mm.h

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#pragma once

#include <stdlib.h>
#include <sys/mman.h>
#include <pthread.h>
#include <core/core.h>
#include <arch/atomic.h>
#include <mm/dymelor.h>

struct segment {
    unsigned char *base;
    unsigned char *brk;
};

struct buddy {
    spinlock_t lock;
    size_t size;
    size_t longest[] __attribute__((aligned(sizeof(size_t))));
};

extern size_t __page_size;
#define PAGE_SIZE ({ \
            if(unlikely(__page_size == 0))\
                __page_size = getpagesize();\
            __page_size;\
          })

struct slab_header {
#ifndef NDEBUG
    atomic_t presence;
#endif
    struct slab_header *prev, *next;
    uint64_t slots;
    uintptr_t refcount;
    struct slab_header *page;
    uint8_t data[] __attribute__((aligned(sizeof(void *))));
};

struct slab_chain {
    spinlock_t lock;
    size_t itemsize, itemcount;
    size_t slabsize, pages_per_alloc;
    uint64_t initial_slotmask, empty_slotmask;
    uintptr_t alignment_mask;
    struct slab_header *partial, *empty, *full;
};

struct memory_map {
    malloc_state *m_state;
    struct buddy *buddy;
    struct slab_chain *slab;
    struct segment *segment;
};

#define PER_LP_PREALLOCATED_MEMORY (262144L * PAGE_SIZE)    // This should be power of 2 multiplied by a page size. This is 1GB per LP.
#define BUDDY_GRANULARITY PAGE_SIZE // This is the smallest chunk released by the buddy in bytes. PER_LP_PREALLOCATED_MEMORY/BUDDY_GRANULARITY must be integer and a power of 2

extern bool allocator_init(void);
extern void allocator_fini(void);
extern void segment_init(void);
extern struct segment *get_segment(GID_t i);
extern void *get_base_pointer(GID_t gid);

extern void initialize_memory_map(struct lp_struct *lp);
extern void finalize_memory_map(struct lp_struct *lp);

extern struct buddy *buddy_new(struct lp_struct *,
                   unsigned long num_of_fragments);
void buddy_destroy(struct buddy *);

extern struct slab_chain *slab_init(const size_t itemsize);
extern void *slab_alloc(struct slab_chain *const sch);
extern void slab_free(struct slab_chain *const sch, const void *const addr);