foedus::soc::SocManager Class Reference

SOC manager, which maintains the shared resource across SOCs and, if this engine is a master engine, manages child SOCs. More...

Detailed Description

SOC manager, which maintains the shared resource across SOCs and, if this engine is a master engine, manages child SOCs.

Initialization of this module is quite special because a master engine launches child SOCs potentially as different processes. Also, to avoid leak of shared memory, we take a bit complicated steps.

Initialization Order

When the user instantiates an Engine object, the engine is initialized in the following order:

• Engine object constructor (which does almost nothing itself)
• (Optional) The user pre-registers user procedures (for emulated or fork children SOCs only).
• The user invokes Engine::initialize() of the master engine
• CAUTION-FROM-HERE. SOCManager allocates shared memory of required sizes.
• SOCManager in master engine launches child SOCs, waits for their progress.
• SOCManager in child SOC engines attach the shared memory and acknowledge it via the shared memory.
• CAUTION-UNTIL-HERE. SOCManager in master engine determines if either all SOCManagers attached the shared memory or there was some error. In either case, it marks the shared memory for reclamation (shmctl(IPC_RMID)).
• Child SOCs move on to other modules' initialization.
• Master SOCManager receives the result of child SOC initilization, then does remaining initialization, such as restart.

Notice the annotated region. If there is an unexpected crash in master engine during this period, we leak shared memory until reboot or manual reclamation (ipcrm command). We must avoid it as much as possible. Be extra careful!

Definition at line 60 of file soc_manager.hpp.

#include <soc_manager.hpp>

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Public Member Functions
	SocManager (Engine *engine)
	~SocManager ()
	SocManager ()=delete
	SocManager (const SocManager &)=delete
SocManager &	operator= (const SocManager &)=delete
ErrorStack	initialize () override
	Acquires resources in this object, usually called right after constructor. More...
bool	is_initialized () const override
	Returns whether the object has been already initialized or not. More...
ErrorStack	uninitialize () override
	An idempotent method to release all resources of this object, if any. More...
SharedMemoryRepo *	get_shared_memory_repo ()
	Returns the shared memories maintained across SOCs. More...
void *	get_shared_user_memory () const
	Shortcut for get_shared_memory_repo()->get_global_user_memory() More...
uint64_t	get_shared_user_memory_size () const
ErrorStack	wait_for_master_module (bool init, ModuleType module)
	Wait for master engine to finish init/uninit the module. More...
ErrorStack	wait_for_children_module (bool init, ModuleType module)
	Wait for other engines to finish init/uninit the module. More...
void	report_engine_fatal_error ()
	Announce fatal error state of this (either master or child) engine if possible. More...
Public Member Functions inherited from foedus::Initializable
virtual	~Initializable ()

Static Public Member Functions
static void	trap_spawned_soc_main ()
	This should be called at the beginning of main() if the executable expects to be spawned as SOC engines. More...
static void	trap_spawned_soc_main (const std::vector< proc::ProcAndName > &procedures)
	This version also receives user-defined procedures to be registered in this SOC. More...

Friends
class	SocManagerPimpl

Constructor & Destructor Documentation

foedus::soc::SocManager::SocManager ( Engine *  engine )

explicit

Definition at line 26 of file soc_manager.cpp.

References SocManagerPimpl.

                                     : pimpl_(nullptr) {
  pimpl_ = new SocManagerPimpl(engine);
}

foedus::soc::SocManager::~SocManager

(

)

Definition at line 29 of file soc_manager.cpp.

                        {
  delete pimpl_;
  pimpl_ = nullptr;
}

foedus::soc::SocManager::SocManager ( )

delete

foedus::soc::SocManager::SocManager ( const SocManager &  )

delete

Member Function Documentation

SharedMemoryRepo * foedus::soc::SocManager::get_shared_memory_repo

(

)

Returns the shared memories maintained across SOCs.

Definition at line 38 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::memory_repo_.

Referenced by foedus::snapshot::LogGleaner::execute(), foedus::snapshot::LogReducerRef::get_buffer(), foedus::snapshot::LogReducerRef::get_cur_snapshot(), foedus::storage::PartitionerMetadata::get_index0_metadata(), foedus::storage::PartitionerMetadata::get_metadata(), foedus::restart::RestartManagerPimpl::initialize_once(), foedus::log::MetaLogger::initialize_once(), foedus::memory::NumaNodeMemory::initialize_once(), foedus::EnginePimpl::initialize_once(), foedus::storage::StorageManagerPimpl::initialize_once(), foedus::proc::ProcManagerPimpl::initialize_once(), foedus::log::LogManagerPimpl::initialize_once(), foedus::xct::XctManagerPimpl::initialize_once(), foedus::savepoint::SavepointManagerPimpl::initialize_once(), foedus::thread::ThreadPimpl::initialize_once(), foedus::snapshot::SnapshotManagerPimpl::initialize_once(), foedus::storage::PartitionerMetadata::locate_data(), foedus::snapshot::LogGleanerRef::LogGleanerRef(), foedus::snapshot::LogReducer::LogReducer(), foedus::snapshot::LogReducerRef::LogReducerRef(), foedus::memory::NumaNodeMemoryRef::NumaNodeMemoryRef(), foedus::EnginePimpl::on_module_initialized(), foedus::EnginePimpl::on_module_uninitialized(), foedus::savepoint::SavepointManagerPimpl::savepoint_main(), foedus::thread::ThreadRef::ThreadRef(), foedus::EnginePimpl::uninitialize_once(), and foedus::snapshot::SnapshotManagerPimpl::uninitialize_once().

{ return &pimpl_->memory_repo_; }

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void * foedus::soc::SocManager::get_shared_user_memory

(

)

const

Shortcut for get_shared_memory_repo()->get_global_user_memory()

Definition at line 40 of file soc_manager.cpp.

References foedus::soc::SharedMemoryRepo::get_global_user_memory(), and foedus::soc::SocManagerPimpl::memory_repo_.

Referenced by foedus::memory::EngineMemory::get_shared_user_memory().

                                               {
  return pimpl_->memory_repo_.get_global_user_memory();
}

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uint64_t foedus::soc::SocManager::get_shared_user_memory_size

(

)

const

Returns

the byte size of shared user-controlled memory. Equivalent to SocOptions.shared_user_memory_size_kb_ << 10.

Definition at line 43 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::engine_, foedus::Engine::get_options(), foedus::soc::SocOptions::shared_user_memory_size_kb_, and foedus::EngineOptions::soc_.

Referenced by foedus::memory::EngineMemory::get_shared_user_memory_size().

                                                       {
  return pimpl_->engine_->get_options().soc_.shared_user_memory_size_kb_ * 1024ULL;
}

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ErrorStack foedus::soc::SocManager::initialize ( )

overridevirtual

Acquires resources in this object, usually called right after constructor.

Precondition

is_initialized() == FALSE

If and only if the return value was not an error, is_initialized() will return TRUE. This method is usually not idempotent, but some implementation can choose to be. In that case, the implementation class should clarify that it's idempotent. This method is responsible for releasing all acquired resources when initialization fails. This method itself is NOT thread-safe. Do not call this in a racy situation.

Implements foedus::Initializable.

Definition at line 34 of file soc_manager.cpp.

References foedus::DefaultInitializable::initialize().

Referenced by foedus::EnginePimpl::initialize_once().

{ return pimpl_->initialize(); }

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bool foedus::soc::SocManager::is_initialized ( ) const

overridevirtual

Returns whether the object has been already initialized or not.

Implements foedus::Initializable.

Definition at line 35 of file soc_manager.cpp.

References foedus::DefaultInitializable::is_initialized().

Referenced by foedus::EnginePimpl::initialize_modules(), and foedus::EnginePimpl::uninitialize_once().

{ return pimpl_->is_initialized(); }

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SocManager& foedus::soc::SocManager::operator= ( const SocManager &  )

delete

void foedus::soc::SocManager::report_engine_fatal_error

(

)

Announce fatal error state of this (either master or child) engine if possible.

Definition at line 64 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::report_engine_fatal_error().

Referenced by foedus::EnginePimpl::initialize_once().

{ pimpl_->report_engine_fatal_error(); }

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void foedus::soc::SocManager::trap_spawned_soc_main ( )

static

This should be called at the beginning of main() if the executable expects to be spawned as SOC engines.

This method detects if the process has been spawned from FOEDUS as an SOC engine. If so, it starts running as an SOC engine and exits the process (via _exit()) when done. This should be called as early as possible like following:

int main(int argc, char** argv) {
  foedus::soc::SocManager::trap_spawned_soc_main();
  // user code ....
  return 0;
}

If the process has not been spawned as FOEDUS's SOC engine, this method does nothing and immediately returns.

Definition at line 48 of file soc_manager.cpp.

                                       {
  std::vector< proc::ProcAndName > procedures;
  trap_spawned_soc_main(procedures);
}

void foedus::soc::SocManager::trap_spawned_soc_main ( const std::vector< proc::ProcAndName > &  procedures )

static

This version also receives user-defined procedures to be registered in this SOC.

Parameters

[in]

procedures

user-defined procedures' name and function pointer in this process.

Example:

ErrorStack my_proc(foedus::thread::Thread* context, ...) {
  ...
  return kRetOk;
}
int main(int argc, char** argv) {
  std::vector< foedus::proc::ProcAndName > procedures;
  procedures.push_back(foedus::proc::ProcAndName("my_proc", &my_proc));
  ...  // register more
  foedus::soc::SocManager::trap_spawned_soc_main(procedures);
  // user code ....
  return 0;
}

Definition at line 53 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::spawned_child_main().

                                                                                     {
  SocManagerPimpl::spawned_child_main(procedures);
}

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ErrorStack foedus::soc::SocManager::uninitialize ( )

overridevirtual

An idempotent method to release all resources of this object, if any.

After this method, is_initialized() will return FALSE. Whether this method encounters an error or not, the implementation should make the best effort to release as many resources as possible. In other words, Do not leak all resources because of one issue. This method itself is NOT thread-safe. Do not call this in a racy situation.

Attention

This method is NOT automatically called from the destructor. This is due to the fundamental limitation in C++. Explicitly call this method as soon as you are done, checking the returned value. You can also use UninitializeGuard to ameliorate the issue, but it's not perfect.

Returns

The error this method encounters, if any. In case there are multiple errors while uninitialization, the implementation should use ErrorStackBatch to produce a batched ErrorStack object.

Implements foedus::Initializable.

Definition at line 36 of file soc_manager.cpp.

References foedus::DefaultInitializable::uninitialize().

Referenced by foedus::EnginePimpl::uninitialize_once().

{ return pimpl_->uninitialize(); }

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ErrorStack foedus::soc::SocManager::wait_for_children_module	(	bool	init,
		ModuleType	module
	)

Wait for other engines to finish init/uninit the module.

Definition at line 57 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::wait_for_children_module().

Referenced by foedus::EnginePimpl::initialize_modules(), and foedus::EnginePimpl::uninitialize_once().

                                                                            {
  return pimpl_->wait_for_children_module(init, module);
}

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ErrorStack foedus::soc::SocManager::wait_for_master_module	(	bool	init,
		ModuleType	module
	)

Wait for master engine to finish init/uninit the module.

Definition at line 61 of file soc_manager.cpp.

References foedus::soc::SocManagerPimpl::wait_for_master_module().

Referenced by foedus::EnginePimpl::initialize_modules(), and foedus::EnginePimpl::uninitialize_once().

                                                                          {
  return pimpl_->wait_for_master_module(init, module);
}

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Friends And Related Function Documentation

friend class SocManagerPimpl

friend

Definition at line 62 of file soc_manager.hpp.

Referenced by SocManager().

---

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

• /home/shino/foedus_code/foedus-core/include/foedus/soc/soc_manager.hpp
• /home/shino/foedus_code/foedus-core/src/foedus/soc/soc_manager.cpp