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Intel Threading Building Blocks
book

Intel Threading Building Blocks

by James Reinders
July 2007
Intermediate to advanced content levelIntermediate to advanced
332 pages
10h 4m
English
O'Reilly Media, Inc.
Content preview from Intel Threading Building Blocks

Name

Template Class — Template class for associative container with concurrent access.concurrent_hash_map<Key,T,HashCompare>

Synopsis

#include "tbb/concurrent_hash_map.h"

template<typename Key, typename T, typename HashCompare> class concurrent_hash_map;

Description

A concurrent_hash_map maps keys to values in a way that permits multiple threads to concurrently access values. The keys are unordered. The interface resembles typical STL associative containers, but with some differences that are critical to supporting concurrent access.

The Key and T types must model the Copy Constructible Concept.

The Hash Compare type specifies how keys are hashed and compared for equality. It must model the HashCompare Concept defined in Table 5-3.

Table 5-3. HashCompare Concept

Pseudosignature

Semantics

HashCompare::HashCompare( const HashCompare & )

Copy constructor

HashCompare::~HashCompare ()

Destructor

bool HashCompare::equal( const Key& j, const Key& k ) const

True if keys are equal

size_t HashCompare::hash( const Key& k )

Hash code for key

As for most hash tables, if two keys are equal, they must hash to the same hash code. That is, for a given HashCompare h and any two keys j and k, the following assertion must hold: !h.equal(j,k)||h.hash(j)==h.hash(k). The importance of this property is the reason that concurrent_hash_map places key equality and hashing in a single object instead of keeping them as separate objects.

Members

 namespace tbb { template<typename Key, typename T, typename ...
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Publisher Resources

ISBN: 9780596514808Errata Page