8252406: Introduce Thread::as_Java_thread() convenience function

Reviewed-by: shade, coleenp, kbarrett, dcubed

src/hotspot/cpu/aarch64/gc/shared/barrierSetNMethod_aarch64.cpp

@@ -101,7 +101,7 @@ void BarrierSetNMethod::deoptimize(nmethod* nm, address* return_address_ptr) {
 
   frame_pointers_t *new_frame = (frame_pointers_t *)(return_address_ptr - 5);
 
-  JavaThread *thread = (JavaThread*)Thread::current();
+  JavaThread *thread = JavaThread::current();
   RegisterMap reg_map(thread, false);
   frame frame = thread->last_frame();
 
@@ -111,14 +111,11 @@ void BarrierSetNMethod::deoptimize(nmethod* nm, address* return_address_ptr) {
 
   LogTarget(Trace, nmethod, barrier) out;
   if (out.is_enabled()) {
-    Thread* thread = Thread::current();
-    assert(thread->is_Java_thread(), "must be JavaThread");
-    JavaThread* jth = (JavaThread*) thread;
     ResourceMark mark;
     log_trace(nmethod, barrier)("deoptimize(nmethod: %s(%p), return_addr: %p, osr: %d, thread: %p(%s), making rsp: %p) -> %p",
                                 nm->method()->name_and_sig_as_C_string(),
-                                nm, *(address *) return_address_ptr, nm->is_osr_method(), jth,
-                                jth->get_thread_name(), frame.sp(), nm->verified_entry_point());
+                                nm, *(address *) return_address_ptr, nm->is_osr_method(), thread,
+                                thread->get_thread_name(), frame.sp(), nm->verified_entry_point());
   }
 
   new_frame->sp = frame.sp();

src/hotspot/cpu/x86/gc/shared/barrierSetNMethod_x86.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2020, 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
@@ -128,9 +128,7 @@ void BarrierSetNMethod::deoptimize(nmethod* nm, address* return_address_ptr) {
 
   LogTarget(Trace, nmethod, barrier) out;
   if (out.is_enabled()) {
-    Thread* thread = Thread::current();
-    assert(thread->is_Java_thread(), "must be JavaThread");
-    JavaThread* jth = (JavaThread*) thread;
+    JavaThread* jth = JavaThread::current();
     ResourceMark mark;
     log_trace(nmethod, barrier)("deoptimize(nmethod: %p, return_addr: %p, osr: %d, thread: %p(%s), making rsp: %p) -> %p",
                                nm, (address *) return_address_ptr, nm->is_osr_method(), jth,

src/hotspot/cpu/zero/frame_zero.cpp

@@ -94,7 +94,7 @@ void frame::patch_pc(Thread* thread, address pc) {
     // We borrow this call to set the thread pointer in the interpreter
     // state; the hook to set up deoptimized frames isn't supplied it.
     assert(pc == NULL, "should be");
-    get_interpreterState()->set_thread((JavaThread *) thread);
+    get_interpreterState()->set_thread(thread->as_Java_thread());
   }
 }
 

src/hotspot/cpu/zero/methodHandles_zero.cpp

@@ -38,7 +38,7 @@
 
 void MethodHandles::invoke_target(Method* method, TRAPS) {
 
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
   InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
   interpreterState istate = frame->interpreter_state();
@@ -55,7 +55,7 @@ void MethodHandles::invoke_target(Method* method, TRAPS) {
 
 oop MethodHandles::popFromStack(TRAPS) {
 
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
   interpreterState istate = frame->interpreter_state();
   intptr_t* topOfStack = istate->stack();
@@ -70,7 +70,7 @@ oop MethodHandles::popFromStack(TRAPS) {
 
 void MethodHandles::throw_AME(Klass* rcvr, Method* interface_method, TRAPS) {
 
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   // Set up the frame anchor if it isn't already
   bool has_last_Java_frame = thread->has_last_Java_frame();
   if (!has_last_Java_frame) {
@@ -101,7 +101,7 @@ void MethodHandles::throw_AME(Klass* rcvr, Method* interface_method, TRAPS) {
 
 int MethodHandles::method_handle_entry_invokeBasic(Method* method, intptr_t UNUSED, TRAPS) {
 
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
   interpreterState istate = frame->interpreter_state();
   intptr_t* topOfStack = istate->stack();
@@ -132,7 +132,7 @@ int MethodHandles::method_handle_entry_linkToStaticOrSpecial(Method* method, int
 }
 
 int MethodHandles::method_handle_entry_linkToInterface(Method* method, intptr_t UNUSED, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
   interpreterState istate = frame->interpreter_state();
 
@@ -172,7 +172,7 @@ int MethodHandles::method_handle_entry_linkToInterface(Method* method, intptr_t
 }
 
 int MethodHandles::method_handle_entry_linkToVirtual(Method* method, intptr_t UNUSED, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
 
   InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
   interpreterState istate = frame->interpreter_state();

src/hotspot/cpu/zero/stack_zero.cpp

@@ -46,7 +46,7 @@ int ZeroStack::suggest_size(Thread *thread) const {
 }
 
 void ZeroStack::handle_overflow(TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
 
   // Set up the frame anchor if it isn't already
   bool has_last_Java_frame = thread->has_last_Java_frame();

src/hotspot/cpu/zero/stubGenerator_zero.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007, 2008, 2010, 2015 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -72,7 +72,7 @@ class StubGenerator: public StubCodeGenerator {
     intptr_t*        parameters,
     int              parameter_words,
     TRAPS) {
-    JavaThread *thread = (JavaThread *) THREAD;
+    JavaThread *thread = THREAD->as_Java_thread();
     ZeroStack *stack = thread->zero_stack();
 
     // Make sure we have no pending exceptions
@@ -316,7 +316,7 @@ EntryFrame *EntryFrame::build(const intptr_t*  parameters,
                               JavaCallWrapper* call_wrapper,
                               TRAPS) {
 
-  ZeroStack *stack = ((JavaThread *) THREAD)->zero_stack();
+  ZeroStack *stack = THREAD->as_Java_thread()->zero_stack();
   stack->overflow_check(header_words + parameter_words, CHECK_NULL);
 
   stack->push(0); // next_frame, filled in later

src/hotspot/cpu/zero/zeroInterpreter_zero.cpp

@@ -106,7 +106,7 @@ InterpreterCodelet* ZeroInterpreter::codelet_containing(address pc) {
   fixup_after_potential_safepoint()
 
 int ZeroInterpreter::normal_entry(Method* method, intptr_t UNUSED, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
 
   // Allocate and initialize our frame.
   InterpreterFrame *frame = InterpreterFrame::build(method, CHECK_0);
@@ -144,7 +144,7 @@ intptr_t narrow(BasicType type, intptr_t result) {
 
 
 void ZeroInterpreter::main_loop(int recurse, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
 
   // If we are entering from a deopt we may need to call
@@ -277,7 +277,7 @@ int ZeroInterpreter::native_entry(Method* method, intptr_t UNUSED, TRAPS) {
   // Make sure method is native and not abstract
   assert(method->is_native() && !method->is_abstract(), "should be");
 
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
 
   // Allocate and initialize our frame
@@ -546,7 +546,7 @@ int ZeroInterpreter::native_entry(Method* method, intptr_t UNUSED, TRAPS) {
 }
 
 int ZeroInterpreter::accessor_entry(Method* method, intptr_t UNUSED, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
   intptr_t *locals = stack->sp();
 
@@ -679,7 +679,7 @@ int ZeroInterpreter::accessor_entry(Method* method, intptr_t UNUSED, TRAPS) {
 }
 
 int ZeroInterpreter::empty_entry(Method* method, intptr_t UNUSED, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
 
   // Drop into the slow path if we need a safepoint check
@@ -698,7 +698,7 @@ int ZeroInterpreter::empty_entry(Method* method, intptr_t UNUSED, TRAPS) {
 // Slots < insert_before will have the same slot number after the insert.
 // Slots >= insert_before will become old_slot + num_slots.
 void ZeroInterpreter::insert_vmslots(int insert_before, int num_slots, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
 
   // Allocate the space
@@ -712,7 +712,7 @@ void ZeroInterpreter::insert_vmslots(int insert_before, int num_slots, TRAPS) {
 }
 
 void ZeroInterpreter::remove_vmslots(int first_slot, int num_slots, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
   intptr_t *vmslots = stack->sp();
 
@@ -745,7 +745,7 @@ JRT_ENTRY(void, ZeroInterpreter::throw_exception(JavaThread* thread,
 JRT_END
 
 InterpreterFrame *InterpreterFrame::build(Method* const method, TRAPS) {
-  JavaThread *thread = (JavaThread *) THREAD;
+  JavaThread *thread = THREAD->as_Java_thread();
   ZeroStack *stack = thread->zero_stack();
 
   // Calculate the size of the frame we'll build, including
@@ -821,7 +821,7 @@ InterpreterFrame *InterpreterFrame::build(Method* const method, TRAPS) {
 }
 
 InterpreterFrame *InterpreterFrame::build(int size, TRAPS) {
-  ZeroStack *stack = ((JavaThread *) THREAD)->zero_stack();
+  ZeroStack *stack = THREAD->as_Java_thread()->zero_stack();
 
   int size_in_words = size >> LogBytesPerWord;
   assert(size_in_words * wordSize == size, "unaligned");

src/hotspot/os/linux/os_linux.cpp

@@ -1040,13 +1040,12 @@ bool os::create_attached_thread(JavaThread* thread) {
     // enabling yellow zone first will crash JVM on SuSE Linux), so there
     // is no gap between the last two virtual memory regions.
 
-    JavaThread *jt = (JavaThread *)thread;
-    address addr = jt->stack_reserved_zone_base();
+    address addr = thread->stack_reserved_zone_base();
     assert(addr != NULL, "initialization problem?");
-    assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
+    assert(thread->stack_available(addr) > 0, "stack guard should not be enabled");
 
     osthread->set_expanding_stack();
-    os::Linux::manually_expand_stack(jt, addr);
+    os::Linux::manually_expand_stack(thread, addr);
     osthread->clear_expanding_stack();
   }
 
@@ -1781,7 +1780,6 @@ void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
                 "'execstack -c <libfile>', or link it with '-z noexecstack'.",
                 filename);
 
-        assert(Thread::current()->is_Java_thread(), "must be Java thread");
         JavaThread *jt = JavaThread::current();
         if (jt->thread_state() != _thread_in_native) {
           // This happens when a compiler thread tries to load a hsdis-<arch>.so file

src/hotspot/os/posix/os_posix.cpp

@@ -2073,9 +2073,7 @@ void Parker::park(bool isAbsolute, jlong time) {
   // since we are doing a lock-free update to _counter.
   if (Atomic::xchg(&_counter, 0) > 0) return;
 
-  Thread* thread = Thread::current();
-  assert(thread->is_Java_thread(), "Must be JavaThread");
-  JavaThread *jt = (JavaThread *)thread;
+  JavaThread *jt = JavaThread::current();
 
   // Optional optimization -- avoid state transitions if there's
   // an interrupt pending.
@@ -2120,7 +2118,7 @@ void Parker::park(bool isAbsolute, jlong time) {
     return;
   }
 
-  OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
+  OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
   jt->set_suspend_equivalent();
   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
 

src/hotspot/os/windows/os_windows.cpp

@@ -2136,19 +2136,19 @@ int os::signal_wait() {
 
 LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
                       address handler) {
-  JavaThread* thread = (JavaThread*) Thread::current_or_null();
+  Thread* thread = Thread::current_or_null();
   // Save pc in thread
 #ifdef _M_AMD64
   // Do not blow up if no thread info available.
-  if (thread) {
-    thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
+  if (thread != NULL) {
+    thread->as_Java_thread()->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
   }
   // Set pc to handler
   exceptionInfo->ContextRecord->Rip = (DWORD64)handler;
 #else
   // Do not blow up if no thread info available.
-  if (thread) {
-    thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
+  if (thread != NULL) {
+    thread->as_Java_thread()->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
   }
   // Set pc to handler
   exceptionInfo->ContextRecord->Eip = (DWORD)(DWORD_PTR)handler;
@@ -2477,7 +2477,7 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
   }
 
   if (t != NULL && t->is_Java_thread()) {
-    JavaThread* thread = (JavaThread*) t;
+    JavaThread* thread = t->as_Java_thread();
     bool in_java = thread->thread_state() == _thread_in_Java;
     bool in_native = thread->thread_state() == _thread_in_native;
     bool in_vm = thread->thread_state() == _thread_in_vm;
@@ -2570,7 +2570,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
 
     if (exception_code == EXCEPTION_IN_PAGE_ERROR) {
       CompiledMethod* nm = NULL;
-      JavaThread* thread = (JavaThread*)t;
       if (in_java) {
         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
         nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;

src/hotspot/os_cpu/aix_ppc/os_aix_ppc.cpp

@@ -228,7 +228,7 @@ JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrec
   if (os::Aix::signal_handlers_are_installed) {
     if (t != NULL) {
       if(t->is_Java_thread()) {
-        thread = (JavaThread*)t;
+        thread = t->as_Java_thread();
       }
       else if(t->is_VM_thread()) {
         vmthread = (VMThread *)t;

src/hotspot/os_cpu/bsd_x86/os_bsd_x86.cpp

@@ -457,7 +457,7 @@ JVM_handle_bsd_signal(int sig,
   if (os::Bsd::signal_handlers_are_installed) {
     if (t != NULL ){
       if(t->is_Java_thread()) {
-        thread = (JavaThread*)t;
+        thread = t->as_Java_thread();
       }
       else if(t->is_VM_thread()){
         vmthread = (VMThread *)t;

src/hotspot/os_cpu/bsd_x86/thread_bsd_x86.cpp

@@ -46,13 +46,10 @@ bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext,
 }
 
 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
-  assert(this->is_Java_thread(), "must be JavaThread");
-  JavaThread* jt = (JavaThread *)this;
-
   // If we have a last_Java_frame, then we should use it even if
   // isInJava == true.  It should be more reliable than ucontext info.
-  if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
-    *fr_addr = jt->pd_last_frame();
+  if (has_last_Java_frame() && frame_anchor()->walkable()) {
+    *fr_addr = pd_last_frame();
     return true;
   }
 
@@ -77,11 +74,11 @@ bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava)
     }
 
     frame ret_frame(ret_sp, ret_fp, addr);
-    if (!ret_frame.safe_for_sender(jt)) {
+    if (!ret_frame.safe_for_sender(this)) {
 #if COMPILER2_OR_JVMCI
       // C2 and JVMCI use ebp as a general register see if NULL fp helps
       frame ret_frame2(ret_sp, NULL, addr);
-      if (!ret_frame2.safe_for_sender(jt)) {
+      if (!ret_frame2.safe_for_sender(this)) {
         // nothing else to try if the frame isn't good
         return false;
       }

src/hotspot/os_cpu/bsd_zero/os_bsd_zero.cpp

@@ -156,7 +156,7 @@ JVM_handle_bsd_signal(int sig,
   if (os::Bsd::signal_handlers_are_installed) {
     if (t != NULL ){
       if(t->is_Java_thread()) {
-        thread = (JavaThread*)t;
+        thread = t->as_Java_thread();
       }
       else if(t->is_VM_thread()){
         vmthread = (VMThread *)t;

src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp

@@ -237,7 +237,7 @@ JVM_handle_linux_signal(int sig,
   if (os::Linux::signal_handlers_are_installed) {
     if (t != NULL ){
       if(t->is_Java_thread()) {
-        thread = (JavaThread*)t;
+        thread = t->as_Java_thread();
       }
       else if(t->is_VM_thread()){
         vmthread = (VMThread *)t;