Given a method M1 and a context class CX, the set MM(CX, M1) of
duke@435 122 // "concrete matching methods" in CX of M1 is the set of every
duke@435 123 // concrete M2 for which it is possible to create an invokevirtual
duke@435 124 // or invokeinterface call site that can reach either M1 or M2.
duke@435 125 // That is, M1 and M2 share a name, signature, and vtable index.
duke@435 126 // We wish to notice when the set MM(CX, M1) is just {M1}, or
duke@435 127 // perhaps a set of two {M1,M2}, and issue dependencies on this.
duke@435 128
duke@435 129 // The set MM(CX, M1) can be computed by starting with any matching
duke@435 130 // concrete M2 that is inherited into CX, and then walking the
duke@435 131 // subtypes* of CX looking for concrete definitions.
duke@435 132
duke@435 133 // The parameters to this dependency are the method M1 and the
duke@435 134 // context class CX. M1 must be either inherited in CX or defined
duke@435 135 // in a subtype* of CX. It asserts that MM(CX, M1) is no greater
duke@435 136 // than {M1}.
duke@435 137 unique_concrete_method, // one unique concrete method under CX
duke@435 138
duke@435 139 // An "exclusive" assertion concerns two methods or subtypes, and
duke@435 140 // declares that there are at most two (or perhaps later N>2)
duke@435 141 // specific items that jointly satisfy the restriction.
duke@435 142 // We list all items explicitly rather than just giving their
duke@435 143 // count, for robustness in the face of complex schema changes.
duke@435 144
duke@435 145 // A context class CX (which may be either abstract or concrete)
duke@435 146 // has two exclusive concrete subtypes* C1, C2 if every concrete
duke@435 147 // subtype* of CX is either C1 or C2. Note that if neither C1 or C2
duke@435 148 // are equal to CX, then CX itself must be abstract. But it is
duke@435 149 // also possible (for example) that C1 is CX (a concrete class)
duke@435 150 // and C2 is a proper subtype of C1.
duke@435 151 abstract_with_exclusive_concrete_subtypes_2,
duke@435 152
duke@435 153 // This dependency asserts that MM(CX, M1) is no greater than {M1,M2}.
duke@435 154 exclusive_concrete_methods_2,
duke@435 155
duke@435 156 // This dependency asserts that no instances of class or it's
duke@435 157 // subclasses require finalization registration.
duke@435 158 no_finalizable_subclasses,
duke@435 159
twisti@3050 160 // This dependency asserts when the CallSite.target value changed.
twisti@3050 161 call_site_target_value,
twisti@3050 162
duke@435 163 TYPE_LIMIT
duke@435 164 };
duke@435 165 enum {
duke@435 166 LG2_TYPE_LIMIT = 4, // assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT))
duke@435 167
duke@435 168 // handy categorizations of dependency types:
twisti@3094 169 all_types = ((1 << TYPE_LIMIT) - 1) & ((-1) << FIRST_TYPE),
twisti@3094 170
twisti@3094 171 non_klass_types = (1 << call_site_target_value),
twisti@3094 172 klass_types = all_types & ~non_klass_types,
twisti@3094 173
twisti@3094 174 non_ctxk_types = (1 << evol_method),
twisti@3094 175 implicit_ctxk_types = (1 << call_site_target_value),
twisti@3094 176 explicit_ctxk_types = all_types & ~(non_ctxk_types | implicit_ctxk_types),
duke@435 177
duke@435 178 max_arg_count = 3, // current maximum number of arguments (incl. ctxk)
duke@435 179
duke@435 180 // A "context type" is a class or interface that
duke@435 181 // provides context for evaluating a dependency.
duke@435 182 // When present, it is one of the arguments (dep_context_arg).
duke@435 183 //
duke@435 184 // If a dependency does not have a context type, there is a
duke@435 185 // default context, depending on the type of the dependency.
duke@435 186 // This bit signals that a default context has been compressed away.
duke@435 187 default_context_type_bit = (1<<LG2_TYPE_LIMIT)
duke@435 188 };
duke@435 189
duke@435 190 static const char* dep_name(DepType dept);
duke@435 191 static int dep_args(DepType dept);
twisti@3094 192
twisti@3094 193 static bool is_klass_type( DepType dept) { return dept_in_mask(dept, klass_types ); }
twisti@3094 194
twisti@3094 195 static bool has_explicit_context_arg(DepType dept) { return dept_in_mask(dept, explicit_ctxk_types); }
twisti@3094 196 static bool has_implicit_context_arg(DepType dept) { return dept_in_mask(dept, implicit_ctxk_types); }
twisti@3094 197
twisti@3094 198 static int dep_context_arg(DepType dept) { return has_explicit_context_arg(dept) ? 0 : -1; }
twisti@3094 199 static int dep_implicit_context_arg(DepType dept) { return has_implicit_context_arg(dept) ? 0 : -1; }
twisti@3094 200
twisti@3050 201 static void check_valid_dependency_type(DepType dept);
duke@435 202
duke@435 203 private:
duke@435 204 // State for writing a new set of dependencies:
duke@435 205 GrowableArray<int>* _dep_seen; // (seen[h->ident] & (1<<dept))
duke@435 206 GrowableArray<ciObject*>* _deps[TYPE_LIMIT];
duke@435 207
duke@435 208 static const char* _dep_name[TYPE_LIMIT];
duke@435 209 static int _dep_args[TYPE_LIMIT];
duke@435 210
duke@435 211 static bool dept_in_mask(DepType dept, int mask) {
duke@435 212 return (int)dept >= 0 && dept < TYPE_LIMIT && ((1<<dept) & mask) != 0;
duke@435 213 }
duke@435 214
duke@435 215 bool note_dep_seen(int dept, ciObject* x) {
duke@435 216 assert(dept < BitsPerInt, "oob");
duke@435 217 int x_id = x->ident();
duke@435 218 assert(_dep_seen != NULL, "deps must be writable");
duke@435 219 int seen = _dep_seen->at_grow(x_id, 0);
duke@435 220 _dep_seen->at_put(x_id, seen | (1<<dept));
duke@435 221 // return true if we've already seen dept/x
duke@435 222 return (seen & (1<<dept)) != 0;
duke@435 223 }
duke@435 224
duke@435 225 bool maybe_merge_ctxk(GrowableArray<ciObject*>* deps,
duke@435 226 int ctxk_i, ciKlass* ctxk);
duke@435 227
duke@435 228 void sort_all_deps();
duke@435 229 size_t estimate_size_in_bytes();
duke@435 230
duke@435 231 // Initialize _deps, etc.
duke@435 232 void initialize(ciEnv* env);
duke@435 233
duke@435 234 // State for making a new set of dependencies:
duke@435 235 OopRecorder* _oop_recorder;
duke@435 236
duke@435 237 // Logging support
duke@435 238 CompileLog* _log;
duke@435 239
duke@435 240 address _content_bytes; // everything but the oop references, encoded
duke@435 241 size_t _size_in_bytes;
duke@435 242
duke@435 243 public:
duke@435 244 // Make a new empty dependencies set.
duke@435 245 Dependencies(ciEnv* env) {
duke@435 246 initialize(env);
duke@435 247 }
duke@435 248
duke@435 249 private:
duke@435 250 // Check for a valid context type.
duke@435 251 // Enforce the restriction against array types.
duke@435 252 static void check_ctxk(ciKlass* ctxk) {
duke@435 253 assert(ctxk->is_instance_klass(), "java types only");
duke@435 254 }
duke@435 255 static void check_ctxk_concrete(ciKlass* ctxk) {
duke@435 256 assert(is_concrete_klass(ctxk->as_instance_klass()), "must be concrete");
duke@435 257 }
duke@435 258 static void check_ctxk_abstract(ciKlass* ctxk) {
duke@435 259 check_ctxk(ctxk);
duke@435 260 assert(!is_concrete_klass(ctxk->as_instance_klass()), "must be abstract");
duke@435 261 }
duke@435 262
duke@435 263 void assert_common_1(DepType dept, ciObject* x);
twisti@3094 264 void assert_common_2(DepType dept, ciObject* x0, ciObject* x1);
twisti@3094 265 void assert_common_3(DepType dept, ciKlass* ctxk, ciObject* x1, ciObject* x2);
duke@435 266
duke@435 267 public:
duke@435 268 // Adding assertions to a new dependency set at compile time:
duke@435 269 void assert_evol_method(ciMethod* m);
duke@435 270 void assert_leaf_type(ciKlass* ctxk);
duke@435 271 void assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck);
duke@435 272 void assert_abstract_with_no_concrete_subtype(ciKlass* ctxk);
duke@435 273 void assert_concrete_with_no_concrete_subtype(ciKlass* ctxk);
duke@435 274 void assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm);
duke@435 275 void assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2);
duke@435 276 void assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2);
duke@435 277 void assert_has_no_finalizable_subclasses(ciKlass* ctxk);
twisti@3094 278 void assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle);
duke@435 279
duke@435 280 // Define whether a given method or type is concrete.
duke@435 281 // These methods define the term "concrete" as used in this module.
duke@435 282 // For this module, an "abstract" class is one which is non-concrete.
duke@435 283 //
duke@435 284 // Future optimizations may allow some classes to remain
duke@435 285 // non-concrete until their first instantiation, and allow some
duke@435 286 // methods to remain non-concrete until their first invocation.
duke@435 287 // In that case, there would be a middle ground between concrete
duke@435 288 // and abstract (as defined by the Java language and VM).
duke@435 289 static bool is_concrete_klass(klassOop k); // k is instantiable
duke@435 290 static bool is_concrete_method(methodOop m); // m is invocable
duke@435 291 static Klass* find_finalizable_subclass(Klass* k);
duke@435 292
duke@435 293 // These versions of the concreteness queries work through the CI.
duke@435 294 // The CI versions are allowed to skew sometimes from the VM
duke@435 295 // (oop-based) versions. The cost of such a difference is a
duke@435 296 // (safely) aborted compilation, or a deoptimization, or a missed
duke@435 297 // optimization opportunity.
duke@435 298 //
duke@435 299 // In order to prevent spurious assertions, query results must
duke@435 300 // remain stable within any single ciEnv instance. (I.e., they must
duke@435 301 // not go back into the VM to get their value; they must cache the
duke@435 302 // bit in the CI, either eagerly or lazily.)
duke@435 303 static bool is_concrete_klass(ciInstanceKlass* k); // k appears instantiable
duke@435 304 static bool is_concrete_method(ciMethod* m); // m appears invocable
duke@435 305 static bool has_finalizable_subclass(ciInstanceKlass* k);
duke@435 306
duke@435 307 // As a general rule, it is OK to compile under the assumption that
duke@435 308 // a given type or method is concrete, even if it at some future
duke@435 309 // point becomes abstract. So dependency checking is one-sided, in
duke@435 310 // that it permits supposedly concrete classes or methods to turn up
duke@435 311 // as really abstract. (This shouldn't happen, except during class
duke@435 312 // evolution, but that's the logic of the checking.) However, if a
duke@435 313 // supposedly abstract class or method suddenly becomes concrete, a
duke@435 314 // dependency on it must fail.
duke@435 315
duke@435 316 // Checking old assertions at run-time (in the VM only):
duke@435 317 static klassOop check_evol_method(methodOop m);
duke@435 318 static klassOop check_leaf_type(klassOop ctxk);
duke@435 319 static klassOop check_abstract_with_unique_concrete_subtype(klassOop ctxk, klassOop conck,
twisti@3050 320 KlassDepChange* changes = NULL);
duke@435 321 static klassOop check_abstract_with_no_concrete_subtype(klassOop ctxk,
twisti@3050 322 KlassDepChange* changes = NULL);
duke@435 323 static klassOop check_concrete_with_no_concrete_subtype(klassOop ctxk,
twisti@3050 324 KlassDepChange* changes = NULL);
duke@435 325 static klassOop check_unique_concrete_method(klassOop ctxk, methodOop uniqm,
twisti@3050 326 KlassDepChange* changes = NULL);
duke@435 327 static klassOop check_abstract_with_exclusive_concrete_subtypes(klassOop ctxk, klassOop k1, klassOop k2,
twisti@3050 328 KlassDepChange* changes = NULL);
duke@435 329 static klassOop check_exclusive_concrete_methods(klassOop ctxk, methodOop m1, methodOop m2,
twisti@3050 330 KlassDepChange* changes = NULL);
twisti@3050 331 static klassOop check_has_no_finalizable_subclasses(klassOop ctxk, KlassDepChange* changes = NULL);
twisti@3094 332 static klassOop check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes = NULL);
duke@435 333 // A returned klassOop is NULL if the dependency assertion is still
duke@435 334 // valid. A non-NULL klassOop is a 'witness' to the assertion
duke@435 335 // failure, a point in the class hierarchy where the assertion has
duke@435 336 // been proven false. For example, if check_leaf_type returns
duke@435 337 // non-NULL, the value is a subtype of the supposed leaf type. This
duke@435 338 // witness value may be useful for logging the dependency failure.
duke@435 339 // Note that, when a dependency fails, there may be several possible
duke@435 340 // witnesses to the failure. The value returned from the check_foo
duke@435 341 // method is chosen arbitrarily.
duke@435 342
duke@435 343 // The 'changes' value, if non-null, requests a limited spot-check
duke@435 344 // near the indicated recent changes in the class hierarchy.
duke@435 345 // It is used by DepStream::spot_check_dependency_at.
duke@435 346
duke@435 347 // Detecting possible new assertions:
duke@435 348 static klassOop find_unique_concrete_subtype(klassOop ctxk);
duke@435 349 static methodOop find_unique_concrete_method(klassOop ctxk, methodOop m);
duke@435 350 static int find_exclusive_concrete_subtypes(klassOop ctxk, int klen, klassOop k[]);
duke@435 351 static int find_exclusive_concrete_methods(klassOop ctxk, int mlen, methodOop m[]);
duke@435 352
duke@435 353 // Create the encoding which will be stored in an nmethod.
duke@435 354 void encode_content_bytes();
duke@435 355
duke@435 356 address content_bytes() {
duke@435 357 assert(_content_bytes != NULL, "encode it first");
duke@435 358 return _content_bytes;
duke@435 359 }
duke@435 360 size_t size_in_bytes() {
duke@435 361 assert(_content_bytes != NULL, "encode it first");
duke@435 362 return _size_in_bytes;
duke@435 363 }
duke@435 364
duke@435 365 OopRecorder* oop_recorder() { return _oop_recorder; }
duke@435 366 CompileLog* log() { return _log; }
duke@435 367
duke@435 368 void copy_to(nmethod* nm);
duke@435 369
duke@435 370 void log_all_dependencies();
duke@435 371 void log_dependency(DepType dept, int nargs, ciObject* args[]) {
duke@435 372 write_dependency_to(log(), dept, nargs, args);
duke@435 373 }
duke@435 374 void log_dependency(DepType dept,
duke@435 375 ciObject* x0,
duke@435 376 ciObject* x1 = NULL,
duke@435 377 ciObject* x2 = NULL) {
duke@435 378 if (log() == NULL) return;
duke@435 379 ciObject* args[max_arg_count];
duke@435 380 args[0] = x0;
duke@435 381 args[1] = x1;
duke@435 382 args[2] = x2;
duke@435 383 assert(2 < max_arg_count, "");
duke@435 384 log_dependency(dept, dep_args(dept), args);
duke@435 385 }
duke@435 386
duke@435 387 static void write_dependency_to(CompileLog* log,
duke@435 388 DepType dept,
duke@435 389 int nargs, ciObject* args[],
duke@435 390 klassOop witness = NULL);
duke@435 391 static void write_dependency_to(CompileLog* log,
duke@435 392 DepType dept,
duke@435 393 int nargs, oop args[],
duke@435 394 klassOop witness = NULL);
duke@435 395 static void write_dependency_to(xmlStream* xtty,
duke@435 396 DepType dept,
duke@435 397 int nargs, oop args[],
duke@435 398 klassOop witness = NULL);
duke@435 399 static void print_dependency(DepType dept,
duke@435 400 int nargs, oop args[],
duke@435 401 klassOop witness = NULL);
duke@435 402
duke@435 403 private:
duke@435 404 // helper for encoding common context types as zero:
duke@435 405 static ciKlass* ctxk_encoded_as_null(DepType dept, ciObject* x);
duke@435 406
duke@435 407 static klassOop ctxk_encoded_as_null(DepType dept, oop x);
duke@435 408
duke@435 409 public:
duke@435 410 // Use this to iterate over an nmethod's dependency set.
duke@435 411 // Works on new and old dependency sets.
duke@435 412 // Usage:
duke@435 413 //
duke@435 414 // ;
duke@435 415 // Dependencies::DepType dept;
duke@435 416 // for (Dependencies::DepStream deps(nm); deps.next(); ) {
duke@435 417 // ...
duke@435 418 // }
duke@435 419 //
duke@435 420 // The caller must be in the VM, since oops are not wrapped in handles.
duke@435 421 class DepStream {
duke@435 422 private:
duke@435 423 nmethod* _code; // null if in a compiler thread
duke@435 424 Dependencies* _deps; // null if not in a compiler thread
duke@435 425 CompressedReadStream _bytes;
duke@435 426 #ifdef ASSERT
duke@435 427 size_t _byte_limit;
duke@435 428 #endif
duke@435 429
duke@435 430 // iteration variables:
duke@435 431 DepType _type;
duke@435 432 int _xi[max_arg_count+1];
duke@435 433
duke@435 434 void initial_asserts(size_t byte_limit) NOT_DEBUG({});
duke@435 435
duke@435 436 inline oop recorded_oop_at(int i);
duke@435 437 // => _code? _code->oop_at(i): *_deps->_oop_recorder->handle_at(i)
duke@435 438
twisti@3050 439 klassOop check_klass_dependency(KlassDepChange* changes);
twisti@3050 440 klassOop check_call_site_dependency(CallSiteDepChange* changes);
twisti@3050 441
twisti@3050 442 void trace_and_log_witness(klassOop witness);
duke@435 443
duke@435 444 public:
duke@435 445 DepStream(Dependencies* deps)
duke@435 446 : _deps(deps),
duke@435 447 _code(NULL),
duke@435 448 _bytes(deps->content_bytes())
duke@435 449 {
duke@435 450 initial_asserts(deps->size_in_bytes());
duke@435 451 }
duke@435 452 DepStream(nmethod* code)
duke@435 453 : _deps(NULL),
duke@435 454 _code(code),
duke@435 455 _bytes(code->dependencies_begin())
duke@435 456 {
duke@435 457 initial_asserts(code->dependencies_size());
duke@435 458 }
duke@435 459
duke@435 460 bool next();
duke@435 461
duke@435 462 DepType type() { return _type; }
duke@435 463 int argument_count() { return dep_args(type()); }
duke@435 464 int argument_index(int i) { assert(0 <= i && i < argument_count(), "oob");
duke@435 465 return _xi[i]; }
duke@435 466 oop argument(int i); // => recorded_oop_at(argument_index(i))
duke@435 467 klassOop context_type();
duke@435 468
twisti@3094 469 bool is_klass_type() { return Dependencies::is_klass_type(type()); }
twisti@3094 470
duke@435 471 methodOop method_argument(int i) {
duke@435 472 oop x = argument(i);
duke@435 473 assert(x->is_method(), "type");
duke@435 474 return (methodOop) x;
duke@435 475 }
duke@435 476 klassOop type_argument(int i) {
duke@435 477 oop x = argument(i);
duke@435 478 assert(x->is_klass(), "type");
duke@435 479 return (klassOop) x;
duke@435 480 }
duke@435 481
twisti@3050 482 // The point of the whole exercise: Is this dep still OK?
duke@435 483 klassOop check_dependency() {
twisti@3050 484 klassOop result = check_klass_dependency(NULL);
twisti@3050 485 if (result != NULL) return result;
twisti@3050 486 return check_call_site_dependency(NULL);
duke@435 487 }
twisti@3050 488
duke@435 489 // A lighter version: Checks only around recent changes in a class
duke@435 490 // hierarchy. (See Universe::flush_dependents_on.)
duke@435 491 klassOop spot_check_dependency_at(DepChange& changes);
duke@435 492
duke@435 493 // Log the current dependency to xtty or compilation log.
duke@435 494 void log_dependency(klassOop witness = NULL);
duke@435 495
duke@435 496 // Print the current dependency to tty.
duke@435 497 void print_dependency(klassOop witness = NULL, bool verbose = false);
duke@435 498 };
duke@435 499 friend class Dependencies::DepStream;
duke@435 500
duke@435 501 static void print_statistics() PRODUCT_RETURN;
duke@435 502 };
duke@435 503
twisti@3050 504
twisti@3050 505 // Every particular DepChange is a sub-class of this class.
duke@435 506 class DepChange : public StackObj {
phh@1558 507 public:
twisti@3050 508 // What kind of DepChange is this?
twisti@3050 509 virtual bool is_klass_change() const { return false; }
twisti@3050 510 virtual bool is_call_site_change() const { return false; }
twisti@3050 511
twisti@3050 512 // Subclass casting with assertions.
twisti@3050 513 KlassDepChange* as_klass_change() {
twisti@3050 514 assert(is_klass_change(), "bad cast");
twisti@3050 515 return (KlassDepChange*) this;
twisti@3050 516 }
twisti@3050 517 CallSiteDepChange* as_call_site_change() {
twisti@3050 518 assert(is_call_site_change(), "bad cast");
twisti@3050 519 return (CallSiteDepChange*) this;
twisti@3050 520 }
twisti@3050 521
twisti@3050 522 void print();
twisti@3050 523
twisti@3050 524 public:
duke@435 525 enum ChangeType {
duke@435 526 NO_CHANGE = 0, // an uninvolved klass
duke@435 527 Change_new_type, // a newly loaded type
duke@435 528 Change_new_sub, // a super with a new subtype
duke@435 529 Change_new_impl, // an interface with a new implementation
duke@435 530 CHANGE_LIMIT,
duke@435 531 Start_Klass = CHANGE_LIMIT // internal indicator for ContextStream
duke@435 532 };
duke@435 533
duke@435 534 // Usage:
duke@435 535 // for (DepChange::ContextStream str(changes); str.next(); ) {
duke@435 536 // klassOop k = str.klass();
duke@435 537 // switch (str.change_type()) {
duke@435 538 // ...
duke@435 539 // }
duke@435 540 // }
duke@435 541 class ContextStream : public StackObj {
duke@435 542 private:
phh@1558 543 DepChange& _changes;
duke@435 544 friend class DepChange;
duke@435 545
duke@435 546 // iteration variables:
phh@1558 547 ChangeType _change_type;
phh@1558 548 klassOop _klass;
phh@1558 549 objArrayOop _ti_base; // i.e., transitive_interfaces
phh@1558 550 int _ti_index;
phh@1558 551 int _ti_limit;
duke@435 552
duke@435 553 // start at the beginning:
twisti@3050 554 void start();
duke@435 555
phh@1558 556 public:
duke@435 557 ContextStream(DepChange& changes)
duke@435 558 : _changes(changes)
duke@435 559 { start(); }
duke@435 560
duke@435 561 ContextStream(DepChange& changes, No_Safepoint_Verifier& nsv)
duke@435 562 : _changes(changes)
duke@435 563 // the nsv argument makes it safe to hold oops like _klass
duke@435 564 { start(); }
duke@435 565
duke@435 566 bool next();
duke@435 567
phh@1558 568 ChangeType change_type() { return _change_type; }
duke@435 569 klassOop klass() { return _klass; }
duke@435 570 };
duke@435 571 friend class DepChange::ContextStream;
twisti@3050 572 };
duke@435 573
twisti@3050 574
twisti@3050 575 // A class hierarchy change coming through the VM (under the Compile_lock).
twisti@3050 576 // The change is structured as a single new type with any number of supers
twisti@3050 577 // and implemented interface types. Other than the new type, any of the
twisti@3050 578 // super types can be context types for a relevant dependency, which the
twisti@3050 579 // new type could invalidate.
twisti@3050 580 class KlassDepChange : public DepChange {
twisti@3050 581 private:
twisti@3050 582 // each change set is rooted in exactly one new type (at present):
twisti@3050 583 KlassHandle _new_type;
twisti@3050 584
twisti@3050 585 void initialize();
twisti@3050 586
twisti@3050 587 public:
twisti@3050 588 // notes the new type, marks it and all its super-types
twisti@3050 589 KlassDepChange(KlassHandle new_type)
twisti@3050 590 : _new_type(new_type)
twisti@3050 591 {
twisti@3050 592 initialize();
twisti@3050 593 }
twisti@3050 594
twisti@3050 595 // cleans up the marks
twisti@3050 596 ~KlassDepChange();
twisti@3050 597
twisti@3050 598 // What kind of DepChange is this?
twisti@3050 599 virtual bool is_klass_change() const { return true; }
twisti@3050 600
twisti@3050 601 klassOop new_type() { return _new_type(); }
twisti@3050 602
twisti@3050 603 // involves_context(k) is true if k is new_type or any of the super types
twisti@3050 604 bool involves_context(klassOop k);
twisti@3050 605 };
twisti@3050 606
twisti@3050 607
twisti@3050 608 // A CallSite has changed its target.
twisti@3050 609 class CallSiteDepChange : public DepChange {
twisti@3050 610 private:
twisti@3050 611 Handle _call_site;
twisti@3050 612 Handle _method_handle;
twisti@3050 613
twisti@3050 614 public:
twisti@3050 615 CallSiteDepChange(Handle call_site, Handle method_handle)
twisti@3050 616 : _call_site(call_site),
twisti@3050 617 _method_handle(method_handle)
twisti@3050 618 {
twisti@3050 619 assert(_call_site() ->is_a(SystemDictionary::CallSite_klass()), "must be");
twisti@3050 620 assert(_method_handle()->is_a(SystemDictionary::MethodHandle_klass()), "must be");
twisti@3050 621 }
twisti@3050 622
twisti@3050 623 // What kind of DepChange is this?
twisti@3050 624 virtual bool is_call_site_change() const { return true; }
twisti@3050 625
twisti@3050 626 oop call_site() const { return _call_site(); }
twisti@3050 627 oop method_handle() const { return _method_handle(); }
duke@435 628 };
stefank@2314 629
stefank@2314 630 #endif // SHARE_VM_CODE_DEPENDENCIES_HPP

mercurial