Memory Manager Library

This library provides routines for manipulating dynamic memory allocation. Dynamic memory allocation (also known as heap-based memory allocation) is the allocation of memory storage for use in a program during the runtime of that program.
Dynamically allocated memory exists until it is released. This is in contrast to static memory allocation, which has a fixed duration. It is said that an object so allocated has a dynamic lifetime.

The heap memory size can be configured in the Edit Project window. Also, user can override heap memory size in the code, by setting the HEAP_SIZE constant.

MM_Init

Prototype	sub procedure MM_Init()
Description	Initializes the memory manager.
Parameters	None.
Returns	Nothing.
Requires	Nothing.
Example	MM_Init() ' Initializes memory manager
Notes	None.

GetMem

Prototype	sub procedure GetMem(dim byref P as ^byte, dim Size as word)
Description	Allocates a block of memory from the memory Heap.
Parameters	`P:` pointer to the allocated memory block. `Size:` Size of the memory block to be allocated.
Returns	Returns a pointer to the fetched memory (of "Size" bytes) in P, if success; Otherwise 0 (no free blocks of memory are large enough).
Requires	Nothing.
Example	GetMem(ptr,20sizeof(PBuffer)) ' ptr will point to a memory block where PBuffer is allocated*
Notes	None.

Malloc

Prototype	sub function Malloc(dim Size as word) as ^byte
Description	Allocates a block of memory from the memory Heap, returning a pointer to the beginning of the block. The content of the newly allocated block of memory is not initialized, remaining with indeterminate values.
Parameters	`Size:` Size of the memory block to be allocated.
Returns	Returns a pointer to the memory block allocated by the function. If the function failed to allocate the requested block of memory, a zero is returned
Requires	Nothing.
Example	dim p as ^longword ' pointer to longword dim a as longword[100] ' array of longwords p = longword(Malloc(sizeof(a))) ' p will point to a memory block where the array is allocated
Notes	None.

FreeMem

Prototype	sub procedure FreeMem(dim byref P as ^byte, dim Size as word)
Description	This function is used to free memory block allocated by GetMem or Malloc.
Parameters	`P:` variable of any pointer type previously assigned by the GetMem procedure. `Size:` specifies the size in bytes of the dynamic variable to dispose of and should be the same as the one used to GetMem.
Returns	Nothing.
Requires	Nothing.
Example	FreeMem(ptr,20sizeof(PBuffer)) ' ptr will point to a memory block where PBuffer is allocated*
Notes	None.

Free

Prototype	sub procedure Free(dim byref P as ^byte, dim Size as word)
Description	This function is used to free memory block allocated by GetMem or Malloc.
Parameters	`P:` pointer to the memory block `Size:` actual size of the memory block.
Returns	Nothing.
Requires	Nothing.
Example	dim p as ^longword ' pointer to longword dim a as longword[100] ' array of longwords p = longword(Malloc(sizeof(a))) ' p will point to a memory block where the array is allocated Free(p, sizeof(p)) ' frees memory block from the Heap allocated by Malloc, pointed to by the p pointer
Notes	None.

MM_LargestFreeMemBlock

Prototype	sub function MM_LargestFreeMemBlock() as word
Description	This function is used to determine largest available free memory of contiguous memory on the heap.
Parameters	None.
Returns	Returns, after defragmentation of the freelist the size (in bytes) of the largest free block of contiguous memory on the heap.
Requires	Nothing.
Example	dim block as word ... block = MM_LargestFreeMemBlock()
Notes	None.

MM_TotalFreeMemSize

Prototype	sub function MM_TotalFreeMemSize() as word
Description	This function is used to determine total free memory size on the heap.
Parameters	None.
Returns	Returns the size (in bytes) of the total free memory on the heap.
Requires	Nothing.
Example	dim total as word ... total = MM_TotalFreeMemSize()
Notes	None.

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