srsLTE/lib/include/srsran/upper/byte_buffer_queue.h

122 lines
3.4 KiB
C++

/**
*
* \section COPYRIGHT
*
* Copyright 2013-2021 Software Radio Systems Limited
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the distribution.
*
*/
/*
* @file byte_buffer_queue.h
*
* @brief Queue of unique pointers to byte buffers used in PDCP and RLC TX queues.
* Uses a blocking queue with bounded capacity to block higher layers
* when pushing uplink traffic
*/
#ifndef SRSRAN_BYTE_BUFFERQUEUE_H
#define SRSRAN_BYTE_BUFFERQUEUE_H
#include "srsran/adt/circular_buffer.h"
#include "srsran/common/block_queue.h"
#include "srsran/common/byte_buffer.h"
#include "srsran/common/common.h"
#include <functional>
#include <pthread.h>
namespace srsran {
class byte_buffer_queue
{
public:
byte_buffer_queue(int capacity = 128) :
queue(capacity, push_callback(unread_bytes, n_sdus), pop_callback(unread_bytes, n_sdus))
{}
void write(unique_byte_buffer_t msg) { queue.push_blocking(std::move(msg)); }
srsran::error_type<unique_byte_buffer_t> try_write(unique_byte_buffer_t&& msg)
{
return queue.try_push(std::move(msg));
}
unique_byte_buffer_t read() { return queue.pop_blocking(); }
bool try_read(unique_byte_buffer_t* msg) { return queue.try_pop(*msg); }
void resize(uint32_t capacity) { queue.set_size(capacity); }
uint32_t size() { return (uint32_t)queue.size(); }
uint32_t get_n_sdus() { return n_sdus; }
uint32_t size_bytes() { return unread_bytes; }
uint32_t size_tail_bytes()
{
uint32_t size_next = 0;
queue.try_call_on_front([&size_next](const unique_byte_buffer_t& front_val) {
if (front_val != nullptr) {
size_next += front_val->N_bytes;
}
});
return size_next;
}
// This is a hack to reset N_bytes counter when queue is corrupted (see line 89)
void reset() { unread_bytes = 0; }
bool is_empty() { return queue.empty(); }
bool is_full() { return queue.full(); }
template <typename F>
bool apply_first(const F& func)
{
return queue.apply_first(func);
}
private:
struct push_callback {
explicit push_callback(std::atomic<uint32_t>& unread_bytes_, std::atomic<uint32_t>& n_sdus_) :
unread_bytes(unread_bytes_), n_sdus(n_sdus_)
{}
void operator()(const unique_byte_buffer_t& msg)
{
unread_bytes.fetch_add(msg->N_bytes, std::memory_order_relaxed);
n_sdus.fetch_add(1, std::memory_order_relaxed);
}
std::atomic<uint32_t>& unread_bytes;
std::atomic<uint32_t>& n_sdus;
};
struct pop_callback {
explicit pop_callback(std::atomic<uint32_t>& unread_bytes_, std::atomic<uint32_t>& n_sdus_) :
unread_bytes(unread_bytes_), n_sdus(n_sdus_)
{}
void operator()(const unique_byte_buffer_t& msg)
{
if (msg == nullptr) {
return;
}
// non-atomic update of both state variables
unread_bytes.fetch_sub(std::min(msg->N_bytes, unread_bytes.load(std::memory_order_relaxed)),
std::memory_order_relaxed);
n_sdus.store(std::max(0, (int32_t)(n_sdus.load(std::memory_order_relaxed)) - 1), std::memory_order_relaxed);
}
std::atomic<uint32_t>& unread_bytes;
std::atomic<uint32_t>& n_sdus;
};
std::atomic<uint32_t> unread_bytes = {0};
std::atomic<uint32_t> n_sdus = {0};
public:
dyn_blocking_queue<unique_byte_buffer_t, push_callback, pop_callback> queue;
};
} // namespace srsran
#endif // SRSRAN_BYTE_BUFFERQUEUE_H