Tue, 24 Sep 2013 15:56:25 +0200
7009641: Don't fail VM when CodeCache is full
Summary: Allocation in the code cache returns NULL instead of failing the entire VM
Reviewed-by: kvn, iveresov
1 /*
2 * Copyright (c) 2003, 2012, 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.
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23 */
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "code/vtableStubs.hpp"
28 #include "interp_masm_x86_64.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/klassVtable.hpp"
32 #include "runtime/sharedRuntime.hpp"
33 #include "vmreg_x86.inline.hpp"
34 #ifdef COMPILER2
35 #include "opto/runtime.hpp"
36 #endif
38 // machine-dependent part of VtableStubs: create VtableStub of correct size and
39 // initialize its code
41 #define __ masm->
43 #ifndef PRODUCT
44 extern "C" void bad_compiled_vtable_index(JavaThread* thread,
45 oop receiver,
46 int index);
47 #endif
49 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
50 const int amd64_code_length = VtableStub::pd_code_size_limit(true);
51 VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);
52 // Can be NULL if there is no free space in the code cache.
53 if (s == NULL) {
54 return NULL;
55 }
57 ResourceMark rm;
58 CodeBuffer cb(s->entry_point(), amd64_code_length);
59 MacroAssembler* masm = new MacroAssembler(&cb);
61 #ifndef PRODUCT
62 if (CountCompiledCalls) {
63 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
64 }
65 #endif
67 // get receiver (need to skip return address on top of stack)
68 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
70 // Free registers (non-args) are rax, rbx
72 // get receiver klass
73 address npe_addr = __ pc();
74 __ load_klass(rax, j_rarg0);
76 #ifndef PRODUCT
77 if (DebugVtables) {
78 Label L;
79 // check offset vs vtable length
80 __ cmpl(Address(rax, InstanceKlass::vtable_length_offset() * wordSize),
81 vtable_index * vtableEntry::size());
82 __ jcc(Assembler::greater, L);
83 __ movl(rbx, vtable_index);
84 __ call_VM(noreg,
85 CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);
86 __ bind(L);
87 }
88 #endif // PRODUCT
90 // load Method* and target address
91 const Register method = rbx;
93 __ lookup_virtual_method(rax, vtable_index, method);
95 if (DebugVtables) {
96 Label L;
97 __ cmpptr(method, (int32_t)NULL_WORD);
98 __ jcc(Assembler::equal, L);
99 __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD);
100 __ jcc(Assembler::notZero, L);
101 __ stop("Vtable entry is NULL");
102 __ bind(L);
103 }
104 // rax: receiver klass
105 // rbx: Method*
106 // rcx: receiver
107 address ame_addr = __ pc();
108 __ jmp( Address(rbx, Method::from_compiled_offset()));
110 __ flush();
112 if (PrintMiscellaneous && (WizardMode || Verbose)) {
113 tty->print_cr("vtable #%d at "PTR_FORMAT"[%d] left over: %d",
114 vtable_index, s->entry_point(),
115 (int)(s->code_end() - s->entry_point()),
116 (int)(s->code_end() - __ pc()));
117 }
118 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
119 // shut the door on sizing bugs
120 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
121 assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
123 s->set_exception_points(npe_addr, ame_addr);
124 return s;
125 }
128 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
129 // Note well: pd_code_size_limit is the absolute minimum we can get
130 // away with. If you add code here, bump the code stub size
131 // returned by pd_code_size_limit!
132 const int amd64_code_length = VtableStub::pd_code_size_limit(false);
133 VtableStub* s = new(amd64_code_length) VtableStub(false, itable_index);
134 // Can be NULL if there is no free space in the code cache.
135 if (s == NULL) {
136 return NULL;
137 }
139 ResourceMark rm;
140 CodeBuffer cb(s->entry_point(), amd64_code_length);
141 MacroAssembler* masm = new MacroAssembler(&cb);
143 #ifndef PRODUCT
144 if (CountCompiledCalls) {
145 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
146 }
147 #endif
149 // Entry arguments:
150 // rax: Interface
151 // j_rarg0: Receiver
153 // Free registers (non-args) are rax (interface), rbx
155 // get receiver (need to skip return address on top of stack)
157 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
158 // get receiver klass (also an implicit null-check)
159 address npe_addr = __ pc();
161 // Most registers are in use; we'll use rax, rbx, r10, r11
162 // (various calling sequences use r[cd]x, r[sd]i, r[89]; stay away from them)
163 __ load_klass(r10, j_rarg0);
165 // If we take a trap while this arg is on the stack we will not
166 // be able to walk the stack properly. This is not an issue except
167 // when there are mistakes in this assembly code that could generate
168 // a spurious fault. Ask me how I know...
170 const Register method = rbx;
171 Label throw_icce;
173 // Get Method* and entrypoint for compiler
174 __ lookup_interface_method(// inputs: rec. class, interface, itable index
175 r10, rax, itable_index,
176 // outputs: method, scan temp. reg
177 method, r11,
178 throw_icce);
180 // method (rbx): Method*
181 // j_rarg0: receiver
183 #ifdef ASSERT
184 if (DebugVtables) {
185 Label L2;
186 __ cmpptr(method, (int32_t)NULL_WORD);
187 __ jcc(Assembler::equal, L2);
188 __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD);
189 __ jcc(Assembler::notZero, L2);
190 __ stop("compiler entrypoint is null");
191 __ bind(L2);
192 }
193 #endif // ASSERT
195 // rbx: Method*
196 // j_rarg0: receiver
197 address ame_addr = __ pc();
198 __ jmp(Address(method, Method::from_compiled_offset()));
200 __ bind(throw_icce);
201 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
203 __ flush();
205 if (PrintMiscellaneous && (WizardMode || Verbose)) {
206 tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d",
207 itable_index, s->entry_point(),
208 (int)(s->code_end() - s->entry_point()),
209 (int)(s->code_end() - __ pc()));
210 }
211 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
212 // shut the door on sizing bugs
213 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
214 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
216 s->set_exception_points(npe_addr, ame_addr);
217 return s;
218 }
220 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
221 if (is_vtable_stub) {
222 // Vtable stub size
223 return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0) +
224 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0);
225 } else {
226 // Itable stub size
227 return (DebugVtables ? 512 : 74) + (CountCompiledCalls ? 13 : 0) +
228 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0);
229 }
230 // In order to tune these parameters, run the JVM with VM options
231 // +PrintMiscellaneous and +WizardMode to see information about
232 // actual itable stubs. Look for lines like this:
233 // itable #1 at 0x5551212[71] left over: 3
234 // Reduce the constants so that the "left over" number is >=3
235 // for the common cases.
236 // Do not aim at a left-over number of zero, because a
237 // large vtable or itable index (>= 32) will require a 32-bit
238 // immediate displacement instead of an 8-bit one.
239 //
240 // The JVM98 app. _202_jess has a megamorphic interface call.
241 // The itable code looks like this:
242 // Decoding VtableStub itbl[1]@12
243 // mov 0x8(%rsi),%r10
244 // mov 0x198(%r10),%r11d
245 // lea 0x218(%r10,%r11,8),%r11
246 // lea 0x8(%r10),%r10
247 // mov (%r11),%rbx
248 // cmp %rbx,%rax
249 // je success
250 // loop:
251 // test %rbx,%rbx
252 // je throw_icce
253 // add $0x10,%r11
254 // mov (%r11),%rbx
255 // cmp %rbx,%rax
256 // jne loop
257 // success:
258 // mov 0x8(%r11),%r11d
259 // mov (%r10,%r11,1),%rbx
260 // jmpq *0x60(%rbx)
261 // throw_icce:
262 // jmpq throw_ICCE_entry
263 }
265 int VtableStub::pd_code_alignment() {
266 return wordSize;
267 }