ysr@777: /*
tonyp@2453:  * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
stefank@2314: #include "gc_implementation/g1/heapRegionSeq.hpp"
stefank@2314: #include "memory/allocation.hpp"
ysr@777: 
ysr@777: // Local to this file.
ysr@777: 
ysr@777: static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
ysr@777:   if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1;
ysr@777:   else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1;
ysr@777:   else if (*hr1p == *hr2p) return 0;
ysr@777:   else {
ysr@777:     assert(false, "We should never compare distinct overlapping regions.");
ysr@777:   }
ysr@777:   return 0;
ysr@777: }
ysr@777: 
iveresov@828: HeapRegionSeq::HeapRegionSeq(const size_t max_size) :
ysr@777:   _alloc_search_start(0),
ysr@777:   // The line below is the worst bit of C++ hackery I've ever written
ysr@777:   // (Detlefs, 11/23).  You should think of it as equivalent to
ysr@777:   // "_regions(100, true)": initialize the growable array and inform it
kvn@2043:   // that it should allocate its elem array(s) on the C heap.
kvn@2043:   //
kvn@2043:   // The first argument, however, is actually a comma expression
kvn@2043:   // (set_allocation_type(this, C_HEAP), 100). The purpose of the
kvn@2043:   // set_allocation_type() call is to replace the default allocation
kvn@2043:   // type for embedded objects STACK_OR_EMBEDDED with C_HEAP. It will
kvn@2043:   // allow to pass the assert in GenericGrowableArray() which checks
kvn@2043:   // that a growable array object must be on C heap if elements are.
kvn@2043:   //
kvn@2043:   // Note: containing object is allocated on C heap since it is CHeapObj.
kvn@2043:   //
kvn@2043:   _regions((ResourceObj::set_allocation_type((address)&_regions,
kvn@2043:                                              ResourceObj::C_HEAP),
iveresov@828:             (int)max_size),
ysr@777:            true),
ysr@777:   _next_rr_candidate(0),
ysr@777:   _seq_bottom(NULL)
ysr@777: {}
ysr@777: 
ysr@777: // Private methods.
ysr@777: 
apetrusenko@1112: void HeapRegionSeq::print_empty_runs() {
ysr@777:   int empty_run = 0;
ysr@777:   int n_empty = 0;
ysr@777:   int empty_run_start;
ysr@777:   for (int i = 0; i < _regions.length(); i++) {
ysr@777:     HeapRegion* r = _regions.at(i);
ysr@777:     if (r->continuesHumongous()) continue;
apetrusenko@1112:     if (r->is_empty()) {
ysr@777:       assert(!r->isHumongous(), "H regions should not be empty.");
ysr@777:       if (empty_run == 0) empty_run_start = i;
ysr@777:       empty_run++;
ysr@777:       n_empty++;
ysr@777:     } else {
ysr@777:       if (empty_run > 0) {
ysr@777:         gclog_or_tty->print("  %d:%d", empty_run_start, empty_run);
ysr@777:         empty_run = 0;
ysr@777:       }
ysr@777:     }
ysr@777:   }
ysr@777:   if (empty_run > 0) {
ysr@777:     gclog_or_tty->print(" %d:%d", empty_run_start, empty_run);
ysr@777:   }
ysr@777:   gclog_or_tty->print_cr(" [tot = %d]", n_empty);
ysr@777: }
ysr@777: 
ysr@777: int HeapRegionSeq::find(HeapRegion* hr) {
ysr@777:   // FIXME: optimized for adjacent regions of fixed size.
ysr@777:   int ind = hr->hrs_index();
ysr@777:   if (ind != -1) {
ysr@777:     assert(_regions.at(ind) == hr, "Mismatch");
ysr@777:   }
ysr@777:   return ind;
ysr@777: }
ysr@777: 
ysr@777: 
ysr@777: // Public methods.
ysr@777: 
ysr@777: void HeapRegionSeq::insert(HeapRegion* hr) {
iveresov@828:   assert(!_regions.is_full(), "Too many elements in HeapRegionSeq");
ysr@777:   if (_regions.length() == 0
ysr@777:       || _regions.top()->end() <= hr->bottom()) {
ysr@777:     hr->set_hrs_index(_regions.length());
ysr@777:     _regions.append(hr);
ysr@777:   } else {
ysr@777:     _regions.append(hr);
ysr@777:     _regions.sort(orderRegions);
ysr@777:     for (int i = 0; i < _regions.length(); i++) {
ysr@777:       _regions.at(i)->set_hrs_index(i);
ysr@777:     }
ysr@777:   }
ysr@777:   char* bot = (char*)_regions.at(0)->bottom();
ysr@777:   if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot;
ysr@777: }
ysr@777: 
ysr@777: size_t HeapRegionSeq::length() {
ysr@777:   return _regions.length();
ysr@777: }
ysr@777: 
ysr@777: size_t HeapRegionSeq::free_suffix() {
ysr@777:   size_t res = 0;
ysr@777:   int first = _regions.length() - 1;
ysr@777:   int cur = first;
ysr@777:   while (cur >= 0 &&
ysr@777:          (_regions.at(cur)->is_empty()
ysr@777:           && (first == cur
ysr@777:               || (_regions.at(cur+1)->bottom() ==
ysr@777:                   _regions.at(cur)->end())))) {
ysr@777:       res++;
ysr@777:       cur--;
ysr@777:   }
ysr@777:   return res;
ysr@777: }
ysr@777: 
tonyp@2472: int HeapRegionSeq::find_contiguous_from(int from, size_t num) {
tonyp@2472:   assert(num > 1, "pre-condition");
tonyp@2472:   assert(0 <= from && from <= _regions.length(),
tonyp@2472:          err_msg("from: %d should be valid and <= than %d",
tonyp@2472:                  from, _regions.length()));
tonyp@2472: 
tonyp@2472:   int curr = from;
tonyp@2472:   int first = -1;
tonyp@2472:   size_t num_so_far = 0;
tonyp@2472:   while (curr < _regions.length() && num_so_far < num) {
tonyp@2472:     HeapRegion* curr_hr = _regions.at(curr);
tonyp@2472:     if (curr_hr->is_empty()) {
tonyp@2472:       if (first == -1) {
tonyp@2472:         first = curr;
tonyp@2472:         num_so_far = 1;
tonyp@2472:       } else {
tonyp@2472:         num_so_far += 1;
tonyp@2472:       }
tonyp@2472:     } else {
tonyp@2472:       first = -1;
tonyp@2472:       num_so_far = 0;
tonyp@2472:     }
tonyp@2472:     curr += 1;
tonyp@2472:   }
tonyp@2472: 
tonyp@2472:   assert(num_so_far <= num, "post-condition");
tonyp@2472:   if (num_so_far == num) {
tonyp@2643:     // we found enough space for the humongous object
tonyp@2472:     assert(from <= first && first < _regions.length(), "post-condition");
tonyp@2472:     assert(first < curr && (curr - first) == (int) num, "post-condition");
tonyp@2472:     for (int i = first; i < first + (int) num; ++i) {
tonyp@2472:       assert(_regions.at(i)->is_empty(), "post-condition");
tonyp@2472:     }
tonyp@2472:     return first;
tonyp@2472:   } else {
tonyp@2472:     // we failed to find enough space for the humongous object
tonyp@2472:     return -1;
tonyp@2472:   }
tonyp@2472: }
tonyp@2472: 
tonyp@2472: int HeapRegionSeq::find_contiguous(size_t num) {
tonyp@2472:   assert(num > 1, "otherwise we should not be calling this");
tonyp@2472:   assert(0 <= _alloc_search_start && _alloc_search_start <= _regions.length(),
tonyp@2472:          err_msg("_alloc_search_start: %d should be valid and <= than %d",
tonyp@2472:                  _alloc_search_start, _regions.length()));
tonyp@2472: 
tonyp@2472:   int start = _alloc_search_start;
tonyp@2472:   int res = find_contiguous_from(start, num);
tonyp@2472:   if (res == -1 && start != 0) {
tonyp@2472:     // Try starting from the beginning. If _alloc_search_start was 0,
tonyp@2472:     // no point in doing this again.
tonyp@2472:     res = find_contiguous_from(0, num);
tonyp@2472:   }
tonyp@2472:   if (res != -1) {
tonyp@2472:     assert(0 <= res && res < _regions.length(),
tonyp@2472:            err_msg("res: %d should be valid", res));
tonyp@2472:     _alloc_search_start = res + (int) num;
tonyp@2492:     assert(0 < _alloc_search_start && _alloc_search_start <= _regions.length(),
tonyp@2492:            err_msg("_alloc_search_start: %d should be valid",
tonyp@2492:                    _alloc_search_start));
tonyp@2472:   }
ysr@777:   return res;
ysr@777: }
ysr@777: 
ysr@777: void HeapRegionSeq::iterate(HeapRegionClosure* blk) {
ysr@777:   iterate_from((HeapRegion*)NULL, blk);
ysr@777: }
ysr@777: 
ysr@777: // The first argument r is the heap region at which iteration begins.
ysr@777: // This operation runs fastest when r is NULL, or the heap region for
ysr@777: // which a HeapRegionClosure most recently returned true, or the
ysr@777: // heap region immediately to its right in the sequence.  In all
ysr@777: // other cases a linear search is required to find the index of r.
ysr@777: 
ysr@777: void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) {
ysr@777: 
ysr@777:   // :::: FIXME ::::
ysr@777:   // Static cache value is bad, especially when we start doing parallel
ysr@777:   // remembered set update. For now just don't cache anything (the
ysr@777:   // code in the def'd out blocks).
ysr@777: 
ysr@777: #if 0
ysr@777:   static int cached_j = 0;
ysr@777: #endif
ysr@777:   int len = _regions.length();
ysr@777:   int j = 0;
ysr@777:   // Find the index of r.
ysr@777:   if (r != NULL) {
ysr@777: #if 0
ysr@777:     assert(cached_j >= 0, "Invariant.");
ysr@777:     if ((cached_j < len) && (r == _regions.at(cached_j))) {
ysr@777:       j = cached_j;
ysr@777:     } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) {
ysr@777:       j = cached_j + 1;
ysr@777:     } else {
ysr@777:       j = find(r);
ysr@777: #endif
ysr@777:       if (j < 0) {
ysr@777:         j = 0;
ysr@777:       }
ysr@777: #if 0
ysr@777:     }
ysr@777: #endif
ysr@777:   }
ysr@777:   int i;
ysr@777:   for (i = j; i < len; i += 1) {
ysr@777:     int res = blk->doHeapRegion(_regions.at(i));
ysr@777:     if (res) {
ysr@777: #if 0
ysr@777:       cached_j = i;
ysr@777: #endif
ysr@777:       blk->incomplete();
ysr@777:       return;
ysr@777:     }
ysr@777:   }
ysr@777:   for (i = 0; i < j; i += 1) {
ysr@777:     int res = blk->doHeapRegion(_regions.at(i));
ysr@777:     if (res) {
ysr@777: #if 0
ysr@777:       cached_j = i;
ysr@777: #endif
ysr@777:       blk->incomplete();
ysr@777:       return;
ysr@777:     }
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) {
ysr@777:   int len = _regions.length();
ysr@777:   int i;
ysr@777:   for (i = idx; i < len; i++) {
ysr@777:     if (blk->doHeapRegion(_regions.at(i))) {
ysr@777:       blk->incomplete();
ysr@777:       return;
ysr@777:     }
ysr@777:   }
ysr@777:   for (i = 0; i < idx; i++) {
ysr@777:     if (blk->doHeapRegion(_regions.at(i))) {
ysr@777:       blk->incomplete();
ysr@777:       return;
ysr@777:     }
ysr@777:   }
ysr@777: }
ysr@777: 
ysr@777: MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes,
ysr@777:                                    size_t& num_regions_deleted) {
tonyp@2472:   // Reset this in case it's currently pointing into the regions that
tonyp@2472:   // we just removed.
tonyp@2472:   _alloc_search_start = 0;
tonyp@2472: 
ysr@777:   assert(shrink_bytes % os::vm_page_size() == 0, "unaligned");
ysr@777:   assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned");
ysr@777: 
ysr@777:   if (_regions.length() == 0) {
ysr@777:     num_regions_deleted = 0;
ysr@777:     return MemRegion();
ysr@777:   }
ysr@777:   int j = _regions.length() - 1;
ysr@777:   HeapWord* end = _regions.at(j)->end();
ysr@777:   HeapWord* last_start = end;
ysr@777:   while (j >= 0 && shrink_bytes > 0) {
ysr@777:     HeapRegion* cur = _regions.at(j);
ysr@777:     // We have to leave humongous regions where they are,
ysr@777:     // and work around them.
ysr@777:     if (cur->isHumongous()) {
ysr@777:       return MemRegion(last_start, end);
ysr@777:     }
ysr@777:     assert(cur == _regions.top(), "Should be top");
ysr@777:     if (!cur->is_empty()) break;
ysr@777:     shrink_bytes -= cur->capacity();
ysr@777:     num_regions_deleted++;
ysr@777:     _regions.pop();
ysr@777:     last_start = cur->bottom();
ysr@777:     // We need to delete these somehow, but can't currently do so here: if
ysr@777:     // we do, the ZF thread may still access the deleted region.  We'll
ysr@777:     // leave this here as a reminder that we have to do something about
ysr@777:     // this.
ysr@777:     // delete cur;
ysr@777:     j--;
ysr@777:   }
ysr@777:   return MemRegion(last_start, end);
ysr@777: }
ysr@777: 
ysr@777: class PrintHeapRegionClosure : public  HeapRegionClosure {
ysr@777: public:
ysr@777:   bool doHeapRegion(HeapRegion* r) {
ysr@777:     gclog_or_tty->print(PTR_FORMAT ":", r);
ysr@777:     r->print();
ysr@777:     return false;
ysr@777:   }
ysr@777: };
ysr@777: 
ysr@777: void HeapRegionSeq::print() {
ysr@777:   PrintHeapRegionClosure cl;
ysr@777:   iterate(&cl);
ysr@777: }