heapuser.c File Reference

#include <rtl.h>
#include <heap.h>
#include <debug.h>

Include dependency graph for heapuser.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
VOID NTAPI	RtlpAddHeapToProcessList (PHEAP Heap)
VOID NTAPI	RtlpRemoveHeapFromProcessList (PHEAP Heap)
VOID NTAPI	RtlInitializeHeapManager (VOID)
ULONG NTAPI	RtlGetProcessHeaps (_In_ ULONG HeapCount, _Out_cap_(HeapCount) HANDLE *HeapArray)

Variables
RTL_CRITICAL_SECTION	RtlpProcessHeapsListLock

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 14 of file heapuser.c.

Function Documentation

RtlGetProcessHeaps()

ULONG NTAPI RtlGetProcessHeaps	(	_In_ ULONG	HeapCount,
		_Out_cap_(HeapCount) HANDLE *	HeapArray
	)

Definition at line 131 of file heapuser.c.

{
    PPEB Peb = RtlGetCurrentPeb();
 
    RtlEnterCriticalSection(&RtlpProcessHeapsListLock);
    ULONG nHeaps = Peb->NumberOfHeaps;
 
    _SEH2_TRY
    {
        if (HeapArray)
        {
            for (ULONG n = 0; n < min(nHeaps, HeapCount); ++n)
            {
                HeapArray[n] = Peb->ProcessHeaps[n];
            }
        }
    }
    _SEH2_FINALLY
    {
        RtlLeaveCriticalSection(&RtlpProcessHeapsListLock);
    }
    _SEH2_END;
 
    /* TODO: Add RtlpDphPageHeapList here */
 
    return nHeaps;
}

RtlInitializeHeapManager()

VOID NTAPI RtlInitializeHeapManager

(

VOID

)

Definition at line 116 of file heapuser.c.

{
    PPEB Peb;
 
    /* Get PEB */
    Peb = RtlGetCurrentPeb();
 
    /* Initialize heap-related fields of PEB */
    Peb->NumberOfHeaps = 0;
 
    /* Initialize the process heaps list protecting lock */
    RtlInitializeCriticalSection(&RtlpProcessHeapsListLock);
}

Referenced by LdrpInitializeProcess().

RtlpAddHeapToProcessList()

VOID NTAPI RtlpAddHeapToProcessList

(

PHEAP

Heap

)

Definition at line 23 of file heapuser.c.

{
    PPEB Peb;
 
    /* Get PEB */
    Peb = RtlGetCurrentPeb();
 
    /* Acquire the lock */
    RtlEnterCriticalSection(&RtlpProcessHeapsListLock);
 
    //_SEH2_TRY {
    /* Check if max number of heaps reached */
    if (Peb->NumberOfHeaps == Peb->MaximumNumberOfHeaps)
    {
        // TODO: Handle this case
        ASSERT(FALSE);
    }
 
    /* Add the heap to the process heaps */
    Peb->ProcessHeaps[Peb->NumberOfHeaps] = Heap;
    Peb->NumberOfHeaps++;
    Heap->ProcessHeapsListIndex = (USHORT)Peb->NumberOfHeaps;
    // } _SEH2_FINALLY {
 
    /* Release the lock */
    RtlLeaveCriticalSection(&RtlpProcessHeapsListLock);
 
    // } _SEH2_END
}

RtlpRemoveHeapFromProcessList()

VOID NTAPI RtlpRemoveHeapFromProcessList

(

PHEAP

Heap

)

Definition at line 56 of file heapuser.c.

{
    PPEB Peb;
    PHEAP *Current, *Next;
    ULONG Count;
 
    /* Get PEB */
    Peb = RtlGetCurrentPeb();
 
    /* Acquire the lock */
    RtlEnterCriticalSection(&RtlpProcessHeapsListLock);
 
    /* Check if we don't need anything to do */
    if ((Heap->ProcessHeapsListIndex == 0) ||
        (Heap->ProcessHeapsListIndex > Peb->NumberOfHeaps) ||
        (Peb->NumberOfHeaps == 0))
    {
        /* Release the lock */
        RtlLeaveCriticalSection(&RtlpProcessHeapsListLock);
 
        return;
    }
 
    /* The process actually has more than one heap.
       Use classic, lernt from university times algorithm for removing an entry
       from a static array */
 
    Current = (PHEAP *)&Peb->ProcessHeaps[Heap->ProcessHeapsListIndex - 1];
    Next = Current + 1;
 
    /* How many items we need to shift to the left */
    Count = Peb->NumberOfHeaps - (Heap->ProcessHeapsListIndex - 1);
 
    /* Move them all in a loop */
    while (--Count)
    {
        /* Copy it and advance next pointer */
        *Current = *Next;
 
        /* Update its index */
        (*Current)->ProcessHeapsListIndex -= 1;
 
        /* Advance pointers */
        Current++;
        Next++;
    }
 
    /* Decrease total number of heaps */
    Peb->NumberOfHeaps--;
 
    /* Zero last unused item */
    Peb->ProcessHeaps[Peb->NumberOfHeaps] = NULL;
    Heap->ProcessHeapsListIndex = 0;
 
    /* Release the lock */
    RtlLeaveCriticalSection(&RtlpProcessHeapsListLock);
}

Variable Documentation

RtlpProcessHeapsListLock

RTL_CRITICAL_SECTION RtlpProcessHeapsListLock

Definition at line 17 of file heapuser.c.

Referenced by RtlGetProcessHeaps(), RtlInitializeHeapManager(), RtlpAddHeapToProcessList(), and RtlpRemoveHeapFromProcessList().