Mon, 10 Jan 2011 18:46:29 -0800
4930919: race condition in MDO creation at back branch locations
Summary: Reuse set_method_data_for_bcp() to setup mdp after MDO creation.
Reviewed-by: kvn, never
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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23 */
25 #include "precompiled.hpp"
26 #include "c1/c1_MacroAssembler.hpp"
27 #include "c1/c1_Runtime1.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "gc_interface/collectedHeap.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "oops/arrayOop.hpp"
32 #include "oops/markOop.hpp"
33 #include "runtime/basicLock.hpp"
34 #include "runtime/biasedLocking.hpp"
35 #include "runtime/os.hpp"
36 #include "runtime/stubRoutines.hpp"
38 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
39 Label L;
40 const Register temp_reg = G3_scratch;
41 // Note: needs more testing of out-of-line vs. inline slow case
42 verify_oop(receiver);
43 load_klass(receiver, temp_reg);
44 cmp(temp_reg, iCache);
45 brx(Assembler::equal, true, Assembler::pt, L);
46 delayed()->nop();
47 AddressLiteral ic_miss(SharedRuntime::get_ic_miss_stub());
48 jump_to(ic_miss, temp_reg);
49 delayed()->nop();
50 align(CodeEntryAlignment);
51 bind(L);
52 }
55 void C1_MacroAssembler::explicit_null_check(Register base) {
56 Unimplemented();
57 }
60 void C1_MacroAssembler::build_frame(int frame_size_in_bytes) {
62 generate_stack_overflow_check(frame_size_in_bytes);
63 // Create the frame.
64 save_frame_c1(frame_size_in_bytes);
65 }
68 void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
69 if (C1Breakpoint) breakpoint_trap();
70 inline_cache_check(receiver, ic_klass);
71 }
74 void C1_MacroAssembler::verified_entry() {
75 if (C1Breakpoint) breakpoint_trap();
76 // build frame
77 verify_FPU(0, "method_entry");
78 }
81 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
82 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
84 Label done;
86 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
88 // The following move must be the first instruction of emitted since debug
89 // information may be generated for it.
90 // Load object header
91 ld_ptr(mark_addr, Rmark);
93 verify_oop(Roop);
95 // save object being locked into the BasicObjectLock
96 st_ptr(Roop, Rbox, BasicObjectLock::obj_offset_in_bytes());
98 if (UseBiasedLocking) {
99 biased_locking_enter(Roop, Rmark, Rscratch, done, &slow_case);
100 }
102 // Save Rbox in Rscratch to be used for the cas operation
103 mov(Rbox, Rscratch);
105 // and mark it unlocked
106 or3(Rmark, markOopDesc::unlocked_value, Rmark);
108 // save unlocked object header into the displaced header location on the stack
109 st_ptr(Rmark, Rbox, BasicLock::displaced_header_offset_in_bytes());
111 // compare object markOop with Rmark and if equal exchange Rscratch with object markOop
112 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
113 casx_under_lock(mark_addr.base(), Rmark, Rscratch, (address)StubRoutines::Sparc::atomic_memory_operation_lock_addr());
114 // if compare/exchange succeeded we found an unlocked object and we now have locked it
115 // hence we are done
116 cmp(Rmark, Rscratch);
117 brx(Assembler::equal, false, Assembler::pt, done);
118 delayed()->sub(Rscratch, SP, Rscratch); //pull next instruction into delay slot
119 // we did not find an unlocked object so see if this is a recursive case
120 // sub(Rscratch, SP, Rscratch);
121 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
122 andcc(Rscratch, 0xfffff003, Rscratch);
123 brx(Assembler::notZero, false, Assembler::pn, slow_case);
124 delayed()->st_ptr(Rscratch, Rbox, BasicLock::displaced_header_offset_in_bytes());
125 bind(done);
126 }
129 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
130 assert_different_registers(Rmark, Roop, Rbox);
132 Label done;
134 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
135 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
137 if (UseBiasedLocking) {
138 // load the object out of the BasicObjectLock
139 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
140 verify_oop(Roop);
141 biased_locking_exit(mark_addr, Rmark, done);
142 }
143 // Test first it it is a fast recursive unlock
144 ld_ptr(Rbox, BasicLock::displaced_header_offset_in_bytes(), Rmark);
145 br_null(Rmark, false, Assembler::pt, done);
146 delayed()->nop();
147 if (!UseBiasedLocking) {
148 // load object
149 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
150 verify_oop(Roop);
151 }
153 // Check if it is still a light weight lock, this is is true if we see
154 // the stack address of the basicLock in the markOop of the object
155 casx_under_lock(mark_addr.base(), Rbox, Rmark, (address)StubRoutines::Sparc::atomic_memory_operation_lock_addr());
156 cmp(Rbox, Rmark);
158 brx(Assembler::notEqual, false, Assembler::pn, slow_case);
159 delayed()->nop();
160 // Done
161 bind(done);
162 }
165 void C1_MacroAssembler::try_allocate(
166 Register obj, // result: pointer to object after successful allocation
167 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
168 int con_size_in_bytes, // object size in bytes if known at compile time
169 Register t1, // temp register
170 Register t2, // temp register
171 Label& slow_case // continuation point if fast allocation fails
172 ) {
173 if (UseTLAB) {
174 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
175 } else {
176 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
177 }
178 }
181 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
182 assert_different_registers(obj, klass, len, t1, t2);
183 if (UseBiasedLocking && !len->is_valid()) {
184 ld_ptr(klass, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes(), t1);
185 } else {
186 set((intx)markOopDesc::prototype(), t1);
187 }
188 st_ptr(t1, obj, oopDesc::mark_offset_in_bytes());
189 if (UseCompressedOops) {
190 // Save klass
191 mov(klass, t1);
192 encode_heap_oop_not_null(t1);
193 stw(t1, obj, oopDesc::klass_offset_in_bytes());
194 } else {
195 st_ptr(klass, obj, oopDesc::klass_offset_in_bytes());
196 }
197 if (len->is_valid()) st(len, obj, arrayOopDesc::length_offset_in_bytes());
198 else if (UseCompressedOops) {
199 store_klass_gap(G0, obj);
200 }
201 }
204 void C1_MacroAssembler::initialize_body(Register base, Register index) {
205 assert_different_registers(base, index);
206 Label loop;
207 bind(loop);
208 subcc(index, HeapWordSize, index);
209 brx(Assembler::greaterEqual, true, Assembler::pt, loop);
210 delayed()->st_ptr(G0, base, index);
211 }
214 void C1_MacroAssembler::allocate_object(
215 Register obj, // result: pointer to object after successful allocation
216 Register t1, // temp register
217 Register t2, // temp register
218 Register t3, // temp register
219 int hdr_size, // object header size in words
220 int obj_size, // object size in words
221 Register klass, // object klass
222 Label& slow_case // continuation point if fast allocation fails
223 ) {
224 assert_different_registers(obj, t1, t2, t3, klass);
225 assert(klass == G5, "must be G5");
227 // allocate space & initialize header
228 if (!is_simm13(obj_size * wordSize)) {
229 // would need to use extra register to load
230 // object size => go the slow case for now
231 br(Assembler::always, false, Assembler::pt, slow_case);
232 delayed()->nop();
233 return;
234 }
235 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
237 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
238 }
240 void C1_MacroAssembler::initialize_object(
241 Register obj, // result: pointer to object after successful allocation
242 Register klass, // object klass
243 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
244 int con_size_in_bytes, // object size in bytes if known at compile time
245 Register t1, // temp register
246 Register t2 // temp register
247 ) {
248 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
250 initialize_header(obj, klass, noreg, t1, t2);
252 #ifdef ASSERT
253 {
254 Label ok;
255 ld(klass, klassOopDesc::header_size() * HeapWordSize + Klass::layout_helper_offset_in_bytes(), t1);
256 if (var_size_in_bytes != noreg) {
257 cmp(t1, var_size_in_bytes);
258 } else {
259 cmp(t1, con_size_in_bytes);
260 }
261 brx(Assembler::equal, false, Assembler::pt, ok);
262 delayed()->nop();
263 stop("bad size in initialize_object");
264 should_not_reach_here();
266 bind(ok);
267 }
269 #endif
271 // initialize body
272 const int threshold = 5 * HeapWordSize; // approximate break even point for code size
273 if (var_size_in_bytes != noreg) {
274 // use a loop
275 add(obj, hdr_size_in_bytes, t1); // compute address of first element
276 sub(var_size_in_bytes, hdr_size_in_bytes, t2); // compute size of body
277 initialize_body(t1, t2);
278 #ifndef _LP64
279 } else if (VM_Version::v9_instructions_work() && con_size_in_bytes < threshold * 2) {
280 // on v9 we can do double word stores to fill twice as much space.
281 assert(hdr_size_in_bytes % 8 == 0, "double word aligned");
282 assert(con_size_in_bytes % 8 == 0, "double word aligned");
283 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += 2 * HeapWordSize) stx(G0, obj, i);
284 #endif
285 } else if (con_size_in_bytes <= threshold) {
286 // use explicit NULL stores
287 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += HeapWordSize) st_ptr(G0, obj, i);
288 } else if (con_size_in_bytes > hdr_size_in_bytes) {
289 // use a loop
290 const Register base = t1;
291 const Register index = t2;
292 add(obj, hdr_size_in_bytes, base); // compute address of first element
293 // compute index = number of words to clear
294 set(con_size_in_bytes - hdr_size_in_bytes, index);
295 initialize_body(base, index);
296 }
298 if (CURRENT_ENV->dtrace_alloc_probes()) {
299 assert(obj == O0, "must be");
300 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
301 relocInfo::runtime_call_type);
302 delayed()->nop();
303 }
305 verify_oop(obj);
306 }
309 void C1_MacroAssembler::allocate_array(
310 Register obj, // result: pointer to array after successful allocation
311 Register len, // array length
312 Register t1, // temp register
313 Register t2, // temp register
314 Register t3, // temp register
315 int hdr_size, // object header size in words
316 int elt_size, // element size in bytes
317 Register klass, // object klass
318 Label& slow_case // continuation point if fast allocation fails
319 ) {
320 assert_different_registers(obj, len, t1, t2, t3, klass);
321 assert(klass == G5, "must be G5");
322 assert(t1 == G1, "must be G1");
324 // determine alignment mask
325 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
327 // check for negative or excessive length
328 // note: the maximum length allowed is chosen so that arrays of any
329 // element size with this length are always smaller or equal
330 // to the largest integer (i.e., array size computation will
331 // not overflow)
332 set(max_array_allocation_length, t1);
333 cmp(len, t1);
334 br(Assembler::greaterUnsigned, false, Assembler::pn, slow_case);
336 // compute array size
337 // note: if 0 <= len <= max_length, len*elt_size + header + alignment is
338 // smaller or equal to the largest integer; also, since top is always
339 // aligned, we can do the alignment here instead of at the end address
340 // computation
341 const Register arr_size = t1;
342 switch (elt_size) {
343 case 1: delayed()->mov(len, arr_size); break;
344 case 2: delayed()->sll(len, 1, arr_size); break;
345 case 4: delayed()->sll(len, 2, arr_size); break;
346 case 8: delayed()->sll(len, 3, arr_size); break;
347 default: ShouldNotReachHere();
348 }
349 add(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask, arr_size); // add space for header & alignment
350 and3(arr_size, ~MinObjAlignmentInBytesMask, arr_size); // align array size
352 // allocate space & initialize header
353 if (UseTLAB) {
354 tlab_allocate(obj, arr_size, 0, t2, slow_case);
355 } else {
356 eden_allocate(obj, arr_size, 0, t2, t3, slow_case);
357 }
358 initialize_header(obj, klass, len, t2, t3);
360 // initialize body
361 const Register base = t2;
362 const Register index = t3;
363 add(obj, hdr_size * wordSize, base); // compute address of first element
364 sub(arr_size, hdr_size * wordSize, index); // compute index = number of words to clear
365 initialize_body(base, index);
367 if (CURRENT_ENV->dtrace_alloc_probes()) {
368 assert(obj == O0, "must be");
369 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
370 relocInfo::runtime_call_type);
371 delayed()->nop();
372 }
374 verify_oop(obj);
375 }
378 #ifndef PRODUCT
380 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
381 if (!VerifyOops) return;
382 verify_oop_addr(Address(SP, stack_offset + STACK_BIAS));
383 }
385 void C1_MacroAssembler::verify_not_null_oop(Register r) {
386 Label not_null;
387 br_zero(Assembler::notEqual, false, Assembler::pt, r, not_null);
388 delayed()->nop();
389 stop("non-null oop required");
390 bind(not_null);
391 if (!VerifyOops) return;
392 verify_oop(r);
393 }
395 void C1_MacroAssembler::invalidate_registers(bool iregisters, bool lregisters, bool oregisters,
396 Register preserve1, Register preserve2) {
397 if (iregisters) {
398 for (int i = 0; i < 6; i++) {
399 Register r = as_iRegister(i);
400 if (r != preserve1 && r != preserve2) set(0xdead, r);
401 }
402 }
403 if (oregisters) {
404 for (int i = 0; i < 6; i++) {
405 Register r = as_oRegister(i);
406 if (r != preserve1 && r != preserve2) set(0xdead, r);
407 }
408 }
409 if (lregisters) {
410 for (int i = 0; i < 8; i++) {
411 Register r = as_lRegister(i);
412 if (r != preserve1 && r != preserve2) set(0xdead, r);
413 }
414 }
415 }
418 #endif