| # Gaudi Framework, version v22r2 |

Home |  | Generated: Tue May 10 2011

Public Member Functions | Private Attributes

# IgHookTraceAlloc Class Reference

`#include <IgHook_IgHookTrace.h>`

List of all members.

## Public Member Functions
| IgHookTraceAlloc (void)
void * | allocate (size_t bytes)
## Private Attributes
void * | m_pool
size_t | m_left

## Detailed Description

Definition at line 15 of file IgHook_IgHookTrace.h.

## Constructor & Destructor Documentation

IgHookTraceAlloc::IgHookTraceAlloc | ( | void | ) |

Definition at line 99 of file IgHook_IgHookTrace.cpp.

        : m_pool (0),
          m_left (0)
    {}

## Member Function Documentation

void * IgHookTraceAlloc::allocate | ( | size_t | bytes ) |

Definition at line 105 of file IgHook_IgHookTrace.cpp.

    {
        // The reason for the existence of this class is to allocate
        // memory directly using mmap() so we don't create calls to
        // malloc() and friends.  This is for two reasons: it must be
        // possible to use this in asynchronous signal handlers, and
        // calling malloc() in those is a really bad idea; and this is
        // meant to be used by profiling code and it's nicer to not
        // allocate memory in ways tracked by the profiler.
        if (m_left < bytes)
        {
            size_t psize = getpagesize ();
            size_t hunk = psize * 20;
            if (hunk < bytes) hunk = (hunk + psize - 1) & ~(psize-1);
            void *addr = mmap (0, hunk, PROT_READ | PROT_WRITE,
                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
            if (addr == MAP_FAILED)
                return 0;

            m_pool = addr;
            m_left = hunk;
        }

        void *ptr = m_pool;
        m_pool = (char *) m_pool + bytes;
        m_left -= bytes;
        return ptr;
    }

## Member Data Documentation

size_t IgHookTraceAlloc::m_left`[private]`

Definition at line 24 of file IgHook_IgHookTrace.h.

void* IgHookTraceAlloc::m_pool`[private]`

Definition at line 23 of file IgHook_IgHookTrace.h.

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

- /afs/.cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v22r2/GaudiProfiling/src/component/IgHook_IgHookTrace.h
- /afs/.cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v22r2/GaudiProfiling/src/component/IgHook_IgHookTrace.cpp

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