// This file is a part of the IncludeOS unikernel - www.includeos.org

//

// Copyright 2015-2016 Oslo and Akershus University College of Applied Sciences

// and Alfred Bratterud

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//#define DEBUG

//#undef NO_DEBUG

#include <debug>

#include <cassert>

#include <malloc.h>

#include <cstdio>

#include <net/buffer_store.hpp>

#include <kernel/syscalls.hpp>

#include <common>

#define PAGE_SIZE 0x1000

namespace net {

BufferStore::BufferStore(size_t num, size_t bufsize) :

poolsize_ {num * bufsize},

bufsize_ {bufsize}

{

assert(num != 0);

assert(bufsize != 0);

const size_t DATA_SIZE = poolsize_;

this->pool_ = (buffer_t) memalign(PAGE_SIZE, DATA_SIZE);

assert(this->pool_);

available_.reserve(num);

for (buffer_t b = pool_end()-bufsize; b >= pool_begin(); b -= bufsize) {

available_.push_back(b);

}

assert(available() == num);

// verify that the "first" buffer is the start of the pool

assert(available_.back() == pool_);

}

BufferStore::~BufferStore() {

free(this->pool_);

}

BufferStore::buffer_t BufferStore::get_buffer() {

if (UNLIKELY(available_.empty())) {

panic("<BufferStore> Storage pool full! Don't know how to increase pool size yet.\n");

}

auto addr = available_.back();

available_.pop_back();

return addr;

}

void BufferStore::release(void* addr)

{

buffer_t buff = (buffer_t) addr;

debug("Release %p...", buff);

// expensive: is_buffer(buff)

if (LIKELY(is_from_pool(buff))) {

available_.push_back(buff);

debug("released\n");

return;

}

// buffer not owned by bufferstore, so just delete it?

debug("deleted\n");

delete[] buff;

}

} //< namespace net