jdk8-mips64-public/hotspot: src/share/vm/code/stubs.cpp@ac27a9c85bea (annotated)

src/share/vm/code/stubs.cpp@ac27a9c85bea (annotated)

src/share/vm/code/stubs.cpp

Thu, 24 May 2018 18:41:44 +0800

author: aoqi
date: Thu, 24 May 2018 18:41:44 +0800
changeset 8856: ac27a9c85bea
parent 6876: 710a3c8b516e
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1997, 2013, 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.
  *
  */
 #include "precompiled.hpp"
 #include "code/codeBlob.hpp"
 #include "code/stubs.hpp"
 #include "memory/allocation.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/mutexLocker.hpp"
 // Implementation of StubQueue
 //
 // Standard wrap-around queue implementation; the queue dimensions
 // are specified by the _queue_begin & _queue_end indices. The queue
 // can be in two states (transparent to the outside):
 //
 // a) contiguous state: all queue entries in one block (or empty)
 //
 // Queue: |...|XXXXXXX|...............|
 //        ^0  ^begin  ^end            ^size = limit
 //            |_______|
 //            one block
 //
 // b) non-contiguous state: queue entries in two blocks
 //
 // Queue: |XXX|.......|XXXXXXX|.......|
 //        ^0  ^end    ^begin  ^limit  ^size
 //        |___|       |_______|
 //         1st block  2nd block
 //
 // In the non-contiguous state, the wrap-around point is
 // indicated via the _buffer_limit index since the last
 // queue entry may not fill up the queue completely in
 // which case we need to know where the 2nd block's end
 // is to do the proper wrap-around. When removing the
 // last entry of the 2nd block, _buffer_limit is reset
 // to _buffer_size.
 //
 // CAUTION: DO NOT MESS WITH THIS CODE IF YOU CANNOT PROVE
 // ITS CORRECTNESS! THIS CODE IS MORE SUBTLE THAN IT LOOKS!
 StubQueue::StubQueue(StubInterface* stub_interface, int buffer_size,
                      Mutex* lock, const char* name) : _mutex(lock) {
   intptr_t size = round_to(buffer_size, 2*BytesPerWord);
   BufferBlob* blob = BufferBlob::create(name, size);
   if( blob == NULL) {
     vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, err_msg("CodeCache: no room for %s", name));
   }
   _stub_interface  = stub_interface;
   _buffer_size     = blob->content_size();
   _buffer_limit    = blob->content_size();
   _stub_buffer     = blob->content_begin();
   _queue_begin     = 0;
   _queue_end       = 0;
   _number_of_stubs = 0;
   register_queue(this);
 }
 StubQueue::~StubQueue() {
   // Note: Currently StubQueues are never destroyed so nothing needs to be done here.
   //       If we want to implement the destructor, we need to release the BufferBlob
   //       allocated in the constructor (i.e., we need to keep it around or look it
   //       up via CodeCache::find_blob(...).
   Unimplemented();
 }
 Stub* StubQueue::stub_containing(address pc) const {
   if (contains(pc)) {
     for (Stub* s = first(); s != NULL; s = next(s)) {
       if (stub_contains(s, pc)) return s;
     }
   }
   return NULL;
 }
 Stub* StubQueue::request_committed(int code_size) {
   Stub* s = request(code_size);
   CodeStrings strings;
   if (s != NULL) commit(code_size, strings);
   return s;
 }
 Stub* StubQueue::request(int requested_code_size) {
   assert(requested_code_size > 0, "requested_code_size must be > 0");
   if (_mutex != NULL) _mutex->lock();
   Stub* s = current_stub();
   int requested_size = round_to(stub_code_size_to_size(requested_code_size), CodeEntryAlignment);
   if (requested_size <= available_space()) {
     if (is_contiguous()) {
       // Queue: |...|XXXXXXX|.............|
       //        ^0  ^begin  ^end          ^size = limit
       assert(_buffer_limit == _buffer_size, "buffer must be fully usable");
       if (_queue_end + requested_size <= _buffer_size) {
         // code fits in at the end => nothing to do
         CodeStrings strings;
         stub_initialize(s, requested_size, strings);
         return s;
       } else {
         // stub doesn't fit in at the queue end
         // => reduce buffer limit & wrap around
         assert(!is_empty(), "just checkin'");
         _buffer_limit = _queue_end;
         _queue_end = 0;
       }
     }
   }
   if (requested_size <= available_space()) {
     assert(!is_contiguous(), "just checkin'");
     assert(_buffer_limit <= _buffer_size, "queue invariant broken");
     // Queue: |XXX|.......|XXXXXXX|.......|
     //        ^0  ^end    ^begin  ^limit  ^size
     s = current_stub();
     CodeStrings strings;
     stub_initialize(s, requested_size, strings);
     return s;
   }
   // Not enough space left
   if (_mutex != NULL) _mutex->unlock();
   return NULL;
 }
 void StubQueue::commit(int committed_code_size, CodeStrings& strings) {
   assert(committed_code_size > 0, "committed_code_size must be > 0");
   int committed_size = round_to(stub_code_size_to_size(committed_code_size), CodeEntryAlignment);
   Stub* s = current_stub();
   assert(committed_size <= stub_size(s), "committed size must not exceed requested size");
   stub_initialize(s, committed_size, strings);
   _queue_end += committed_size;
   _number_of_stubs++;
   if (_mutex != NULL) _mutex->unlock();
   debug_only(stub_verify(s);)
 }
 void StubQueue::remove_first() {
   if (number_of_stubs() == 0) return;
   Stub* s = first();
   debug_only(stub_verify(s);)
   stub_finalize(s);
   _queue_begin += stub_size(s);
   assert(_queue_begin <= _buffer_limit, "sanity check");
   if (_queue_begin == _queue_end) {
     // buffer empty
     // => reset queue indices
     _queue_begin  = 0;
     _queue_end    = 0;
     _buffer_limit = _buffer_size;
   } else if (_queue_begin == _buffer_limit) {
     // buffer limit reached
     // => reset buffer limit & wrap around
     _buffer_limit = _buffer_size;
     _queue_begin = 0;
   }
   _number_of_stubs--;
 }
 void StubQueue::remove_first(int n) {
   int i = MIN2(n, number_of_stubs());
   while (i-- > 0) remove_first();
 }
 void StubQueue::remove_all(){
   debug_only(verify();)
   remove_first(number_of_stubs());
   assert(number_of_stubs() == 0, "sanity check");
 }
 enum { StubQueueLimit = 10 };  // there are only a few in the world
 static StubQueue* registered_stub_queues[StubQueueLimit];
 void StubQueue::register_queue(StubQueue* sq) {
   for (int i = 0; i < StubQueueLimit; i++) {
     if (registered_stub_queues[i] == NULL) {
       registered_stub_queues[i] = sq;
       return;
     }
   }
   ShouldNotReachHere();
 }
 void StubQueue::queues_do(void f(StubQueue* sq)) {
   for (int i = 0; i < StubQueueLimit; i++) {
     if (registered_stub_queues[i] != NULL) {
       f(registered_stub_queues[i]);
     }
   }
 }
 void StubQueue::stubs_do(void f(Stub* s)) {
   debug_only(verify();)
   MutexLockerEx lock(_mutex);
   for (Stub* s = first(); s != NULL; s = next(s)) f(s);
 }
 void StubQueue::verify() {
   // verify only if initialized
   if (_stub_buffer == NULL) return;
   MutexLockerEx lock(_mutex);
   // verify index boundaries
   guarantee(0 <= _buffer_size, "buffer size must be positive");
   guarantee(0 <= _buffer_limit && _buffer_limit <= _buffer_size , "_buffer_limit out of bounds");
   guarantee(0 <= _queue_begin  && _queue_begin  <  _buffer_limit, "_queue_begin out of bounds");
   guarantee(0 <= _queue_end    && _queue_end    <= _buffer_limit, "_queue_end   out of bounds");
   // verify alignment
   guarantee(_buffer_size  % CodeEntryAlignment == 0, "_buffer_size  not aligned");
   guarantee(_buffer_limit % CodeEntryAlignment == 0, "_buffer_limit not aligned");
   guarantee(_queue_begin  % CodeEntryAlignment == 0, "_queue_begin  not aligned");
   guarantee(_queue_end    % CodeEntryAlignment == 0, "_queue_end    not aligned");
   // verify buffer limit/size relationship
   if (is_contiguous()) {
     guarantee(_buffer_limit == _buffer_size, "_buffer_limit must equal _buffer_size");
   }
   // verify contents
   int n = 0;
   for (Stub* s = first(); s != NULL; s = next(s)) {
     stub_verify(s);
     n++;
   }
   guarantee(n == number_of_stubs(), "number of stubs inconsistent");
   guarantee(_queue_begin != _queue_end || n == 0, "buffer indices must be the same");
 }
 void StubQueue::print() {
   MutexLockerEx lock(_mutex);
   for (Stub* s = first(); s != NULL; s = next(s)) {
     stub_print(s);
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/code/stubs.cpp@ac27a9c85bea (annotated)

src/share/vm/code/stubs.cpp