1.1 --- a/src/share/vm/utilities/hashtable.cpp Fri May 17 17:52:07 2013 -0700
1.2 +++ b/src/share/vm/utilities/hashtable.cpp Sat May 18 20:41:01 2013 -0700
1.3 @@ -33,6 +33,7 @@
1.4 #include "utilities/dtrace.hpp"
1.5 #include "utilities/hashtable.hpp"
1.6 #include "utilities/hashtable.inline.hpp"
1.7 +#include "utilities/numberSeq.hpp"
1.8
1.9
1.10 // This is a generic hashtable, designed to be used for the symbol
1.11 @@ -237,6 +238,57 @@
1.12 }
1.13 }
1.14
1.15 +template <class T, MEMFLAGS F> int Hashtable<T, F>::literal_size(Symbol *symbol) {
1.16 + return symbol->size() * HeapWordSize;
1.17 +}
1.18 +
1.19 +template <class T, MEMFLAGS F> int Hashtable<T, F>::literal_size(oop oop) {
1.20 + // NOTE: this would over-count if (pre-JDK8) java_lang_Class::has_offset_field() is true,
1.21 + // and the String.value array is shared by several Strings. However, starting from JDK8,
1.22 + // the String.value array is not shared anymore.
1.23 + assert(oop != NULL && oop->klass() == SystemDictionary::String_klass(), "only strings are supported");
1.24 + return (oop->size() + java_lang_String::value(oop)->size()) * HeapWordSize;
1.25 +}
1.26 +
1.27 +// Dump footprint and bucket length statistics
1.28 +//
1.29 +// Note: if you create a new subclass of Hashtable<MyNewType, F>, you will need to
1.30 +// add a new function Hashtable<T, F>::literal_size(MyNewType lit)
1.31 +
1.32 +template <class T, MEMFLAGS F> void Hashtable<T, F>::dump_table(outputStream* st, const char *table_name) {
1.33 + NumberSeq summary;
1.34 + int literal_bytes = 0;
1.35 + for (int i = 0; i < this->table_size(); ++i) {
1.36 + int count = 0;
1.37 + for (HashtableEntry<T, F>* e = bucket(i);
1.38 + e != NULL; e = e->next()) {
1.39 + count++;
1.40 + literal_bytes += literal_size(e->literal());
1.41 + }
1.42 + summary.add((double)count);
1.43 + }
1.44 + double num_buckets = summary.num();
1.45 + double num_entries = summary.sum();
1.46 +
1.47 + int bucket_bytes = (int)num_buckets * sizeof(bucket(0));
1.48 + int entry_bytes = (int)num_entries * sizeof(HashtableEntry<T, F>);
1.49 + int total_bytes = literal_bytes + bucket_bytes + entry_bytes;
1.50 +
1.51 + double bucket_avg = (num_buckets <= 0) ? 0 : (bucket_bytes / num_buckets);
1.52 + double entry_avg = (num_entries <= 0) ? 0 : (entry_bytes / num_entries);
1.53 + double literal_avg = (num_entries <= 0) ? 0 : (literal_bytes / num_entries);
1.54 +
1.55 + st->print_cr("%s statistics:", table_name);
1.56 + st->print_cr("Number of buckets : %9d = %9d bytes, avg %7.3f", (int)num_buckets, bucket_bytes, bucket_avg);
1.57 + st->print_cr("Number of entries : %9d = %9d bytes, avg %7.3f", (int)num_entries, entry_bytes, entry_avg);
1.58 + st->print_cr("Number of literals : %9d = %9d bytes, avg %7.3f", (int)num_entries, literal_bytes, literal_avg);
1.59 + st->print_cr("Total footprint : %9s = %9d bytes", "", total_bytes);
1.60 + st->print_cr("Average bucket size : %9.3f", summary.avg());
1.61 + st->print_cr("Variance of bucket size : %9.3f", summary.variance());
1.62 + st->print_cr("Std. dev. of bucket size: %9.3f", summary.sd());
1.63 + st->print_cr("Maximum bucket size : %9d", (int)summary.maximum());
1.64 +}
1.65 +
1.66
1.67 // Dump the hash table buckets.
1.68
