sync_per_thread Class

Describes a synchronization filter that provides a separate cache object for each thread.

Syntax

template <class Cache>
class sync_per_thread

Parameters

Cache
The type of cache associated with the synchronization filter. It can be cache_chunklist, cache_freelist, or cache_suballoc.

Remarks

Allocators that use sync_per_thread can compare equal even though blocks allocated in one thread cannot be deallocated from another thread. When using one of these allocators memory blocks allocated in one thread should not be made visible to other threads. In practice this means that a container that uses one of these allocators should only be accessed by a single thread.

Member functions

Requirements

Header: <allocators>

Namespace: stdext

sync_per_thread::allocate

Allocates a block of memory.

void *allocate(std::size_t count);

Parameters

count
The number of elements in the array to be allocated.

Remarks

The member function returns the result of a call to cache::allocate(count) on the cache object belonging to the current thread. If no cache object has been allocated for the current thread, it first allocates one.

sync_per_thread::deallocate

Frees a specified number of objects from storage beginning at a specified position.

void deallocate(void* ptr, std::size_t count);

Parameters

ptr
A pointer to the first object to be deallocated from storage.

count
The number of objects to be deallocated from storage.

Remarks

The member function calls deallocate on the cache object belonging to the current thread. If no cache object has been allocated for the current thread, it first allocates one.

sync_per_thread::equals

Compares two caches for equality.

bool equals(const sync<Cache>& Other) const;

Parameters

Cache
The cache object of the synchronization filter.

Other
The cache object to compare for equality.

Return Value

false if no cache object has been allocated for this object or for Other in the current thread. Otherwise it returns the result of applying operator== to the two cache objects.

Remarks

See also

<allocators>