/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the test suite of the Qt Toolkit.
**
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#include <malloc.h>
#include <limits.h>
#include <stdio.h>
#include <exception>

#if !defined(Q_OS_WIN)
#  include "3rdparty/memcheck.h"
#endif

static bool mallocFailActive = false;
static int mallocFailIndex = 0;
static int mallocCount = 0;

static void my_terminate_handler()
{
    // set a breakpoint here to get a backtrace for your uncaught exceptions
    fprintf(stderr, "Uncaught Exception Detected. Set a breakpoint in my_terminate_handler()\n");
    exit(1);
}

#if defined(__GLIBC__) && !defined(__UCLIBC__)
/* Use glibc's memory allocation hooks */

// From glibc 2.14, the malloc hook variables are declared volatile.
// Note: The malloc hook implementation is marked as deprecated.

#if !defined(__MALLOC_HOOK_VOLATILE)
#  define __MALLOC_HOOK_VOLATILE
#endif

/* our hooks */
static void *my_malloc_hook(size_t, const void *);
static void *my_realloc_hook(void *, size_t, const void *);
static void *my_memalign_hook(size_t, size_t, const void *);
static void my_free_hook(void *, const void *);

/* original hooks. */
static void *(*__MALLOC_HOOK_VOLATILE old_malloc_hook)(size_t, const void *);
static void *(*__MALLOC_HOOK_VOLATILE old_realloc_hook)(void *, size_t, const void *);
static void *(*__MALLOC_HOOK_VOLATILE old_memalign_hook)(size_t, size_t, const void *);
static void  (*__MALLOC_HOOK_VOLATILE old_free_hook)(void *, const void *);

/* initializer function */
static void my_init_hook();

/* Override initialising hook from the C library. */

void (*__MALLOC_HOOK_VOLATILE __malloc_initialize_hook) (void) = my_init_hook;

static void disableHooks()
{
    __malloc_hook = old_malloc_hook;
    __realloc_hook = old_realloc_hook;
    __memalign_hook = old_memalign_hook;
    __free_hook = old_free_hook;
}

static void enableHooks()
{
    __malloc_hook = my_malloc_hook;
    __realloc_hook = my_realloc_hook;
    __memalign_hook = my_memalign_hook;
    __free_hook = my_free_hook;
}

void my_init_hook()
{
    old_malloc_hook = __malloc_hook;
    old_realloc_hook = __realloc_hook;
    old_memalign_hook = __memalign_hook;
    old_free_hook = __free_hook;
    enableHooks();
}

void *my_malloc_hook(size_t size, const void *)
{
    ++mallocCount;

    if (mallocFailActive && --mallocFailIndex < 0)
        return 0; // simulate OOM

    __malloc_hook = old_malloc_hook;
    void *result = ::malloc (size);
    __malloc_hook = my_malloc_hook;

    return result;
}

void *my_memalign_hook(size_t alignment, size_t size, const void *)
{
    ++mallocCount;

    if (mallocFailActive && --mallocFailIndex < 0)
        return 0; // simulate OOM

    __memalign_hook = old_memalign_hook;
    void *result = ::memalign(alignment, size);
    __memalign_hook = my_memalign_hook;

    return result;
}

void *my_realloc_hook(void *ptr, size_t size, const void *)
{
    ++mallocCount;

    if (mallocFailActive && --mallocFailIndex < 0)
        return 0; // simulate OOM

    __realloc_hook = old_realloc_hook;
    __malloc_hook = old_malloc_hook;
    void *result = ::realloc(ptr, size);
    __malloc_hook = my_malloc_hook;
    __realloc_hook = my_realloc_hook;

    return result;
}

void my_free_hook(void *ptr, const void *)
{
    __free_hook = old_free_hook;
    ::free(ptr);
    __free_hook = my_free_hook;
}

#elif defined(Q_CC_MSVC)

#include "crtdbg.h"

static int qCrtAllocHook(int allocType, void * /*userData*/, size_t /*size*/,
                         int blockType, long /*requestNumber*/,
                         const unsigned char * /*filename*/, int /*lineNumber*/)
{
    if (blockType == _CRT_BLOCK)
        return true; // ignore allocations from the C library

    switch (allocType) {
        case _HOOK_ALLOC:
        case _HOOK_REALLOC:
            ++mallocCount;
            if (mallocFailActive && --mallocFailIndex < 0)
                return false; // simulate OOM
    }

    return true;
}

static struct QCrtDebugRegistrator
{
    QCrtDebugRegistrator()
    {
        _CrtSetAllocHook(qCrtAllocHook);
    }

} crtDebugRegistrator;

#else

static void disableHooks()
{
}

#endif

struct AllocFailer
{
    inline AllocFailer(int index) { reactivateAt(index); }
    inline ~AllocFailer() { deactivate(); }

    inline void reactivateAt(int index)
    {
#ifdef RUNNING_ON_VALGRIND
        if (RUNNING_ON_VALGRIND)
            VALGRIND_ENABLE_OOM_AT_ALLOC_INDEX(VALGRIND_GET_ALLOC_INDEX + index + 1);
#endif
        mallocFailIndex = index;
        mallocFailActive = true;
    }

    inline void deactivate()
    {
        mallocFailActive = false;
#ifdef RUNNING_ON_VALGRIND
        VALGRIND_ENABLE_OOM_AT_ALLOC_INDEX(0);
#endif
    }

    inline int currentAllocIndex() const
    {
#ifdef RUNNING_ON_VALGRIND
        if (RUNNING_ON_VALGRIND)
            return VALGRIND_GET_ALLOC_INDEX;
#endif
        return mallocCount;
    }

    static bool initialize()
    {
        std::set_terminate(my_terminate_handler);
#ifdef RUNNING_ON_VALGRIND
        if (RUNNING_ON_VALGRIND) {
            if (VALGRIND_GET_ALLOC_INDEX == -1u) {
                qWarning("You must use a valgrind with oom simulation support");
                return false;
            }
            // running in valgrind - don't use glibc hooks
            disableHooks();

            // never stop simulating OOM
            VALGRIND_DISABLE_OOM_AT_ALLOC_INDEX(-1u);
        }
#endif
         return true;
    }
};

static void *new_helper(std::size_t size)
{
    void *ptr = malloc(size);
#ifndef QT_NO_EXCEPTIONS
    if (!ptr)
        throw std::bad_alloc();
#endif
    return ptr;
}

#ifdef Q_CC_MSVC
#  pragma warning(push)
#  pragma warning(disable: 4290)
#endif

// overload operator new
#ifndef QT_NO_EXCEPTIONS
void* operator new(size_t size) throw (std::bad_alloc) { return new_helper(size); }
void* operator new[](size_t size) throw (std::bad_alloc) { return new_helper(size); }
#endif
void* operator new(size_t size, const std::nothrow_t&) throw() { return malloc(size); }
void* operator new[](std::size_t size, const std::nothrow_t&) throw() { return malloc(size); }

// overload operator delete
void operator delete(void *ptr) throw() { if (ptr) free(ptr); }
void operator delete[](void *ptr) throw() { if (ptr) free(ptr); }
void operator delete(void *ptr, const std::nothrow_t&) throw() { if (ptr) free(ptr); }
void operator delete[](void *ptr, const std::nothrow_t&) throw() { if (ptr) free (ptr); }

#ifdef Q_CC_MSVC
#  pragma warning(pop)
#endif

// ignore placement new and placement delete - those don't allocate.


