1 /*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 package sun.jvm.hotspot.code;
26
27 import java.io.*;
28 import java.util.*;
29 import sun.jvm.hotspot.debugger.*;
30 import sun.jvm.hotspot.oops.*;
31 import sun.jvm.hotspot.runtime.*;
32 import sun.jvm.hotspot.types.*;
33 import sun.jvm.hotspot.utilities.*;
34
35 public class NMethod extends CompiledMethod {
36 private static long pcDescSize;
37 /** != InvocationEntryBci if this nmethod is an on-stack replacement method */
38 private static CIntegerField entryBCIField;
39 /** To support simple linked-list chaining of nmethods */
40 private static AddressField osrLinkField;
41
42 /** Offsets for different nmethod parts */
43 private static CIntegerField exceptionOffsetField;
44 private static CIntegerField origPCOffsetField;
45 private static CIntegerField stubOffsetField;
46 private static CIntegerField oopsOffsetField;
47 private static CIntegerField metadataOffsetField;
48 private static CIntegerField scopesPCsOffsetField;
49 private static CIntegerField dependenciesOffsetField;
50 private static CIntegerField handlerTableOffsetField;
51 private static CIntegerField nulChkTableOffsetField;
52 private static CIntegerField nmethodEndOffsetField;
53
54 /** Offsets for entry points */
55 /** Entry point with class check */
56 private static AddressField entryPointField;
57 /** Entry point without class check */
58 private static AddressField verifiedEntryPointField;
59 /** Entry point for on stack replacement */
60 private static AddressField osrEntryPointField;
61
62 // FIXME: add access to flags (how?)
63
64 /** NMethod Flushing lock (if non-zero, then the nmethod is not removed) */
65 private static JIntField lockCountField;
66
67 /** not_entrant method removal. Each mark_sweep pass will update
68 this mark to current sweep invocation count if it is seen on the
69 stack. An not_entrant method can be removed when there is no
70 more activations, i.e., when the _stack_traversal_mark is less than
71 current sweep traversal index. */
72 private static CIntegerField stackTraversalMarkField;
73
74 private static CIntegerField compLevelField;
75
76 static {
77 VM.registerVMInitializedObserver(new Observer() {
78 public void update(Observable o, Object data) {
79 initialize(VM.getVM().getTypeDataBase());
80 }
81 });
82 }
83
84 private static void initialize(TypeDataBase db) {
85 Type type = db.lookupType("nmethod");
86
87 entryBCIField = type.getCIntegerField("_entry_bci");
88 osrLinkField = type.getAddressField("_osr_link");
89
90 exceptionOffsetField = type.getCIntegerField("_exception_offset");
91 origPCOffsetField = type.getCIntegerField("_orig_pc_offset");
92 stubOffsetField = type.getCIntegerField("_stub_offset");
93 oopsOffsetField = type.getCIntegerField("_oops_offset");
94 metadataOffsetField = type.getCIntegerField("_metadata_offset");
95 scopesPCsOffsetField = type.getCIntegerField("_scopes_pcs_offset");
96 dependenciesOffsetField = type.getCIntegerField("_dependencies_offset");
97 handlerTableOffsetField = type.getCIntegerField("_handler_table_offset");
98 nulChkTableOffsetField = type.getCIntegerField("_nul_chk_table_offset");
99 nmethodEndOffsetField = type.getCIntegerField("_nmethod_end_offset");
100 entryPointField = type.getAddressField("_entry_point");
101 verifiedEntryPointField = type.getAddressField("_verified_entry_point");
102 osrEntryPointField = type.getAddressField("_osr_entry_point");
103 lockCountField = type.getJIntField("_lock_count");
104 stackTraversalMarkField = type.getCIntegerField("_stack_traversal_mark");
105 compLevelField = type.getCIntegerField("_comp_level");
106 pcDescSize = db.lookupType("PcDesc").getSize();
107 }
108
109 public NMethod(Address addr) {
110 super(addr);
111 }
112
113 // Accessors
114 public Address getAddress() {
115 return addr;
116 }
117
118 // Type info
119 public boolean isNMethod() { return true; }
120 public boolean isJavaMethod() { return !getMethod().isNative(); }
121 public boolean isNativeMethod() { return getMethod().isNative(); }
122 public boolean isOSRMethod() { return getEntryBCI() != VM.getVM().getInvocationEntryBCI(); }
123
124 /** Boundaries for different parts */
125 public Address constantsBegin() { return contentBegin(); }
126 public Address constantsEnd() { return getEntryPoint(); }
127 public Address instsBegin() { return codeBegin(); }
128 public Address instsEnd() { return headerBegin().addOffsetTo(getStubOffset()); }
129 public Address exceptionBegin() { return headerBegin().addOffsetTo(getExceptionOffset()); }
130 public Address stubBegin() { return headerBegin().addOffsetTo(getStubOffset()); }
131 public Address stubEnd() { return headerBegin().addOffsetTo(getOopsOffset()); }
132 public Address oopsBegin() { return headerBegin().addOffsetTo(getOopsOffset()); }
133 public Address oopsEnd() { return headerBegin().addOffsetTo(getMetadataOffset()); }
134 public Address metadataBegin() { return headerBegin().addOffsetTo(getMetadataOffset()); }
135 public Address metadataEnd() { return scopesDataBegin(); }
136 public Address scopesDataEnd() { return headerBegin().addOffsetTo(getScopesPCsOffset()); }
137 public Address scopesPCsBegin() { return headerBegin().addOffsetTo(getScopesPCsOffset()); }
138 public Address scopesPCsEnd() { return headerBegin().addOffsetTo(getDependenciesOffset()); }
139 public Address dependenciesBegin() { return headerBegin().addOffsetTo(getDependenciesOffset()); }
140 public Address dependenciesEnd() { return headerBegin().addOffsetTo(getHandlerTableOffset()); }
141 public Address handlerTableBegin() { return headerBegin().addOffsetTo(getHandlerTableOffset()); }
142 public Address handlerTableEnd() { return headerBegin().addOffsetTo(getNulChkTableOffset()); }
143 public Address nulChkTableBegin() { return headerBegin().addOffsetTo(getNulChkTableOffset()); }
144 public Address nulChkTableEnd() { return headerBegin().addOffsetTo(getNMethodEndOffset()); }
145
146 public int constantsSize() { return (int) constantsEnd() .minus(constantsBegin()); }
147 public int instsSize() { return (int) instsEnd() .minus(instsBegin()); }
148 public int stubSize() { return (int) stubEnd() .minus(stubBegin()); }
149 public int oopsSize() { return (int) oopsEnd() .minus(oopsBegin()); }
150 public int metadataSize() { return (int) metadataEnd() .minus(metadataBegin()); }
151 public int scopesDataSize() { return (int) scopesDataEnd() .minus(scopesDataBegin()); }
152 public int scopesPCsSize() { return (int) scopesPCsEnd() .minus(scopesPCsBegin()); }
153 public int dependenciesSize() { return (int) dependenciesEnd().minus(dependenciesBegin()); }
154 public int handlerTableSize() { return (int) handlerTableEnd().minus(handlerTableBegin()); }
155 public int nulChkTableSize() { return (int) nulChkTableEnd() .minus(nulChkTableBegin()); }
156 public int origPCOffset() { return (int) origPCOffsetField.getValue(addr); }
157
158 public int totalSize() {
159 return
160 constantsSize() +
161 instsSize() +
162 stubSize() +
163 scopesDataSize() +
164 scopesPCsSize() +
165 dependenciesSize() +
166 handlerTableSize() +
167 nulChkTableSize();
168 }
169
170 public boolean constantsContains (Address addr) { return constantsBegin() .lessThanOrEqual(addr) && constantsEnd() .greaterThan(addr); }
171 public boolean instsContains (Address addr) { return instsBegin() .lessThanOrEqual(addr) && instsEnd() .greaterThan(addr); }
172 public boolean stubContains (Address addr) { return stubBegin() .lessThanOrEqual(addr) && stubEnd() .greaterThan(addr); }
173 public boolean oopsContains (Address addr) { return oopsBegin() .lessThanOrEqual(addr) && oopsEnd() .greaterThan(addr); }
174 public boolean metadataContains (Address addr) { return metadataBegin() .lessThanOrEqual(addr) && metadataEnd() .greaterThan(addr); }
175 public boolean scopesDataContains (Address addr) { return scopesDataBegin() .lessThanOrEqual(addr) && scopesDataEnd() .greaterThan(addr); }
176 public boolean scopesPCsContains (Address addr) { return scopesPCsBegin() .lessThanOrEqual(addr) && scopesPCsEnd() .greaterThan(addr); }
177 public boolean handlerTableContains(Address addr) { return handlerTableBegin().lessThanOrEqual(addr) && handlerTableEnd().greaterThan(addr); }
178 public boolean nulChkTableContains (Address addr) { return nulChkTableBegin() .lessThanOrEqual(addr) && nulChkTableEnd() .greaterThan(addr); }
179
180 public int getOopsLength() { return (int) (oopsSize() / VM.getVM().getOopSize()); }
181 public int getMetadataLength() { return (int) (metadataSize() / VM.getVM().getOopSize()); }
182
183 /** Entry points */
184 public Address getEntryPoint() { return entryPointField.getValue(addr); }
185 public Address getVerifiedEntryPoint() { return verifiedEntryPointField.getValue(addr); }
186
187 /** Support for oops in scopes and relocs. Note: index 0 is reserved for null. */
188 public OopHandle getOopAt(int index) {
189 if (index == 0) return null;
190 if (Assert.ASSERTS_ENABLED) {
191 Assert.that(index > 0 && index <= getOopsLength(), "must be a valid non-zero index");
192 }
193 return oopsBegin().getOopHandleAt((index - 1) * VM.getVM().getOopSize());
194 }
195
196 /** Support for metadata in scopes and relocs. Note: index 0 is reserved for null. */
197 public Address getMetadataAt(int index) {
198 if (index == 0) return null;
199 if (Assert.ASSERTS_ENABLED) {
200 Assert.that(index > 0 && index <= getMetadataLength(), "must be a valid non-zero index");
201 }
202 return metadataBegin().getAddressAt((index - 1) * VM.getVM().getOopSize());
203 }
204
205 public Method getMethodAt(int index) {
206 return (Method)Metadata.instantiateWrapperFor(getMetadataAt(index));
207 }
208
209 // FIXME: add interpreter_entry_point()
210 // FIXME: add lazy_interpreter_entry_point() for C2
211
212 // **********
213 // * FIXME: * ADD ACCESS TO FLAGS!!!!
214 // **********
215 // public boolean isInUse();
216 // public boolean isAlive();
217 // public boolean isNotEntrant();
218 // public boolean isZombie();
219
220 // ********************************
221 // * MAJOR FIXME: MAJOR HACK HERE *
222 // ********************************
223 public boolean isZombie() { return false; }
224
225 // public boolean isUnloaded();
226 // public boolean isYoung();
227 // public boolean isOld();
228 // public int age();
229 // public boolean isMarkedForDeoptimization();
230 // public boolean isMarkedForUnloading();
231 // public int level();
232 // public int version();
233
234 // FIXME: add mutators for above
235 // FIXME: add exception cache access?
236
237 /** On-stack replacement support */
238 // FIXME: add mutators
239 public int getOSREntryBCI() {
240 if (Assert.ASSERTS_ENABLED) {
241 Assert.that(getEntryBCI() != VM.getVM().getInvocationEntryBCI(), "wrong kind of nmethod");
242 }
243 return getEntryBCI();
244 }
245
246 public NMethod getOSRLink() {
247 return (NMethod) VMObjectFactory.newObject(NMethod.class, osrLinkField.getValue(addr));
248 }
249
250 // MethodHandle
251 public boolean isMethodHandleReturn(Address returnPc) {
252 // Hard to read a bit fields from Java and it's only there for performance
253 // so just go directly to the PCDesc
254 // if (!hasMethodHandleInvokes()) return false;
255 PCDesc pd = getPCDescAt(returnPc);
256 if (pd == null)
257 return false;
258 return pd.isMethodHandleInvoke();
259 }
260
261 // Deopt
262 // Return true is the PC is one would expect if the frame is being deopted.
263 public boolean isDeoptPc (Address pc) { return isDeoptEntry(pc) || isDeoptMhEntry(pc); }
264 public boolean isDeoptEntry (Address pc) { return pc == deoptHandlerBegin(); }
265 public boolean isDeoptMhEntry (Address pc) { return pc == deoptMhHandlerBegin(); }
266
267 /** Tells whether frames described by this nmethod can be
268 deoptimized. Note: native wrappers cannot be deoptimized. */
269 public boolean canBeDeoptimized() { return isJavaMethod(); }
270
271 // FIXME: add inline cache support
272 // FIXME: add flush()
273
274 public boolean isLockedByVM() { return lockCountField.getValue(addr) > 0; }
275
276 // FIXME: add mark_as_seen_on_stack
277 // FIXME: add can_not_entrant_be_converted
278
279 // FIXME: add GC support
280 // void follow_roots_or_mark_for_unloading(bool unloading_occurred, bool& marked_for_unloading);
281 // void follow_root_or_mark_for_unloading(oop* root, bool unloading_occurred, bool& marked_for_unloading);
282 // void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, void f(oop*));
283 // void adjust_pointers();
284
285 /** Finds a PCDesc with real-pc equal to "pc" */
286 public PCDesc getPCDescAt(Address pc) {
287 // FIXME: consider adding cache like the one down in the VM
288 for (Address p = scopesPCsBegin(); p.lessThan(scopesPCsEnd()); p = p.addOffsetTo(pcDescSize)) {
289 PCDesc pcDesc = new PCDesc(p);
290 if (pcDesc.getRealPC(this).equals(pc)) {
291 return pcDesc;
292 }
293 }
294 return null;
295 }
296
297 /** ScopeDesc for an instruction */
298 public ScopeDesc getScopeDescAt(Address pc) {
299 PCDesc pd = getPCDescAt(pc);
300 if (Assert.ASSERTS_ENABLED) {
301 Assert.that(pd != null, "scope must be present");
302 }
303 return new ScopeDesc(this, pd.getScopeDecodeOffset(), pd.getObjDecodeOffset(), pd.getReexecute());
304 }
305
306 /** This is only for use by the debugging system, and is only
307 intended for use in the topmost frame, where we are not
308 guaranteed to be at a PC for which we have a PCDesc. It finds
309 the PCDesc with realPC closest to the current PC. */
310 public PCDesc getPCDescNearDbg(Address pc) {
311 PCDesc bestGuessPCDesc = null;
312 long bestDistance = 0;
313 for (Address p = scopesPCsBegin(); p.lessThan(scopesPCsEnd()); p = p.addOffsetTo(pcDescSize)) {
314 PCDesc pcDesc = new PCDesc(p);
315 // In case pc is null
316 long distance = -pcDesc.getRealPC(this).minus(pc);
317 if ((bestGuessPCDesc == null) ||
318 ((distance >= 0) && (distance < bestDistance))) {
319 bestGuessPCDesc = pcDesc;
320 bestDistance = distance;
321 }
322 }
323 return bestGuessPCDesc;
324 }
325
326 PCDesc find_pc_desc(long pc, boolean approximate) {
327 return find_pc_desc_internal(pc, approximate);
328 }
329
330 // Finds a PcDesc with real-pc equal to "pc"
331 PCDesc find_pc_desc_internal(long pc, boolean approximate) {
332 long base_address = VM.getAddressValue(codeBegin());
333 int pc_offset = (int) (pc - base_address);
334
335 // Fallback algorithm: quasi-linear search for the PcDesc
336 // Find the last pc_offset less than the given offset.
337 // The successor must be the required match, if there is a match at all.
338 // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
339 Address lower = scopesPCsBegin();
340 Address upper = scopesPCsEnd();
341 upper = upper.addOffsetTo(-pcDescSize); // exclude final sentinel
342 if (lower.greaterThan(upper)) return null; // native method; no PcDescs at all
343
344 // Take giant steps at first (4096, then 256, then 16, then 1)
345 int LOG2_RADIX = 4;
346 int RADIX = (1 << LOG2_RADIX);
347 Address mid;
348 for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
349 while ((mid = lower.addOffsetTo(step * pcDescSize)).lessThan(upper)) {
350 PCDesc m = new PCDesc(mid);
351 if (m.getPCOffset() < pc_offset) {
352 lower = mid;
353 } else {
354 upper = mid;
355 break;
356 }
357 }
358 }
359 // Sneak up on the value with a linear search of length ~16.
360 while (true) {
361 mid = lower.addOffsetTo(pcDescSize);
362 PCDesc m = new PCDesc(mid);
363 if (m.getPCOffset() < pc_offset) {
364 lower = mid;
365 } else {
366 upper = mid;
367 break;
368 }
369 }
370
371 PCDesc u = new PCDesc(upper);
372 if (match_desc(u, pc_offset, approximate)) {
373 return u;
374 } else {
375 return null;
376 }
377 }
378
379 // ScopeDesc retrieval operation
380 PCDesc pc_desc_at(long pc) { return find_pc_desc(pc, false); }
381 // pc_desc_near returns the first PCDesc at or after the givne pc.
382 PCDesc pc_desc_near(long pc) { return find_pc_desc(pc, true); }
383
384 // Return a the last scope in (begin..end]
385 public ScopeDesc scope_desc_in(long begin, long end) {
386 PCDesc p = pc_desc_near(begin+1);
387 if (p != null && VM.getAddressValue(p.getRealPC(this)) <= end) {
388 return new ScopeDesc(this, p.getScopeDecodeOffset(), p.getObjDecodeOffset(), p.getReexecute());
389 }
390 return null;
391 }
392
393 static boolean match_desc(PCDesc pc, int pc_offset, boolean approximate) {
394 if (!approximate) {
395 return pc.getPCOffset() == pc_offset;
396 } else {
397 PCDesc prev = new PCDesc(pc.getAddress().addOffsetTo(-pcDescSize));
398 return prev.getPCOffset() < pc_offset && pc_offset <= pc.getPCOffset();
399 }
400 }
401
402 /** This is only for use by the debugging system, and is only
403 intended for use in the topmost frame, where we are not
404 guaranteed to be at a PC for which we have a PCDesc. It finds
405 the ScopeDesc closest to the current PC. NOTE that this may
406 return NULL for compiled methods which don't have any
407 ScopeDescs! */
408 public ScopeDesc getScopeDescNearDbg(Address pc) {
409 PCDesc pd = getPCDescNearDbg(pc);
410 if (pd == null) return null;
411 return new ScopeDesc(this, pd.getScopeDecodeOffset(), pd.getObjDecodeOffset(), pd.getReexecute());
412 }
413
414 public Map/*<Address, PCDesc>*/ getSafepoints() {
415 Map safepoints = new HashMap(); // Map<Address, PCDesc>
416 sun.jvm.hotspot.debugger.Address p = null;
417 for (p = scopesPCsBegin(); p.lessThan(scopesPCsEnd());
418 p = p.addOffsetTo(pcDescSize)) {
419 PCDesc pcDesc = new PCDesc(p);
420 sun.jvm.hotspot.debugger.Address pc = pcDesc.getRealPC(this);
421 safepoints.put(pc, pcDesc);
422 }
423 return safepoints;
424 }
425
426 // FIXME: add getPCOffsetForBCI()
427 // FIXME: add embeddedOopAt()
428 // FIXME: add isDependentOn()
429 // FIXME: add isPatchableAt()
430
431 /** Support for code generation. Only here for proof-of-concept. */
432 public static int getEntryPointOffset() { return (int) entryPointField.getOffset(); }
433 public static int getVerifiedEntryPointOffset() { return (int) verifiedEntryPointField.getOffset(); }
434 public static int getOSREntryPointOffset() { return (int) osrEntryPointField.getOffset(); }
435 public static int getEntryBCIOffset() { return (int) entryBCIField.getOffset(); }
436
437 public void print() {
438 printOn(System.out);
439 }
440
441 protected void printComponentsOn(PrintStream tty) {
442 // FIXME: add relocation information
443 tty.println(" content: [" + contentBegin() + ", " + contentEnd() + "), " +
444 " code: [" + codeBegin() + ", " + codeEnd() + "), " +
445 " data: [" + dataBegin() + ", " + dataEnd() + "), " +
446 " oops: [" + oopsBegin() + ", " + oopsEnd() + "), " +
447 " frame size: " + getFrameSize());
448 }
449
450 public String toString() {
451 Method method = getMethod();
452 return "NMethod for " +
453 method.getMethodHolder().getName().asString() + "." +
454 method.getName().asString() + method.getSignature().asString() + "==>n" +
455 super.toString();
456 }
457
458 public String flagsToString() {
459 // FIXME need access to flags...
460 return "";
461 }
462
463 public String getName() {
464 Method method = getMethod();
465 return "NMethod for " +
466 method.getMethodHolder().getName().asString() + "." +
467 method.getName().asString() +
468 method.getSignature().asString();
469 }
470
471 public void dumpReplayData(PrintStream out) {
472 HashMap h = new HashMap();
473 for (int i = 1; i < getMetadataLength(); i++) {
474 Metadata meta = Metadata.instantiateWrapperFor(getMetadataAt(i));
475 System.err.println(meta);
476 if (h.get(meta) != null) continue;
477 h.put(meta, meta);
478 if (meta instanceof InstanceKlass) {
479 ((InstanceKlass)meta).dumpReplayData(out);
480 } else if (meta instanceof Method) {
481 ((Method)meta).dumpReplayData(out);
482 MethodData mdo = ((Method)meta).getMethodData();
483 if (mdo != null) {
484 mdo.dumpReplayData(out);
485 }
486 }
487 }
488 Method method = getMethod();
489 if (h.get(method) == null) {
490 method.dumpReplayData(out);
491 MethodData mdo = method.getMethodData();
492 if (mdo != null) {
493 mdo.dumpReplayData(out);
494 }
495 }
496 if (h.get(method.getMethodHolder()) == null) {
497 ((InstanceKlass)method.getMethodHolder()).dumpReplayData(out);
498 }
499 Klass holder = method.getMethodHolder();
500 out.println("compile " + holder.getName().asString() + " " +
501 OopUtilities.escapeString(method.getName().asString()) + " " +
502 method.getSignature().asString() + " " +
503 getEntryBCI() + " " + getCompLevel());
504
505 }
506
507 //--------------------------------------------------------------------------------
508 // Internals only below this point
509 //
510
511 private int getEntryBCI() { return (int) entryBCIField .getValue(addr); }
512 private int getExceptionOffset() { return (int) exceptionOffsetField .getValue(addr); }
513 private int getStubOffset() { return (int) stubOffsetField .getValue(addr); }
514 private int getOopsOffset() { return (int) oopsOffsetField .getValue(addr); }
515 private int getMetadataOffset() { return (int) metadataOffsetField .getValue(addr); }
516 private int getScopesPCsOffset() { return (int) scopesPCsOffsetField .getValue(addr); }
517 private int getDependenciesOffset() { return (int) dependenciesOffsetField.getValue(addr); }
518 private int getHandlerTableOffset() { return (int) handlerTableOffsetField.getValue(addr); }
519 private int getNulChkTableOffset() { return (int) nulChkTableOffsetField .getValue(addr); }
520 private int getNMethodEndOffset() { return (int) nmethodEndOffsetField .getValue(addr); }
521 private int getCompLevel() { return (int) compLevelField .getValue(addr); }
522 }