--- a/hotspot/src/share/vm/gc/g1/dirtyCardQueue.cpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/dirtyCardQueue.cpp Thu Mar 10 21:57:27 2016 +0000
@@ -115,9 +115,8 @@
uint worker_i) {
bool res = true;
if (_buf != NULL) {
- res = apply_closure_to_buffer(cl, _buf, _index, _sz,
- consume,
- worker_i);
+ BufferNode* node = BufferNode::make_node_from_buffer(_buf, _index);
+ res = apply_closure_to_buffer(cl, node, _sz, consume, worker_i);
if (res && consume) {
_index = _sz;
}
@@ -126,25 +125,28 @@
}
bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
- void** buf,
- size_t index, size_t sz,
+ BufferNode* node,
+ size_t buffer_size,
bool consume,
uint worker_i) {
if (cl == NULL) return true;
- size_t limit = byte_index_to_index(sz);
- for (size_t i = byte_index_to_index(index); i < limit; ++i) {
+ void** buf = BufferNode::make_buffer_from_node(node);
+ size_t limit = byte_index_to_index(buffer_size);
+ for (size_t i = byte_index_to_index(node->index()); i < limit; ++i) {
jbyte* card_ptr = static_cast<jbyte*>(buf[i]);
- if (card_ptr != NULL) {
- // Set the entry to null, so we don't do it again (via the test
- // above) if we reconsider this buffer.
+ assert(card_ptr != NULL, "invariant");
+ if (!cl->do_card_ptr(card_ptr, worker_i)) {
if (consume) {
- buf[i] = NULL;
+ size_t new_index = index_to_byte_index(i + 1);
+ assert(new_index <= buffer_size, "invariant");
+ node->set_index(new_index);
}
- if (!cl->do_card_ptr(card_ptr, worker_i)) {
- return false;
- }
+ return false;
}
}
+ if (consume) {
+ node->set_index(buffer_size);
+ }
return true;
}
@@ -188,14 +190,15 @@
t->dirty_card_queue().handle_zero_index();
}
-bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
+bool DirtyCardQueueSet::mut_process_buffer(BufferNode* node) {
guarantee(_free_ids != NULL, "must be");
// claim a par id
uint worker_i = _free_ids->claim_par_id();
- bool b = DirtyCardQueue::apply_closure_to_buffer(_mut_process_closure, buf, 0,
- _sz, true, worker_i);
+ bool b = DirtyCardQueue::apply_closure_to_buffer(_mut_process_closure,
+ node, _sz,
+ true, worker_i);
if (b) {
Atomic::inc(&_processed_buffers_mut);
}
@@ -239,49 +242,30 @@
if (nd == NULL) {
return false;
} else {
- void** buf = BufferNode::make_buffer_from_node(nd);
- size_t index = nd->index();
- if (DirtyCardQueue::apply_closure_to_buffer(cl,
- buf, index, _sz,
- true, worker_i)) {
+ if (DirtyCardQueue::apply_closure_to_buffer(cl, nd, _sz, true, worker_i)) {
// Done with fully processed buffer.
- deallocate_buffer(buf);
+ deallocate_buffer(nd);
Atomic::inc(&_processed_buffers_rs_thread);
return true;
} else {
// Return partially processed buffer to the queue.
- enqueue_complete_buffer(buf, index);
+ enqueue_complete_buffer(nd);
return false;
}
}
}
-void DirtyCardQueueSet::apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
- BufferNode* nd = _completed_buffers_head;
- while (nd != NULL) {
- bool b =
- DirtyCardQueue::apply_closure_to_buffer(cl,
- BufferNode::make_buffer_from_node(nd),
- 0, _sz, false);
- guarantee(b, "Should not stop early.");
- nd = nd->next();
- }
-}
-
void DirtyCardQueueSet::par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
BufferNode* nd = _cur_par_buffer_node;
while (nd != NULL) {
- BufferNode* next = (BufferNode*)nd->next();
- BufferNode* actual = (BufferNode*)Atomic::cmpxchg_ptr((void*)next, (volatile void*)&_cur_par_buffer_node, (void*)nd);
+ BufferNode* next = nd->next();
+ void* actual = Atomic::cmpxchg_ptr(next, &_cur_par_buffer_node, nd);
if (actual == nd) {
- bool b =
- DirtyCardQueue::apply_closure_to_buffer(cl,
- BufferNode::make_buffer_from_node(actual),
- 0, _sz, false);
+ bool b = DirtyCardQueue::apply_closure_to_buffer(cl, nd, _sz, false);
guarantee(b, "Should not stop early.");
nd = next;
} else {
- nd = actual;
+ nd = static_cast<BufferNode*>(actual);
}
}
}
@@ -304,7 +288,7 @@
while (buffers_to_delete != NULL) {
BufferNode* nd = buffers_to_delete;
buffers_to_delete = nd->next();
- deallocate_buffer(BufferNode::make_buffer_from_node(nd));
+ deallocate_buffer(nd);
}
}
@@ -320,6 +304,13 @@
shared_dirty_card_queue()->reset();
}
+void DirtyCardQueueSet::concatenate_log(DirtyCardQueue& dcq) {
+ if (!dcq.is_empty()) {
+ enqueue_complete_buffer(
+ BufferNode::make_node_from_buffer(dcq.get_buf(), dcq.get_index()));
+ dcq.reinitialize();
+ }
+}
void DirtyCardQueueSet::concatenate_logs() {
// Iterate over all the threads, if we find a partial log add it to
@@ -329,23 +320,9 @@
_max_completed_queue = max_jint;
assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
for (JavaThread* t = Threads::first(); t; t = t->next()) {
- DirtyCardQueue& dcq = t->dirty_card_queue();
- if (dcq.size() != 0) {
- void** buf = dcq.get_buf();
- // We must NULL out the unused entries, then enqueue.
- size_t limit = dcq.byte_index_to_index(dcq.get_index());
- for (size_t i = 0; i < limit; ++i) {
- buf[i] = NULL;
- }
- enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
- dcq.reinitialize();
- }
+ concatenate_log(t->dirty_card_queue());
}
- if (_shared_dirty_card_queue.size() != 0) {
- enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
- _shared_dirty_card_queue.get_index());
- _shared_dirty_card_queue.reinitialize();
- }
+ concatenate_log(_shared_dirty_card_queue);
// Restore the completed buffer queue limit.
_max_completed_queue = save_max_completed_queue;
}
--- a/hotspot/src/share/vm/gc/g1/dirtyCardQueue.hpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/dirtyCardQueue.hpp Thu Mar 10 21:57:27 2016 +0000
@@ -52,21 +52,24 @@
// Process queue entries and release resources.
void flush() { flush_impl(); }
- // Apply the closure to all elements, and reset the index to make the
- // buffer empty. If a closure application returns "false", return
- // "false" immediately, halting the iteration. If "consume" is true,
- // deletes processed entries from logs.
+ // Apply the closure to the elements from _index to _sz. If all
+ // closure applications return true, then returns true. Stops
+ // processing after the first closure application that returns
+ // false, and returns false from this function. If "consume" is
+ // true, _index is updated to follow the last processed element.
bool apply_closure(CardTableEntryClosure* cl,
bool consume = true,
uint worker_i = 0);
- // Apply the closure to all elements of "buf", down to "index"
- // (inclusive.) If returns "false", then a closure application returned
- // "false", and we return immediately. If "consume" is true, entries are
- // set to NULL as they are processed, so they will not be processed again
- // later.
+ // Apply the closure to the elements of "node" from it's index to
+ // buffer_size. If all closure applications return true, then
+ // returns true. Stops processing after the first closure
+ // application that returns false, and returns false from this
+ // function. If "consume" is true, the node's index is updated to
+ // follow the last processed element.
static bool apply_closure_to_buffer(CardTableEntryClosure* cl,
- void** buf, size_t index, size_t sz,
+ BufferNode* node,
+ size_t buffer_size,
bool consume = true,
uint worker_i = 0);
void **get_buf() { return _buf;}
@@ -94,8 +97,7 @@
DirtyCardQueue _shared_dirty_card_queue;
- // Override.
- bool mut_process_buffer(void** buf);
+ bool mut_process_buffer(BufferNode* node);
// Protected by the _cbl_mon.
FreeIdSet* _free_ids;
@@ -107,6 +109,9 @@
// Current buffer node used for parallel iteration.
BufferNode* volatile _cur_par_buffer_node;
+
+ void concatenate_log(DirtyCardQueue& dcq);
+
public:
DirtyCardQueueSet(bool notify_when_complete = true);
@@ -126,12 +131,13 @@
static void handle_zero_index_for_thread(JavaThread* t);
// If there exists some completed buffer, pop it, then apply the
- // specified closure to all its elements, nulling out those elements
- // processed. If all elements are processed, returns "true". If no
- // completed buffers exist, returns false. If a completed buffer exists,
- // but is only partially completed before a "yield" happens, the
- // partially completed buffer (with its processed elements set to NULL)
- // is returned to the completed buffer set, and this call returns false.
+ // specified closure to its active elements. If all active elements
+ // are processed, returns "true". If no completed buffers exist,
+ // returns false. If a completed buffer exists, but is only
+ // partially completed before a "yield" happens, the partially
+ // completed buffer (with its index updated to exclude the processed
+ // elements) is returned to the completed buffer set, and this call
+ // returns false.
bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
uint worker_i,
size_t stop_at,
@@ -139,13 +145,10 @@
BufferNode* get_completed_buffer(size_t stop_at);
- // Applies the current closure to all completed buffers,
- // non-consumptively.
- void apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
-
void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; }
// Applies the current closure to all completed buffers, non-consumptively.
- // Parallel version.
+ // Can be used in parallel, all callers using the iteration state initialized
+ // by reset_for_par_iteration.
void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl);
DirtyCardQueue* shared_dirty_card_queue() {
--- a/hotspot/src/share/vm/gc/g1/ptrQueue.cpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/ptrQueue.cpp Thu Mar 10 21:57:27 2016 +0000
@@ -43,16 +43,12 @@
void PtrQueue::flush_impl() {
if (!_permanent && _buf != NULL) {
- if (_index == _sz) {
+ BufferNode* node = BufferNode::make_node_from_buffer(_buf, _index);
+ if (is_empty()) {
// No work to do.
- qset()->deallocate_buffer(_buf);
+ qset()->deallocate_buffer(node);
} else {
- // We must NULL out the unused entries, then enqueue.
- size_t limit = byte_index_to_index(_index);
- for (size_t i = 0; i < limit; ++i) {
- _buf[i] = NULL;
- }
- qset()->enqueue_complete_buffer(_buf);
+ qset()->enqueue_complete_buffer(node);
}
_buf = NULL;
_index = 0;
@@ -74,7 +70,7 @@
assert(_index <= _sz, "Invariant.");
}
-void PtrQueue::locking_enqueue_completed_buffer(void** buf) {
+void PtrQueue::locking_enqueue_completed_buffer(BufferNode* node) {
assert(_lock->owned_by_self(), "Required.");
// We have to unlock _lock (which may be Shared_DirtyCardQ_lock) before
@@ -82,7 +78,7 @@
// have the same rank and we may get the "possible deadlock" message
_lock->unlock();
- qset()->enqueue_complete_buffer(buf);
+ qset()->enqueue_complete_buffer(node);
// We must relock only because the caller will unlock, for the normal
// case.
_lock->lock_without_safepoint_check();
@@ -157,10 +153,9 @@
return BufferNode::make_buffer_from_node(node);
}
-void PtrQueueSet::deallocate_buffer(void** buf) {
+void PtrQueueSet::deallocate_buffer(BufferNode* node) {
assert(_sz > 0, "Didn't set a buffer size.");
MutexLockerEx x(_fl_owner->_fl_lock, Mutex::_no_safepoint_check_flag);
- BufferNode *node = BufferNode::make_node_from_buffer(buf);
node->set_next(_fl_owner->_buf_free_list);
_fl_owner->_buf_free_list = node;
_fl_owner->_buf_free_list_sz++;
@@ -211,10 +206,10 @@
// preventing the subsequent the multiple enqueue, and
// install a newly allocated buffer below.
- void** buf = _buf; // local pointer to completed buffer
+ BufferNode* node = BufferNode::make_node_from_buffer(_buf, _index);
_buf = NULL; // clear shared _buf field
- locking_enqueue_completed_buffer(buf); // enqueue completed buffer
+ locking_enqueue_completed_buffer(node); // enqueue completed buffer
// While the current thread was enqueueing the buffer another thread
// may have a allocated a new buffer and inserted it into this pointer
@@ -224,9 +219,11 @@
if (_buf != NULL) return;
} else {
- if (qset()->process_or_enqueue_complete_buffer(_buf)) {
+ BufferNode* node = BufferNode::make_node_from_buffer(_buf, _index);
+ if (qset()->process_or_enqueue_complete_buffer(node)) {
// Recycle the buffer. No allocation.
- _sz = qset()->buffer_size();
+ assert(_buf == BufferNode::make_buffer_from_node(node), "invariant");
+ assert(_sz == qset()->buffer_size(), "invariant");
_index = _sz;
return;
}
@@ -238,12 +235,12 @@
_index = _sz;
}
-bool PtrQueueSet::process_or_enqueue_complete_buffer(void** buf) {
+bool PtrQueueSet::process_or_enqueue_complete_buffer(BufferNode* node) {
if (Thread::current()->is_Java_thread()) {
// We don't lock. It is fine to be epsilon-precise here.
if (_max_completed_queue == 0 || _max_completed_queue > 0 &&
_n_completed_buffers >= _max_completed_queue + _completed_queue_padding) {
- bool b = mut_process_buffer(buf);
+ bool b = mut_process_buffer(node);
if (b) {
// True here means that the buffer hasn't been deallocated and the caller may reuse it.
return true;
@@ -251,14 +248,12 @@
}
}
// The buffer will be enqueued. The caller will have to get a new one.
- enqueue_complete_buffer(buf);
+ enqueue_complete_buffer(node);
return false;
}
-void PtrQueueSet::enqueue_complete_buffer(void** buf, size_t index) {
+void PtrQueueSet::enqueue_complete_buffer(BufferNode* cbn) {
MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
- BufferNode* cbn = BufferNode::make_node_from_buffer(buf);
- cbn->set_index(index);
cbn->set_next(NULL);
if (_completed_buffers_tail == NULL) {
assert(_completed_buffers_head == NULL, "Well-formedness");
--- a/hotspot/src/share/vm/gc/g1/ptrQueue.hpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/ptrQueue.hpp Thu Mar 10 21:57:27 2016 +0000
@@ -33,6 +33,7 @@
// the addresses of modified old-generation objects. This type supports
// this operation.
+class BufferNode;
class PtrQueueSet;
class PtrQueue VALUE_OBJ_CLASS_SPEC {
friend class VMStructs;
@@ -104,7 +105,7 @@
// get into an infinite loop).
virtual bool should_enqueue_buffer() { return true; }
void handle_zero_index();
- void locking_enqueue_completed_buffer(void** buf);
+ void locking_enqueue_completed_buffer(BufferNode* node);
void enqueue_known_active(void* ptr);
@@ -136,6 +137,10 @@
return ind / sizeof(void*);
}
+ static size_t index_to_byte_index(size_t ind) {
+ return ind * sizeof(void*);
+ }
+
// To support compiler.
protected:
@@ -186,10 +191,13 @@
// Free a BufferNode.
static void deallocate(BufferNode* node);
- // Return the BufferNode containing the buffer.
- static BufferNode* make_node_from_buffer(void** buffer) {
- return reinterpret_cast<BufferNode*>(
- reinterpret_cast<char*>(buffer) - buffer_offset());
+ // Return the BufferNode containing the buffer, after setting its index.
+ static BufferNode* make_node_from_buffer(void** buffer, size_t index) {
+ BufferNode* node =
+ reinterpret_cast<BufferNode*>(
+ reinterpret_cast<char*>(buffer) - buffer_offset());
+ node->set_index(index);
+ return node;
}
// Return the buffer for node.
@@ -243,7 +251,7 @@
// A mutator thread does the the work of processing a buffer.
// Returns "true" iff the work is complete (and the buffer may be
// deallocated).
- virtual bool mut_process_buffer(void** buf) {
+ virtual bool mut_process_buffer(BufferNode* node) {
ShouldNotReachHere();
return false;
}
@@ -267,13 +275,13 @@
// Return an empty buffer to the free list. The "buf" argument is
// required to be a pointer to the head of an array of length "_sz".
- void deallocate_buffer(void** buf);
+ void deallocate_buffer(BufferNode* node);
// Declares that "buf" is a complete buffer.
- void enqueue_complete_buffer(void** buf, size_t index = 0);
+ void enqueue_complete_buffer(BufferNode* node);
// To be invoked by the mutator.
- bool process_or_enqueue_complete_buffer(void** buf);
+ bool process_or_enqueue_complete_buffer(BufferNode* node);
bool completed_buffers_exist_dirty() {
return _n_completed_buffers > 0;
--- a/hotspot/src/share/vm/gc/g1/satbMarkQueue.cpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/satbMarkQueue.cpp Thu Mar 10 21:57:27 2016 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -100,6 +100,10 @@
return true;
}
+inline bool retain_entry(const void* entry, G1CollectedHeap* heap) {
+ return requires_marking(entry, heap) && !heap->isMarkedNext((oop)entry);
+}
+
// This method removes entries from a SATB buffer that will not be
// useful to the concurrent marking threads. Entries are retained if
// they require marking and are not already marked. Retained entries
@@ -114,43 +118,28 @@
return;
}
- // Used for sanity checking at the end of the loop.
- DEBUG_ONLY(size_t entries = 0; size_t retained = 0;)
+ assert(_index <= _sz, "invariant");
- assert(_index <= _sz, "invariant");
- void** limit = &buf[byte_index_to_index(_index)];
- void** src = &buf[byte_index_to_index(_sz)];
- void** dst = src;
-
- while (limit < src) {
- DEBUG_ONLY(entries += 1;)
- --src;
+ // Two-fingered compaction toward the end.
+ void** src = &buf[byte_index_to_index(_index)];
+ void** dst = &buf[byte_index_to_index(_sz)];
+ for ( ; src < dst; ++src) {
+ // Search low to high for an entry to keep.
void* entry = *src;
- // NULL the entry so that unused parts of the buffer contain NULLs
- // at the end. If we are going to retain it we will copy it to its
- // final place. If we have retained all entries we have visited so
- // far, we'll just end up copying it to the same place.
- *src = NULL;
-
- if (requires_marking(entry, g1h) && !g1h->isMarkedNext((oop)entry)) {
- --dst;
- assert(*dst == NULL, "filtering destination should be clear");
- *dst = entry;
- DEBUG_ONLY(retained += 1;);
+ if (retain_entry(entry, g1h)) {
+ // Found keeper. Search high to low for an entry to discard.
+ while (src < --dst) {
+ if (!retain_entry(*dst, g1h)) {
+ *dst = entry; // Replace discard with keeper.
+ break;
+ }
+ }
+ // If discard search failed (src == dst), the outer loop will also end.
}
}
- size_t new_index = pointer_delta(dst, buf, 1);
-
-#ifdef ASSERT
- size_t entries_calc = (_sz - _index) / sizeof(void*);
- assert(entries == entries_calc, "the number of entries we counted "
- "should match the number of entries we calculated");
- size_t retained_calc = (_sz - new_index) / sizeof(void*);
- assert(retained == retained_calc, "the number of retained entries we counted "
- "should match the number of retained entries we calculated");
-#endif // ASSERT
-
- _index = new_index;
+ // dst points to the lowest retained entry, or the end of the buffer
+ // if all the entries were filtered out.
+ _index = pointer_delta(dst, buf, 1);
}
// This method will first apply the above filtering to the buffer. If
@@ -286,19 +275,11 @@
}
if (nd != NULL) {
void **buf = BufferNode::make_buffer_from_node(nd);
- // Skip over NULL entries at beginning (e.g. push end) of buffer.
- // Filtering can result in non-full completed buffers; see
- // should_enqueue_buffer.
- assert(_sz % sizeof(void*) == 0, "invariant");
- size_t limit = SATBMarkQueue::byte_index_to_index(_sz);
- for (size_t i = 0; i < limit; ++i) {
- if (buf[i] != NULL) {
- // Found the end of the block of NULLs; process the remainder.
- cl->do_buffer(buf + i, limit - i);
- break;
- }
- }
- deallocate_buffer(buf);
+ size_t index = SATBMarkQueue::byte_index_to_index(nd->index());
+ size_t size = SATBMarkQueue::byte_index_to_index(_sz);
+ assert(index <= size, "invariant");
+ cl->do_buffer(buf + index, size - index);
+ deallocate_buffer(nd);
return true;
} else {
return false;
@@ -355,7 +336,7 @@
while (buffers_to_delete != NULL) {
BufferNode* nd = buffers_to_delete;
buffers_to_delete = nd->next();
- deallocate_buffer(BufferNode::make_buffer_from_node(nd));
+ deallocate_buffer(nd);
}
assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
// So we can safely manipulate these queues.
--- a/hotspot/src/share/vm/gc/g1/satbMarkQueue.hpp Thu Mar 10 13:43:47 2016 -0500
+++ b/hotspot/src/share/vm/gc/g1/satbMarkQueue.hpp Thu Mar 10 21:57:27 2016 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -115,9 +115,8 @@
// If there exists some completed buffer, pop and process it, and
// return true. Otherwise return false. Processing a buffer
- // consists of applying the closure to the buffer range starting
- // with the first non-NULL entry to the end of the buffer; the
- // leading entries may be NULL due to filtering.
+ // consists of applying the closure to the active range of the
+ // buffer; the leading entries may be excluded due to filtering.
bool apply_closure_to_completed_buffer(SATBBufferClosure* cl);
#ifndef PRODUCT