You can choose whether or not to allocate emergency memory
that is to be used for throwing a std::bad_alloc exception
when the heap is exhausted.
To allocate emergency memory, you must include the symbol __ARM_exceptions_buffer_required in
the link. A call is then made to __ARM_exceptions_buffer_init() as
part of the exceptions system initialization. The symbol is not
included by default.
The following routines manage the exceptions emergency buffer:
extern "C" void *__ARM_exceptions_buffer_init()Called once during runtime to allocate the emergency buffer memory. It returns a pointer to the emergency buffer memory, or
NULLif no memory is allocated.extern "C" void *__ARM_exceptions_buffer_allocate(void *buffer, size_tsize)Called when an exception is about to be thrown, but there is not enough heap memory available to allocate the exceptions object.
buffer__ARM_exceptions_buffer_init(), orNULLif that routine was not called.__ARM_exceptions_buffer_allocate()returns a pointer tosizeNULLif the allocation is not possible.extern "C" void *__ARM_exceptions_buffer_free(void *buffer, void *addr)Called to free memory possibly allocated by
__ARM_exceptions_buffer_allocate().buffer__ARM_exceptions_buffer_init(), orNULLif that routine was not called. The routine determines whether the passed address has been allocated from the emergency memory buffer, and if so, frees it appropriately, then returns a non-NULLvalue. If the memory ataddr__ARM_exceptions_buffer_allocate(), the routine must returnNULL.
Default definitions of these routines are present in the image,
but you can supply your own versions to override the defaults supplied
by the library. The default routines reserve enough space for a
single std::bad_alloc exceptions object.
If you do not require an emergency buffer, it is safe to redefine
all these routines to return only NULL.
See also
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