// SPDX-License-Identifier: GPL-2.0
#include "sharded_mutex.h"

#include <stdlib.h>

struct sharded_mutex *sharded_mutex__new(size_t num_shards)
{
        struct sharded_mutex *result;
        size_t size;
        unsigned int bits;

        for (bits = 0; ((size_t)1 << bits) < num_shards; bits++)
                ;

        size = sizeof(*result) + sizeof(struct mutex) * (1 << bits);
        result = malloc(size);
        if (!result)
                return NULL;

        result->cap_bits = bits;
        for (size_t i = 0; i < ((size_t)1 << bits); i++)
                mutex_init(&result->mutexes[i]);

        return result;
}

void sharded_mutex__delete(struct sharded_mutex *sm)
{
        for (size_t i = 0; i < ((size_t)1 << sm->cap_bits); i++)
                mutex_destroy(&sm->mutexes[i]);

        free(sm);
}