src/share/vm/classfile/stringTable.cpp

rev 12679 : 8176593: Throwable::getStackTrace performance regression
Reviewed-by: jiangli, iklam

*** 115,129 ****
      vm_exit_out_of_memory(length, OOM_MALLOC_ERROR, "unable to create Unicode string for verification");
      return 0;
    }
  }
  
! oop StringTable::lookup_shared(jchar* name, int len) {
!   // java_lang_String::hash_code() was used to compute hash values in the shared table. Don't
!   // use the hash value from StringTable::hash_string() as it might use alternate hashcode.
!   return _shared_table.lookup((const char*)name,
!                               java_lang_String::hash_code(name, len), len);
  }
  
  oop StringTable::lookup_in_main_table(int index, jchar* name,
                                  int len, unsigned int hash) {
    int count = 0;
--- 115,128 ----
      vm_exit_out_of_memory(length, OOM_MALLOC_ERROR, "unable to create Unicode string for verification");
      return 0;
    }
  }
  
! oop StringTable::lookup_shared(jchar* name, int len, unsigned int hash) {
!   assert(hash == java_lang_String::hash_code(name, len),
!          "hash must be computed using java_lang_String::hash_code");
!   return _shared_table.lookup((const char*)name, hash, len);
  }
  
  oop StringTable::lookup_in_main_table(int index, jchar* name,
                                  int len, unsigned int hash) {
    int count = 0;
*** 197,228 ****
    }
  #endif
  }
  
  oop StringTable::lookup(jchar* name, int len) {
!   oop string = lookup_shared(name, len);
    if (string != NULL) {
      return string;
    }
! 
!   unsigned int hash = hash_string(name, len);
    int index = the_table()->hash_to_index(hash);
    string = the_table()->lookup_in_main_table(index, name, len, hash);
  
    ensure_string_alive(string);
  
    return string;
  }
  
  oop StringTable::intern(Handle string_or_null, jchar* name,
                          int len, TRAPS) {
!   oop found_string = lookup_shared(name, len);
    if (found_string != NULL) {
      return found_string;
    }
! 
!   unsigned int hashValue = hash_string(name, len);
    int index = the_table()->hash_to_index(hashValue);
    found_string = the_table()->lookup_in_main_table(index, name, len, hashValue);
  
    // Found
    if (found_string != NULL) {
--- 196,231 ----
    }
  #endif
  }
  
  oop StringTable::lookup(jchar* name, int len) {
!   unsigned int hash = java_lang_String::hash_code(name, len);
!   oop string = lookup_shared(name, len, hash);
    if (string != NULL) {
      return string;
    }
!   if (use_alternate_hashcode()) {
!       hash = hash_string(name, len);
!   }
    int index = the_table()->hash_to_index(hash);
    string = the_table()->lookup_in_main_table(index, name, len, hash);
  
    ensure_string_alive(string);
  
    return string;
  }
  
  oop StringTable::intern(Handle string_or_null, jchar* name,
                          int len, TRAPS) {
!   unsigned int hashValue = java_lang_String::hash_code(name, len);
!   oop found_string = lookup_shared(name, len, hashValue);
    if (found_string != NULL) {
      return found_string;
    }
!   if (use_alternate_hashcode()) {
!       hashValue = hash_string(name, len);
!   }
    int index = the_table()->hash_to_index(hashValue);
    found_string = the_table()->lookup_in_main_table(index, name, len, hashValue);
  
    // Found
    if (found_string != NULL) {