spot/bricks/brick-hashset.h
Etienne Renault c515ee92e2 bricks: add missing override
* bricks/brick-assert.h, bricks/brick-hashset.h,
bricks/brick-shmem.h: here.
2020-06-03 10:33:53 +02:00

1581 lines
44 KiB
C++

// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*-
/*
* Fast hash tables.
*/
/*
* (c) 2010-2014 Petr Ročkai <me@mornfall.net>
* (c) 2012-2014 Jiří Weiser <xweiser1@fi.muni.cz>
* (c) 2013-2014 Vladimír Štill <xstill@fi.muni.cz>
*/
/* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE. */
#include <bricks/brick-hash.h>
#include <bricks/brick-shmem.h>
#include <bricks/brick-bitlevel.h>
#include <bricks/brick-assert.h>
#include <bricks/brick-types.h>
#include <type_traits>
#include <set>
#ifndef BRICK_HASHSET_H
#define BRICK_HASHSET_H
namespace brick {
namespace hashset {
using hash::hash64_t;
using hash::hash128_t;
/*
* Hash table cell implementations (tables are represented as vectors of
* cells).
*/
template< typename T, typename _Hasher >
struct CellBase
{
using value_type = T;
using Hasher = _Hasher;
};
template< typename T, typename Hasher >
struct FastCell : CellBase< T, Hasher >
{
T _value;
hash64_t _hash;
template< typename Value >
bool is( Value v, hash64_t hash, Hasher &h ) {
return _hash == hash && h.equal( _value, v );
}
bool empty() { return !_hash; }
void store( T bn, hash64_t hash ) {
_hash = hash;
_value = bn;
}
T &fetch() { return _value; }
T copy() { return _value; }
hash64_t hash( Hasher & ) { return _hash; }
};
template< typename T, typename Hasher >
struct CompactCell : CellBase< T, Hasher >
{
T _value;
template< typename Value >
bool is( Value v, hash64_t, Hasher &h ) {
return h.equal( _value, v );
}
bool empty() { return !_value; } /* meh */
void store( T bn, hash64_t ) { _value = bn; }
T &fetch() { return _value; }
T copy() { return _value; }
hash64_t hash( Hasher &h ) { return h.hash( _value ).first; }
};
template< typename T, typename Hasher >
struct FastAtomicCell : CellBase< T, Hasher >
{
std::atomic< hash64_t > hashLock;
T value;
bool empty() { return hashLock == 0; }
bool invalid() { return hashLock == 3; }
/* returns old cell value */
FastAtomicCell invalidate() {
// wait for write to end
hash64_t prev = 0;
while ( !hashLock.compare_exchange_weak( prev, 0x3 ) ) {
if ( prev == 3 )
return FastAtomicCell( prev, value );
prev &= ~(0x3); // clean flags
}
return FastAtomicCell( prev, value );
}
T &fetch() { return value; }
T copy() { return value; }
// TODO: this loses bits and hence doesn't quite work
// hash64_t hash( Hasher & ) { return hashLock >> 2; }
hash64_t hash( Hasher &h ) { return h.hash( value ).first; }
// wait for another write; returns false if cell was invalidated
bool wait() {
while( hashLock & 1 )
if ( invalid() )
return false;
return true;
}
bool tryStore( T v, hash64_t hash ) {
hash |= 0x1;
hash64_t chl = 0;
if ( hashLock.compare_exchange_strong( chl, (hash << 2) | 1 ) ) {
value = v;
hashLock.exchange( hash << 2 );
return true;
}
return false;
}
template< typename Value >
bool is( Value v, hash64_t hash, Hasher &h ) {
hash |= 0x1;
if ( ( (hash << 2) | 1) != (hashLock | 1) )
return false;
if ( !wait() )
return false;
return h.equal( value, v );
}
FastAtomicCell() : hashLock( 0 ), value() {}
FastAtomicCell( const FastAtomicCell & ) : hashLock( 0 ), value() {}
FastAtomicCell( hash64_t hash, T value ) : hashLock( hash ), value( value ) { }
};
template< typename T, typename = void >
struct Tagged {
T t;
uint32_t _tag;
static const int tagBits = 16;
void setTag( uint32_t v ) { _tag = v; }
uint32_t tag() { return _tag; }
Tagged() noexcept : t(), _tag( 0 ) {}
Tagged( const T &t ) : t( t ), _tag( 0 ) {}
};
template< typename T >
struct Tagged< T, typename std::enable_if< (T::tagBits > 0) >::type >
{
T t;
static const int tagBits = T::tagBits;
void setTag( uint32_t value ) { t.setTag( value ); }
uint32_t tag() { return t.tag(); }
Tagged() noexcept : t() {}
Tagged( const T &t ) : t( t ) {}
};
template< typename T, typename Hasher >
struct AtomicCell : CellBase< T, Hasher >
{
std::atomic< Tagged< T > > value;
static_assert( sizeof( std::atomic< Tagged< T > > ) == sizeof( Tagged< T > ),
"std::atomic< Tagged< T > > must be lock-free" );
static_assert( Tagged< T >::tagBits > 0, "T has at least a one-bit tagspace" );
bool empty() { return !value.load().t; }
bool invalid() {
Tagged< T > v = value.load();
return (v.tag() == 0 && v.t) || (v.tag() != 0 && !v.t);
}
static hash64_t hashToTag( hash64_t hash, int bits = Tagged< T >::tagBits )
{
// use different part of hash than used for storing
return ( hash >> ( sizeof( hash64_t ) * 8 - bits ) ) | 0x1;
}
/* returns old cell value */
AtomicCell invalidate() {
Tagged< T > v = value;
v.setTag( v.tag() ? 0 : 1 ); // set tag to 1 if it was empty -> empty != invalid
return AtomicCell( value.exchange( v ) );
}
Tagged< T > &deatomize() {
value.load(); // fence
return *reinterpret_cast< Tagged< T > * >( &value );
}
T &fetch() { return deatomize().t; }
T copy() { Tagged< T > v = value; v.setTag( 0 ); return v.t; }
bool wait() { return !invalid(); }
void store( T bn, hash64_t hash ) {
return tryStore( bn, hash );
}
bool tryStore( T b, hash64_t hash ) {
Tagged< T > zero;
Tagged< T > next( b );
next.setTag( hashToTag( hash ) );
auto rv = value.compare_exchange_strong( zero, next );
return rv;
}
template< typename Value >
bool is( Value v, hash64_t hash, Hasher &h ) {
return value.load().tag() == hashToTag( hash ) &&
h.equal( value.load().t, v );
}
hash64_t hash( Hasher &h ) { return h.hash( value.load().t ).first; }
// AtomicCell &operator=( const AtomicCell &cc ) = delete;
AtomicCell() : value() {}
AtomicCell( const AtomicCell & ) : value() {}
AtomicCell( Tagged< T > val ) : value() {
value.store( val );
}
};
// default hash implementation
template< typename T >
struct default_hasher {};
template< typename T >
struct Found : types::Wrapper< T >
{
bool _found;
Found( const T &t, bool found ) : types::Wrapper< T >( t ), _found( found ) {}
bool isnew() { return !_found; }
bool found() { return _found; }
};
template< typename S, typename F >
types::FMap< Found, S, F > fmap( F f, Found< S > n ) {
return types::FMap< Found, S, F >( f( n.unwrap() ), n._found );
}
template< typename T >
Found< T > isNew( const T &x, bool y ) {
return Found< T >( x, !y );
}
template< typename Cell >
struct HashSetBase
{
struct ThreadData {};
using value_type = typename Cell::value_type;
using Hasher = typename Cell::Hasher;
static const unsigned cacheLine = 64; // bytes
static const unsigned thresh = cacheLine / sizeof( Cell );
static const unsigned threshMSB = bitlevel::compiletime::MSB( thresh );
static const unsigned maxcollisions = 1 << 16; // 2^16
static const unsigned growthreshold = 75; // percent
Hasher hasher;
struct iterator {
Cell *_cell;
bool _new;
iterator( Cell *c = nullptr, bool n = false ) : _cell( c ), _new( n ) {}
value_type *operator->() { return &(_cell->fetch()); }
value_type &operator*() { return _cell->fetch(); }
value_type copy() { return _cell->copy(); }
bool valid() { return _cell; }
bool isnew() { return _new; }
};
iterator end() { return iterator(); }
static size_t index( hash64_t h, size_t i, size_t mask ) {
h &= ~hash64_t( thresh - 1 );
const unsigned Q = 1, R = 1;
if ( i < thresh )
return ( h + i ) & mask;
else {
size_t j = i & ( thresh - 1 );
i = i >> threshMSB;
size_t hop = ( (2 * Q + 1) * i + 2 * R * (i * i) ) << threshMSB;
return ( h + j + hop ) & mask;
}
}
HashSetBase( const Hasher &h ) : hasher( h ) {}
};
/**
* An implementation of high-performance hash table, used as a set. It's an
* open-hashing implementation with a combination of linear and quadratic
* probing. It also uses a hash-compacted prefilter to avoid fetches when
* looking up an item and the item stored at the current lookup position is
* distinct (a collision).
*
* An initial size may be provided to improve performance in cases where it is
* known there will be many elements. Table growth is exponential with base 2
* and is triggered at 75% load. (See maxcollision().)
*/
template< typename Cell >
struct _HashSet : HashSetBase< Cell >
{
using Base = HashSetBase< Cell >;
typedef std::vector< Cell > Table;
_HashSet< Cell > &withTD( typename Base::ThreadData & ) { return *this; }
using typename Base::iterator;
using typename Base::value_type;
using typename Base::Hasher;
Table _table;
int _used;
int _bits;
size_t _maxsize;
bool _growing;
size_t size() const { return _table.size(); }
bool empty() const { return !_used; }
int count( const value_type &i ) { return find( i ).valid(); }
hash64_t hash( const value_type &i ) { return hash128( i ).first; }
hash128_t hash128( const value_type &i ) { return this->hasher.hash( i ); }
iterator insert( value_type i ) { return insertHinted( i, hash( i ) ); }
template< typename T >
iterator find( const T &i ) {
return findHinted( i, hash( i ) );
}
template< typename T >
iterator findHinted( const T &item, hash64_t hash )
{
size_t idx;
for ( size_t i = 0; i < this->maxcollisions; ++i ) {
idx = this->index( hash, i, _bits );
if ( _table[ idx ].empty() )
return this->end();
if ( _table[ idx ].is( item, hash, this->hasher ) )
return iterator( &_table[ idx ] );
}
// we can be sure that the element is not in the table *because*: we
// never create chains longer than "mc", and if we haven't found the
// key in this many steps, it can't be in the table
return this->end();
}
iterator insertHinted( const value_type &i, hash64_t h ) {
return insertHinted( i, h, _table, _used );
}
iterator insertHinted( const value_type &item, hash64_t h, Table &table, int &used )
{
if ( !_growing && size_t( _used ) > (size() / 100) * 75 )
grow();
size_t idx;
for ( size_t i = 0; i < this->maxcollisions; ++i ) {
idx = this->index( h, i, _bits );
if ( table[ idx ].empty() ) {
++ used;
table[ idx ].store( item, h );
return iterator( &table[ idx ], true );
}
if ( table[ idx ].is( item, h, this->hasher ) )
return iterator( &table[ idx ], false );
}
grow();
return insertHinted( item, h, table, used );
}
void grow() {
if ( 2 * size() >= _maxsize )
ASSERT_UNREACHABLE( "ran out of space in the hash table" );
if( _growing )
ASSERT_UNREACHABLE( "too many collisions during table growth" );
_growing = true;
int used = 0;
Table table;
table.resize( 2 * size(), Cell() );
_bits |= (_bits << 1); // unmask more
for ( auto cell : _table ) {
if ( cell.empty() )
continue;
insertHinted( cell.fetch(), cell.hash( this->hasher ),
table, used );
}
std::swap( table, _table );
ASSERT_EQ( used, _used );
_growing = false;
}
void setSize( size_t s )
{
_bits = 0;
while ((s = s >> 1))
_bits |= s;
_table.resize( _bits + 1, Cell() );
}
void clear() {
_used = 0;
std::fill( _table.begin(), _table.end(), value_type() );
}
bool valid( int off ) {
return !_table[ off ].empty();
}
value_type &operator[]( int off ) {
return _table[ off ].fetch();
}
_HashSet() : _HashSet( Hasher() ) {}
explicit _HashSet( Hasher h ) : _HashSet( h, 32 ) {}
_HashSet( Hasher h, int initial )
: Base( h ), _used( 0 ), _maxsize( -1 ), _growing( false )
{
setSize( initial );
}
};
template< typename T, typename Hasher = default_hasher< T > >
using Fast = _HashSet< FastCell< T, Hasher > >;
template< typename T, typename Hasher = default_hasher< T > >
using Compact = _HashSet< CompactCell< T, Hasher > >;
template< typename Cell >
struct _ConcurrentHashSet : HashSetBase< Cell >
{
using Base = HashSetBase< Cell >;
using typename Base::Hasher;
using typename Base::value_type;
using typename Base::iterator;
enum class Resolution {
Success, // the item has been inserted successfully
Failed, // cannot insert value, table growth has been triggered while
// we were looking for a free cell
Found, // item was already in the table
NotFound,
NoSpace, // there's is not enough space in the table
Growing // table is growing or was already resized, retry
};
struct _Resolution {
Resolution r;
Cell *c;
_Resolution( Resolution r, Cell *c = nullptr ) : r( r ), c( c ) {}
};
using Insert = _Resolution;
using Find = _Resolution;
struct ThreadData {
unsigned inserts;
unsigned currentRow;
ThreadData() : inserts( 0 ), currentRow( 0 ) {}
};
struct Row {
std::atomic< Cell * > _data;
size_t _size;
size_t size() const { return _size; }
void size( size_t s ) {
ASSERT( empty() );
_size = std::max( s, size_t( 1 ) );
}
bool empty() const { return begin() == nullptr; }
void resize( size_t n ) {
Cell *old = _data.exchange( new Cell[ n ] );
_size = n;
delete[] old;
}
void free() {
Cell *old = _data.exchange( nullptr );
_size = 0;
delete[] old;
}
Cell &operator[]( size_t i ) {
return _data.load( std::memory_order_relaxed )[ i ];
}
Cell *begin() {
return _data.load( std::memory_order_relaxed );
}
Cell *begin() const {
return _data.load( std::memory_order_relaxed );
}
Cell *end() {
return begin() + size();
}
Cell *end() const {
return begin() + size();
}
Row() : _data( nullptr ), _size( 0 ) {}
~Row() { free(); }
};
static const unsigned segmentSize = 1 << 16;// 2^16 = 65536
static const unsigned syncPoint = 1 << 10;// 2^10 = 1024
struct Data
{
Hasher hasher;
std::vector< Row > table;
std::vector< std::atomic< unsigned short > > tableWorkers;
std::atomic< unsigned > currentRow;
std::atomic< int > availableSegments;
std::atomic< unsigned > doneSegments;
std::atomic< size_t > used;
std::atomic< bool > growing;
Data( const Hasher &h, unsigned maxGrows )
: hasher( h ), table( maxGrows ), tableWorkers( maxGrows ), currentRow( 0 ),
availableSegments( 0 ), used( 0 ), growing( false )
{}
};
Data _d;
ThreadData _global; /* for single-thread access */
static size_t nextSize( size_t s ) {
if ( s < 512 * 1024 )
return s * 16;
if ( s < 16 * 1024 * 1024 )
return s * 8;
if ( s < 32 * 1024 * 1024 )
return s * 4;
return s * 2;
}
struct WithTD
{
using iterator = typename Base::iterator;
using value_type = typename Base::value_type;
Data &_d;
ThreadData &_td;
WithTD( Data &d, ThreadData &td ) : _d( d ), _td( td ) {}
size_t size() { return current().size(); }
Row &current() { return _d.table[ _d.currentRow ]; }
Row &current( unsigned index ) { return _d.table[ index ]; }
bool changed( unsigned row ) { return row < _d.currentRow || _d.growing; }
iterator insert( value_type x ) {
return insertHinted( x, _d.hasher.hash( x ).first );
}
template< typename T >
iterator find( T x ) {
return findHinted( x, _d.hasher.hash( x ).first );
}
int count( value_type x ) {
return find( x ).valid() ? 1 : 0;
}
iterator insertHinted( value_type x, hash64_t h )
{
while ( true ) {
Insert ir = insertCell< false >( x, h );
switch ( ir.r ) {
case Resolution::Success:
increaseUsage();
return iterator( ir.c, true );
case Resolution::Found:
return iterator( ir.c, false );
case Resolution::NoSpace:
if ( grow( _td.currentRow + 1 ) ) {
++_td.currentRow;
break;
}
case Resolution::Growing:
helpWithRehashing();
updateIndex( _td.currentRow );
break;
default:
ASSERT_UNREACHABLE("impossible result from insertCell");
}
}
ASSERT_UNREACHABLE("broken loop");
}
template< typename T >
iterator findHinted( T x, hash64_t h ) {
while ( true ) {
Find fr = findCell( x, h, _td.currentRow );
switch ( fr.r ) {
case Resolution::Found:
return iterator( fr.c );
case Resolution::NotFound:
return iterator();
case Resolution::Growing:
helpWithRehashing();
updateIndex( _td.currentRow );
break;
default:
ASSERT_UNREACHABLE("impossible result from findCell");
}
}
ASSERT_UNREACHABLE("broken loop");
}
template< typename T >
Find findCell( T v, hash64_t h, unsigned rowIndex )
{
if ( changed( rowIndex ) )
return Find( Resolution::Growing );
Row &row = current( rowIndex );
if ( row.empty() )
return Find( Resolution::NotFound );
const size_t mask = row.size() - 1;
for ( size_t i = 0; i < Base::maxcollisions; ++i ) {
if ( changed( rowIndex ) )
return Find( Resolution::Growing );
Cell &cell = row[ Base::index( h, i, mask ) ];
if ( cell.empty() )
return Find( Resolution::NotFound );
if ( cell.is( v, h, _d.hasher ) )
return Find( Resolution::Found, &cell );
if ( cell.invalid() )
return Find( Resolution::Growing );
}
return Find( Resolution::NotFound );
}
template< bool force >
Insert insertCell( value_type x, hash64_t h )
{
Row &row = current( _td.currentRow );
if ( !force ) {
// read usage first to guarantee usage <= size
size_t u = _d.used.load();
// usage >= 75% of table size
// usage is never greater than size
if ( row.empty() || double( row.size() ) <= double( 4 * u ) / 3 )
return Insert( Resolution::NoSpace );
if ( changed( _td.currentRow ) )
return Insert( Resolution::Growing );
}
ASSERT( !row.empty() );
const size_t mask = row.size() - 1;
for ( size_t i = 0; i < Base::maxcollisions; ++i )
{
Cell &cell = row[ Base::index( h, i, mask ) ];
if ( cell.empty() ) {
if ( cell.tryStore( x, h ) )
return Insert( Resolution::Success, &cell );
if ( !force && changed( _td.currentRow ) )
return Insert( Resolution::Growing );
}
if ( cell.is( x, h, _d.hasher ) )
return Insert( Resolution::Found, &cell );
if ( !force && changed( _td.currentRow ) )
return Insert( Resolution::Growing );
}
return Insert( Resolution::NoSpace );
}
bool grow( unsigned rowIndex )
{
ASSERT( rowIndex );
if ( rowIndex >= _d.table.size() )
ASSERT_UNREACHABLE( "out of growth space" );
if ( _d.currentRow >= rowIndex )
return false;
while ( _d.growing.exchange( true ) ) // acquire growing lock
helpWithRehashing();
if ( _d.currentRow >= rowIndex ) {
_d.growing.exchange( false ); // release the lock
return false;
}
Row &row = current( rowIndex - 1 );
_d.table[ rowIndex ].resize( nextSize( row.size() ) );
_d.currentRow.exchange( rowIndex );
_d.tableWorkers[ rowIndex ] = 1;
_d.doneSegments.exchange( 0 );
// current row is fake, so skip the rehashing
if ( row.empty() ) {
rehashingDone();
return true;
}
const unsigned segments = std::max( row.size() / segmentSize, size_t( 1 ) );
_d.availableSegments.exchange( segments );
while ( rehashSegment() );
return true;
}
void helpWithRehashing() {
while ( _d.growing )
while( rehashSegment() );
}
void rehashingDone() {
releaseRow( _d.currentRow - 1 );
_d.growing.exchange( false ); /* done */
}
bool rehashSegment() {
int segment;
if ( _d.availableSegments <= 0 )
return false;
if ( ( segment = --_d.availableSegments ) < 0 )
return false;
Row &row = current( _d.currentRow - 1 );
size_t segments = std::max( row.size() / segmentSize, size_t( 1 ) );
auto it = row.begin() + segmentSize * segment;
auto end = it + segmentSize;
if ( end > row.end() )
end = row.end();
ASSERT( it < end );
ThreadData td;
td.currentRow = _d.currentRow;
// every cell has to be invalidated
for ( ; it != end; ++it ) {
Cell old = it->invalidate();
if ( old.empty() || old.invalid() )
continue;
value_type value = old.fetch();
Resolution r = WithTD( _d, td ).insertCell< true >( value, old.hash( _d.hasher ) ).r;
switch( r ) {
case Resolution::Success:
break;
case Resolution::NoSpace:
ASSERT_UNREACHABLE( "ran out of space during growth" );
default:
ASSERT_UNREACHABLE( "internal error" );
}
}
if ( ++_d.doneSegments == segments )
rehashingDone();
return segment > 0;
}
void updateIndex( unsigned &index ) {
unsigned row = _d.currentRow;
if ( row != index ) {
releaseRow( index );
acquireRow( row );
index = row;
}
}
void releaseRow( unsigned index ) {
// special case - zero index
if ( !_d.tableWorkers[ index ] )
return;
// only last thread releases memory
if ( !--_d.tableWorkers[ index ] )
_d.table[ index ].free();
}
void acquireRow( unsigned &index ) {
unsigned short refCount = _d.tableWorkers[ index ];
do {
if ( !refCount ) {
index = _d.currentRow;
refCount = _d.tableWorkers[ index ];
continue;
}
if (_d.tableWorkers[ index ].compare_exchange_weak( refCount, refCount + 1 ))
break;
} while( true );
}
void increaseUsage() {
if ( ++_td.inserts == syncPoint ) {
_d.used += syncPoint;
_td.inserts = 0;
}
}
};
WithTD withTD( ThreadData &td ) { return WithTD( _d, td ); }
explicit _ConcurrentHashSet( Hasher h = Hasher(), unsigned maxGrows = 64 )
: Base( h ), _d( h, maxGrows )
{
setSize( 16 ); // by default
}
/* XXX only usable before the first insert; rename? */
void setSize( size_t s ) {
s = bitlevel::fill( s - 1 ) + 1;
size_t toSet = 1;
while ( nextSize( toSet ) < s )
toSet <<= 1;
_d.table[ 0 ].size( toSet );
}
hash64_t hash( const value_type &t ) { return hash128( t ).first; }
hash128_t hash128( const value_type &t ) { return _d.hasher.hash( t ); }
iterator insert( const value_type &t ) { return withTD( _global ).insert( t ); }
int count( const value_type &t ) { return withTD( _global ).count( t ); }
size_t size() { return withTD( _global ).size(); }
_ConcurrentHashSet( const _ConcurrentHashSet & ) = delete;
_ConcurrentHashSet &operator=( const _ConcurrentHashSet & )= delete;
/* multiple threads may use operator[], but not concurrently with insertions */
value_type operator[]( size_t index ) { // XXX return a reference
return _d.table[ _d.currentRow ][ index ].fetch();
}
bool valid( size_t index ) {
return !_d.table[ _d.currentRow ][ index ].empty();
}
};
template< typename T, typename Hasher = default_hasher< T > >
using FastConcurrent = _ConcurrentHashSet< FastAtomicCell< T, Hasher > >;
template< typename T, typename Hasher = default_hasher< T > >
using CompactConcurrent = _ConcurrentHashSet< AtomicCell< T, Hasher > >;
#ifdef BRICKS_FORCE_FAST_CONCURRENT_SET
template< typename T, typename Hasher = default_hasher< T > >
using Concurrent = FastConcurrent< T, Hasher >;
#elif BRICKS_FORCE_COMPACT_CONCURRENT_SET
template< typename T, typename Hasher = default_hasher< T > >
using Concurrent = CompactConcurrent< T, Hasher >;
#else
template< typename T, typename Hasher = default_hasher< T > >
using Concurrent = _ConcurrentHashSet< typename std::conditional< (
sizeof( Tagged< T > ) > 8 // most platforms do not have CAS for data types bigger then 64bit
// for example 16B CAS does not link in clang 3.4 on x86_64
|| sizeof( std::atomic< Tagged< T > > ) > sizeof( Tagged< T > ) // atomic is not lock-free
|| sizeof( AtomicCell< T, Hasher > ) >= sizeof( FastAtomicCell< T, Hasher > ) ),
FastAtomicCell< T, Hasher >, AtomicCell< T, Hasher > >::type >;
#endif
}
}
/* unit tests */
namespace brick_test {
namespace hashset {
using namespace ::brick::hashset;
template< template< typename > class HS >
struct Sequential
{
TEST(basic) {
HS< int > set;
ASSERT( !set.count( 1 ) );
ASSERT( set.insert( 1 ).isnew() );
ASSERT( set.count( 1 ) );
unsigned count = 0;
for ( unsigned i = 0; i != set.size(); ++i )
if ( set[ i ] )
++count;
ASSERT_EQ( count, 1u );
}
TEST(stress) {
HS< int > set;
for ( int i = 1; i < 32*1024; ++i ) {
set.insert( i );
ASSERT( set.count( i ) );
}
for ( int i = 1; i < 32*1024; ++i ) {
ASSERT( set.count( i ) );
}
}
TEST(set) {
HS< int > set;
for ( int i = 1; i < 32*1024; ++i ) {
ASSERT( !set.count( i ) );
}
for ( int i = 1; i < 32*1024; ++i ) {
set.insert( i );
ASSERT( set.count( i ) );
ASSERT( !set.count( i + 1 ) );
}
for ( int i = 1; i < 32*1024; ++i ) {
ASSERT( set.count( i ) );
}
for ( int i = 32*1024; i < 64 * 1024; ++i ) {
ASSERT( !set.count( i ) );
}
}
};
template< template< typename > class HS >
struct Parallel
{
struct Insert : shmem::Thread {
HS< int > *_set;
typename HS< int >::ThreadData td;
int from, to;
bool overlap;
void main() override {
auto set = _set->withTD( td );
for ( int i = from; i < to; ++i ) {
set.insert( i );
ASSERT( !set.insert( i ).isnew() );
if ( !overlap && i < to - 1 )
ASSERT( !set.count( i + 1 ) );
}
}
};
TEST(insert) {
HS< int > set;
set.setSize( 4 * 1024 );
Insert a;
a._set = &set;
a.from = 1;
a.to = 32 * 1024;
a.overlap = false;
a.main();
for ( int i = 1; i < 32*1024; ++i )
ASSERT( set.count( i ) );
}
static void _par( HS< int > *set, int f1, int t1, int f2, int t2 )
{
Insert a, b;
a.from = f1;
a.to = t1;
b.from = f2;
b.to = t2;
a._set = set;
b._set = set;
a.overlap = b.overlap = (t1 > f2);
a.start();
b.start();
a.join();
b.join();
}
static void _multi( HS< int > *set, std::size_t count, int from, int to )
{
Insert *arr = new Insert[ count ];
for ( std::size_t i = 0; i < count; ++i ) {
arr[ i ].from = from;
arr[ i ].to = to;
arr[ i ]._set = set;
arr[ i ].overlap = true;
}
for ( std::size_t i = 0; i < count; ++i )
arr[ i ].start();
for ( std::size_t i = 0; i < count; ++i )
arr[ i ].join();
delete[] arr;
}
TEST(multi)
{
HS< int > set;
set.setSize( 4 * 1024 );
_multi( &set, 10, 1, 32 * 1024 );
for ( int i = 1; i < 32 * 1024; ++i )
ASSERT( set.count( i ) );
int count = 0;
std::set< int > s;
for ( size_t i = 0; i != set.size(); ++i ) {
if ( set[ i ] ) {
if ( s.find( set[ i ] ) == s.end() )
s.insert( set[ i ] );
++count;
}
}
ASSERT_EQ( count, 32 * 1024 - 1 );
}
TEST(stress)
{
HS< int > set;
set.setSize( 4 * 1024 );
_par( &set, 1, 16*1024, 8*1024, 32*1024 );
for ( int i = 1; i < 32*1024; ++i )
ASSERT( set.count( i ) );
}
TEST(set) {
HS< int > set;
set.setSize( 4 * 1024 );
for ( int i = 1; i < 32*1024; ++i )
ASSERT( !set.count( i ) );
_par( &set, 1, 16*1024, 16*1024, 32*1024 );
for ( int i = 1; i < 32*1024; ++i )
ASSERT_EQ( i, i * set.count( i ) );
for ( int i = 32*1024; i < 64 * 1024; ++i )
ASSERT( !set.count( i ) );
}
};
template< typename T >
struct test_hasher {
template< typename X >
test_hasher( X& ) { }
test_hasher() = default;
hash128_t hash( int t ) const { return std::make_pair( t, t ); }
bool valid( int t ) const { return t != 0; }
bool equal( int a, int b ) const { return a == b; }
};
template< typename T > using CS = Compact< T, test_hasher< T > >;
template< typename T > using FS = Fast< T, test_hasher< T > >;
template< typename T > using ConCS = CompactConcurrent< T, test_hasher< T > >;
template< typename T > using ConFS = FastConcurrent< T, test_hasher< T > >;
/* instantiate the testcases */
template struct Sequential< CS >;
template struct Sequential< FS >;
template struct Sequential< ConCS >;
template struct Sequential< ConFS >;
template struct Parallel< ConCS >;
template struct Parallel< ConFS >;
}
}
#ifdef BRICK_BENCHMARK_REG
#include <brick-hlist.h>
#include <brick-benchmark.h>
#include <unordered_set>
#ifdef BRICKS_HAVE_TBB
#include <tbb/concurrent_hash_map.h>
#include <tbb/concurrent_unordered_set.h>
#endif
namespace brick_test {
namespace hashset {
template< typename HS >
struct RandomThread : shmem::Thread {
HS *_set;
typename HS::ThreadData td;
int count, id;
std::mt19937 rand;
std::uniform_int_distribution<> dist;
bool insert;
int max;
RandomThread() : insert( true ) {}
void main() {
rand.seed( id );
auto set = _set->withTD( td );
for ( int i = 0; i < count; ++i ) {
int v = dist( rand );
if ( max < std::numeric_limits< int >::max() ) {
v = v % max;
v = v * v + v + 41; /* spread out the values */
}
if ( insert )
set.insert( v );
else
set.count( v );
}
};
};
namespace {
Axis axis_items( int min = 16, int max = 16 * 1024 ) {
Axis a;
a.type = Axis::Quantitative;
a.name = "items";
a.log = true;
a.step = sqrt(sqrt(2));
a.normalize = Axis::Div;
a.unit = "k";
a.unit_div = 1000;
a.min = min * 1000;
a.max = max * 1000;
return a;
}
Axis axis_threads( int max = 16 ) {
Axis a;
a.type = Axis::Quantitative;
a.name = "threads";
a.normalize = Axis::Mult;
a.unit = "";
a.min = 1;
a.max = max;
a.step = 1;
return a;
}
Axis axis_reserve( int max = 200, int step = 50 )
{
Axis a;
a.type = Axis::Quantitative;
a.name = "reserve";
a.unit = "%";
a.min = 0;
a.max = max;
a.step = step;
return a;
}
Axis axis_types( int count )
{
Axis a;
a.type = Axis::Qualitative;
a.name = "type";
a.unit = "";
a.min = 0;
a.max = count - 1;
a.step = 1;
return a;
}
}
template< typename T > struct TN {};
template< typename > struct _void { typedef void T; };
template< typename Ts >
struct Run : BenchmarkGroup
{
template< typename, int Id >
std::string render( int, hlist::not_preferred ) { return ""; }
template< typename Tss = Ts, int Id = 0, typename = typename Tss::Head >
std::string render( int id, hlist::preferred = hlist::preferred() )
{
if ( id == Id )
return TN< typename Tss::Head >::n();
return render< typename Tss::Tail, Id + 1 >( id, hlist::preferred() );
}
std::string describe() {
std::string s;
for ( int i = 0; i < int( Ts::length ); ++i )
s += " type:" + render( i );
return std::string( s, 1, s.size() );
}
template< template< typename > class, typename Self, int, typename, typename... Args >
static void run( Self *, hlist::not_preferred, Args... ) {
ASSERT_UNREACHABLE( "brick_test::hashset::Run fell off the cliff" );
}
template< template< typename > class RI, typename Self, int id,
typename Tss, typename... Args >
static auto run( Self *self, hlist::preferred, Args... args )
-> typename _void< typename Tss::Head >::T
{
if ( self->type() == id ) {
RI< typename Tss::Head > x( self, args... );
self->reset(); // do not count the constructor
x( self );
} else
run< RI, Self, id + 1, typename Tss::Tail, Args... >( self, hlist::preferred(), args... );
}
template< template< typename > class RI, typename Self, typename... Args >
static void run( Self *self, Args... args ) {
run< RI, Self, 0, Ts, Args... >( self, hlist::preferred(), args... );
}
int type() { return 0; } // default
};
template< int _threads, typename T >
struct ItemsVsReserve : Run< hlist::TypeList< T > >
{
ItemsVsReserve() {
this->x = axis_items();
this->y = axis_reserve();
}
std::string fixed() {
std::stringstream s;
s << "threads:" << _threads;
return s.str();
}
int threads() { return _threads; }
int items() { return this->p; }
double reserve() { return this->q / 100; }
double normal() { return _threads; }
};
template< int _max_threads, int _reserve, typename T >
struct ItemsVsThreads : Run< hlist::TypeList< T > >
{
ItemsVsThreads() {
this->x = axis_items();
this->y = axis_threads( _max_threads );
}
std::string fixed() {
std::stringstream s;
s << "reserve:" << _reserve;
return s.str();
}
int threads() { return this->q; }
int items() { return this->p; }
double reserve() { return _reserve / 100.0; }
};
template< int _items, typename T >
struct ThreadsVsReserve : Run< hlist::TypeList< T > >
{
ThreadsVsReserve() {
this->x = axis_threads();
this->y = axis_reserve();
}
std::string fixed() {
std::stringstream s;
s << "items:" << _items << "k";
return s.str();
}
int threads() { return this->p; }
int reserve() { return this->q; }
int items() { return _items * 1000; }
};
template< int _threads, int _reserve, typename... Ts >
struct ItemsVsTypes : Run< hlist::TypeList< Ts... > >
{
ItemsVsTypes() {
this->x = axis_items();
this->y = axis_types( sizeof...( Ts ) );
this->y._render = [this]( int i ) {
return this->render( i );
};
}
std::string fixed() {
std::stringstream s;
s << "threads:" << _threads << " reserve:" << _reserve;
return s.str();
}
int threads() { return _threads; }
double reserve() { return _reserve / 100.0; }
int items() { return this->p; }
int type() { return this->q; }
double normal() { return _threads; }
};
template< int _items, int _reserve, int _threads, typename... Ts >
struct ThreadsVsTypes : Run< hlist::TypeList< Ts... > >
{
ThreadsVsTypes() {
this->x = axis_threads( _threads );
this->y = axis_types( sizeof...( Ts ) );
this->y._render = [this]( int i ) {
return this->render( i );
};
}
std::string fixed() {
std::stringstream s;
s << "items:" << _items << "k reserve:" << _reserve;
return s.str();
}
int threads() { return this->p; }
double reserve() { return _reserve / 100.0; }
int items() { return _items * 1000; }
int type() { return this->q; }
double normal() { return 1.0 / items(); }
};
template< typename T >
struct RandomInsert {
bool insert;
int max;
using HS = typename T::template HashTable< int >;
HS t;
template< typename BG >
RandomInsert( BG *bg, int max = std::numeric_limits< int >::max() )
: insert( true ), max( max )
{
if ( bg->reserve() > 0 )
t.setSize( bg->items() * bg->reserve() );
}
template< typename BG >
void operator()( BG *bg )
{
RandomThread< HS > *ri = new RandomThread< HS >[ bg->threads() ];
for ( int i = 0; i < bg->threads(); ++i ) {
ri[i].id = i;
ri[i].insert = insert;
ri[i].max = max;
ri[i].count = bg->items() / bg->threads();
ri[i]._set = &t;
}
for ( int i = 0; i < bg->threads(); ++i )
ri[i].start();
for ( int i = 0; i < bg->threads(); ++i )
ri[i].join();
}
};
template< typename T >
struct RandomLookup : RandomInsert< T > {
template< typename BG >
RandomLookup( BG *bg, int ins_max, int look_max )
: RandomInsert< T >( bg, ins_max )
{
(*this)( bg );
this->max = look_max;
this->insert = false;
}
};
template< typename Param >
struct Bench : Param
{
std::string describe() {
return "category:hashset " + Param::describe() + " " +
Param::fixed() + " " + this->describe_axes();
}
BENCHMARK(random_insert_1x) {
this->template run< RandomInsert >( this );
}
BENCHMARK(random_insert_2x) {
this->template run< RandomInsert >( this, this->items() / 2 );
}
BENCHMARK(random_insert_4x) {
this->template run< RandomInsert >( this, this->items() / 4 );
}
BENCHMARK(random_lookup_100) {
this->template run< RandomInsert >( this );
}
BENCHMARK(random_lookup_50) {
this->template run< RandomLookup >(
this, this->items() / 2, this->items() );
}
BENCHMARK(random_lookup_25) {
this->template run< RandomLookup >(
this, this->items() / 4, this->items() );
}
};
template< template< typename > class C >
struct wrap_hashset {
template< typename T > using HashTable = C< T >;
};
template< template< typename > class C >
struct wrap_set {
template< typename T >
struct HashTable {
C< T > *t;
struct ThreadData {};
HashTable< T > withTD( ThreadData & ) { return *this; }
void setSize( int s ) { t->rehash( s ); }
void insert( T i ) { t->insert( i ); }
int count( T i ) { return t->count( i ); }
HashTable() : t( new C< T > ) {}
};
};
struct empty {};
template< template< typename > class C >
struct wrap_map {
template< typename T >
struct HashTable : wrap_set< C >::template HashTable< T >
{
template< typename TD >
HashTable< T > &withTD( TD & ) { return *this; }
void insert( int v ) {
this->t->insert( std::make_pair( v, empty() ) );
}
};
};
template< typename T >
using unordered_set = std::unordered_set< T >;
using A = wrap_set< unordered_set >;
using B = wrap_hashset< CS >;
using C = wrap_hashset< FS >;
using D = wrap_hashset< ConCS >;
using E = wrap_hashset< ConFS >;
template<> struct TN< A > { static const char *n() { return "std"; } };
template<> struct TN< B > { static const char *n() { return "scs"; } };
template<> struct TN< C > { static const char *n() { return "sfs"; } };
template<> struct TN< D > { static const char *n() { return "ccs"; } };
template<> struct TN< E > { static const char *n() { return "cfs"; } };
#define FOR_SEQ(M) M(A) M(B) M(C)
#define SEQ A, B, C
#ifdef BRICKS_HAVE_TBB
#define FOR_PAR(M) M(D) M(E) M(F) M(G)
#define PAR D, E, F, G
template< typename T > using cus = tbb::concurrent_unordered_set< T >;
template< typename T > using chm = tbb::concurrent_hash_map< T, empty >;
using F = wrap_set< cus >;
using G = wrap_map< chm >;
template<> struct TN< F > { static const char *n() { return "cus"; } };
template<> struct TN< G > { static const char *n() { return "chm"; } };
#else
#define FOR_PAR(M) M(D) M(E)
#define PAR D, E
#endif
#define TvT(N) \
template struct Bench< ThreadsVsTypes< N, 50, 4, PAR > >;
TvT(1024)
TvT(16 * 1024)
#define IvTh_PAR(T) \
template struct Bench< ItemsVsThreads< 4, 0, T > >;
template struct Bench< ItemsVsTypes< 1, 0, SEQ, PAR > >;
template struct Bench< ItemsVsTypes< 2, 0, PAR > >;
template struct Bench< ItemsVsTypes< 4, 0, PAR > >;
#define IvR_SEQ(T) \
template struct Bench< ItemsVsReserve< 1, T > >;
#define IvR_PAR(T) \
template struct Bench< ItemsVsReserve< 1, T > >; \
template struct Bench< ItemsVsReserve< 2, T > >; \
template struct Bench< ItemsVsReserve< 4, T > >;
FOR_PAR(IvTh_PAR)
FOR_SEQ(IvR_SEQ)
FOR_PAR(IvR_PAR)
#undef FOR_SEQ
#undef FOR_PAR
#undef SEQ
#undef PAR
#undef IvT_PAR
#undef IvR_SEQ
#undef IvR_PAR
}
}
#endif // benchmarks
#endif
// vim: syntax=cpp tabstop=4 shiftwidth=4 expandtab