C-Hybrid-TLSF-fixed-heap

C UNIX only hybrid TLSF fixed heap allocator for managing pre-allocated heap memory via an anonymous memory map.

Credits

Implementation is based on Matt Conte's TLSF: https://github.com/mattconte/tlsf

Methods

Signature	Description
Allocator* alloc htfh_create(size_t bytes)	Instantiates an new allocator with default values and creates an anonymous memory map of size bytes as the heap
int htfh_destroy(Allocator* alloc)	Handled freeing of allocator with checking on heap state
void* htfh_malloc(Allocator* alloc, unsigned nbytes)	Allocate memory from the mapped region for a given size
void* htfh_calloc(Allocator* alloc, unsigned count, unsigned nbytes)	Allocate contiguous memory from the mapped region for a given number of elements of given size
void* htfh_realloc(Allocator* alloc, void* ap, unsigned nbytes)	Re-size a given block of memory to a new size, that was previously allocated by htfh_malloc or htfh_calloc.
void htfh_free(Allocator* alloc, void* ap)	Free the memory currently held by the provided pointer to a region of the mapped memory

Error Handling

Errors are handled in the same manner as standard usage of perror(char* prefix) follows, except with a custom method alloc_perror(char* prefix). Any call made with the HTFH methods, should follow with a return value check, in the case on an invalid/erroneous value, alloc_perror(char* prefix) should be called to display the error, file, line number and function name in stderr.

An example of an error being logged as a result of alloc_perror("An error occured: ") is as follows:

An error occured: Managed heap has already been allocated
	at main(/Users/EngineersBox/Desktop/Projects/C:C++/C-fixed-heap-allocator/src/main.c:25)
	at htfh_init(/Users/EngineersBox/Desktop/Projects/C:C++/C-fixed-heap-allocator/src/allocator/tlsf.c:112)

These locations correspond the following:

Main.c:25

// ... snip ...
if (htfh_init(alloc, 16 * 10000) != 0) {
    alloc_perror("An error occured: ");
    return 1;
}
// ... snip ...

Tlsf.c:112

// ... snip ...
} else if (alloc->heap != NULL) {
    set_alloc_errno(HEAP_ALREADY_MAPPED);
    __htfh_lock_unlock_handled(&alloc->mutex);
    return -1;
}
// ... snip ...

Usage

There are two ways to utilise the allocator, one is through handled static construction and dynamic instantiation.

Static

TODO

Dynamic

TODO