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

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Detailed Description

Definition at line 16 of file IgHook_IgHookTrace.h.

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Constructor & Destructor Documentation

IgHookTraceAlloc::IgHookTraceAlloc

(

void

)

Definition at line 99 of file IgHook_IgHookTrace.cpp.

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

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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;
}

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Member Data Documentation

size_t IgHookTraceAlloc::m_left [private]

Definition at line 25 of file IgHook_IgHookTrace.h.

void* IgHookTraceAlloc::m_pool [private]

Definition at line 24 of file IgHook_IgHookTrace.h.

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

• /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v23r0/GaudiProfiling/src/component/IgHook_IgHookTrace.h
• /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v23r0/GaudiProfiling/src/component/IgHook_IgHookTrace.cpp