1.1 --- a/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Wed Jun 08 21:48:38 2011 -0400
1.2 +++ b/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Fri Jun 10 13:16:40 2011 -0400
1.3 @@ -23,259 +23,182 @@
1.4 */
1.5
1.6 #include "precompiled.hpp"
1.7 +#include "gc_implementation/g1/heapRegion.hpp"
1.8 +#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
1.9 +#include "gc_implementation/g1/heapRegionSets.hpp"
1.10 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
1.11 -#include "gc_implementation/g1/heapRegionSeq.hpp"
1.12 #include "memory/allocation.hpp"
1.13
1.14 -// Local to this file.
1.15 +// Private
1.16
1.17 -static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
1.18 - if ((*hr1p)->end() <= (*hr2p)->bottom()) return -1;
1.19 - else if ((*hr2p)->end() <= (*hr1p)->bottom()) return 1;
1.20 - else if (*hr1p == *hr2p) return 0;
1.21 - else {
1.22 - assert(false, "We should never compare distinct overlapping regions.");
1.23 - }
1.24 - return 0;
1.25 -}
1.26 +size_t HeapRegionSeq::find_contiguous_from(size_t from, size_t num) {
1.27 + size_t len = length();
1.28 + assert(num > 1, "use this only for sequences of length 2 or greater");
1.29 + assert(from <= len,
1.30 + err_msg("from: "SIZE_FORMAT" should be valid and <= than "SIZE_FORMAT,
1.31 + from, len));
1.32
1.33 -HeapRegionSeq::HeapRegionSeq(const size_t max_size) :
1.34 - _alloc_search_start(0),
1.35 - // The line below is the worst bit of C++ hackery I've ever written
1.36 - // (Detlefs, 11/23). You should think of it as equivalent to
1.37 - // "_regions(100, true)": initialize the growable array and inform it
1.38 - // that it should allocate its elem array(s) on the C heap.
1.39 - //
1.40 - // The first argument, however, is actually a comma expression
1.41 - // (set_allocation_type(this, C_HEAP), 100). The purpose of the
1.42 - // set_allocation_type() call is to replace the default allocation
1.43 - // type for embedded objects STACK_OR_EMBEDDED with C_HEAP. It will
1.44 - // allow to pass the assert in GenericGrowableArray() which checks
1.45 - // that a growable array object must be on C heap if elements are.
1.46 - //
1.47 - // Note: containing object is allocated on C heap since it is CHeapObj.
1.48 - //
1.49 - _regions((ResourceObj::set_allocation_type((address)&_regions,
1.50 - ResourceObj::C_HEAP),
1.51 - (int)max_size),
1.52 - true),
1.53 - _next_rr_candidate(0),
1.54 - _seq_bottom(NULL)
1.55 -{}
1.56 -
1.57 -// Private methods.
1.58 -
1.59 -void HeapRegionSeq::print_empty_runs() {
1.60 - int empty_run = 0;
1.61 - int n_empty = 0;
1.62 - int empty_run_start;
1.63 - for (int i = 0; i < _regions.length(); i++) {
1.64 - HeapRegion* r = _regions.at(i);
1.65 - if (r->continuesHumongous()) continue;
1.66 - if (r->is_empty()) {
1.67 - assert(!r->isHumongous(), "H regions should not be empty.");
1.68 - if (empty_run == 0) empty_run_start = i;
1.69 - empty_run++;
1.70 - n_empty++;
1.71 - } else {
1.72 - if (empty_run > 0) {
1.73 - gclog_or_tty->print(" %d:%d", empty_run_start, empty_run);
1.74 - empty_run = 0;
1.75 - }
1.76 - }
1.77 - }
1.78 - if (empty_run > 0) {
1.79 - gclog_or_tty->print(" %d:%d", empty_run_start, empty_run);
1.80 - }
1.81 - gclog_or_tty->print_cr(" [tot = %d]", n_empty);
1.82 -}
1.83 -
1.84 -int HeapRegionSeq::find(HeapRegion* hr) {
1.85 - // FIXME: optimized for adjacent regions of fixed size.
1.86 - int ind = hr->hrs_index();
1.87 - if (ind != -1) {
1.88 - assert(_regions.at(ind) == hr, "Mismatch");
1.89 - }
1.90 - return ind;
1.91 -}
1.92 -
1.93 -
1.94 -// Public methods.
1.95 -
1.96 -void HeapRegionSeq::insert(HeapRegion* hr) {
1.97 - assert(!_regions.is_full(), "Too many elements in HeapRegionSeq");
1.98 - if (_regions.length() == 0
1.99 - || _regions.top()->end() <= hr->bottom()) {
1.100 - hr->set_hrs_index(_regions.length());
1.101 - _regions.append(hr);
1.102 - } else {
1.103 - _regions.append(hr);
1.104 - _regions.sort(orderRegions);
1.105 - for (int i = 0; i < _regions.length(); i++) {
1.106 - _regions.at(i)->set_hrs_index(i);
1.107 - }
1.108 - }
1.109 - char* bot = (char*)_regions.at(0)->bottom();
1.110 - if (_seq_bottom == NULL || bot < _seq_bottom) _seq_bottom = bot;
1.111 -}
1.112 -
1.113 -size_t HeapRegionSeq::length() {
1.114 - return _regions.length();
1.115 -}
1.116 -
1.117 -size_t HeapRegionSeq::free_suffix() {
1.118 - size_t res = 0;
1.119 - int first = _regions.length() - 1;
1.120 - int cur = first;
1.121 - while (cur >= 0 &&
1.122 - (_regions.at(cur)->is_empty()
1.123 - && (first == cur
1.124 - || (_regions.at(cur+1)->bottom() ==
1.125 - _regions.at(cur)->end())))) {
1.126 - res++;
1.127 - cur--;
1.128 - }
1.129 - return res;
1.130 -}
1.131 -
1.132 -int HeapRegionSeq::find_contiguous_from(int from, size_t num) {
1.133 - assert(num > 1, "pre-condition");
1.134 - assert(0 <= from && from <= _regions.length(),
1.135 - err_msg("from: %d should be valid and <= than %d",
1.136 - from, _regions.length()));
1.137 -
1.138 - int curr = from;
1.139 - int first = -1;
1.140 + size_t curr = from;
1.141 + size_t first = G1_NULL_HRS_INDEX;
1.142 size_t num_so_far = 0;
1.143 - while (curr < _regions.length() && num_so_far < num) {
1.144 - HeapRegion* curr_hr = _regions.at(curr);
1.145 - if (curr_hr->is_empty()) {
1.146 - if (first == -1) {
1.147 + while (curr < len && num_so_far < num) {
1.148 + if (at(curr)->is_empty()) {
1.149 + if (first == G1_NULL_HRS_INDEX) {
1.150 first = curr;
1.151 num_so_far = 1;
1.152 } else {
1.153 num_so_far += 1;
1.154 }
1.155 } else {
1.156 - first = -1;
1.157 + first = G1_NULL_HRS_INDEX;
1.158 num_so_far = 0;
1.159 }
1.160 curr += 1;
1.161 }
1.162 -
1.163 assert(num_so_far <= num, "post-condition");
1.164 if (num_so_far == num) {
1.165 // we found enough space for the humongous object
1.166 - assert(from <= first && first < _regions.length(), "post-condition");
1.167 - assert(first < curr && (curr - first) == (int) num, "post-condition");
1.168 - for (int i = first; i < first + (int) num; ++i) {
1.169 - assert(_regions.at(i)->is_empty(), "post-condition");
1.170 + assert(from <= first && first < len, "post-condition");
1.171 + assert(first < curr && (curr - first) == num, "post-condition");
1.172 + for (size_t i = first; i < first + num; ++i) {
1.173 + assert(at(i)->is_empty(), "post-condition");
1.174 }
1.175 return first;
1.176 } else {
1.177 // we failed to find enough space for the humongous object
1.178 - return -1;
1.179 + return G1_NULL_HRS_INDEX;
1.180 }
1.181 }
1.182
1.183 -int HeapRegionSeq::find_contiguous(size_t num) {
1.184 - assert(num > 1, "otherwise we should not be calling this");
1.185 - assert(0 <= _alloc_search_start && _alloc_search_start <= _regions.length(),
1.186 - err_msg("_alloc_search_start: %d should be valid and <= than %d",
1.187 - _alloc_search_start, _regions.length()));
1.188 +// Public
1.189
1.190 - int start = _alloc_search_start;
1.191 - int res = find_contiguous_from(start, num);
1.192 - if (res == -1 && start != 0) {
1.193 - // Try starting from the beginning. If _alloc_search_start was 0,
1.194 - // no point in doing this again.
1.195 - res = find_contiguous_from(0, num);
1.196 +void HeapRegionSeq::initialize(HeapWord* bottom, HeapWord* end,
1.197 + size_t max_length) {
1.198 + assert((size_t) bottom % HeapRegion::GrainBytes == 0,
1.199 + "bottom should be heap region aligned");
1.200 + assert((size_t) end % HeapRegion::GrainBytes == 0,
1.201 + "end should be heap region aligned");
1.202 +
1.203 + _length = 0;
1.204 + _heap_bottom = bottom;
1.205 + _heap_end = end;
1.206 + _region_shift = HeapRegion::LogOfHRGrainBytes;
1.207 + _next_search_index = 0;
1.208 + _allocated_length = 0;
1.209 + _max_length = max_length;
1.210 +
1.211 + _regions = NEW_C_HEAP_ARRAY(HeapRegion*, max_length);
1.212 + memset(_regions, 0, max_length * sizeof(HeapRegion*));
1.213 + _regions_biased = _regions - ((size_t) bottom >> _region_shift);
1.214 +
1.215 + assert(&_regions[0] == &_regions_biased[addr_to_index_biased(bottom)],
1.216 + "bottom should be included in the region with index 0");
1.217 +}
1.218 +
1.219 +MemRegion HeapRegionSeq::expand_by(HeapWord* old_end,
1.220 + HeapWord* new_end,
1.221 + FreeRegionList* list) {
1.222 + assert(old_end < new_end, "don't call it otherwise");
1.223 + G1CollectedHeap* g1h = G1CollectedHeap::heap();
1.224 +
1.225 + HeapWord* next_bottom = old_end;
1.226 + assert(_heap_bottom <= next_bottom, "invariant");
1.227 + while (next_bottom < new_end) {
1.228 + assert(next_bottom < _heap_end, "invariant");
1.229 + size_t index = length();
1.230 +
1.231 + assert(index < _max_length, "otherwise we cannot expand further");
1.232 + if (index == 0) {
1.233 + // We have not allocated any regions so far
1.234 + assert(next_bottom == _heap_bottom, "invariant");
1.235 + } else {
1.236 + // next_bottom should match the end of the last/previous region
1.237 + assert(next_bottom == at(index - 1)->end(), "invariant");
1.238 + }
1.239 +
1.240 + if (index == _allocated_length) {
1.241 + // We have to allocate a new HeapRegion.
1.242 + HeapRegion* new_hr = g1h->new_heap_region(index, next_bottom);
1.243 + if (new_hr == NULL) {
1.244 + // allocation failed, we bail out and return what we have done so far
1.245 + return MemRegion(old_end, next_bottom);
1.246 + }
1.247 + assert(_regions[index] == NULL, "invariant");
1.248 + _regions[index] = new_hr;
1.249 + increment_length(&_allocated_length);
1.250 + }
1.251 + // Have to increment the length first, otherwise we will get an
1.252 + // assert failure at(index) below.
1.253 + increment_length(&_length);
1.254 + HeapRegion* hr = at(index);
1.255 + list->add_as_tail(hr);
1.256 +
1.257 + next_bottom = hr->end();
1.258 }
1.259 - if (res != -1) {
1.260 - assert(0 <= res && res < _regions.length(),
1.261 - err_msg("res: %d should be valid", res));
1.262 - _alloc_search_start = res + (int) num;
1.263 - assert(0 < _alloc_search_start && _alloc_search_start <= _regions.length(),
1.264 - err_msg("_alloc_search_start: %d should be valid",
1.265 - _alloc_search_start));
1.266 + assert(next_bottom == new_end, "post-condition");
1.267 + return MemRegion(old_end, next_bottom);
1.268 +}
1.269 +
1.270 +size_t HeapRegionSeq::free_suffix() {
1.271 + size_t res = 0;
1.272 + size_t index = length();
1.273 + while (index > 0) {
1.274 + index -= 1;
1.275 + if (!at(index)->is_empty()) {
1.276 + break;
1.277 + }
1.278 + res += 1;
1.279 }
1.280 return res;
1.281 }
1.282
1.283 -void HeapRegionSeq::iterate(HeapRegionClosure* blk) {
1.284 - iterate_from((HeapRegion*)NULL, blk);
1.285 +size_t HeapRegionSeq::find_contiguous(size_t num) {
1.286 + assert(num > 1, "use this only for sequences of length 2 or greater");
1.287 + assert(_next_search_index <= length(),
1.288 + err_msg("_next_search_indeex: "SIZE_FORMAT" "
1.289 + "should be valid and <= than "SIZE_FORMAT,
1.290 + _next_search_index, length()));
1.291 +
1.292 + size_t start = _next_search_index;
1.293 + size_t res = find_contiguous_from(start, num);
1.294 + if (res == G1_NULL_HRS_INDEX && start > 0) {
1.295 + // Try starting from the beginning. If _next_search_index was 0,
1.296 + // no point in doing this again.
1.297 + res = find_contiguous_from(0, num);
1.298 + }
1.299 + if (res != G1_NULL_HRS_INDEX) {
1.300 + assert(res < length(),
1.301 + err_msg("res: "SIZE_FORMAT" should be valid", res));
1.302 + _next_search_index = res + num;
1.303 + assert(_next_search_index <= length(),
1.304 + err_msg("_next_search_indeex: "SIZE_FORMAT" "
1.305 + "should be valid and <= than "SIZE_FORMAT,
1.306 + _next_search_index, length()));
1.307 + }
1.308 + return res;
1.309 }
1.310
1.311 -// The first argument r is the heap region at which iteration begins.
1.312 -// This operation runs fastest when r is NULL, or the heap region for
1.313 -// which a HeapRegionClosure most recently returned true, or the
1.314 -// heap region immediately to its right in the sequence. In all
1.315 -// other cases a linear search is required to find the index of r.
1.316 +void HeapRegionSeq::iterate(HeapRegionClosure* blk) const {
1.317 + iterate_from((HeapRegion*) NULL, blk);
1.318 +}
1.319
1.320 -void HeapRegionSeq::iterate_from(HeapRegion* r, HeapRegionClosure* blk) {
1.321 +void HeapRegionSeq::iterate_from(HeapRegion* hr, HeapRegionClosure* blk) const {
1.322 + size_t hr_index = 0;
1.323 + if (hr != NULL) {
1.324 + hr_index = (size_t) hr->hrs_index();
1.325 + }
1.326
1.327 - // :::: FIXME ::::
1.328 - // Static cache value is bad, especially when we start doing parallel
1.329 - // remembered set update. For now just don't cache anything (the
1.330 - // code in the def'd out blocks).
1.331 -
1.332 -#if 0
1.333 - static int cached_j = 0;
1.334 -#endif
1.335 - int len = _regions.length();
1.336 - int j = 0;
1.337 - // Find the index of r.
1.338 - if (r != NULL) {
1.339 -#if 0
1.340 - assert(cached_j >= 0, "Invariant.");
1.341 - if ((cached_j < len) && (r == _regions.at(cached_j))) {
1.342 - j = cached_j;
1.343 - } else if ((cached_j + 1 < len) && (r == _regions.at(cached_j + 1))) {
1.344 - j = cached_j + 1;
1.345 - } else {
1.346 - j = find(r);
1.347 -#endif
1.348 - if (j < 0) {
1.349 - j = 0;
1.350 - }
1.351 -#if 0
1.352 - }
1.353 -#endif
1.354 - }
1.355 - int i;
1.356 - for (i = j; i < len; i += 1) {
1.357 - int res = blk->doHeapRegion(_regions.at(i));
1.358 + size_t len = length();
1.359 + for (size_t i = hr_index; i < len; i += 1) {
1.360 + bool res = blk->doHeapRegion(at(i));
1.361 if (res) {
1.362 -#if 0
1.363 - cached_j = i;
1.364 -#endif
1.365 blk->incomplete();
1.366 return;
1.367 }
1.368 }
1.369 - for (i = 0; i < j; i += 1) {
1.370 - int res = blk->doHeapRegion(_regions.at(i));
1.371 + for (size_t i = 0; i < hr_index; i += 1) {
1.372 + bool res = blk->doHeapRegion(at(i));
1.373 if (res) {
1.374 -#if 0
1.375 - cached_j = i;
1.376 -#endif
1.377 - blk->incomplete();
1.378 - return;
1.379 - }
1.380 - }
1.381 -}
1.382 -
1.383 -void HeapRegionSeq::iterate_from(int idx, HeapRegionClosure* blk) {
1.384 - int len = _regions.length();
1.385 - int i;
1.386 - for (i = idx; i < len; i++) {
1.387 - if (blk->doHeapRegion(_regions.at(i))) {
1.388 - blk->incomplete();
1.389 - return;
1.390 - }
1.391 - }
1.392 - for (i = 0; i < idx; i++) {
1.393 - if (blk->doHeapRegion(_regions.at(i))) {
1.394 blk->incomplete();
1.395 return;
1.396 }
1.397 @@ -283,54 +206,92 @@
1.398 }
1.399
1.400 MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes,
1.401 - size_t& num_regions_deleted) {
1.402 + size_t* num_regions_deleted) {
1.403 // Reset this in case it's currently pointing into the regions that
1.404 // we just removed.
1.405 - _alloc_search_start = 0;
1.406 + _next_search_index = 0;
1.407
1.408 assert(shrink_bytes % os::vm_page_size() == 0, "unaligned");
1.409 assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned");
1.410 + assert(length() > 0, "the region sequence should not be empty");
1.411 + assert(length() <= _allocated_length, "invariant");
1.412 + assert(_allocated_length > 0, "we should have at least one region committed");
1.413
1.414 - if (_regions.length() == 0) {
1.415 - num_regions_deleted = 0;
1.416 - return MemRegion();
1.417 - }
1.418 - int j = _regions.length() - 1;
1.419 - HeapWord* end = _regions.at(j)->end();
1.420 + // around the loop, i will be the next region to be removed
1.421 + size_t i = length() - 1;
1.422 + assert(i > 0, "we should never remove all regions");
1.423 + // [last_start, end) is the MemRegion that covers the regions we will remove.
1.424 + HeapWord* end = at(i)->end();
1.425 HeapWord* last_start = end;
1.426 - while (j >= 0 && shrink_bytes > 0) {
1.427 - HeapRegion* cur = _regions.at(j);
1.428 - // We have to leave humongous regions where they are,
1.429 - // and work around them.
1.430 - if (cur->isHumongous()) {
1.431 - return MemRegion(last_start, end);
1.432 - }
1.433 - assert(cur == _regions.top(), "Should be top");
1.434 + *num_regions_deleted = 0;
1.435 + while (shrink_bytes > 0) {
1.436 + HeapRegion* cur = at(i);
1.437 + // We should leave the humongous regions where they are.
1.438 + if (cur->isHumongous()) break;
1.439 + // We should stop shrinking if we come across a non-empty region.
1.440 if (!cur->is_empty()) break;
1.441 +
1.442 + i -= 1;
1.443 + *num_regions_deleted += 1;
1.444 shrink_bytes -= cur->capacity();
1.445 - num_regions_deleted++;
1.446 - _regions.pop();
1.447 last_start = cur->bottom();
1.448 - // We need to delete these somehow, but can't currently do so here: if
1.449 - // we do, the ZF thread may still access the deleted region. We'll
1.450 - // leave this here as a reminder that we have to do something about
1.451 - // this.
1.452 - // delete cur;
1.453 - j--;
1.454 + decrement_length(&_length);
1.455 + // We will reclaim the HeapRegion. _allocated_length should be
1.456 + // covering this index. So, even though we removed the region from
1.457 + // the active set by decreasing _length, we still have it
1.458 + // available in the future if we need to re-use it.
1.459 + assert(i > 0, "we should never remove all regions");
1.460 + assert(length() > 0, "we should never remove all regions");
1.461 }
1.462 return MemRegion(last_start, end);
1.463 }
1.464
1.465 -class PrintHeapRegionClosure : public HeapRegionClosure {
1.466 -public:
1.467 - bool doHeapRegion(HeapRegion* r) {
1.468 - gclog_or_tty->print(PTR_FORMAT ":", r);
1.469 - r->print();
1.470 - return false;
1.471 +#ifndef PRODUCT
1.472 +void HeapRegionSeq::verify_optional() {
1.473 + guarantee(_length <= _allocated_length,
1.474 + err_msg("invariant: _length: "SIZE_FORMAT" "
1.475 + "_allocated_length: "SIZE_FORMAT,
1.476 + _length, _allocated_length));
1.477 + guarantee(_allocated_length <= _max_length,
1.478 + err_msg("invariant: _allocated_length: "SIZE_FORMAT" "
1.479 + "_max_length: "SIZE_FORMAT,
1.480 + _allocated_length, _max_length));
1.481 + guarantee(_next_search_index <= _length,
1.482 + err_msg("invariant: _next_search_index: "SIZE_FORMAT" "
1.483 + "_length: "SIZE_FORMAT,
1.484 + _next_search_index, _length));
1.485 +
1.486 + HeapWord* prev_end = _heap_bottom;
1.487 + for (size_t i = 0; i < _allocated_length; i += 1) {
1.488 + HeapRegion* hr = _regions[i];
1.489 + guarantee(hr != NULL, err_msg("invariant: i: "SIZE_FORMAT, i));
1.490 + guarantee(hr->bottom() == prev_end,
1.491 + err_msg("invariant i: "SIZE_FORMAT" "HR_FORMAT" "
1.492 + "prev_end: "PTR_FORMAT,
1.493 + i, HR_FORMAT_PARAMS(hr), prev_end));
1.494 + guarantee(hr->hrs_index() == i,
1.495 + err_msg("invariant: i: "SIZE_FORMAT" hrs_index(): "SIZE_FORMAT,
1.496 + i, hr->hrs_index()));
1.497 + if (i < _length) {
1.498 + // Asserts will fire if i is >= _length
1.499 + HeapWord* addr = hr->bottom();
1.500 + guarantee(addr_to_region(addr) == hr, "sanity");
1.501 + guarantee(addr_to_region_unsafe(addr) == hr, "sanity");
1.502 + } else {
1.503 + guarantee(hr->is_empty(), "sanity");
1.504 + guarantee(!hr->isHumongous(), "sanity");
1.505 + // using assert instead of guarantee here since containing_set()
1.506 + // is only available in non-product builds.
1.507 + assert(hr->containing_set() == NULL, "sanity");
1.508 + }
1.509 + if (hr->startsHumongous()) {
1.510 + prev_end = hr->orig_end();
1.511 + } else {
1.512 + prev_end = hr->end();
1.513 + }
1.514 }
1.515 -};
1.516 -
1.517 -void HeapRegionSeq::print() {
1.518 - PrintHeapRegionClosure cl;
1.519 - iterate(&cl);
1.520 + for (size_t i = _allocated_length; i < _max_length; i += 1) {
1.521 + guarantee(_regions[i] == NULL, err_msg("invariant i: "SIZE_FORMAT, i));
1.522 + }
1.523 }
1.524 +#endif // PRODUCT
