[heap] Use size_t in free list and evacuation candidate selection.

src/heap/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 575 matching lines @@
       return "MAP_SPACE";
     case LO_SPACE:
       return "LO_SPACE";
     default:
       UNREACHABLE();
   }
 
   return NULL;
 }
 
-
 void MarkCompactCollector::ComputeEvacuationHeuristics(
-    int area_size, int* target_fragmentation_percent,
-    int* max_evacuated_bytes) {
+    size_t area_size, int* target_fragmentation_percent,
+    size_t* max_evacuated_bytes) {
   // For memory reducing and optimize for memory mode we directly define both
   // constants.
   const int kTargetFragmentationPercentForReduceMemory = 20;
-  const int kMaxEvacuatedBytesForReduceMemory = 12 * MB;
+  const size_t kMaxEvacuatedBytesForReduceMemory = 12 * MB;
   const int kTargetFragmentationPercentForOptimizeMemory = 20;
-  const int kMaxEvacuatedBytesForOptimizeMemory = 6 * MB;
+  const size_t kMaxEvacuatedBytesForOptimizeMemory = 6 * MB;
 
   // For regular mode (which is latency critical) we define less aggressive
   // defaults to start and switch to a trace-based (using compaction speed)
   // approach as soon as we have enough samples.
   const int kTargetFragmentationPercent = 70;
-  const int kMaxEvacuatedBytes = 4 * MB;
+  const size_t kMaxEvacuatedBytes = 4 * MB;
   // Time to take for a single area (=payload of page). Used as soon as there
   // exist enough compaction speed samples.
   const float kTargetMsPerArea = .5;
 
   if (heap()->ShouldReduceMemory()) {
     *target_fragmentation_percent = kTargetFragmentationPercentForReduceMemory;
     *max_evacuated_bytes = kMaxEvacuatedBytesForReduceMemory;
   } else if (heap()->ShouldOptimizeForMemoryUsage()) {
     *target_fragmentation_percent =
         kTargetFragmentationPercentForOptimizeMemory;
@@ skipping 18 matching lines @@
     }
     *max_evacuated_bytes = kMaxEvacuatedBytes;
   }
 }
 
 
 void MarkCompactCollector::CollectEvacuationCandidates(PagedSpace* space) {
   DCHECK(space->identity() == OLD_SPACE || space->identity() == CODE_SPACE);
 
   int number_of_pages = space->CountTotalPages();
-  int area_size = space->AreaSize();
+  size_t area_size = space->AreaSize();
 
   // Pairs of (live_bytes_in_page, page).
-  typedef std::pair<int, Page*> LiveBytesPagePair;
+  typedef std::pair<size_t, Page*> LiveBytesPagePair;
   std::vector<LiveBytesPagePair> pages;
   pages.reserve(number_of_pages);
 
   for (Page* p : *space) {
     if (p->NeverEvacuate()) continue;
     // Invariant: Evacuation candidates are just created when marking is
     // started. This means that sweeping has finished. Furthermore, at the end
     // of a GC all evacuation candidates are cleared and their slot buffers are
     // released.
     CHECK(!p->IsEvacuationCandidate());
     CHECK_NULL(p->old_to_old_slots());
     CHECK_NULL(p->typed_old_to_old_slots());
     CHECK(p->SweepingDone());
     DCHECK(p->area_size() == area_size);
     pages.push_back(std::make_pair(p->LiveBytesFromFreeList(), p));
   }
 
   int candidate_count = 0;
-  int total_live_bytes = 0;
+  size_t total_live_bytes = 0;
 
   const bool reduce_memory = heap()->ShouldReduceMemory();
   if (FLAG_manual_evacuation_candidates_selection) {
     for (size_t i = 0; i < pages.size(); i++) {
       Page* p = pages[i].second;
       if (p->IsFlagSet(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING)) {
         candidate_count++;
         total_live_bytes += pages[i].first;
         p->ClearFlag(MemoryChunk::FORCE_EVACUATION_CANDIDATE_FOR_TESTING);
         AddEvacuationCandidate(p);
@@ skipping 15 matching lines @@
     // candidate, or not:
     // * Target fragmentation: How fragmented is a page, i.e., how is the ratio
     //   between live bytes and capacity of this page (= area).
     // * Evacuation quota: A global quota determining how much bytes should be
     //   compacted.
     //
     // The algorithm sorts all pages by live bytes and then iterates through
     // them starting with the page with the most free memory, adding them to the
     // set of evacuation candidates as long as both conditions (fragmentation
     // and quota) hold.
-    int max_evacuated_bytes;
+    size_t max_evacuated_bytes;
     int target_fragmentation_percent;
     ComputeEvacuationHeuristics(area_size, &target_fragmentation_percent,
                                 &max_evacuated_bytes);
 
-    const intptr_t free_bytes_threshold =
+    const size_t free_bytes_threshold =
         target_fragmentation_percent * (area_size / 100);
 
     // Sort pages from the most free to the least free, then select
     // the first n pages for evacuation such that:
     // - the total size of evacuated objects does not exceed the specified
     // limit.
     // - fragmentation of (n+1)-th page does not exceed the specified limit.
     std::sort(pages.begin(), pages.end(),
               [](const LiveBytesPagePair& a, const LiveBytesPagePair& b) {
                 return a.first < b.first;
               });
     for (size_t i = 0; i < pages.size(); i++) {
-      int live_bytes = pages[i].first;
-      int free_bytes = area_size - live_bytes;
+      size_t live_bytes = pages[i].first;
+      DCHECK_GE(area_size, live_bytes);
+      size_t free_bytes = area_size - live_bytes;
       if (FLAG_always_compact ||
           ((free_bytes >= free_bytes_threshold) &&
            ((total_live_bytes + live_bytes) <= max_evacuated_bytes))) {
         candidate_count++;
         total_live_bytes += live_bytes;
       }
       if (FLAG_trace_fragmentation_verbose) {
         PrintIsolate(isolate(),
-                     "compaction-selection-page: space=%s free_bytes_page=%d "
+                     "compaction-selection-page: space=%s free_bytes_page=%zu "
                      "fragmentation_limit_kb=%" V8PRIdPTR
-                     " fragmentation_limit_percent=%d sum_compaction_kb=%d "
-                     "compaction_limit_kb=%d\n",
+                     " fragmentation_limit_percent=%d sum_compaction_kb=%zu "
+                     "compaction_limit_kb=%zu\n",
                      AllocationSpaceName(space->identity()), free_bytes / KB,
                      free_bytes_threshold / KB, target_fragmentation_percent,
                      total_live_bytes / KB, max_evacuated_bytes / KB);
       }
     }
     // How many pages we will allocated for the evacuated objects
     // in the worst case: ceil(total_live_bytes / area_size)
-    int estimated_new_pages = (total_live_bytes + area_size - 1) / area_size;
+    int estimated_new_pages =
+        static_cast<int>((total_live_bytes + area_size - 1) / area_size);
     DCHECK_LE(estimated_new_pages, candidate_count);
     int estimated_released_pages = candidate_count - estimated_new_pages;
     // Avoid (compact -> expand) cycles.
     if ((estimated_released_pages == 0) && !FLAG_always_compact) {
       candidate_count = 0;
     }
     for (int i = 0; i < candidate_count; i++) {
       AddEvacuationCandidate(pages[i].second);
     }
   }
 
   if (FLAG_trace_fragmentation) {
     PrintIsolate(isolate(),
                  "compaction-selection: space=%s reduce_memory=%d pages=%d "
-                 "total_live_bytes=%d\n",
+                 "total_live_bytes=%zu\n",
                  AllocationSpaceName(space->identity()), reduce_memory,
                  candidate_count, total_live_bytes / KB);
   }
 }
 
 
 void MarkCompactCollector::AbortCompaction() {
   if (compacting_) {
     RememberedSet<OLD_TO_OLD>::ClearAll(heap());
     for (Page* p : evacuation_candidates_) {
@@ skipping 2594 matching lines @@
   intptr_t freed_bytes = 0;
   intptr_t max_freed_bytes = 0;
   int curr_region = -1;
 
   LiveObjectIterator<kBlackObjects> it(p);
   HeapObject* object = NULL;
   while ((object = it.Next()) != NULL) {
     DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(object)));
     Address free_end = object->address();
     if (free_end != free_start) {
-      int size = static_cast<int>(free_end - free_start);
+      CHECK_GT(free_end, free_start);
+      size_t size = static_cast<size_t>(free_end - free_start);
       if (free_space_mode == ZAP_FREE_SPACE) {
         memset(free_start, 0xcc, size);
       }
       if (free_list_mode == REBUILD_FREE_LIST) {
         freed_bytes = reinterpret_cast<PagedSpace*>(space)->UnaccountedFree(
             free_start, size);
         max_freed_bytes = Max(freed_bytes, max_freed_bytes);
       } else {
-        p->heap()->CreateFillerObjectAt(free_start, size,
+        p->heap()->CreateFillerObjectAt(free_start, static_cast<int>(size),
                                         ClearRecordedSlots::kNo);
       }
     }
     Map* map = object->synchronized_map();
     int size = object->SizeFromMap(map);
     if (rebuild_skip_list) {
       int new_region_start = SkipList::RegionNumber(free_end);
       int new_region_end =
           SkipList::RegionNumber(free_end + size - kPointerSize);
       if (new_region_start != curr_region || new_region_end != curr_region) {
         skip_list->AddObject(free_end, size);
         curr_region = new_region_end;
       }
     }
     free_start = free_end + size;
   }
 
   // Clear the mark bits of that page and reset live bytes count.
   p->ClearLiveness();
 
   if (free_start != p->area_end()) {
-    int size = static_cast<int>(p->area_end() - free_start);
+    CHECK_GT(p->area_end(), free_start);
+    size_t size = static_cast<size_t>(p->area_end() - free_start);
     if (free_space_mode == ZAP_FREE_SPACE) {
       memset(free_start, 0xcc, size);
     }
     if (free_list_mode == REBUILD_FREE_LIST) {
       freed_bytes = reinterpret_cast<PagedSpace*>(space)->UnaccountedFree(
           free_start, size);
       max_freed_bytes = Max(freed_bytes, max_freed_bytes);
     } else {
-      p->heap()->CreateFillerObjectAt(free_start, size,
+      p->heap()->CreateFillerObjectAt(free_start, static_cast<int>(size),
                                       ClearRecordedSlots::kNo);
     }
   }
   p->concurrent_sweeping_state().SetValue(Page::kSweepingDone);
   if (free_list_mode == IGNORE_FREE_LIST) return 0;
   return FreeList::GuaranteedAllocatable(static_cast<int>(max_freed_bytes));
 }
 
 void MarkCompactCollector::InvalidateCode(Code* code) {
   Page* page = Page::FromAddress(code->address());
@@ skipping 433 matching lines @@
                                                 Page* page) {
   DCHECK(sweeping_in_progress_);
   PrepareToBeSweptPage(space, page);
   late_pages_ = true;
   AddSweepingPageSafe(space, page);
 }
 
 void MarkCompactCollector::Sweeper::PrepareToBeSweptPage(AllocationSpace space,
                                                          Page* page) {
   page->concurrent_sweeping_state().SetValue(Page::kSweepingPending);
-  int to_sweep = page->area_size() - page->LiveBytes();
+  DCHECK_GE(page->area_size(), static_cast<size_t>(page->LiveBytes()));
+  size_t to_sweep = page->area_size() - page->LiveBytes();
   if (space != NEW_SPACE)
     heap_->paged_space(space)->accounting_stats_.ShrinkSpace(to_sweep);
 }
 
 Page* MarkCompactCollector::Sweeper::GetSweepingPageSafe(
     AllocationSpace space) {
   base::LockGuard<base::Mutex> guard(&mutex_);
   Page* page = nullptr;
   if (!sweeping_list_[space].empty()) {
     page = sweeping_list_[space].front();
@@ skipping 126 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8