CodeCacheAccessor< CompilationContext > Class Template Reference

#include <CodeCacheAccessor.h>

Collaboration diagram for CodeCacheAccessor< CompilationContext >:

Public Member Functions
	CodeCacheAccessor (size_t cache_size, std::string name="")
CodeCacheVal< CompilationContext >	get_value (const CodeCacheKey &key)
void	put (const CodeCacheKey &key, CodeCacheVal< CompilationContext > &value)
CodeCacheVal < CompilationContext > *	get_or_wait (const CodeCacheKey &key)
void	swap (const CodeCacheKey &key, CodeCacheVal< CompilationContext > &&value)
void	clear ()
void	evictFractionEntries (const float fraction)

Private Attributes
CodeCache< CompilationContext >	code_cache_
int64_t	get_count_
int64_t	found_count_
int64_t	put_count_
int64_t	ignore_count_
int64_t	overwrite_count_
int64_t	evict_count_
const std::string	name_
std::mutex	code_cache_mutex_
std::condition_variable	compilation_cv_

Friends
std::ostream &	operator<< (std::ostream &os, CodeCacheAccessor &c)

Detailed Description

template<typename CompilationContext>
class CodeCacheAccessor< CompilationContext >

Definition at line 25 of file CodeCacheAccessor.h.

Constructor & Destructor Documentation

template<typename CompilationContext >

CodeCacheAccessor< CompilationContext >::CodeCacheAccessor ( size_t  cache_size, std::string  name = ""  )

inline

Definition at line 27 of file CodeCacheAccessor.h.

      : code_cache_(cache_size)
      , get_count_(0)
      , found_count_(0)
      , put_count_(0)
      , ignore_count_(0)
      , overwrite_count_(0)
      , evict_count_(0)
      , name_(std::move(name)) {}

Member Function Documentation

template<typename CompilationContext >

void CodeCacheAccessor< CompilationContext >::clear

(

)

Definition at line 102 of file CodeCacheAccessor.cpp.

                                                  {
  std::lock_guard<std::mutex> lock(code_cache_mutex_);
  code_cache_.clear();
}

template<typename CompilationContext >

void CodeCacheAccessor< CompilationContext >::evictFractionEntries ( const float  fraction )

inline

Definition at line 46 of file CodeCacheAccessor.h.

References CodeCacheAccessor< CompilationContext >::code_cache_, CodeCacheAccessor< CompilationContext >::code_cache_mutex_, and CodeCacheAccessor< CompilationContext >::evict_count_.

                                                  {
    std::lock_guard<std::mutex> lock(code_cache_mutex_);
    evict_count_++;
    code_cache_.evictFractionEntries(fraction);
  }

template<typename CompilationContext >

CodeCacheVal< CompilationContext > * CodeCacheAccessor< CompilationContext >::get_or_wait

(

const CodeCacheKey &

key

)

Definition at line 55 of file CodeCacheAccessor.cpp.

References CHECK.

                             {
  CodeCacheVal<CompilationContext>* cached_code = nullptr;
  std::unique_lock<std::mutex> lk(code_cache_mutex_);
  get_count_++;
  cached_code = code_cache_.get(key);
  if (cached_code) {
    if (cached_code->get()) {
      found_count_++;
      return cached_code;
    } else {
      // Wait until compiling thread inserts code to cache. TODO: this
      // wait also locks other unrelated get_or_wait calls on
      // different keys. This is suboptimal as it will block in
      // addition to others threads get_or_wait(key) calls, also
      // independent get_or_wait(other_key) calls. To fix this, we'll
      // need a key specific mutex or use some other approach that
      // would allow threads with other keys to proceed.
      compilation_cv_.wait(lk, [&] { return !!(code_cache_.get(key)->get()); });
      cached_code = code_cache_.get(key);
      CHECK(cached_code->get());
      found_count_++;
      return cached_code;
    }
  }
  // This is the first time the key is used to acquire code from
  // cache. Insert null value to cache so that other threads acquiring
  // the same key will wait (see above) until the code is inserted to
  // cache (by put method below):
  CodeCacheVal<CompilationContext> not_a_code(nullptr);
  code_cache_.put(key, std::move(not_a_code));
  return nullptr;  // caller must trigger code compilation for the given key
}

template<typename CompilationContext >

CodeCacheVal< CompilationContext > CodeCacheAccessor< CompilationContext >::get_value

(

const CodeCacheKey &

key

)

Definition at line 21 of file CodeCacheAccessor.cpp.

                             {
  std::lock_guard<std::mutex> lock(code_cache_mutex_);
  get_count_++;
  auto it = code_cache_.find(key);
  if (it != code_cache_.cend()) {
    found_count_++;
    return it->second;
  }
  return {};
}

template<typename CompilationContext >

void CodeCacheAccessor< CompilationContext >::put	(	const CodeCacheKey &	key,
		CodeCacheVal< CompilationContext > &	value
	)

Definition at line 34 of file CodeCacheAccessor.cpp.

References LOG, and logger::WARNING.

                                                                                         {
  bool warn = false;
  {
    std::lock_guard<std::mutex> lock(code_cache_mutex_);
    // if key is in cache, put is no-op
    auto it = code_cache_.find(key);
    put_count_++;
    if (it == code_cache_.cend()) {
      code_cache_.put(key, value);
    } else {
      ignore_count_++;
      warn = true;
    }
  }
  if (warn) {
    LOG(WARNING) << *this << ": code already in cache, ignoring.\n";
  }
}

template<typename CompilationContext >

void CodeCacheAccessor< CompilationContext >::swap	(	const CodeCacheKey &	key,
		CodeCacheVal< CompilationContext > &&	value
	)

Definition at line 90 of file CodeCacheAccessor.cpp.

References CHECK, and run_benchmark_import::result.

                                              {
  std::lock_guard<std::mutex> lock(code_cache_mutex_);
  auto result = code_cache_.get(key);
  CHECK(result);          // get_or_wait has inserted not_a_code to code cache
  CHECK(!result->get());  // ensure that result really contains not_a_code per get_or_wait
  result->swap(value);    // swap not_a_code with actual code
  compilation_cv_.notify_all();  // notify waiting get_or_wait(..) calls
}

Friends And Related Function Documentation

template<typename CompilationContext >

std::ostream& operator<< ( std::ostream &  os, CodeCacheAccessor< CompilationContext > &  c  )

friend

Definition at line 52 of file CodeCacheAccessor.h.

                                                                      {
    std::lock_guard<std::mutex> lock(c.code_cache_mutex_);
    os << "CodeCacheAccessor<" << c.name_ << ">[current size=" << c.code_cache_.size()
       << ", total get/found count=" << c.get_count_ << "/" << c.found_count_
       << ", total put/ignore/overwrite count=" << c.put_count_ << "/" << c.ignore_count_
       << "/" << c.overwrite_count_ << ", total evict count=" << c.evict_count_ << "]";
    return os;
  }

Member Data Documentation

template<typename CompilationContext >

CodeCache<CompilationContext> CodeCacheAccessor< CompilationContext >::code_cache_

private

Definition at line 62 of file CodeCacheAccessor.h.

Referenced by CodeCacheAccessor< CompilationContext >::evictFractionEntries().

template<typename CompilationContext >

std::mutex CodeCacheAccessor< CompilationContext >::code_cache_mutex_

private

Definition at line 69 of file CodeCacheAccessor.h.

Referenced by CodeCacheAccessor< CompilationContext >::evictFractionEntries().

template<typename CompilationContext >

std::condition_variable CodeCacheAccessor< CompilationContext >::compilation_cv_

private

Definition at line 72 of file CodeCacheAccessor.h.

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::evict_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

Referenced by CodeCacheAccessor< CompilationContext >::evictFractionEntries().

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::found_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::get_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::ignore_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

template<typename CompilationContext >

const std::string CodeCacheAccessor< CompilationContext >::name_

private

Definition at line 67 of file CodeCacheAccessor.h.

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::overwrite_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

template<typename CompilationContext >

int64_t CodeCacheAccessor< CompilationContext >::put_count_

private

Definition at line 64 of file CodeCacheAccessor.h.

---

The documentation for this class was generated from the following files:

• /home/jenkins-slave/workspace/core-os-doxygen/QueryEngine/CodeCacheAccessor.h
• /home/jenkins-slave/workspace/core-os-doxygen/QueryEngine/CodeCacheAccessor.cpp