You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
741 lines
27 KiB
741 lines
27 KiB
#pragma once
|
|
|
|
#include <iostream>
|
|
|
|
#include <unordered_map>
|
|
#include <shared_mutex>
|
|
#include <mutex>
|
|
#include <memory>
|
|
|
|
#include <sched.h>
|
|
#include <numa.h>
|
|
#include <numaif.h>
|
|
|
|
#include <dml/dml.hpp>
|
|
|
|
namespace dml {
|
|
inline const std::string StatusCodeToString(const dml::status_code code) {
|
|
switch (code) {
|
|
case dml::status_code::ok: return "ok";
|
|
case dml::status_code::false_predicate: return "false predicate";
|
|
case dml::status_code::partial_completion: return "partial completion";
|
|
case dml::status_code::nullptr_error: return "nullptr error";
|
|
case dml::status_code::bad_size: return "bad size";
|
|
case dml::status_code::bad_length: return "bad length";
|
|
case dml::status_code::inconsistent_size: return "inconsistent size";
|
|
case dml::status_code::dualcast_bad_padding: return "dualcast bad padding";
|
|
case dml::status_code::bad_alignment: return "bad alignment";
|
|
case dml::status_code::buffers_overlapping: return "buffers overlapping";
|
|
case dml::status_code::delta_delta_empty: return "delta delta empty";
|
|
case dml::status_code::batch_overflow: return "batch overflow";
|
|
case dml::status_code::execution_failed: return "execution failed";
|
|
case dml::status_code::unsupported_operation: return "unsupported operation";
|
|
case dml::status_code::queue_busy: return "queue busy";
|
|
case dml::status_code::error: return "unknown error";
|
|
case dml::status_code::config_error: return "config error";
|
|
default: return "unhandled error";
|
|
}
|
|
}
|
|
}
|
|
|
|
namespace dsacache {
|
|
class Cache;
|
|
|
|
/*
|
|
* Class Description:
|
|
* Holds all required information on one cache entry and is used
|
|
* both internally by the Cache and externally by the user.
|
|
*
|
|
* Important Usage Notes:
|
|
* The pointer is only updated in WaitOnCompletion() which
|
|
* therefore must be called by the user at some point in order
|
|
* to use the cached data. Using this class as T for
|
|
* std::shared_ptr<T> is not recommended as references are
|
|
* already counted internally.
|
|
*
|
|
* Cache Lifetime:
|
|
* As long as the instance is referenced, the pointer it stores
|
|
* is guaranteed to be either nullptr or pointing to a valid copy.
|
|
*
|
|
* Implementation Detail:
|
|
* Performs self-reference counting with a shared atomic integer.
|
|
* Therefore on creating a copy the reference count is increased
|
|
* and with the destructor it is deacresed. If the last copy is
|
|
* destroyed the actual underlying data is freed and all shared
|
|
* variables deleted.
|
|
*
|
|
* Notes on Thread Safety:
|
|
* Class is thread safe in any possible state and performs
|
|
* reference counting and deallocation itself entirely atomically.
|
|
*/
|
|
|
|
class CacheData {
|
|
public:
|
|
using dml_handler = dml::handler<dml::mem_copy_operation, std::allocator<uint8_t>>;
|
|
|
|
private:
|
|
static constexpr uint64_t maxptr = 0xffff'ffff'ffff'ffff;
|
|
|
|
// set to false if we do not own the cache pointer
|
|
bool delete_ = false;
|
|
|
|
// data source and size of the block
|
|
uint8_t* src_;
|
|
size_t size_;
|
|
|
|
// global reference counting object
|
|
std::atomic<int32_t>* active_;
|
|
|
|
// global cache-location pointer
|
|
std::atomic<uint8_t*>* cache_;
|
|
|
|
// object-local incomplete cache location pointer
|
|
// contract: only access when being in sole posession of handlers
|
|
uint8_t** incomplete_cache_;
|
|
|
|
// dml handler vector pointer which is used
|
|
// to wait on caching task completion
|
|
std::atomic<std::vector<dml_handler>*>* handlers_;
|
|
|
|
// deallocates the global cache-location
|
|
// and invalidates it
|
|
void Deallocate();
|
|
|
|
size_t GetSize() const { return size_; }
|
|
uint8_t* GetSource() const { return src_; }
|
|
int32_t GetRefCount() const { return active_->load(); }
|
|
void SetTaskHandlersAndCache(uint8_t* cache, std::vector<dml_handler>* handlers);
|
|
|
|
// initializes the class after which it is thread safe
|
|
// but may only be destroyed safely after setting handlers
|
|
void Init();
|
|
|
|
friend Cache;
|
|
|
|
public:
|
|
CacheData(uint8_t* data, const size_t size);
|
|
CacheData(const CacheData& other);
|
|
~CacheData();
|
|
|
|
// waits on completion of caching operations
|
|
// for this task and is safe to be called in
|
|
// any state of the object
|
|
void WaitOnCompletion();
|
|
|
|
// returns the cache data location for this
|
|
// instance which is valid as long as the
|
|
// instance is alive - !!! this may also
|
|
// yield a nullptr !!!
|
|
uint8_t* GetDataLocation() const { return cache_->load(); }
|
|
};
|
|
|
|
/*
|
|
* Class Description:
|
|
* Class will handle access to data through internal copies.
|
|
* These are obtained via work submission to the Intel DSA which takes
|
|
* care of asynchronously duplicating the data. The user will define
|
|
* where these copies lie and which system nodes will perform the copy.
|
|
* This is done through policy functions set during initialization.
|
|
*
|
|
* Placement Policy:
|
|
* The Placement Policy Function decides on which node a particular
|
|
* entry is to be placed, given the current executing node and the
|
|
* data source node and data size. This in turn means that for one
|
|
* datum, multiple cached copies may exist at one time.
|
|
*
|
|
* Cache Lifetime:
|
|
* When accessing the cache, a CacheData-object will be returned.
|
|
* As long as this object lives, the pointer which it holds is
|
|
* guaranteed to be either nullptr or a valid copy. When destroyed
|
|
* the entry is marked for deletion which is only carried out
|
|
* when system memory pressure drives an automated cache flush.
|
|
*
|
|
* Restrictions:
|
|
* - Overlapping Pointers may lead to undefined behaviour during
|
|
* manual cache invalidation which should not be used if you
|
|
* intend to have these types of pointers
|
|
* - Cache Invalidation may only be performed manually and gives
|
|
* no ordering guarantees. Therefore, it is the users responsibility
|
|
* to ensure that results after invalidation have been generated
|
|
* using the latest state of data. The cache is best suited
|
|
* to static data.
|
|
*
|
|
* Notes on Thread Safety:
|
|
* - Cache is completely thread-safe after initialization
|
|
* - CacheData-class will handle deallocation of data itself by
|
|
* performing self-reference-counting atomically and only
|
|
* deallocating if the last reference is destroyed
|
|
* - The internal cache state has one lock which is either
|
|
* acquired shared for reading the state (upon accessing an already
|
|
* cached element) or unique (accessing a new element, flushing, invalidating)
|
|
* - Waiting on copy completion is done over an atomic-wait in copies
|
|
* of the original CacheData-instance
|
|
* - Overall this class may experience performance issues due to the use
|
|
* of locking (in any configuration), lock contention (worsens with higher
|
|
* core count, node count and utilization) and atomics (worse in the same
|
|
* situations as lock contention)
|
|
*
|
|
* Improving Performance:
|
|
* When data is never shared between threads or memory size for the cache is
|
|
* not an issue you may consider having one Cache-instance per thread and removing
|
|
* the lock in Cache and modifying the reference counting and waiting mechanisms
|
|
* of CacheData accordingly (although this is high effort and will yield little due
|
|
* to the atomics not being shared among cores/nodes).
|
|
* Otherwise, one Cache-instance per node could also be considered. This will allow
|
|
* the placement policy function to be barebones and reduces the lock contention and
|
|
* synchronization impact of the atomic variables.
|
|
*/
|
|
|
|
class Cache {
|
|
public:
|
|
// cache policy is defined as a type here to allow flexible usage of the cacher
|
|
// given a numa destination node (where the data will be needed), the numa source
|
|
// node (current location of the data) and the data size, this function should
|
|
// return optimal cache placement
|
|
// dst node and returned value can differ if the system, for example, has HBM
|
|
// attached accessible directly to node n under a different node id m
|
|
typedef int (CachePolicy)(const int numa_dst_node, const int numa_src_node, const size_t data_size);
|
|
|
|
// copy policy specifies the copy-executing nodes for a given task
|
|
// which allows flexibility in assignment for optimizing raw throughput
|
|
// or choosing a conservative usage policy
|
|
typedef std::vector<int> (CopyPolicy)(const int numa_dst_node, const int numa_src_node, const size_t data_size);
|
|
|
|
private:
|
|
// mutex for accessing the cache state map
|
|
|
|
|
|
// map from [dst-numa-node,map2]
|
|
// map2 from [data-ptr,cache-structure]
|
|
|
|
struct LockedNodeCacheState {
|
|
std::shared_mutex cache_mutex_;
|
|
std::unordered_map<uint8_t*, CacheData> node_cache_state_;
|
|
};
|
|
|
|
std::unordered_map<uint8_t, LockedNodeCacheState*> cache_state_;
|
|
|
|
CachePolicy* cache_policy_function_ = nullptr;
|
|
CopyPolicy* copy_policy_function_ = nullptr;
|
|
|
|
// function used to submit a copy task on a specific node to the dml
|
|
// engine on that node - will change the current threads node assignment
|
|
// to achieve this so take care to restore this
|
|
dml::handler<dml::mem_copy_operation, std::allocator<uint8_t>> ExecuteCopy(
|
|
const uint8_t* src, uint8_t* dst, const size_t size, const int node
|
|
) const;
|
|
|
|
// allocates the required memory on the destination node
|
|
// and then submits task to the dml library for processing
|
|
// and attaches the handlers to the cache data structure
|
|
void SubmitTask(CacheData* task, const int dst_node, const int src_node);
|
|
|
|
// querries the policy functions for the given data and size
|
|
// to obtain destination cache node, also returns the datas
|
|
// source node for further usage
|
|
// output may depend on the calling threads node assignment
|
|
// as this is set as the "optimal placement" node
|
|
void GetCacheNode(uint8_t* src, const size_t size, int* OUT_DST_NODE, int* OUT_SRC_NODE) const;
|
|
|
|
// allocates memory of size "size" on the numa node "node"
|
|
// and returns nullptr if this is not possible, also may
|
|
// try to flush the cache of the requested node to
|
|
// alleviate encountered shortage
|
|
uint8_t* AllocOnNode(const size_t size, const int node);
|
|
|
|
// checks whether the cache contains an entry for
|
|
// the given data in the given memory node and
|
|
// returns it, otherwise returns nullptr
|
|
std::unique_ptr<CacheData> GetFromCache(uint8_t* src, const size_t size, const int dst_node);
|
|
|
|
public:
|
|
~Cache();
|
|
Cache() = default;
|
|
Cache(const Cache& other) = delete;
|
|
|
|
// initializes the cache with the two policy functions
|
|
// only after this is it safe to use in a threaded environment
|
|
void Init(CachePolicy* cache_policy_function, CopyPolicy* copy_policy_function);
|
|
|
|
// function to perform data access through the cache
|
|
std::unique_ptr<CacheData> Access(uint8_t* data, const size_t size);
|
|
|
|
// flushes the cache of inactive entries
|
|
// if node is -1 then the whole cache is
|
|
// checked and otherwise the specified
|
|
// node - no checks on node validity
|
|
void Flush(const int node = -1);
|
|
|
|
// forces out all entries from the
|
|
// cache and therefore will also "forget"
|
|
// still-in-use entries, these will still
|
|
// be properly deleted, but the cache
|
|
// will be fresh - use for testing
|
|
void Clear();
|
|
|
|
void Invalidate(uint8_t* data);
|
|
};
|
|
}
|
|
|
|
inline void dsacache::Cache::Clear() {
|
|
for (auto& nc : cache_state_) {
|
|
std::unique_lock<std::shared_mutex> lock(nc.second->cache_mutex_);
|
|
nc.second->node_cache_state_.clear();
|
|
}
|
|
}
|
|
|
|
inline void dsacache::Cache::Init(CachePolicy* cache_policy_function, CopyPolicy* copy_policy_function) {
|
|
cache_policy_function_ = cache_policy_function;
|
|
copy_policy_function_ = copy_policy_function;
|
|
|
|
// initialize numa library
|
|
|
|
numa_available();
|
|
|
|
// obtain all available nodes
|
|
// and those we may allocate
|
|
// memory on
|
|
|
|
const int nodes_max = numa_num_configured_nodes();
|
|
const bitmask* valid_nodes = numa_get_mems_allowed();
|
|
|
|
// prepare the cache state with entries
|
|
// for all given nodes
|
|
|
|
for (int node = 0; node < nodes_max; node++) {
|
|
if (numa_bitmask_isbitset(valid_nodes, node)) {
|
|
void* block = numa_alloc_onnode(sizeof(LockedNodeCacheState), node);
|
|
auto* state = new(block)LockedNodeCacheState;
|
|
cache_state_.insert({node,state});
|
|
}
|
|
}
|
|
}
|
|
|
|
inline std::unique_ptr<dsacache::CacheData> dsacache::Cache::Access(uint8_t* data, const size_t size) {
|
|
// get destination numa node for the cache
|
|
|
|
int dst_node = -1;
|
|
int src_node = -1;
|
|
|
|
GetCacheNode(data, size, &dst_node, &src_node);
|
|
|
|
// TODO: at this point it could be beneficial to check whether
|
|
// TODO: the given destination node is present as an entry
|
|
// TODO: in the cache state to see if it is valid
|
|
|
|
// check whether the data is already cached
|
|
|
|
std::unique_ptr<CacheData> task = GetFromCache(data, size, dst_node);
|
|
|
|
if (task != nullptr) {
|
|
return std::move(task);
|
|
}
|
|
|
|
// at this point the requested data is not present in cache
|
|
// and we create a caching task for it
|
|
|
|
task = std::make_unique<CacheData>(data, size);
|
|
|
|
{
|
|
LockedNodeCacheState* local_cache_state = cache_state_[dst_node];
|
|
|
|
std::unique_lock<std::shared_mutex> lock(local_cache_state->cache_mutex_);
|
|
|
|
const auto state = local_cache_state->node_cache_state_.emplace(task->GetSource(), *task);
|
|
|
|
// if state.second is false then no insertion took place
|
|
// which means that concurrently whith this thread
|
|
// some other thread must have accessed the same
|
|
// resource in which case we return the other
|
|
// threads data cache structure
|
|
|
|
if (!state.second) {
|
|
std::cout << "[!] Found another cache instance for 0x" << std::hex << (uint64_t)task->GetSource() << std::dec << std::endl;
|
|
return std::move(std::make_unique<CacheData>(state.first->second));
|
|
}
|
|
|
|
// initialize the task now for thread safety
|
|
// as we are now sure that we will submit work
|
|
// to it and will not delete it beforehand
|
|
|
|
task->Init();
|
|
}
|
|
|
|
SubmitTask(task.get(), dst_node, src_node);
|
|
|
|
return std::move(task);
|
|
}
|
|
|
|
inline uint8_t* dsacache::Cache::AllocOnNode(const size_t size, const int node) {
|
|
// allocate data on this node and flush the unused parts of the
|
|
// cache if the operation fails and retry once
|
|
// TODO: smarter flush strategy could keep some stuff cached
|
|
|
|
// check currently free memory to see if the data fits
|
|
|
|
long long int free_space = 0;
|
|
numa_node_size64(node, &free_space);
|
|
|
|
if (free_space < size) {
|
|
std::cout << "[!] Memory shortage when allocating " << size << "B on node " << node << std::endl;
|
|
|
|
// dst node lacks memory space so we flush the cache for this
|
|
// node hoping to free enough currently unused entries to make
|
|
// the second allocation attempt successful
|
|
|
|
Flush(node);
|
|
|
|
// re-test by getting the free space and checking again
|
|
|
|
numa_node_size64(node, &free_space);
|
|
|
|
if (free_space < size) {
|
|
std::cout << "[x] Memory shortage after flush when allocating " << size << "B on node " << node << std::endl;
|
|
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
uint8_t* dst = reinterpret_cast<uint8_t*>(numa_alloc_onnode(size, node));
|
|
|
|
if (dst == nullptr) {
|
|
std::cout << "[x] Allocation try failed for " << size << "B on node " << node << std::endl;
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
return dst;
|
|
}
|
|
|
|
inline void dsacache::Cache::SubmitTask(CacheData* task, const int dst_node, const int src_node) {
|
|
uint8_t* dst = AllocOnNode(task->GetSize(), dst_node);
|
|
|
|
if (dst == nullptr) {
|
|
std::cout << "[x] Allocation failed so we can not cache" << std::endl;
|
|
return;
|
|
}
|
|
|
|
// querry copy policy function for the nodes to use for the copy
|
|
|
|
const std::vector<int> executing_nodes = copy_policy_function_(dst_node, src_node, task->GetSize());
|
|
const size_t task_count = executing_nodes.size();
|
|
|
|
// each task will copy one fair part of the total size
|
|
// and in case the total size is not a factor of the
|
|
// given task count the last node must copy the remainder
|
|
|
|
const size_t size = task->GetSize() / task_count;
|
|
const size_t last_size = size + task->GetSize() % task_count;
|
|
|
|
// save the current numa node mask to restore later
|
|
// as executing the copy task will place this thread
|
|
// on a different node
|
|
|
|
bitmask* nodemask = numa_get_run_node_mask();
|
|
|
|
auto handlers = new std::vector<CacheData::dml_handler>();
|
|
|
|
for (uint32_t i = 0; i < task_count; i++) {
|
|
const size_t local_size = i + 1 == task_count ? size : last_size;
|
|
const size_t local_offset = i * size;
|
|
const uint8_t* local_src = task->GetSource() + local_offset;
|
|
uint8_t* local_dst = dst + local_offset;
|
|
|
|
handlers->emplace_back(ExecuteCopy(local_src, local_dst, local_size, executing_nodes[i]));
|
|
}
|
|
|
|
task->SetTaskHandlersAndCache(dst, handlers);
|
|
|
|
// restore the previous nodemask
|
|
|
|
numa_run_on_node_mask(nodemask);
|
|
numa_free_nodemask(nodemask);
|
|
}
|
|
|
|
inline dml::handler<dml::mem_copy_operation, std::allocator<uint8_t>> dsacache::Cache::ExecuteCopy(
|
|
const uint8_t* src, uint8_t* dst, const size_t size, const int node
|
|
) const {
|
|
numa_run_on_node(node);
|
|
|
|
dml::const_data_view srcv = dml::make_view(src, size);
|
|
dml::data_view dstv = dml::make_view(dst, size);
|
|
|
|
return dml::submit<dml::hardware>(dml::mem_copy.block_on_fault(), srcv, dstv);
|
|
}
|
|
|
|
inline void dsacache::Cache::GetCacheNode(uint8_t* src, const size_t size, int* OUT_DST_NODE, int* OUT_SRC_NODE) const {
|
|
// obtain numa node of current thread to determine where the data is needed
|
|
|
|
const int current_cpu = sched_getcpu();
|
|
const int current_node = numa_node_of_cpu(current_cpu);
|
|
|
|
// obtain node that the given data pointer is allocated on
|
|
|
|
*OUT_SRC_NODE = -1;
|
|
get_mempolicy(OUT_SRC_NODE, NULL, 0, (void*)src, MPOL_F_NODE | MPOL_F_ADDR);
|
|
|
|
// querry cache policy function for the destination numa node
|
|
|
|
*OUT_DST_NODE = cache_policy_function_(current_node, *OUT_SRC_NODE, size);
|
|
}
|
|
|
|
inline void dsacache::Cache::Flush(const int node) {
|
|
// this lambda is used because below we have two code paths that
|
|
// flush nodes, either one single or all successively
|
|
|
|
const auto FlushNode = [](std::unordered_map<uint8_t*,CacheData>& map) {
|
|
// begin at the front of the map
|
|
|
|
auto it = map.begin();
|
|
|
|
// loop until we reach the end of the map
|
|
|
|
while (it != map.end()) {
|
|
// if the iterator points to an inactive element
|
|
// then we may erase it
|
|
|
|
if (it->second.GetRefCount() <= 1) {
|
|
// erase the iterator from the map
|
|
|
|
map.erase(it);
|
|
|
|
// as the erasure invalidated out iterator
|
|
// we must start at the beginning again
|
|
|
|
it = map.begin();
|
|
}
|
|
else {
|
|
// if element is active just move over to the next one
|
|
|
|
it++;
|
|
}
|
|
}
|
|
};
|
|
|
|
// we require exclusive lock as we modify the cache state
|
|
// node == -1 means that cache on all nodes should be flushed
|
|
|
|
if (node == -1) {
|
|
for (auto& nc : cache_state_) {
|
|
std::unique_lock<std::shared_mutex> lock(nc.second->cache_mutex_);
|
|
FlushNode(nc.second->node_cache_state_);
|
|
}
|
|
}
|
|
else {
|
|
std::unique_lock<std::shared_mutex> lock(cache_state_[node]->cache_mutex_);
|
|
FlushNode(cache_state_[node]->node_cache_state_);
|
|
}
|
|
}
|
|
|
|
inline std::unique_ptr<dsacache::CacheData> dsacache::Cache::GetFromCache(uint8_t* src, const size_t size, const int dst_node) {
|
|
// the best situation is if this data is already cached
|
|
// which we check in an unnamed block in which the cache
|
|
// is locked for reading to prevent another thread
|
|
// from marking the element we may find as unused and
|
|
// clearing it
|
|
|
|
LockedNodeCacheState* local_cache_state = cache_state_[dst_node];
|
|
|
|
// lock the cache state in shared-mode because we read
|
|
|
|
std::shared_lock<std::shared_mutex> lock(local_cache_state->cache_mutex_);
|
|
|
|
// search for the data in our cache state structure at the given node
|
|
|
|
const auto search = local_cache_state->node_cache_state_.find(src);
|
|
|
|
// if the data is in our structure we continue
|
|
|
|
if (search != local_cache_state->node_cache_state_.end()) {
|
|
|
|
// now check whether the sizes match
|
|
|
|
if (search->second.GetSize() >= size) {
|
|
// return a unique copy of the entry which uses the object
|
|
// lifetime and destructor to safely handle deallocation
|
|
|
|
return std::move(std::make_unique<CacheData>(search->second));
|
|
}
|
|
else {
|
|
// if the sizes missmatch then we clear the current entry from cache
|
|
// which will cause its deletion only after the last possible outside
|
|
// reference is also destroyed
|
|
|
|
local_cache_state->node_cache_state_.erase(search);
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
void dsacache::Cache::Invalidate(uint8_t* data) {
|
|
// as the cache is modified we must obtain a unique writers lock
|
|
// loop through all per-node-caches available
|
|
|
|
for (auto node : cache_state_) {
|
|
std::unique_lock<std::shared_mutex> lock(node.second->cache_mutex_);
|
|
|
|
// search for an entry for the given data pointer
|
|
|
|
auto search = node.second->node_cache_state_.find(data);
|
|
|
|
if (search != node.second->node_cache_state_.end()) {
|
|
// if the data is represented in-cache
|
|
// then it will be erased to re-trigger
|
|
// caching on next access
|
|
|
|
node.second->node_cache_state_.erase(search);
|
|
}
|
|
}
|
|
}
|
|
|
|
inline dsacache::Cache::~Cache() {
|
|
for (auto node : cache_state_) {
|
|
node.second->~LockedNodeCacheState();
|
|
numa_free(reinterpret_cast<void*>(node.second), sizeof(LockedNodeCacheState));
|
|
}
|
|
}
|
|
|
|
inline dsacache::CacheData::CacheData(uint8_t* data, const size_t size) {
|
|
src_ = data;
|
|
size_ = size;
|
|
delete_ = false;
|
|
active_ = new std::atomic<int32_t>(1);
|
|
cache_ = new std::atomic<uint8_t*>(data);
|
|
handlers_ = new std::atomic<std::vector<dml_handler>*>();
|
|
incomplete_cache_ = new uint8_t*(nullptr);
|
|
}
|
|
|
|
inline dsacache::CacheData::CacheData(const dsacache::CacheData& other) {
|
|
// we copy the ptr to the global atomic reference counter
|
|
// and increase the amount of active references
|
|
|
|
active_ = other.active_;
|
|
const int current_active = active_->fetch_add(1);
|
|
|
|
src_ = other.src_;
|
|
size_ = other.size_;
|
|
cache_ = other.cache_;
|
|
|
|
incomplete_cache_ = other.incomplete_cache_;
|
|
handlers_ = other.handlers_;
|
|
}
|
|
|
|
inline dsacache::CacheData::~CacheData() {
|
|
// due to fetch_sub returning the preivously held value
|
|
// we must subtract one locally to get the current value
|
|
|
|
const int32_t v = active_->fetch_sub(1) - 1;
|
|
|
|
// if the returned value is zero or lower
|
|
// then we must execute proper deletion
|
|
// as this was the last reference
|
|
|
|
if (v == 0) {
|
|
// on deletion we must ensure that all offloaded
|
|
// operations have completed successfully
|
|
|
|
WaitOnCompletion();
|
|
|
|
// only then can we deallocate the memory
|
|
|
|
Deallocate();
|
|
|
|
delete active_;
|
|
delete cache_;
|
|
delete handlers_;
|
|
delete incomplete_cache_;
|
|
}
|
|
}
|
|
|
|
inline void dsacache::CacheData::Deallocate() {
|
|
// although deallocate should only be called from
|
|
// a safe context to do so, it can not hurt to
|
|
// defensively perform the operation atomically
|
|
// and check for incomplete cache if no deallocation
|
|
// takes place for the retrieved local cache
|
|
|
|
uint8_t* cache_local = cache_->exchange(nullptr);
|
|
if (cache_local != nullptr && delete_) numa_free(cache_local, size_);
|
|
else if (*incomplete_cache_ != nullptr) numa_free(*incomplete_cache_, size_);
|
|
else;
|
|
}
|
|
|
|
inline void dsacache::CacheData::WaitOnCompletion() {
|
|
// first check if waiting is even neccessary as a valid
|
|
// cache pointer signals that no waiting is to be performed
|
|
|
|
if (cache_->load() != nullptr) {
|
|
return;
|
|
}
|
|
|
|
// then check if the handlers are available
|
|
|
|
handlers_->wait(nullptr);
|
|
|
|
// exchange the global handlers pointer with nullptr to have a local
|
|
// copy - this signals that this thread is the sole owner and therefore
|
|
// responsible for waiting for them. we can not set to nullptr here but
|
|
// set to maximum of 64-bit in order to prevent deadlocks from the above
|
|
// waiting construct
|
|
|
|
std::vector<dml_handler>* local_handlers = handlers_->exchange(reinterpret_cast<std::vector<dml_handler>*>(maxptr));
|
|
|
|
// ensure that no other thread snatched the handlers before us
|
|
// and in case one did, wait again and then return
|
|
|
|
if (local_handlers == nullptr || local_handlers == reinterpret_cast<std::vector<dml_handler>*>(maxptr)) {
|
|
cache_->wait(nullptr);
|
|
return;
|
|
}
|
|
|
|
// at this point we are responsible for waiting for the handlers
|
|
// and handling any error that comes through them gracefully
|
|
|
|
bool error = false;
|
|
|
|
for (auto& handler : *local_handlers) {
|
|
auto result = handler.get();
|
|
|
|
if (result.status != dml::status_code::ok) {
|
|
std::cerr << "[x] Encountered bad status code for operation: " << dml::StatusCodeToString(result.status) << std::endl;
|
|
|
|
// if one of the copy tasks failed we abort the whole task
|
|
// after all operations are completed on it
|
|
error = true;
|
|
}
|
|
}
|
|
|
|
// at this point all handlers have been waited for
|
|
// and therefore may be decomissioned
|
|
|
|
delete local_handlers;
|
|
|
|
// handle errors now by aborting the cache
|
|
|
|
if (error) {
|
|
cache_->store(src_);
|
|
numa_free(*incomplete_cache_, size_);
|
|
delete_ = false;
|
|
*incomplete_cache_ = nullptr;
|
|
}
|
|
else {
|
|
cache_->store(*incomplete_cache_);
|
|
}
|
|
|
|
// notify all waiting threads so they wake up quickly
|
|
|
|
cache_->notify_all();
|
|
handlers_->notify_all();
|
|
}
|
|
|
|
void dsacache::CacheData::SetTaskHandlersAndCache(uint8_t* cache, std::vector<dml_handler>* handlers) {
|
|
*incomplete_cache_ = cache;
|
|
handlers_->store(handlers);
|
|
handlers_->notify_one();
|
|
}
|
|
|
|
void dsacache::CacheData::Init() {
|
|
cache_->store(nullptr);
|
|
delete_ = true;
|
|
}
|