Mercurial > hg > truffle
view src/share/vm/libadt/vectset.cpp @ 1716:be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam
author | ysr |
---|---|
date | Mon, 16 Aug 2010 15:58:42 -0700 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
line wrap: on
line source
/* * Copyright (c) 1997, 2005, 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. * */ // Vector Sets - An Abstract Data Type #include "incls/_precompiled.incl" #include "incls/_vectset.cpp.incl" // %%%%% includes not needed with AVM framework - Ungar // #include "port.hpp" //IMPLEMENTATION // #include "vectset.hpp" // BitsInByte is a lookup table which tells the number of bits that // are in the looked-up number. It is very useful in VectorSet_Size. uint8 bitsInByte[256] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 }; //------------------------------VectorSet-------------------------------------- // Create a new, empty Set. VectorSet::VectorSet(Arena *arena) : Set(arena) { size = 2; // Small initial size data = (uint32 *)_set_arena->Amalloc(size*sizeof(uint32)); data[0] = 0; // No elements data[1] = 0; } //------------------------------Construct-------------------------------------- Set &VectorSet_Construct(Arena *arena) { return *(new VectorSet(arena)); } //------------------------------operator=-------------------------------------- Set &VectorSet::operator = (const Set &set) { if( &set == this ) return *this; FREE_FAST(data); // The cast is a virtual function that checks that "set" is a VectorSet. slamin(*(set.asVectorSet())); return *this; } //------------------------------slamin----------------------------------------- // Initialize one set with another. No regard is made to the existing Set. void VectorSet::slamin(const VectorSet& s) { size = s.size; // Use new size data = (uint32*)s._set_arena->Amalloc(size*sizeof(uint32)); // Make array of required size memcpy( data, s.data, size*sizeof(uint32) ); // Fill the array } //------------------------------grow------------------------------------------- // Expand the existing set to a bigger size void VectorSet::grow( uint newsize ) { newsize = (newsize+31) >> 5; // Convert to longwords uint x = size; while( x < newsize ) x <<= 1; data = (uint32 *)_set_arena->Arealloc(data, size*sizeof(uint32), x*sizeof(uint32)); memset((char *)(data + size), 0, (x - size)*sizeof(uint32)); size = x; } //------------------------------operator<<=------------------------------------ // Insert a member into an existing Set. Set &VectorSet::operator <<= (uint elem) { register uint word = elem >> 5; // Get the longword offset register uint32 mask = 1L << (elem & 31); // Get bit mask if( word >= size ) // Need to grow set? grow(elem+1); // Then grow it data[word] |= mask; // Set new bit return *this; } //------------------------------operator>>=------------------------------------ // Delete a member from an existing Set. Set &VectorSet::operator >>= (uint elem) { register uint word = elem >> 5; // Get the longword offset if( word >= size ) // Beyond the last? return *this; // Then it's clear & return clear register uint32 mask = 1L << (elem & 31); // Get bit mask data[word] &= ~mask; // Clear bit return *this; } //------------------------------operator&=------------------------------------- // Intersect one set into another. VectorSet &VectorSet::operator &= (const VectorSet &s) { // NOTE: The intersection is never any larger than the smallest set. if( s.size < size ) size = s.size; // Get smaller size register uint32 *u1 = data; // Pointer to the destination data register uint32 *u2 = s.data; // Pointer to the source data for( uint i=0; i<size; i++) // For data in set *u1++ &= *u2++; // Copy and AND longwords return *this; // Return set } //------------------------------operator&=------------------------------------- Set &VectorSet::operator &= (const Set &set) { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) &= *(set.asVectorSet()); } //------------------------------operator|=------------------------------------- // Union one set into another. VectorSet &VectorSet::operator |= (const VectorSet &s) { // This many words must be unioned register uint cnt = ((size<s.size)?size:s.size); register uint32 *u1 = data; // Pointer to the destination data register uint32 *u2 = s.data; // Pointer to the source data for( uint i=0; i<cnt; i++) // Copy and OR the two sets *u1++ |= *u2++; if( size < s.size ) { // Is set 2 larger than set 1? // Extend result by larger set grow(s.size*sizeof(uint32)*8); memcpy(&data[cnt], u2, (s.size - cnt)*sizeof(uint32)); } return *this; // Return result set } //------------------------------operator|=------------------------------------- Set &VectorSet::operator |= (const Set &set) { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) |= *(set.asVectorSet()); } //------------------------------operator-=------------------------------------- // Difference one set from another. VectorSet &VectorSet::operator -= (const VectorSet &s) { // This many words must be unioned register uint cnt = ((size<s.size)?size:s.size); register uint32 *u1 = data; // Pointer to the destination data register uint32 *u2 = s.data; // Pointer to the source data for( uint i=0; i<cnt; i++ ) // For data in set *u1++ &= ~(*u2++); // A <-- A & ~B with longwords return *this; // Return new set } //------------------------------operator-=------------------------------------- Set &VectorSet::operator -= (const Set &set) { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) -= *(set.asVectorSet()); } //------------------------------compare---------------------------------------- // Compute 2 booleans: bits in A not B, bits in B not A. // Return X0 -- A is not a subset of B // X1 -- A is a subset of B // 0X -- B is not a subset of A // 1X -- B is a subset of A int VectorSet::compare (const VectorSet &s) const { register uint32 *u1 = data; // Pointer to the destination data register uint32 *u2 = s.data; // Pointer to the source data register uint32 AnotB = 0, BnotA = 0; // This many words must be unioned register uint cnt = ((size<s.size)?size:s.size); // Get bits for both sets uint i; // Exit value of loop for( i=0; i<cnt; i++ ) { // For data in BOTH sets register uint32 A = *u1++; // Data from one guy register uint32 B = *u2++; // Data from other guy AnotB |= (A & ~B); // Compute bits in A not B BnotA |= (B & ~A); // Compute bits in B not A } // Get bits from bigger set if( size < s.size ) { for( ; i<s.size; i++ ) // For data in larger set BnotA |= *u2++; // These bits are in B not A } else { for( ; i<size; i++ ) // For data in larger set AnotB |= *u1++; // These bits are in A not B } // Set & return boolean flags return ((!BnotA)<<1) + (!AnotB); } //------------------------------operator==------------------------------------- // Test for set equality int VectorSet::operator == (const VectorSet &s) const { return compare(s) == 3; // TRUE if A and B are mutual subsets } //------------------------------operator==------------------------------------- int VectorSet::operator == (const Set &set) const { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) == *(set.asVectorSet()); } //------------------------------disjoint--------------------------------------- // Check for sets being disjoint. int VectorSet::disjoint(const Set &set) const { // The cast is a virtual function that checks that "set" is a VectorSet. const VectorSet &s = *(set.asVectorSet()); // NOTE: The intersection is never any larger than the smallest set. register uint small = ((size<s.size)?size:s.size); register uint32 *u1 = data; // Pointer to the destination data register uint32 *u2 = s.data; // Pointer to the source data for( uint i=0; i<small; i++) // For data in set if( *u1++ & *u2++ ) // If any elements in common return 0; // Then not disjoint return 1; // Else disjoint } //------------------------------operator<-------------------------------------- // Test for strict subset int VectorSet::operator < (const VectorSet &s) const { return compare(s) == 1; // A subset B, B not subset A } //------------------------------operator<-------------------------------------- int VectorSet::operator < (const Set &set) const { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) < *(set.asVectorSet()); } //------------------------------operator<=------------------------------------- // Test for subset int VectorSet::operator <= (const VectorSet &s) const { return compare(s) & 1; // A subset B } //------------------------------operator<=------------------------------------- int VectorSet::operator <= (const Set &set) const { // The cast is a virtual function that checks that "set" is a VectorSet. return (*this) <= *(set.asVectorSet()); } //------------------------------operator[]------------------------------------- // Test for membership. A Zero/Non-Zero value is returned! int VectorSet::operator[](uint elem) const { register uint word = elem >> 5; // Get the longword offset if( word >= size ) // Beyond the last? return 0; // Then it's clear register uint32 mask = 1L << (elem & 31); // Get bit mask return ((data[word] & mask))!=0; // Return the sense of the bit } //------------------------------getelem---------------------------------------- // Get any element from the set. uint VectorSet::getelem(void) const { uint i; // Exit value of loop for( i=0; i<size; i++ ) if( data[i] ) break; uint32 word = data[i]; int j; // Exit value of loop for( j= -1; word; j++, word>>=1 ); return (i<<5)+j; } //------------------------------Clear------------------------------------------ // Clear a set void VectorSet::Clear(void) { if( size > 100 ) { // Reclaim storage only if huge FREE_RESOURCE_ARRAY(uint32,data,size); size = 2; // Small initial size data = NEW_RESOURCE_ARRAY(uint32,size); } memset( data, 0, size*sizeof(uint32) ); } //------------------------------Size------------------------------------------- // Return number of elements in a Set uint VectorSet::Size(void) const { uint sum = 0; // Cumulative size so far. uint8 *currByte = (uint8*)data; for( uint32 i = 0; i < (size<<2); i++) // While have bytes to process sum += bitsInByte[*currByte++]; // Add bits in current byte to size. return sum; } //------------------------------Sort------------------------------------------- // Sort the elements for the next forall statement void VectorSet::Sort(void) { } //------------------------------hash------------------------------------------- int VectorSet::hash() const { uint32 _xor = 0; uint lim = ((size<4)?size:4); for( uint i = 0; i < lim; i++ ) _xor ^= data[i]; return (int)_xor; } //------------------------------iterate---------------------------------------- SetI_ *VectorSet::iterate(uint &elem) const { VSetI_ *foo = (new(ResourceObj::C_HEAP) VSetI_(this)); elem = foo->next(); return foo; } //============================================================================= //------------------------------VSetI_----------------------------------------- // Initialize the innards of a VectorSet iterator VSetI_::VSetI_( const VectorSet *vset ) : s(vset) { i = (uint)-1L; j = (uint)-1L; mask = (unsigned)(1L<<31); } //------------------------------next------------------------------------------- // Find and return the next element of a vector set, or return garbage and // make "VSetI_::test()" fail. uint VSetI_::next(void) { j++; // Next element in word mask = (mask & max_jint) << 1;// Next bit in word do { // Do While still have words while( mask ) { // While have bits in word if( s->data[i] & mask ) { // If found a bit return (i<<5)+j; // Return the bit address } j++; // Skip to next bit mask = (mask & max_jint) << 1; } j = 0; // No more bits in word; setup for next word mask = 1; for( i++; (i<s->size) && (!s->data[i]); i++ ); // Skip to non-zero word } while( i<s->size ); return max_juint; // No element, iterated them all }