This class defines a concrete "counting" allocator mechanism that implements the bslma::Allocator protocol, and provides instrumentation to track: (1) the number of bytes currently in use, and (2) the cumulative number of bytes that have ever been allocated. The accumulated statistics are based solely on the number of bytes requested (see allocate).
Note that, like many other allocators, this allocator relies on the currently installed default allocator (see bslma_default). Clients may, however, override this allocator by supplying (at construction) any other allocator implementing the bslma::Allocator protocol provided that it is fully thread-safe.
| Name | Description |
|---|---|
bslma::Allocator | This protocol class provides a pure abstract interface and contract for clients and suppliers of raw memory. If the requested memory cannot be returned, the contract requires that an std::bad_alloc exception be thrown. Note that memory is guaranteed to be sufficiently aligned for any object of the requested size on the current platform, which may be less than the maximal alignment guarantee afforded by global operator new. |
| Name | Description |
|---|---|
size_type | Alias for an unsigned integral type capable of representing the number of bytes in this platform's virtual address space. |
| Name | Description |
|---|---|
CountingAllocator [constructor] | Constructors |
~CountingAllocator [destructor] [virtual] | Destroy this allocator object. Note that destroying this allocator has no effect on any outstanding allocated memory. |
operator= | |
allocate | allocate overloads |
deallocate | Return the memory block at the specified address back to this allocator. If address is 0, this function has no effect (e.g., on allocation statistics). Otherwise, decrease the number of currently allocated bytes by the size originally requested for the block. The behavior is undefined unless address was allocated using this allocator object and has not already been deallocated. |
deleteObject | deleteObject overloads |
deleteObjectRaw | deleteObjectRaw overloads |
is_equal | |
name | Return the name of this counting allocator, or 0 if no name was specified at construction. |
numBytesInUse | Return the number of bytes currently allocated from this object. Note that numBytesInUse() <= numBytesTotal(). |
numBytesTotal | Return the cumulative number of bytes ever allocated from this object. Note that numBytesInUse() <= numBytesTotal(). |
print | Write the accumulated state information held in this allocator to the specified stream in some reasonable (multi-line) format, and return a reference to stream. |
| Name | Description |
|---|---|
throwBadAlloc | Throw std::bad_alloc if exceptions are enabled or abort the program otherwise. Derived classes and helper functions will typically call this function when they are unable to satisfy an allocation request. This function never returns. |
| Name | Description |
|---|---|
do_allocate [virtual] | Return a newly allocated block of memory of (at least) the specified positive bytes and having at least the specified alignment. Unless overriden in a derived class, the return value is this->allocate(bytes). If this allocator cannot return the requested number of bytes or cannot satisfy the alignment request, then it will throw a std::bad_alloc exception in an exception-enabled build, or else will abort the program in a non-exception build. Unless overriden in a derived class, this function will forward the allocation request to the allocate virtual function, padding bytes and adjusting the return value as necessary to ensure sufficient alignment. Note that if bytes is 0, the same non-null value will be returned every time. |
do_deallocate [virtual] | Return the memory block at the specified p address, having the specified bytes and specified alignment, back to this allocator. Unless overriden in a derived class, this function will forward the deallocation request to the deallocate virtual function, padding bytes and adjusting p as necessary to account for alignment values other than the natural alignment for an object of size bytes. The behavior is undefined unless address is a block allocated from this allocator object using the same bytes and alignment and not already deallocated. |
do_is_equal [virtual] | Return true if this allocator is equal to the specified other allocator, meaning (at least) that a memory block allocated by one can be deallocated by the other; otherwise return false. Unless overriden, this method returns this == &other. |