8340416: Remove ArchiveBuilder::estimate_archive_size()

Reviewed-by: iklam, ccheung

Author: Sonia Zaldana Calles

src/hotspot/share/cds/archiveBuilder.cpp

@@ -154,9 +154,7 @@ void ArchiveBuilder::SourceObjList::relocate(int i, ArchiveBuilder* builder) {
 ArchiveBuilder::ArchiveBuilder() :
   _current_dump_region(nullptr),
   _buffer_bottom(nullptr),
-  _last_verified_top(nullptr),
   _num_dump_regions_used(0),
-  _other_region_used_bytes(0),
   _requested_static_archive_bottom(nullptr),
   _requested_static_archive_top(nullptr),
   _requested_dynamic_archive_bottom(nullptr),
@@ -173,9 +171,7 @@ ArchiveBuilder::ArchiveBuilder() :
   _ro_src_objs(),
   _src_obj_table(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE),
   _buffered_to_src_table(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE),
-  _total_heap_region_size(0),
-  _estimated_metaspaceobj_bytes(0),
-  _estimated_hashtable_bytes(0)
+  _total_heap_region_size(0)
 {
   _klasses = new (mtClassShared) GrowableArray<Klass*>(4 * K, mtClassShared);
   _symbols = new (mtClassShared) GrowableArray<Symbol*>(256 * K, mtClassShared);
@@ -238,20 +234,13 @@ bool ArchiveBuilder::gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool re
         assert(klass->is_instance_klass(), "must be");
       }
     }
-    // See RunTimeClassInfo::get_for(): make sure we have enough space for both maximum
-    // Klass alignment as well as the RuntimeInfo* pointer we will embed in front of a Klass.
-    _estimated_metaspaceobj_bytes += align_up(BytesPerWord, CompressedKlassPointers::klass_alignment_in_bytes()) +
-        align_up(sizeof(void*), SharedSpaceObjectAlignment);
   } else if (ref->msotype() == MetaspaceObj::SymbolType) {
     // Make sure the symbol won't be GC'ed while we are dumping the archive.
     Symbol* sym = (Symbol*)ref->obj();
     sym->increment_refcount();
     _symbols->append(sym);
   }
 
-  int bytes = ref->size() * BytesPerWord;
-  _estimated_metaspaceobj_bytes += align_up(bytes, SharedSpaceObjectAlignment);
-
   return true; // recurse
 }
 
@@ -294,10 +283,6 @@ void ArchiveBuilder::gather_klasses_and_symbols() {
     log_info(cds)("Sorting symbols ... ");
     _symbols->sort(compare_symbols_by_address);
     sort_klasses();
-
-    // TODO -- we need a proper estimate for the archived modules, etc,
-    // but this should be enough for now
-    _estimated_metaspaceobj_bytes += 200 * 1024 * 1024;
   }
 
   AOTClassLinker::add_candidates();
@@ -321,39 +306,8 @@ void ArchiveBuilder::sort_klasses() {
   _klasses->sort(compare_klass_by_name);
 }
 
-size_t ArchiveBuilder::estimate_archive_size() {
-  // size of the symbol table and two dictionaries, plus the RunTimeClassInfo's
-  size_t symbol_table_est = SymbolTable::estimate_size_for_archive();
-  size_t dictionary_est = SystemDictionaryShared::estimate_size_for_archive();
-  _estimated_hashtable_bytes = symbol_table_est + dictionary_est;
-
-  if (CDSConfig::is_dumping_aot_linked_classes()) {
-    // This is difficult to estimate when dumping the dynamic archive, as the
-    // AOTLinkedClassTable may need to contain classes in the static archive as well.
-    //
-    // Just give a generous estimate for now. We will remove estimate_archive_size()
-    // in JDK-8340416
-    _estimated_hashtable_bytes += 20 * 1024 * 1024;
-  }
-
-  size_t total = 0;
-
-  total += _estimated_metaspaceobj_bytes;
-  total += _estimated_hashtable_bytes;
-
-  // allow fragmentation at the end of each dump region
-  total += _total_dump_regions * MetaspaceShared::core_region_alignment();
-
-  log_info(cds)("_estimated_hashtable_bytes = " SIZE_FORMAT " + " SIZE_FORMAT " = " SIZE_FORMAT,
-                symbol_table_est, dictionary_est, _estimated_hashtable_bytes);
-  log_info(cds)("_estimated_metaspaceobj_bytes = " SIZE_FORMAT, _estimated_metaspaceobj_bytes);
-  log_info(cds)("total estimate bytes = " SIZE_FORMAT, total);
-
-  return align_up(total, MetaspaceShared::core_region_alignment());
-}
-
 address ArchiveBuilder::reserve_buffer() {
-  size_t buffer_size = estimate_archive_size();
+  size_t buffer_size = LP64_ONLY(CompressedClassSpaceSize) NOT_LP64(256 * M);
   ReservedSpace rs = MemoryReserver::reserve(buffer_size,
                                              MetaspaceShared::core_region_alignment(),
                                              os::vm_page_size());
@@ -370,10 +324,8 @@ address ArchiveBuilder::reserve_buffer() {
   _shared_rs = rs;
 
   _buffer_bottom = buffer_bottom;
-  _last_verified_top = buffer_bottom;
   _current_dump_region = &_rw_region;
   _num_dump_regions_used = 1;
-  _other_region_used_bytes = 0;
   _current_dump_region->init(&_shared_rs, &_shared_vs);
 
   ArchivePtrMarker::initialize(&_ptrmap, &_shared_vs);
@@ -592,28 +544,9 @@ ArchiveBuilder::FollowMode ArchiveBuilder::get_follow_mode(MetaspaceClosure::Ref
 }
 
 void ArchiveBuilder::start_dump_region(DumpRegion* next) {
-  address bottom = _last_verified_top;
-  address top = (address)(current_dump_region()->top());
-  _other_region_used_bytes += size_t(top - bottom);
-
   current_dump_region()->pack(next);
   _current_dump_region = next;
   _num_dump_regions_used ++;
-
-  _last_verified_top = (address)(current_dump_region()->top());
-}
-
-void ArchiveBuilder::verify_estimate_size(size_t estimate, const char* which) {
-  address bottom = _last_verified_top;
-  address top = (address)(current_dump_region()->top());
-  size_t used = size_t(top - bottom) + _other_region_used_bytes;
-  int diff = int(estimate) - int(used);
-
-  log_info(cds)("%s estimate = " SIZE_FORMAT " used = " SIZE_FORMAT "; diff = %d bytes", which, estimate, used, diff);
-  assert(diff >= 0, "Estimate is too small");
-
-  _last_verified_top = top;
-  _other_region_used_bytes = 0;
 }
 
 char* ArchiveBuilder::ro_strdup(const char* s) {

src/hotspot/share/cds/archiveBuilder.hpp

@@ -96,9 +96,7 @@ class ArchiveBuilder : public StackObj {
 protected:
   DumpRegion* _current_dump_region;
   address _buffer_bottom;                      // for writing the contents of rw/ro regions
-  address _last_verified_top;
   int _num_dump_regions_used;
-  size_t _other_region_used_bytes;
 
   // These are the addresses where we will request the static and dynamic archives to be
   // mapped at run time. If the request fails (due to ASLR), we will map the archives at
@@ -273,16 +271,9 @@ class ArchiveBuilder : public StackObj {
 protected:
   virtual void iterate_roots(MetaspaceClosure* it) = 0;
 
-  // Conservative estimate for number of bytes needed for:
-  size_t _estimated_metaspaceobj_bytes;   // all archived MetaspaceObj's.
-  size_t _estimated_hashtable_bytes;     // symbol table and dictionaries
-
   static const int _total_dump_regions = 2;
 
-  size_t estimate_archive_size();
-
   void start_dump_region(DumpRegion* next);
-  void verify_estimate_size(size_t estimate, const char* which);
 
 public:
   address reserve_buffer();

src/hotspot/share/cds/dynamicArchive.cpp

@@ -133,8 +133,6 @@ class DynamicArchiveBuilder : public ArchiveBuilder {
     dump_ro_metadata();
     relocate_metaspaceobj_embedded_pointers();
 
-    verify_estimate_size(_estimated_metaspaceobj_bytes, "MetaspaceObjs");
-
     sort_methods();
 
     log_info(cds)("Make classes shareable");
@@ -159,8 +157,6 @@ class DynamicArchiveBuilder : public ArchiveBuilder {
       ArchiveBuilder::serialize_dynamic_archivable_items(&wc);
     }
 
-    verify_estimate_size(_estimated_hashtable_bytes, "Hashtables");
-
     log_info(cds)("Adjust lambda proxy class dictionary");
     SystemDictionaryShared::adjust_lambda_proxy_class_dictionary();