/* * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions.
*/
TEST_VM(SymbolTable, temp_new_symbol) { // Assert messages assume these symbols are unique, and the refcounts start at // one, but code does not rely on this.
JavaThread* THREAD = JavaThread::current(); // the thread should be in vm to use locks
ThreadInVMfromNative ThreadInVMfromNative(THREAD);
Symbol* abc = SymbolTable::new_symbol("abc"); int abccount = abc->refcount();
TempNewSymbol ss = abc;
ASSERT_EQ(ss->refcount(), abccount) << "only one abc";
ASSERT_EQ(ss->refcount(), abc->refcount()) << "should match TempNewSymbol";
Symbol* efg = SymbolTable::new_symbol("efg");
Symbol* hij = SymbolTable::new_symbol("hij"); int efgcount = efg->refcount(); int hijcount = hij->refcount();
// Assignment operator
s1 = s2;
ASSERT_EQ(hij->refcount(), hijcount + 1) << "should be two hij";
ASSERT_EQ(efg->refcount(), efgcount - 1) << "should be no efg";
s1 = ss; // s1 is abc
ASSERT_EQ(s1->refcount(), abccount + 1) << "should be two abc (s1 and ss)";
ASSERT_EQ(hij->refcount(), hijcount) << "should only have one hij now (s2)";
s1 = *&s1; // self assignment
ASSERT_EQ(s1->refcount(), abccount + 1) << "should still be two abc (s1 and ss)";
Symbol* xyz = SymbolTable::new_symbol("xyz"); int xyzcount = xyz->refcount();
{ // inner scope
TempNewSymbol s_inner = xyz;
}
ASSERT_EQ(xyz->refcount(), xyzcount - 1)
<< "Should have been decremented by dtor in inner scope";
// Test overflowing refcount making symbol permanent
Symbol* bigsym = SymbolTable::new_symbol("bigsym"); for (int i = 0; i < PERM_REFCOUNT + 100; i++) {
bigsym->increment_refcount();
}
ASSERT_EQ(bigsym->refcount(), PERM_REFCOUNT) << "should not have overflowed";
// Test that PERM_REFCOUNT is sticky for (int i = 0; i < 10; i++) {
bigsym->decrement_refcount();
}
ASSERT_EQ(bigsym->refcount(), PERM_REFCOUNT) << "should be sticky";
}
// TODO: Make two threads one decrementing the refcount and the other trying to increment. // try_increment_refcount should return false
TEST_VM(SymbolTable, test_symbol_refcount_parallel) {
constexpr int symbol_name_length = 30; char symbol_name[symbol_name_length]; // Find a symbol where there will probably be only one instance. for (int i = 0; i < 100; i++) {
os::snprintf(symbol_name, symbol_name_length, "some_symbol%d", i);
TempNewSymbol ts = SymbolTable::new_symbol(symbol_name); if (ts->refcount() == 1) {
EXPECT_TRUE(ts->refcount() == 1) << "Symbol is just created"; break; // found a unique symbol
}
}
constexpr int symTestThreadCount = 5; auto symbolThread= [&](Thread* _current, int _id) { for (int i = 0; i < 1000; i++) {
TempNewSymbol sym = SymbolTable::new_symbol(symbol_name); // Create and destroy new symbol
EXPECT_TRUE(sym->refcount() != 0) << "Symbol refcount unexpectedly zeroed";
}
};
TestThreadGroup<decltype(symbolThread)> ttg(symbolThread, symTestThreadCount);
ttg.doit();
ttg.join();
}
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