Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 // Wrapper for all entry points to the virtual machine.

 // The HandleMarkCleaner is a faster version of HandleMark.

 // It relies on the fact that there is a HandleMark further

 // down the stack (in JavaCalls::call_helper), and just resets

 // to the saved values in that HandleMark.

 class HandleMarkCleaner: public StackObj {

  private:

   Thread* _thread;

  public:

   HandleMarkCleaner(Thread* thread) {

     _thread = thread;

     _thread->last_handle_mark()->push();

   }

   ~HandleMarkCleaner() {

     _thread->last_handle_mark()->pop_and_restore();

   }

  private:

   inline void* operator new(size_t size, void* ptr) {

     return ptr;

   }

 };

 // InterfaceSupport provides functionality used by the __LEAF and __ENTRY

 // macros. These macros are used to guard entry points into the VM and

 // perform checks upon leave of the VM.

 class InterfaceSupport: AllStatic {

 # ifdef ASSERT

  public:

   static long _scavenge_alot_counter;

   static long _fullgc_alot_counter;

   static long _number_of_calls;

   static long _fullgc_alot_invocation;

   // tracing

   static void trace(const char* result_type, const char* header);

   // Helper methods used to implement +ScavengeALot and +FullGCALot

   static void check_gc_alot() { if (ScavengeALot || FullGCALot) gc_alot(); }

   static void gc_alot();

   static void walk_stack_from(vframe* start_vf);

   static void walk_stack();

 # ifdef ENABLE_ZAP_DEAD_LOCALS

   static void zap_dead_locals_old();

 # endif

   static void zombieAll();

   static void deoptimizeAll();

   static void stress_derived_pointers();

   static void verify_stack();

   static void verify_last_frame();

 # endif

  public:

   // OS dependent stuff

   #include "incls/_interfaceSupport_pd.hpp.incl"

 };

 // Basic class for all thread transition classes.

 class ThreadStateTransition : public StackObj {

  protected:

   JavaThread* _thread;

  public:

   ThreadStateTransition(JavaThread *thread) {

     _thread = thread;

     assert(thread != NULL && thread->is_Java_thread(), "must be Java thread");

   }

   // Change threadstate in a manner, so safepoint can detect changes.

   // Time-critical: called on exit from every runtime routine

   static inline void transition(JavaThread *thread, JavaThreadState from, JavaThreadState to) {

     assert(from != _thread_in_Java, "use transition_from_java");

     assert(from != _thread_in_native, "use transition_from_native");

     assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");

     assert(thread->thread_state() == from, "coming from wrong thread state");

     // Change to transition state (assumes total store ordering!  -Urs)

     thread->set_thread_state((JavaThreadState)(from + 1));

     // Make sure new state is seen by VM thread

     if (os::is_MP()) {

       if (UseMembar) {

         // Force a fence between the write above and read below

         OrderAccess::fence();

       } else {

         // store to serialize page so VM thread can do pseudo remote membar

         os::write_memory_serialize_page(thread);

       }

     }

     if (SafepointSynchronize::do_call_back()) {

       SafepointSynchronize::block(thread);

     }

     thread->set_thread_state(to);

     CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)

   }

   // transition_and_fence must be used on any thread state transition

   // where there might not be a Java call stub on the stack, in

   // particular on Windows where the Structured Exception Handler is

   // set up in the call stub. os::write_memory_serialize_page() can

   // fault and we can't recover from it on Windows without a SEH in

   // place.

   static inline void transition_and_fence(JavaThread *thread, JavaThreadState from, JavaThreadState to) {

     assert(thread->thread_state() == from, "coming from wrong thread state");

     assert((from & 1) == 0 && (to & 1) == 0, "odd numbers are transitions states");

     // Change to transition state (assumes total store ordering!  -Urs)

     thread->set_thread_state((JavaThreadState)(from + 1));

     // Make sure new state is seen by VM thread

     if (os::is_MP()) {

       if (UseMembar) {

         // Force a fence between the write above and read below

         OrderAccess::fence();

       } else {

         // Must use this rather than serialization page in particular on Windows

         InterfaceSupport::serialize_memory(thread);

       }

     }

     if (SafepointSynchronize::do_call_back()) {

       SafepointSynchronize::block(thread);

     }

     thread->set_thread_state(to);

     CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)

   }

   // Same as above, but assumes from = _thread_in_Java. This is simpler, since we

   // never block on entry to the VM. This will break the code, since e.g. preserve arguments

   // have not been setup.

   static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {

     assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");

     thread->set_thread_state(to);

   }

   static inline void transition_from_native(JavaThread *thread, JavaThreadState to) {

     assert((to & 1) == 0, "odd numbers are transitions states");

     assert(thread->thread_state() == _thread_in_native, "coming from wrong thread state");

     // Change to transition state (assumes total store ordering!  -Urs)

     thread->set_thread_state(_thread_in_native_trans);

     // Make sure new state is seen by GC thread

     if (os::is_MP()) {

       if (UseMembar) {

         // Force a fence between the write above and read below

         OrderAccess::fence();

       } else {

         // Must use this rather than serialization page in particular on Windows

         InterfaceSupport::serialize_memory(thread);

       }

     }

     // We never install asynchronous exceptions when coming (back) in

     // to the runtime from native code because the runtime is not set

     // up to handle exceptions floating around at arbitrary points.

     if (SafepointSynchronize::do_call_back() || thread->is_suspend_after_native()) {

       JavaThread::check_safepoint_and_suspend_for_native_trans(thread);

       // Clear unhandled oops anywhere where we could block, even if we don't.

       CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)

     }

     thread->set_thread_state(to);

   }

  protected:

    void trans(JavaThreadState from, JavaThreadState to)  { transition(_thread, from, to); }

    void trans_from_java(JavaThreadState to)              { transition_from_java(_thread, to); }

    void trans_from_native(JavaThreadState to)            { transition_from_native(_thread, to); }

    void trans_and_fence(JavaThreadState from, JavaThreadState to) { transition_and_fence(_thread, from, to); }

 };

 class ThreadInVMfromJava : public ThreadStateTransition {

  public:

   ThreadInVMfromJava(JavaThread* thread) : ThreadStateTransition(thread) {

     trans_from_java(_thread_in_vm);

   }

   ~ThreadInVMfromJava()  {

     trans(_thread_in_vm, _thread_in_Java);

     // Check for pending. async. exceptions or suspends.

     if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition();

   }

 };

 class ThreadInVMfromUnknown {

  private:

   JavaThread* _thread;

  public:

   ThreadInVMfromUnknown() : _thread(NULL) {

     Thread* t = Thread::current();

     if (t->is_Java_thread()) {

       JavaThread* t2 = (JavaThread*) t;

       if (t2->thread_state() == _thread_in_native) {

         _thread = t2;

         ThreadStateTransition::transition_from_native(t2, _thread_in_vm);

         // Used to have a HandleMarkCleaner but that is dangerous as

         // it could free a handle in our (indirect, nested) caller.

         // We expect any handles will be short lived and figure we

         // don't need an actual HandleMark.

       }

     }

   }

   ~ThreadInVMfromUnknown()  {

     if (_thread) {

       ThreadStateTransition::transition_and_fence(_thread, _thread_in_vm, _thread_in_native);

     }

   }

 };

 class ThreadInVMfromNative : public ThreadStateTransition {

  public:

   ThreadInVMfromNative(JavaThread* thread) : ThreadStateTransition(thread) {

     trans_from_native(_thread_in_vm);

   }

   ~ThreadInVMfromNative() {

     trans_and_fence(_thread_in_vm, _thread_in_native);

   }

 };

 class ThreadToNativeFromVM : public ThreadStateTransition {

  public:

   ThreadToNativeFromVM(JavaThread *thread) : ThreadStateTransition(thread) {

     // We are leaving the VM at this point and going directly to native code.

     // Block, if we are in the middle of a safepoint synchronization.

     assert(!thread->owns_locks(), "must release all locks when leaving VM");

     thread->frame_anchor()->make_walkable(thread);

     trans_and_fence(_thread_in_vm, _thread_in_native);

     // Check for pending. async. exceptions or suspends.

     if (_thread->has_special_runtime_exit_condition()) _thread->handle_special_runtime_exit_condition(false);

   }

   ~ThreadToNativeFromVM() {

     trans_from_native(_thread_in_vm);

     // We don't need to clear_walkable because it will happen automagically when we return to java

   }

 };

 class ThreadBlockInVM : public ThreadStateTransition {

  public:

   ThreadBlockInVM(JavaThread *thread)

   : ThreadStateTransition(thread) {

     // Once we are blocked vm expects stack to be walkable

     thread->frame_anchor()->make_walkable(thread);

     trans_and_fence(_thread_in_vm, _thread_blocked);

   }

   ~ThreadBlockInVM() {

     trans_and_fence(_thread_blocked, _thread_in_vm);

     // We don't need to clear_walkable because it will happen automagically when we return to java

   }

 };

 // This special transition class is only used to prevent asynchronous exceptions

 // from being installed on vm exit in situations where we can't tolerate them.

 // See bugs: 4324348, 4854693, 4998314, 5040492, 5050705.

 class ThreadInVMfromJavaNoAsyncException : public ThreadStateTransition {

  public:

   ThreadInVMfromJavaNoAsyncException(JavaThread* thread) : ThreadStateTransition(thread) {

     trans_from_java(_thread_in_vm);

   }

   ~ThreadInVMfromJavaNoAsyncException()  {

     trans(_thread_in_vm, _thread_in_Java);

     // NOTE: We do not check for pending. async. exceptions.

     // If we did and moved the pending async exception over into the

     // pending exception field, we would need to deopt (currently C2

     // only). However, to do so would require that we transition back

     // to the _thread_in_vm state. Instead we postpone the handling of

     // the async exception.

     // Check for pending. suspends only.

     if (_thread->has_special_runtime_exit_condition())

       _thread->handle_special_runtime_exit_condition(false);

   }

 };

 // Debug class instantiated in JRT_ENTRY and ITR_ENTRY macro.

 // Can be used to verify properties on enter/exit of the VM.

 #ifdef ASSERT

 class VMEntryWrapper {

  public:

   VMEntryWrapper() {

     if (VerifyLastFrame) {

       InterfaceSupport::verify_last_frame();

     }

   }

   ~VMEntryWrapper() {

     InterfaceSupport::check_gc_alot();

     if (WalkStackALot) {

       InterfaceSupport::walk_stack();

     }

 #ifdef ENABLE_ZAP_DEAD_LOCALS

     if (ZapDeadLocalsOld) {

       InterfaceSupport::zap_dead_locals_old();

     }

 #endif

 #ifdef COMPILER2

     // This option is not used by Compiler 1

     if (StressDerivedPointers) {

       InterfaceSupport::stress_derived_pointers();

     }

 #endif

     if (DeoptimizeALot || DeoptimizeRandom) {

       InterfaceSupport::deoptimizeAll();

     }

     if (ZombieALot) {

       InterfaceSupport::zombieAll();

     }

     // do verification AFTER potential deoptimization

     if (VerifyStack) {

       InterfaceSupport::verify_stack();

     }

   }

 };

 class VMNativeEntryWrapper {

  public:

   VMNativeEntryWrapper() {

     if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();

   }

   ~VMNativeEntryWrapper() {

     if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();

   }

 };

 #endif

 // VM-internal runtime interface support

 #ifdef ASSERT

 class RuntimeHistogramElement : public HistogramElement {

   public:

    RuntimeHistogramElement(const char* name);

 };

 #define TRACE_CALL(result_type, header)                            \

   InterfaceSupport::_number_of_calls++;                            \

   if (TraceRuntimeCalls)                                           \

     InterfaceSupport::trace(#result_type, #header);                \

   if (CountRuntimeCalls) {                                         \

     static RuntimeHistogramElement* e = new RuntimeHistogramElement(#header); \

     if (e != NULL) e->increment_count();                           \

   }

 #else

 #define TRACE_CALL(result_type, header)                            \

   /* do nothing */

 #endif

 // LEAF routines do not lock, GC or throw exceptions

 #define __LEAF(result_type, header)                                  \

   TRACE_CALL(result_type, header)                                    \

   debug_only(NoHandleMark __hm;)                                     \

   /* begin of body */

 // ENTRY routines may lock, GC and throw exceptions

 #define __ENTRY(result_type, header, thread)                         \

   TRACE_CALL(result_type, header)                                    \

   HandleMarkCleaner __hm(thread);                                    \

   Thread* THREAD = thread;                                           \

   /* begin of body */

 // QUICK_ENTRY routines behave like ENTRY but without a handle mark

 #define __QUICK_ENTRY(result_type, header, thread)                   \

   TRACE_CALL(result_type, header)                                    \

   debug_only(NoHandleMark __hm;)                                     \

   Thread* THREAD = thread;                                           \

   /* begin of body */

 // Definitions for IRT (Interpreter Runtime)

 // (thread is an argument passed in to all these routines)

 #define IRT_ENTRY(result_type, header)                               \

   result_type header {                                               \

     ThreadInVMfromJava __tiv(thread);                                \

     __ENTRY(result_type, header, thread)                             \

     debug_only(VMEntryWrapper __vew;)

 #define IRT_LEAF(result_type, header)                                \

   result_type header {                                               \

     __LEAF(result_type, header)                                      \

     debug_only(No_Safepoint_Verifier __nspv(true);)

 #define IRT_ENTRY_NO_ASYNC(result_type, header)                      \

   result_type header {                                               \

     ThreadInVMfromJavaNoAsyncException __tiv(thread);                \

     __ENTRY(result_type, header, thread)                             \

     debug_only(VMEntryWrapper __vew;)

 // Another special case for nmethod_entry_point so the nmethod that the

 // interpreter is about to branch to doesn't get flushed before as we

 // branch to it's interpreter_entry_point.  Skip stress testing here too.

 // Also we don't allow async exceptions because it is just too painful.

 #define IRT_ENTRY_FOR_NMETHOD(result_type, header)                   \

   result_type header {                                               \

     nmethodLocker _nmlock(nm);                                       \

     ThreadInVMfromJavaNoAsyncException __tiv(thread);                                \

     __ENTRY(result_type, header, thread)

 #define IRT_END }

 // Definitions for JRT (Java (Compiler/Shared) Runtime)

 #define JRT_ENTRY(result_type, header)                               \

   result_type header {                                               \

     ThreadInVMfromJava __tiv(thread);                                \

     __ENTRY(result_type, header, thread)                             \

     debug_only(VMEntryWrapper __vew;)

 #define JRT_LEAF(result_type, header)                                \

   result_type header {                                               \

   __LEAF(result_type, header)                                        \

   debug_only(JRT_Leaf_Verifier __jlv;)

 #define JRT_ENTRY_NO_ASYNC(result_type, header)                      \

   result_type header {                                               \

     ThreadInVMfromJavaNoAsyncException __tiv(thread);                \

     __ENTRY(result_type, header, thread)                             \

     debug_only(VMEntryWrapper __vew;)

 // Same as JRT Entry but allows for return value after the safepoint

 // to get back into Java from the VM

 #define JRT_BLOCK_ENTRY(result_type, header)                         \

   result_type header {                                               \

     TRACE_CALL(result_type, header)                                  \

     HandleMarkCleaner __hm(thread);

 #define JRT_BLOCK                                                    \

     {                                                                \

     ThreadInVMfromJava __tiv(thread);                                \

     Thread* THREAD = thread;                                         \

     debug_only(VMEntryWrapper __vew;)

 #define JRT_BLOCK_END }

 #define JRT_END }

 // Definitions for JNI

 #define JNI_ENTRY(result_type, header)                               \

     JNI_ENTRY_NO_PRESERVE(result_type, header)                       \

     WeakPreserveExceptionMark __wem(thread);

 #define JNI_ENTRY_NO_PRESERVE(result_type, header)             \

 extern "C" {                                                         \

   result_type JNICALL header {                                \

     JavaThread* thread=JavaThread::thread_from_jni_environment(env); \

     assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \

     ThreadInVMfromNative __tiv(thread);                              \

     debug_only(VMNativeEntryWrapper __vew;)                          \

     __ENTRY(result_type, header, thread)

 // Ensure that the VMNativeEntryWrapper constructor, which can cause

 // a GC, is called outside the NoHandleMark (set via __QUICK_ENTRY).

 #define JNI_QUICK_ENTRY(result_type, header)                         \

 extern "C" {                                                         \

   result_type JNICALL header {                                \

     JavaThread* thread=JavaThread::thread_from_jni_environment(env); \

     assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \

     ThreadInVMfromNative __tiv(thread);                              \

     debug_only(VMNativeEntryWrapper __vew;)                          \

     __QUICK_ENTRY(result_type, header, thread)

 #define JNI_LEAF(result_type, header)                                \

 extern "C" {                                                         \

   result_type JNICALL header {                                \

     JavaThread* thread=JavaThread::thread_from_jni_environment(env); \

     assert( !VerifyJNIEnvThread || (thread == Thread::current()), "JNIEnv is only valid in same thread"); \

     __LEAF(result_type, header)

 // Close the routine and the extern "C"

 #define JNI_END } }

 // Definitions for JVM

 #define JVM_ENTRY(result_type, header)                               \

 extern "C" {                                                         \

   result_type JNICALL header {                                       \

     JavaThread* thread=JavaThread::thread_from_jni_environment(env); \

     ThreadInVMfromNative __tiv(thread);                              \

     debug_only(VMNativeEntryWrapper __vew;)                          \

     __ENTRY(result_type, header, thread)

 #define JVM_ENTRY_NO_ENV(result_type, header)                        \

 extern "C" {                                                         \

   result_type JNICALL header {                                       \

     JavaThread* thread = (JavaThread*)ThreadLocalStorage::thread();  \

     ThreadInVMfromNative __tiv(thread);                              \

     debug_only(VMNativeEntryWrapper __vew;)                          \

     __ENTRY(result_type, header, thread)

 #define JVM_QUICK_ENTRY(result_type, header)                         \

 extern "C" {                                                         \

   result_type JNICALL header {                                       \

     JavaThread* thread=JavaThread::thread_from_jni_environment(env); \

     ThreadInVMfromNative __tiv(thread);                              \

     debug_only(VMNativeEntryWrapper __vew;)                          \

     __QUICK_ENTRY(result_type, header, thread)

 #define JVM_LEAF(result_type, header)                                \

 extern "C" {                                                         \

   result_type JNICALL header {                                       \

     VM_Exit::block_if_vm_exited();                                   \

     __LEAF(result_type, header)

 #define JVM_END } }