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#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <pthread.h>
#include <unistd.h>
#include <assert.h>
#include <linux/gfp.h>
#include <linux/poison.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <urcu/uatomic.h>
int nr_allocated;
int preempt_count;
int kmalloc_verbose;
struct kmem_cache {
pthread_mutex_t lock;
int size;
int nr_objs;
void *objs;
void (*ctor)(void *);
};
void *kmem_cache_alloc(struct kmem_cache *cachep, int flags)
{
struct radix_tree_node *node;
if (flags & __GFP_NOWARN)
return NULL;
pthread_mutex_lock(&cachep->lock);
if (cachep->nr_objs) {
cachep->nr_objs--;
node = cachep->objs;
cachep->objs = node->private_data;
pthread_mutex_unlock(&cachep->lock);
node->private_data = NULL;
} else {
pthread_mutex_unlock(&cachep->lock);
node = malloc(cachep->size);
if (cachep->ctor)
cachep->ctor(node);
}
uatomic_inc(&nr_allocated);
if (kmalloc_verbose)
printf("Allocating %p from slab\n", node);
return node;
}
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
{
assert(objp);
uatomic_dec(&nr_allocated);
if (kmalloc_verbose)
printf("Freeing %p to slab\n", objp);
pthread_mutex_lock(&cachep->lock);
if (cachep->nr_objs > 10) {
memset(objp, POISON_FREE, cachep->size);
free(objp);
} else {
struct radix_tree_node *node = objp;
cachep->nr_objs++;
node->private_data = cachep->objs;
cachep->objs = node;
}
pthread_mutex_unlock(&cachep->lock);
}
void *kmalloc(size_t size, gfp_t gfp)
{
void *ret = malloc(size);
uatomic_inc(&nr_allocated);
if (kmalloc_verbose)
printf("Allocating %p from malloc\n", ret);
return ret;
}
void kfree(void *p)
{
if (!p)
return;
uatomic_dec(&nr_allocated);
if (kmalloc_verbose)
printf("Freeing %p to malloc\n", p);
free(p);
}
struct kmem_cache *
kmem_cache_create(const char *name, size_t size, size_t offset,
unsigned long flags, void (*ctor)(void *))
{
struct kmem_cache *ret = malloc(sizeof(*ret));
pthread_mutex_init(&ret->lock, NULL);
ret->size = size;
ret->nr_objs = 0;
ret->objs = NULL;
ret->ctor = ctor;
return ret;
}
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