BloombergLP::bslma::MallocFreeAllocator

Name

Description

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

MallocFreeAllocator [constructor]

Create an allocator that uses std::malloc and std::free to supply memory. Note that all objects of this class share the same underlying resource.

~MallocFreeAllocator [destructor] [virtual]

Destroy this allocator. Note that the behavior of destroying an allocator while memory is allocated from it is not specified. (Unless you know that it is valid to do so, don't!)

operator=

allocate

Return a newly allocated block of memory of (at least) the specified positive size (in bytes). If size is 0, a null pointer is returned with no other effect. If this allocator cannot return the requested number of bytes, then it will return a null pointer. The behavior is undefined unless 0 <= size. Note that the alignment of the address returned is the maximum alignment for any type defined on this platform. Also note that std::malloc is not called when size is 0 (in order to avoid having to acquire a lock, and potential contention in multi‐treaded programs).

deallocate

Return the memory block at the specified address back to this allocator. If address is 0, this function has no effect. The behavior is undefined unless address was allocated using this allocator object and has not already been deallocated. Note that std::free is not called when address is 0 (in order to avoid having to acquire a lock, and potential contention in multi‐treaded programs).

deleteObject

deleteObject overloads

deleteObjectRaw

deleteObjectRaw overloads

is_equal

Name

Description

singleton

Return a reference to a valid object of this class. Note that this object is guaranteed to be valid from the time of this call onward (i.e., not just until exiting main).

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.