Mercurial > hg > graal-compiler
view src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp @ 3430:089aee76df10
Merge
author | asaha |
---|---|
date | Wed, 04 May 2011 16:38:05 -0700 |
parents | 1d1603768966 |
children | da4be62fb889 |
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/* * Copyright (c) 1999, 2011, 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. * */ // no precompiled headers #include "assembler_sparc.inline.hpp" #include "classfile/classLoader.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/vmSymbols.hpp" #include "code/icBuffer.hpp" #include "code/vtableStubs.hpp" #include "interpreter/interpreter.hpp" #include "jvm_linux.h" #include "memory/allocation.inline.hpp" #include "mutex_linux.inline.hpp" #include "nativeInst_sparc.hpp" #include "os_share_linux.hpp" #include "prims/jniFastGetField.hpp" #include "prims/jvm.h" #include "prims/jvm_misc.hpp" #include "runtime/arguments.hpp" #include "runtime/extendedPC.hpp" #include "runtime/frame.inline.hpp" #include "runtime/interfaceSupport.hpp" #include "runtime/java.hpp" #include "runtime/javaCalls.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/osThread.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/stubRoutines.hpp" #include "runtime/timer.hpp" #include "thread_linux.inline.hpp" #include "utilities/events.hpp" #include "utilities/vmError.hpp" #ifdef COMPILER1 #include "c1/c1_Runtime1.hpp" #endif #ifdef COMPILER2 #include "opto/runtime.hpp" #endif // Linux/Sparc has rather obscure naming of registers in sigcontext // different between 32 and 64 bits #ifdef _LP64 #define SIG_PC(x) ((x)->sigc_regs.tpc) #define SIG_NPC(x) ((x)->sigc_regs.tnpc) #define SIG_REGS(x) ((x)->sigc_regs) #else #define SIG_PC(x) ((x)->si_regs.pc) #define SIG_NPC(x) ((x)->si_regs.npc) #define SIG_REGS(x) ((x)->si_regs) #endif // those are to reference registers in sigcontext enum { CON_G0 = 0, CON_G1, CON_G2, CON_G3, CON_G4, CON_G5, CON_G6, CON_G7, CON_O0, CON_O1, CON_O2, CON_O3, CON_O4, CON_O5, CON_O6, CON_O7, }; static inline void set_cont_address(sigcontext* ctx, address addr) { SIG_PC(ctx) = (intptr_t)addr; SIG_NPC(ctx) = (intptr_t)(addr+4); } // For Forte Analyzer AsyncGetCallTrace profiling support - thread is // currently interrupted by SIGPROF. // os::Solaris::fetch_frame_from_ucontext() tries to skip nested // signal frames. Currently we don't do that on Linux, so it's the // same as os::fetch_frame_from_context(). ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { assert(thread != NULL, "just checking"); assert(ret_sp != NULL, "just checking"); assert(ret_fp != NULL, "just checking"); return os::fetch_frame_from_context(uc, ret_sp, ret_fp); } ExtendedPC os::fetch_frame_from_context(void* ucVoid, intptr_t** ret_sp, intptr_t** ret_fp) { ucontext_t* uc = (ucontext_t*) ucVoid; ExtendedPC epc; if (uc != NULL) { epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); if (ret_sp) { *ret_sp = os::Linux::ucontext_get_sp(uc); } if (ret_fp) { *ret_fp = os::Linux::ucontext_get_fp(uc); } } else { // construct empty ExtendedPC for return value checking epc = ExtendedPC(NULL); if (ret_sp) { *ret_sp = (intptr_t*) NULL; } if (ret_fp) { *ret_fp = (intptr_t*) NULL; } } return epc; } frame os::fetch_frame_from_context(void* ucVoid) { intptr_t* sp; intptr_t* fp; ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); return frame(sp, fp, epc.pc()); } frame os::get_sender_for_C_frame(frame* fr) { return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); } frame os::current_frame() { fprintf(stderr, "current_frame()"); intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()(); frame myframe(sp, frame::unpatchable, CAST_FROM_FN_PTR(address, os::current_frame)); if (os::is_first_C_frame(&myframe)) { // stack is not walkable return frame(NULL, frame::unpatchable, NULL); } else { return os::get_sender_for_C_frame(&myframe); } } address os::current_stack_pointer() { register void *sp __asm__ ("sp"); return (address)sp; } static void current_stack_region(address* bottom, size_t* size) { if (os::Linux::is_initial_thread()) { // initial thread needs special handling because pthread_getattr_np() // may return bogus value. *bottom = os::Linux::initial_thread_stack_bottom(); *size = os::Linux::initial_thread_stack_size(); } else { pthread_attr_t attr; int rslt = pthread_getattr_np(pthread_self(), &attr); // JVM needs to know exact stack location, abort if it fails if (rslt != 0) { if (rslt == ENOMEM) { vm_exit_out_of_memory(0, "pthread_getattr_np"); } else { fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); } } if (pthread_attr_getstack(&attr, (void**)bottom, size) != 0) { fatal("Can not locate current stack attributes!"); } pthread_attr_destroy(&attr); } assert(os::current_stack_pointer() >= *bottom && os::current_stack_pointer() < *bottom + *size, "just checking"); } address os::current_stack_base() { address bottom; size_t size; current_stack_region(&bottom, &size); return bottom + size; } size_t os::current_stack_size() { // stack size includes normal stack and HotSpot guard pages address bottom; size_t size; current_stack_region(&bottom, &size); return size; } char* os::non_memory_address_word() { // Must never look like an address returned by reserve_memory, // even in its subfields (as defined by the CPU immediate fields, // if the CPU splits constants across multiple instructions). // On SPARC, 0 != %hi(any real address), because there is no // allocation in the first 1Kb of the virtual address space. return (char*) 0; } void os::initialize_thread() {} void os::print_context(outputStream *st, void *context) { if (context == NULL) return; ucontext_t* uc = (ucontext_t*)context; sigcontext* sc = (sigcontext*)context; st->print_cr("Registers:"); st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT, SIG_REGS(sc).u_regs[CON_G1], SIG_REGS(sc).u_regs[CON_G2], SIG_REGS(sc).u_regs[CON_G3], SIG_REGS(sc).u_regs[CON_G4]); st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT " G7=" INTPTR_FORMAT " Y=" INTPTR_FORMAT, SIG_REGS(sc).u_regs[CON_G5], SIG_REGS(sc).u_regs[CON_G6], SIG_REGS(sc).u_regs[CON_G7], SIG_REGS(sc).y); st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT, SIG_REGS(sc).u_regs[CON_O0], SIG_REGS(sc).u_regs[CON_O1], SIG_REGS(sc).u_regs[CON_O2], SIG_REGS(sc).u_regs[CON_O3]); st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT, SIG_REGS(sc).u_regs[CON_O4], SIG_REGS(sc).u_regs[CON_O5], SIG_REGS(sc).u_regs[CON_O6], SIG_REGS(sc).u_regs[CON_O7]); intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); st->print_cr(" L0=" INTPTR_FORMAT " L1=" INTPTR_FORMAT " L2=" INTPTR_FORMAT " L3=" INTPTR_FORMAT, sp[L0->sp_offset_in_saved_window()], sp[L1->sp_offset_in_saved_window()], sp[L2->sp_offset_in_saved_window()], sp[L3->sp_offset_in_saved_window()]); st->print_cr(" L4=" INTPTR_FORMAT " L5=" INTPTR_FORMAT " L6=" INTPTR_FORMAT " L7=" INTPTR_FORMAT, sp[L4->sp_offset_in_saved_window()], sp[L5->sp_offset_in_saved_window()], sp[L6->sp_offset_in_saved_window()], sp[L7->sp_offset_in_saved_window()]); st->print_cr(" I0=" INTPTR_FORMAT " I1=" INTPTR_FORMAT " I2=" INTPTR_FORMAT " I3=" INTPTR_FORMAT, sp[I0->sp_offset_in_saved_window()], sp[I1->sp_offset_in_saved_window()], sp[I2->sp_offset_in_saved_window()], sp[I3->sp_offset_in_saved_window()]); st->print_cr(" I4=" INTPTR_FORMAT " I5=" INTPTR_FORMAT " I6=" INTPTR_FORMAT " I7=" INTPTR_FORMAT, sp[I4->sp_offset_in_saved_window()], sp[I5->sp_offset_in_saved_window()], sp[I6->sp_offset_in_saved_window()], sp[I7->sp_offset_in_saved_window()]); st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT, SIG_PC(sc), SIG_NPC(sc)); st->cr(); st->cr(); st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t)); st->cr(); // Note: it may be unsafe to inspect memory near pc. For example, pc may // point to garbage if entry point in an nmethod is corrupted. Leave // this at the end, and hope for the best. address pc = os::Linux::ucontext_get_pc(uc); st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); } void os::print_register_info(outputStream *st, void *context) { if (context == NULL) return; ucontext_t *uc = (ucontext_t*)context; intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); st->print_cr("Register to memory mapping:"); st->cr(); // this is only for the "general purpose" registers st->print("G1="); print_location(st, SIG_REGS(sc).u_regs[CON__G1]); st->print("G2="); print_location(st, SIG_REGS(sc).u_regs[CON__G2]); st->print("G3="); print_location(st, SIG_REGS(sc).u_regs[CON__G3]); st->print("G4="); print_location(st, SIG_REGS(sc).u_regs[CON__G4]); st->print("G5="); print_location(st, SIG_REGS(sc).u_regs[CON__G5]); st->print("G6="); print_location(st, SIG_REGS(sc).u_regs[CON__G6]); st->print("G7="); print_location(st, SIG_REGS(sc).u_regs[CON__G7]); st->cr(); st->print("O0="); print_location(st, SIG_REGS(sc).u_regs[CON__O0]); st->print("O1="); print_location(st, SIG_REGS(sc).u_regs[CON__O1]); st->print("O2="); print_location(st, SIG_REGS(sc).u_regs[CON__O2]); st->print("O3="); print_location(st, SIG_REGS(sc).u_regs[CON__O3]); st->print("O4="); print_location(st, SIG_REGS(sc).u_regs[CON__O4]); st->print("O5="); print_location(st, SIG_REGS(sc).u_regs[CON__O5]); st->print("O6="); print_location(st, SIG_REGS(sc).u_regs[CON__O6]); st->print("O7="); print_location(st, SIG_REGS(sc).u_regs[CON__O7]); st->cr(); st->print("L0="); print_location(st, sp[L0->sp_offset_in_saved_window()]); st->print("L1="); print_location(st, sp[L1->sp_offset_in_saved_window()]); st->print("L2="); print_location(st, sp[L2->sp_offset_in_saved_window()]); st->print("L3="); print_location(st, sp[L3->sp_offset_in_saved_window()]); st->print("L4="); print_location(st, sp[L4->sp_offset_in_saved_window()]); st->print("L5="); print_location(st, sp[L5->sp_offset_in_saved_window()]); st->print("L6="); print_location(st, sp[L6->sp_offset_in_saved_window()]); st->print("L7="); print_location(st, sp[L7->sp_offset_in_saved_window()]); st->cr(); st->print("I0="); print_location(st, sp[I0->sp_offset_in_saved_window()]); st->print("I1="); print_location(st, sp[I1->sp_offset_in_saved_window()]); st->print("I2="); print_location(st, sp[I2->sp_offset_in_saved_window()]); st->print("I3="); print_location(st, sp[I3->sp_offset_in_saved_window()]); st->print("I4="); print_location(st, sp[I4->sp_offset_in_saved_window()]); st->print("I5="); print_location(st, sp[I5->sp_offset_in_saved_window()]); st->print("I6="); print_location(st, sp[I6->sp_offset_in_saved_window()]); st->print("I7="); print_location(st, sp[I7->sp_offset_in_saved_window()]); st->cr(); } address os::Linux::ucontext_get_pc(ucontext_t* uc) { return (address) SIG_PC((sigcontext*)uc); } intptr_t* os::Linux::ucontext_get_sp(ucontext_t *uc) { return (intptr_t*) ((intptr_t)SIG_REGS((sigcontext*)uc).u_regs[CON_O6] + STACK_BIAS); } // not used on Sparc intptr_t* os::Linux::ucontext_get_fp(ucontext_t *uc) { ShouldNotReachHere(); return NULL; } // Utility functions extern "C" void Fetch32PFI(); extern "C" void Fetch32Resume(); extern "C" void FetchNPFI(); extern "C" void FetchNResume(); inline static bool checkPrefetch(sigcontext* uc, address pc) { if (pc == (address) Fetch32PFI) { set_cont_address(uc, address(Fetch32Resume)); return true; } if (pc == (address) FetchNPFI) { set_cont_address(uc, address(FetchNResume)); return true; } return false; } inline static bool checkOverflow(sigcontext* uc, address pc, address addr, JavaThread* thread, address* stub) { // check if fault address is within thread stack if (addr < thread->stack_base() && addr >= thread->stack_base() - thread->stack_size()) { // stack overflow if (thread->in_stack_yellow_zone(addr)) { thread->disable_stack_yellow_zone(); if (thread->thread_state() == _thread_in_Java) { // Throw a stack overflow exception. Guard pages will be reenabled // while unwinding the stack. *stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); } else { // Thread was in the vm or native code. Return and try to finish. return true; } } else if (thread->in_stack_red_zone(addr)) { // Fatal red zone violation. Disable the guard pages and fall through // to handle_unexpected_exception way down below. thread->disable_stack_red_zone(); tty->print_raw_cr("An irrecoverable stack overflow has occurred."); } else { // Accessing stack address below sp may cause SEGV if current // thread has MAP_GROWSDOWN stack. This should only happen when // current thread was created by user code with MAP_GROWSDOWN flag // and then attached to VM. See notes in os_linux.cpp. if (thread->osthread()->expanding_stack() == 0) { thread->osthread()->set_expanding_stack(); if (os::Linux::manually_expand_stack(thread, addr)) { thread->osthread()->clear_expanding_stack(); return true; } thread->osthread()->clear_expanding_stack(); } else { fatal("recursive segv. expanding stack."); } } } return false; } inline static bool checkPollingPage(address pc, address fault, address* stub) { if (fault == os::get_polling_page()) { *stub = SharedRuntime::get_poll_stub(pc); return true; } return false; } inline static bool checkByteBuffer(address pc, address* stub) { // BugId 4454115: A read from a MappedByteBuffer can fault // here if the underlying file has been truncated. // Do not crash the VM in such a case. CodeBlob* cb = CodeCache::find_blob_unsafe(pc); nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; if (nm != NULL && nm->has_unsafe_access()) { *stub = StubRoutines::handler_for_unsafe_access(); return true; } return false; } inline static bool checkVerifyOops(address pc, address fault, address* stub) { if (pc >= MacroAssembler::_verify_oop_implicit_branch[0] && pc < MacroAssembler::_verify_oop_implicit_branch[1] ) { *stub = MacroAssembler::_verify_oop_implicit_branch[2]; warning("fixed up memory fault in +VerifyOops at address " INTPTR_FORMAT, fault); return true; } return false; } inline static bool checkFPFault(address pc, int code, JavaThread* thread, address* stub) { if (code == FPE_INTDIV || code == FPE_FLTDIV) { *stub = SharedRuntime:: continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); return true; } return false; } inline static bool checkNullPointer(address pc, intptr_t fault, JavaThread* thread, address* stub) { if (!MacroAssembler::needs_explicit_null_check(fault)) { // Determination of interpreter/vtable stub/compiled code null // exception *stub = SharedRuntime:: continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); return true; } return false; } inline static bool checkFastJNIAccess(address pc, address* stub) { address addr = JNI_FastGetField::find_slowcase_pc(pc); if (addr != (address)-1) { *stub = addr; return true; } return false; } inline static bool checkSerializePage(JavaThread* thread, address addr) { return os::is_memory_serialize_page(thread, addr); } inline static bool checkZombie(sigcontext* uc, address* pc, address* stub) { if (nativeInstruction_at(*pc)->is_zombie()) { // zombie method (ld [%g0],%o7 instruction) *stub = SharedRuntime::get_handle_wrong_method_stub(); // At the stub it needs to look like a call from the caller of this // method (not a call from the segv site). *pc = (address)SIG_REGS(uc).u_regs[CON_O7]; return true; } return false; } inline static bool checkICMiss(sigcontext* uc, address* pc, address* stub) { #ifdef COMPILER2 if (nativeInstruction_at(*pc)->is_ic_miss_trap()) { #ifdef ASSERT #ifdef TIERED CodeBlob* cb = CodeCache::find_blob_unsafe(pc); assert(cb->is_compiled_by_c2(), "Wrong compiler"); #endif // TIERED #endif // ASSERT // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken. *stub = SharedRuntime::get_ic_miss_stub(); // At the stub it needs to look like a call from the caller of this // method (not a call from the segv site). *pc = (address)SIG_REGS(uc).u_regs[CON_O7]; return true; } #endif // COMPILER2 return false; } extern "C" JNIEXPORT int JVM_handle_linux_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) { // in fact this isn't ucontext_t* at all, but struct sigcontext* // but Linux porting layer uses ucontext_t, so to minimize code change // we cast as needed ucontext_t* ucFake = (ucontext_t*) ucVoid; sigcontext* uc = (sigcontext*)ucVoid; Thread* t = ThreadLocalStorage::get_thread_slow(); SignalHandlerMark shm(t); // Note: it's not uncommon that JNI code uses signal/sigset to install // then restore certain signal handler (e.g. to temporarily block SIGPIPE, // or have a SIGILL handler when detecting CPU type). When that happens, // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To // avoid unnecessary crash when libjsig is not preloaded, try handle signals // that do not require siginfo/ucontext first. if (sig == SIGPIPE || sig == SIGXFSZ) { // allow chained handler to go first if (os::Linux::chained_handler(sig, info, ucVoid)) { return true; } else { if (PrintMiscellaneous && (WizardMode || Verbose)) { char buf[64]; warning("Ignoring %s - see bugs 4229104 or 646499219", os::exception_name(sig, buf, sizeof(buf))); } return true; } } JavaThread* thread = NULL; VMThread* vmthread = NULL; if (os::Linux::signal_handlers_are_installed) { if (t != NULL ){ if(t->is_Java_thread()) { thread = (JavaThread*)t; } else if(t->is_VM_thread()){ vmthread = (VMThread *)t; } } } // decide if this trap can be handled by a stub address stub = NULL; address pc = NULL; address npc = NULL; //%note os_trap_1 if (info != NULL && uc != NULL && thread != NULL) { pc = address(SIG_PC(uc)); npc = address(SIG_NPC(uc)); // Check to see if we caught the safepoint code in the // process of write protecting the memory serialization page. // It write enables the page immediately after protecting it // so we can just return to retry the write. if ((sig == SIGSEGV) && checkSerializePage(thread, (address)info->si_addr)) { // Block current thread until the memory serialize page permission restored. os::block_on_serialize_page_trap(); return 1; } if (checkPrefetch(uc, pc)) { return 1; } // Handle ALL stack overflow variations here if (sig == SIGSEGV) { if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) { return 1; } } if (sig == SIGBUS && thread->thread_state() == _thread_in_vm && thread->doing_unsafe_access()) { stub = StubRoutines::handler_for_unsafe_access(); } if (thread->thread_state() == _thread_in_Java) { do { // Java thread running in Java code => find exception handler if any // a fault inside compiled code, the interpreter, or a stub if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) { break; } if ((sig == SIGBUS) && checkByteBuffer(pc, &stub)) { break; } if ((sig == SIGSEGV || sig == SIGBUS) && checkVerifyOops(pc, (address)info->si_addr, &stub)) { break; } if ((sig == SIGSEGV) && checkZombie(uc, &pc, &stub)) { break; } if ((sig == SIGILL) && checkICMiss(uc, &pc, &stub)) { break; } if ((sig == SIGFPE) && checkFPFault(pc, info->si_code, thread, &stub)) { break; } if ((sig == SIGSEGV) && checkNullPointer(pc, (intptr_t)info->si_addr, thread, &stub)) { break; } } while (0); // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in // and the heap gets shrunk before the field access. if ((sig == SIGSEGV) || (sig == SIGBUS)) { checkFastJNIAccess(pc, &stub); } } if (stub != NULL) { // save all thread context in case we need to restore it thread->set_saved_exception_pc(pc); thread->set_saved_exception_npc(npc); set_cont_address(uc, stub); return true; } } // signal-chaining if (os::Linux::chained_handler(sig, info, ucVoid)) { return true; } if (!abort_if_unrecognized) { // caller wants another chance, so give it to him return false; } if (pc == NULL && uc != NULL) { pc = os::Linux::ucontext_get_pc((ucontext_t*)uc); } // unmask current signal sigset_t newset; sigemptyset(&newset); sigaddset(&newset, sig); sigprocmask(SIG_UNBLOCK, &newset, NULL); VMError err(t, sig, pc, info, ucVoid); err.report_and_die(); ShouldNotReachHere(); } void os::Linux::init_thread_fpu_state(void) { // Nothing to do } int os::Linux::get_fpu_control_word() { return 0; } void os::Linux::set_fpu_control_word(int fpu) { // nothing } bool os::is_allocatable(size_t bytes) { #ifdef _LP64 return true; #else if (bytes < 2 * G) { return true; } char* addr = reserve_memory(bytes, NULL); if (addr != NULL) { release_memory(addr, bytes); } return addr != NULL; #endif // _LP64 } /////////////////////////////////////////////////////////////////////////////// // thread stack size_t os::Linux::min_stack_allowed = 128 * K; // pthread on Ubuntu is always in floating stack mode bool os::Linux::supports_variable_stack_size() { return true; } // return default stack size for thr_type size_t os::Linux::default_stack_size(os::ThreadType thr_type) { // default stack size (compiler thread needs larger stack) size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); return s; } size_t os::Linux::default_guard_size(os::ThreadType thr_type) { // Creating guard page is very expensive. Java thread has HotSpot // guard page, only enable glibc guard page for non-Java threads. return (thr_type == java_thread ? 0 : page_size()); }