Files
allwpilib/ntcore/src/main/native/cpp/InstanceImpl.cpp
Peter Johnson 8f1f64ffb6 Remove year from file copyright message (NFC) (#2972)
Also update copyright to include "and other WPILib contributors" and clarify
license referral language to not be restricted to FIRST teams.
2020-12-26 14:12:05 -08:00

107 lines
2.7 KiB
C++

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.
#include "InstanceImpl.h"
using namespace nt;
std::atomic<int> InstanceImpl::s_default{-1};
std::atomic<InstanceImpl*> InstanceImpl::s_fast_instances[10];
wpi::UidVector<InstanceImpl*, 10> InstanceImpl::s_instances;
wpi::mutex InstanceImpl::s_mutex;
using namespace std::placeholders;
InstanceImpl::InstanceImpl(int inst)
: logger_impl(inst),
logger(std::bind(&LoggerImpl::Log, &logger_impl, _1, _2, _3, _4)),
connection_notifier(inst),
entry_notifier(inst, logger),
rpc_server(inst, logger),
storage(entry_notifier, rpc_server, logger),
dispatcher(storage, connection_notifier, logger),
ds_client(dispatcher, logger) {
logger.set_min_level(logger_impl.GetMinLevel());
}
InstanceImpl::~InstanceImpl() { logger.SetLogger(nullptr); }
InstanceImpl* InstanceImpl::GetDefault() { return Get(GetDefaultIndex()); }
InstanceImpl* InstanceImpl::Get(int inst) {
if (inst < 0) return nullptr;
// fast path, just an atomic read
if (static_cast<unsigned int>(inst) <
(sizeof(s_fast_instances) / sizeof(s_fast_instances[0]))) {
InstanceImpl* ptr = s_fast_instances[inst];
if (ptr) return ptr;
}
// slow path
std::scoped_lock lock(s_mutex);
// static fast-path block
if (static_cast<unsigned int>(inst) <
(sizeof(s_fast_instances) / sizeof(s_fast_instances[0]))) {
// double-check
return s_fast_instances[inst];
}
// vector
if (static_cast<unsigned int>(inst) < s_instances.size()) {
return s_instances[inst];
}
// doesn't exist
return nullptr;
}
int InstanceImpl::GetDefaultIndex() {
int inst = s_default;
if (inst >= 0) return inst;
// slow path
std::scoped_lock lock(s_mutex);
// double-check
inst = s_default;
if (inst >= 0) return inst;
// alloc and save
inst = AllocImpl();
s_default = inst;
return inst;
}
int InstanceImpl::Alloc() {
std::scoped_lock lock(s_mutex);
return AllocImpl();
}
int InstanceImpl::AllocImpl() {
unsigned int inst = s_instances.emplace_back(nullptr);
InstanceImpl* ptr = new InstanceImpl(inst);
s_instances[inst] = ptr;
if (inst < (sizeof(s_fast_instances) / sizeof(s_fast_instances[0]))) {
s_fast_instances[inst] = ptr;
}
return static_cast<int>(inst);
}
void InstanceImpl::Destroy(int inst) {
std::scoped_lock lock(s_mutex);
if (inst < 0 || static_cast<unsigned int>(inst) >= s_instances.size()) return;
if (static_cast<unsigned int>(inst) <
(sizeof(s_fast_instances) / sizeof(s_fast_instances[0]))) {
s_fast_instances[inst] = nullptr;
}
delete s_instances[inst];
s_instances.erase(inst);
}