PageAccessControlSvc Class Reference

Service to monitor access to memory pages. More...

#include <PageAccessControlSvc.h>

Inheritance diagram for PageAccessControlSvc:

Collaboration diagram for PageAccessControlSvc:

Public Member Functions
	PageAccessControlSvc (const std::string &name, ISvcLocator *pSvcLocator) ATLAS_CTORDTOR_NOT_THREAD_SAFE
	Standard GAUDI constructor. More...
virtual	~PageAccessControlSvc ()
	Destructor. More...
MsgStream &	msg () const
MsgStream &	msg (const MSG::Level lvl) const
bool	msgLvl (const MSG::Level lvl) const
IPageAccessControlSvc implementation
virtual bool	startMonitoring ()
	In baseline implementation, protect pages and install a SEGV handler that counts the number of accesses to a protected address. More...
virtual bool	stopMonitoring ()
virtual bool	accessed (const void *address) const
	has this pointer been accessed (read/written) More...
virtual void	report () const
	In baseline implementation, controlled via PageAccessControlSvc.OutputLevel More...
virtual bool	controlPage (const void *address)
	control access to the page containing address More...

Static Public Member Functions
static const InterfaceID &	interfaceID ()
	Retrieve interface ID. More...

Gaudi implementation
struct sigaction	m_saveSEGVaction
	the default action for SIGSEGV More...
PageAccessControl	m_accessControl
PtrAccessSEGVHandler	m_SEGVHandler
BooleanProperty	m_autoMonitor
	start on init, stop on finalize More...
virtual StatusCode	queryInterface (const InterfaceID &riid, void **ppvInterface)
virtual StatusCode	initialize ()
virtual StatusCode	finalize ()

Detailed Description

Service to monitor access to memory pages.

Author

Paolo Calafiura

This service uses

Definition at line 51 of file PageAccessControlSvc.h.

Constructor & Destructor Documentation

PageAccessControlSvc()

PageAccessControlSvc::PageAccessControlSvc	(	const std::string &	name,
		ISvcLocator *	pSvcLocator
	)

Standard GAUDI constructor.

Definition at line 8 of file PageAccessControlSvc.cxx.

                                                   : 
  AthService(name, pSvcLocator), m_saveSEGVaction(),
  m_accessControl(), m_SEGVHandler(m_accessControl)
{
  //pass m_SEGVHandler pointer to cPtrAccessSEGVHandler
  setPtrAccessSEGVHandler(&m_SEGVHandler);
  declareProperty("AutoMonitoring", m_autoMonitor=true, 
          "start monitoring on initialize, stop on finalize");
}

~PageAccessControlSvc()

virtual PageAccessControlSvc::~PageAccessControlSvc ( )

inlinevirtual

Destructor.

Definition at line 59 of file PageAccessControlSvc.h.

{} 

Member Function Documentation

accessed()

bool PageAccessControlSvc::accessed ( const void *  address ) const

virtual

has this pointer been accessed (read/written)

Implements IPageAccessControlSvc.

Definition at line 36 of file PageAccessControlSvc.cxx.

                                                             {
  return m_accessControl.accessed(address);
}

controlPage()

virtual bool PageAccessControlSvc::controlPage ( const void *  address )

inlinevirtual

control access to the page containing address

Implements IPageAccessControlSvc.

Definition at line 73 of file PageAccessControlSvc.h.

                                                {
    return m_accessControl.forbidPage(address);
  }

finalize()

StatusCode PageAccessControlSvc::finalize ( )

virtual

Definition at line 47 of file PageAccessControlSvc.cxx.

                                          {
  StatusCode sc(StatusCode::SUCCESS);
  if (m_autoMonitor.value()) {
    if (this->stopMonitoring()) this->report();
    else sc = StatusCode::FAILURE;
  }
  return sc;
}

initialize()

StatusCode PageAccessControlSvc::initialize ( )

virtual

Definition at line 40 of file PageAccessControlSvc.cxx.

                                            {
  StatusCode sc(StatusCode::SUCCESS);
  msg(MSG::INFO) << "Initializing " << name() << endmsg ;
  if (m_autoMonitor.value() && !this->startMonitoring()) sc = StatusCode::FAILURE;
  return sc;
}

interfaceID()

const InterfaceID & IPageAccessControlSvc::interfaceID ( )

inlinestaticinherited

Retrieve interface ID.

Definition at line 56 of file IPageAccessControlSvc.h.

{
  static const InterfaceID IID_IPageAccessControlSvc("IPageAccessControlSvc", 1, 0);
  return IID_IPageAccessControlSvc;
}

msg() [1/2]

MsgStream& AthCommonMsg< Service >::msg ( ) const

inlineinherited

Definition at line 24 of file AthCommonMsg.h.

                                {
    return this->msgStream();
  }

msg() [2/2]

MsgStream& AthCommonMsg< Service >::msg ( const MSG::Level  lvl ) const

inlineinherited

Definition at line 27 of file AthCommonMsg.h.

                                                  {
    return this->msgStream(lvl);
  }

msgLvl()

bool AthCommonMsg< Service >::msgLvl ( const MSG::Level  lvl ) const

inlineinherited

Definition at line 30 of file AthCommonMsg.h.

                                               {
    return this->msgLevel(lvl);
  }

queryInterface()

StatusCode PageAccessControlSvc::queryInterface ( const InterfaceID &  riid, void **  ppvInterface  )

virtual

Definition at line 61 of file PageAccessControlSvc.cxx.

{
    if ( IPageAccessControlSvc::interfaceID().versionMatch(riid) )    {
        *ppvInterface = (IPageAccessControlSvc*)this;
    }
    else  {
    // Interface is not directly available: try out a base class
    return Service::queryInterface(riid, ppvInterface);
    }
    this->addRef();
    return StatusCode::SUCCESS;
}

report()

void PageAccessControlSvc::report ( ) const

virtual

In baseline implementation, controlled via PageAccessControlSvc.OutputLevel

Implements IPageAccessControlSvc.

Definition at line 75 of file PageAccessControlSvc.cxx.

                                        {
  msg(MSG::INFO) << "Access monitoring report" << endmsg;
  PtrAccessSEGVHandler::const_iterator i(m_SEGVHandler.beginAccessedPtrs()),
    e(m_SEGVHandler.endAccessedPtrs());
  while (i != e) {
    msg(MSG::DEBUG) << "accessed pointer at @" << std::hex << *i++ << endmsg; 
  }
  PageAccessControl::const_iterator ia(m_accessControl.beginProtectedPtrs()),
    ea(m_accessControl.endProtectedPtrs());
  while (ia != ea) {
    msg(MSG::DEBUG) << "protected page at @" << std::hex << ia->addr
            << " accessed "<< ia->restored << " times" << endmsg; 
    ++ia;
  }
}

startMonitoring()

bool PageAccessControlSvc::startMonitoring ( )

virtual

In baseline implementation, protect pages and install a SEGV handler that counts the number of accesses to a protected address.

Implements IPageAccessControlSvc.

Definition at line 19 of file PageAccessControlSvc.cxx.

                                            {
  int rc = sigaction(SIGSEGV,nullptr, &m_saveSEGVaction);
  if (0==rc) {
    struct sigaction sa(m_saveSEGVaction);
    sa.sa_sigaction= cPtrAccessSEGVHandler; 
    sa.sa_flags=SA_SIGINFO;
    //off we go
    rc=sigaction(SIGSEGV,&sa,nullptr);
  }
  return (0==rc);
}

stopMonitoring()

bool PageAccessControlSvc::stopMonitoring ( )

virtual

Implements IPageAccessControlSvc.

Definition at line 31 of file PageAccessControlSvc.cxx.

                                           {
  return (0 == sigaction(SIGSEGV,&m_saveSEGVaction, nullptr));
}

Member Data Documentation

m_accessControl

PageAccessControl PageAccessControlSvc::m_accessControl

private

Definition at line 90 of file PageAccessControlSvc.h.

m_autoMonitor

BooleanProperty PageAccessControlSvc::m_autoMonitor

private

start on init, stop on finalize

Definition at line 92 of file PageAccessControlSvc.h.

m_saveSEGVaction

struct sigaction PageAccessControlSvc::m_saveSEGVaction

private

the default action for SIGSEGV

Definition at line 83 of file PageAccessControlSvc.h.

m_SEGVHandler

PtrAccessSEGVHandler PageAccessControlSvc::m_SEGVHandler

private

Definition at line 91 of file PageAccessControlSvc.h.

---

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

• PageAccessControlSvc.h
• PageAccessControlSvc.cxx