| # Gaudi Framework, version v25r0 |

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Public Member Functions | Private Attributes | List of all members
IgHookTraceAlloc Class Reference

`#include <IgHook_IgHookTrace.h>`

## Public Member Functions
| IgHookTraceAlloc (void)
void * | allocate (size_t bytes)

## Private Attributes
void * | m_pool
size_t | m_left

## Detailed Description

Definition at line 16 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 25 of file IgHook_IgHookTrace.h.

void* IgHookTraceAlloc::m_pool
| private

Definition at line 24 of file IgHook_IgHookTrace.h.

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

- /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v25r0/GaudiProfiling/src/component/IgHook_IgHookTrace.h
- /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v25r0/GaudiProfiling/src/component/IgHook_IgHookTrace.cpp