mem.cpp

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/*
All original material Copyright (C) 2002-2020 UFO: Alien Invasion.

Original file from Quake 2 v3.21: quake2-2.31/game/q_shared.c
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "common.h"
#include <SDL_thread.h>

#define MEM_MAX_POOLNAME 64
#define MEM_HASH         11

struct memBlockFoot_t {
    uint32_t sentinel;      
};

struct memBlock_t {
    memBlock_t* next;

    uint32_t topSentinel;   
    memPool_t* pool;        
    int tagNum;             
    char const* allocFile;  
    int allocLine;          
    size_t memSize;         
    uint32_t botSentinel;   
};

struct memPool_t {
    char name[MEM_MAX_POOLNAME]; 
    bool inUse;             
    memBlock_t* blocks[MEM_HASH]; 
    uint32_t blockCount;    
    uint32_t byteCount;     
    char const* createFile; 
    int createLine;         
};

#define MEM_HEAD_SENTINEL_TOP   0xFEBDFAED
#define MEM_HEAD_SENTINEL_BOT   0xD0BAF0FF
#define MEM_FOOT_SENTINEL       0xF00DF00D

static SDL_mutex* z_lock;

#define MEM_MAX_POOLCOUNT   32

static memPool_t m_poolList[MEM_MAX_POOLCOUNT];
static uint32_t m_numPools;

/*==============================================================================
POOL MANAGEMENT
==============================================================================*/

static memPool_t* Mem_FindPool (const char* name)
{
    memPool_t* pool;
    uint32_t i;

    for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
        if (!pool->inUse)
            continue;
        if (!Q_streq(name, pool->name))
            continue;

        return pool;
    }

    return nullptr;
}

memPool_t* _Mem_CreatePool (const char* name, const char* fileName, const int fileLine)
{
    /* Check name */
    if (!name || !name[0])
        Sys_Error("Mem_CreatePool: nullptr name %s:#%i", fileName, fileLine);
    if (strlen(name) + 1 >= MEM_MAX_POOLNAME)
        Com_Printf("Mem_CreatePoole: name '%s' too long, truncating!\n", name);

    /* See if it already exists */
    memPool_t* pool = Mem_FindPool(name);
    if (pool)
        return pool;

    /* Nope, create a slot */
    uint32_t i;
    for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
        if (!pool->inUse)
            break;
    }
    if (i == m_numPools) {
        if (m_numPools + 1 >= MEM_MAX_POOLCOUNT)
            Sys_Error("Mem_CreatePool: MEM_MAX_POOLCOUNT");
        pool = &m_poolList[m_numPools++];
    }

    /* Store values */
    for (i = 0; i < MEM_HASH; i++)
        pool->blocks[i] = nullptr;
    pool->blockCount = 0;
    pool->byteCount = 0;
    pool->createFile = fileName;
    pool->createLine = fileLine;
    pool->inUse = true;
    Q_strncpyz(pool->name, name, sizeof(pool->name));

    return pool;
}

void _Mem_DeletePool (memPool_t* pool, const char* fileName, const int fileLine)
{
    if (!pool)
        return;

    /* Release all allocated memory */
    _Mem_FreePool(pool, fileName, fileLine);

    /* Simple, yes? */
    pool->inUse = false;
    pool->name[0] = '\0';
}

/*==============================================================================
POOL AND TAG MEMORY ALLOCATION
==============================================================================*/

static memBlock_t* Mem_PtrToBlock(void* const ptr)
{
    return static_cast<memBlock_t*>(ptr) - 1;
}

static void* Mem_BlockToPtr(memBlock_t* const mem)
{
    return mem + 1;
}

static memBlockFoot_t* Mem_BlockToFooter(memBlock_t* const mem)
{
    return reinterpret_cast<memBlockFoot_t*>(reinterpret_cast<byte*>(Mem_BlockToPtr(mem)) + mem->memSize);
}

static size_t Mem_BlockRawSize(memBlock_t const* const mem)
{
    return mem->memSize + sizeof(memBlock_t) + sizeof(memBlockFoot_t);
}

static void _Mem_CheckSentinels (memBlock_t* const mem, const char* fileName, const int fileLine)
{
    /* Check sentinels */
    if (mem->topSentinel != MEM_HEAD_SENTINEL_TOP) {
        Sys_Error("Mem_CheckSentinels: bad memory header top sentinel [buffer underflow]\n"
            "free: %s:#%i", fileName, fileLine);
    } else if (mem->botSentinel != MEM_HEAD_SENTINEL_BOT) {
        Sys_Error("Mem_CheckSentinels: bad memory header bottom sentinel [buffer underflow]\n"
            "free: %s:#%i", fileName, fileLine);
    } else if (Mem_BlockToFooter(mem)->sentinel != MEM_FOOT_SENTINEL) {
        Sys_Error("Mem_CheckSentinels: bad memory footer sentinel [buffer overflow]\n"
            "pool: %s\n"
            "alloc: %s:#%i\n"
            "free: %s:#%i",
            mem->pool ? mem->pool->name : "UNKNOWN", mem->allocFile, mem->allocLine, fileName, fileLine);
    }
}

void _Mem_Free (void* ptr, const char* fileName, const int fileLine)
{
    if (!ptr)
        return;

    memBlock_t* const mem = Mem_PtrToBlock(ptr);
    _Mem_CheckSentinels(mem, fileName, fileLine);

    SDL_LockMutex(z_lock);

    /* Decrement counters */
    mem->pool->blockCount--;
    mem->pool->byteCount -= Mem_BlockRawSize(mem);

    /* De-link it */
    memBlock_t** prev = &mem->pool->blocks[(uintptr_t)mem % MEM_HASH];
    for (;;) {
        memBlock_t* search = *prev;
        if (!search)
            break;

        if (search == mem) {
            *prev = search->next;
            break;
        }
        prev = &search->next;
    }

    SDL_UnlockMutex(z_lock);

    /* Free it */
    free(mem);
}

void _Mem_FreeTag (memPool_t* pool, const int tagNum, const char* fileName, const int fileLine)
{
    if (!pool)
        return;

    for (int j = 0; j < MEM_HASH; j++) {
        for (memBlock_t* mem = pool->blocks[j], *next = nullptr; mem; mem = next) {
            next = mem->next;
            if (mem->tagNum == tagNum)
                _Mem_Free(Mem_BlockToPtr(mem), fileName, fileLine);
        }
    }
}

void _Mem_FreePool (memPool_t* pool, const char* fileName, const int fileLine)
{
    if (!pool)
        return;

    for (int j = 0; j < MEM_HASH; j++) {
        for (memBlock_t* mem = pool->blocks[j], *next = nullptr; mem; mem = next) {
            next = mem->next;
            _Mem_Free(Mem_BlockToPtr(mem), fileName, fileLine);
        }
    }

    assert(pool->blockCount == 0);
    assert(pool->byteCount == 0);
}

void* _Mem_Alloc (size_t size, bool zeroFill, memPool_t* pool, const int tagNum, const char* fileName, const int fileLine)
{
    /* Check pool */
    if (!pool)
        Sys_Error("Mem_Alloc: Error - no pool given\n" "alloc: %s:#%i", fileName, fileLine);

    /* Check size */
    if (size <= 0)
        Sys_Error("Mem_Alloc: Attempted allocation of '" UFO_SIZE_T "' memory ignored\n" "alloc: %s:#%i", size, fileName, fileLine);

    if (size > 0x40000000)
        Sys_Error("Mem_Alloc: Attempted allocation of '" UFO_SIZE_T "' bytes!\n" "alloc: %s:#%i", size, fileName, fileLine);

    /* Add header and round to cacheline */
    size = (size + sizeof(memBlock_t) + sizeof(memBlockFoot_t) + 31) & ~31;
    memBlock_t* mem = static_cast<memBlock_t* >(malloc(size));
    if (!mem)
        Sys_Error("Mem_Alloc: failed on allocation of '" UFO_SIZE_T "' bytes\n" "alloc: %s:#%i", size, fileName, fileLine);

    /* Zero fill */
    if (zeroFill)
        memset(mem, 0, size);

    /* Fill in the header */
    mem->topSentinel = MEM_HEAD_SENTINEL_TOP;
    mem->tagNum = tagNum;
    mem->memSize = size - sizeof(memBlock_t) - sizeof(memBlockFoot_t);
    mem->pool = pool;
    mem->allocFile = fileName;
    mem->allocLine = fileLine;
    mem->botSentinel = MEM_HEAD_SENTINEL_BOT;

    /* Fill in the footer */
    Mem_BlockToFooter(mem)->sentinel = MEM_FOOT_SENTINEL;

    SDL_LockMutex(z_lock);

    /* For integrity checking and stats */
    pool->blockCount++;
    pool->byteCount += size;

    /* Link it in to the appropriate pool */
    mem->next = pool->blocks[(uintptr_t)mem % MEM_HASH];
    pool->blocks[(uintptr_t)mem % MEM_HASH] = mem;

    SDL_UnlockMutex(z_lock);

    return Mem_BlockToPtr(mem);
}

void* _Mem_ReAlloc (void* ptr, size_t size, const char* fileName, const int fileLine)
{
    if (!size)
        Sys_Error("Use Mem_Free instead");

    if (!ptr)
        Sys_Error("Use Mem_Alloc instead");

    memBlock_t* const mem = Mem_PtrToBlock(ptr);
    _Mem_CheckSentinels(mem, fileName, fileLine);

    /* if size matches, do nothing */
    if (mem->memSize == size)
        return ptr;

    memPool_t* pool = mem->pool;

    /* allocate memory for the new size */
    void* newPtr = _Mem_Alloc(size, false, pool, mem->tagNum, fileName, fileLine);

    /* copy old data */
    memcpy(newPtr, ptr, std::min(mem->memSize, size));
    if (mem->memSize < size) {
        const size_t delta = size - mem->memSize;
        memset((byte*)newPtr + mem->memSize, 0, delta);
    }

    /* if there was old data, free it */
    _Mem_Free(ptr, fileName, fileLine);

    _Mem_CheckSentinels(Mem_PtrToBlock(newPtr), fileName, fileLine);

    return newPtr;
}

/*==============================================================================
MISC FUNCTIONS
==============================================================================*/

char* _Mem_PoolStrDupTo (const char* in, char** out, memPool_t* pool, const int tagNum, const char* fileName, const int fileLine)
{
    if (!out)
        return nullptr;
    *out = _Mem_PoolStrDup(in, pool, tagNum, fileName, fileLine);
    return *out;
}

void* _Mem_PoolDup (const void* in, size_t size, memPool_t* pool, const int tagNum, const char* fileName, const int fileLine)
{
    assert(in != nullptr);
    assert(size > 0);

    void* copy = _Mem_Alloc(size, false, pool, tagNum, fileName, fileLine);
    memcpy(copy, in, size);
    return copy;
}

char* _Mem_PoolStrDup (const char* in, memPool_t* pool, const int tagNum, const char* fileName, const int fileLine)
{
    char* out = (char*)_Mem_Alloc((size_t)(strlen(in) + 1), true, pool, tagNum, fileName, fileLine);
    strcpy(out, in);

    return out;
}

uint32_t _Mem_PoolSize (memPool_t* pool)
{
    if (!pool)
        return 0;

    return pool->byteCount;
}

uint32_t _Mem_ChangeTag (memPool_t* pool, const int tagFrom, const int tagTo)
{
    if (!pool)
        return 0;

    uint32_t numChanged = 0;

    for (int j = 0; j < MEM_HASH; j++) {
        for (memBlock_t* mem = pool->blocks[j]; mem; mem = mem->next) {
            if (mem->tagNum == tagFrom) {
                mem->tagNum = tagTo;
                numChanged++;
            }
        }
    }

    return numChanged;
}

static void _Mem_CheckPoolIntegrity (memPool_t* pool, const char* fileName, const int fileLine)
{
    uint32_t blocks;
    uint32_t size;
    int j = 0;

    assert(pool);
    if (!pool)
        return;

    /* Check sentinels */
    for (j = 0, blocks = 0, size = 0; j < MEM_HASH; j++) {
        for (memBlock_t* mem = pool->blocks[j]; mem; blocks++, mem = mem->next) {
            size += Mem_BlockRawSize(mem);
            _Mem_CheckSentinels(mem, fileName, fileLine);
        }
    }

    /* Check block/byte counts */
    if (pool->blockCount != blocks)
        Sys_Error("Mem_CheckPoolIntegrity: bad block count\n" "check: %s:#%i", fileName, fileLine);
    if (pool->byteCount != size)
        Sys_Error("Mem_CheckPoolIntegrity: bad pool size\n" "check: %s:#%i", fileName, fileLine);
}

void _Mem_CheckGlobalIntegrity (const char* fileName, const int fileLine)
{
    memPool_t* pool;
    uint32_t i;

    for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
        if (pool->inUse)
            _Mem_CheckPoolIntegrity(pool, fileName, fileLine);
    }
}

bool _Mem_AllocatedInPool (memPool_t* pool, const void* pointer)
{
    if (!pool)
        return false;

    /* if it's in the pool, it must be in THIS block */
    memBlock_t* mem = pool->blocks[(uintptr_t)pointer % MEM_HASH];
    /* Cycle through the blocks */
    for ( ; mem; mem = mem->next) {
        if (Mem_BlockToPtr(mem) == pointer)
            return true;
    }

    return false;
}

#ifdef COMPILE_UFO
/*==============================================================================
CONSOLE COMMANDS
==============================================================================*/

static void Mem_Check_f (void)
{
    Mem_CheckGlobalIntegrity();
}

static void Mem_Stats_f (void)
{
    uint32_t totalBytes, i;
    memPool_t* pool;

    if (Cmd_Argc() > 1) {
        memPool_t* best;
        memBlock_t* mem;

        best = nullptr;
        for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
            if (!pool->inUse)
                continue;
            if (strstr(pool->name, Cmd_Args())) {
                if (best) {
                    Com_Printf("Too many matches for '%s'...\n", Cmd_Args());
                    return;
                }
                best = pool;
            }
        }
        if (!best) {
            Com_Printf("No matches for '%s'...\n", Cmd_Args());
            return;
        }

        Com_Printf("Pool stats for '%s':\n", best->name);
        Com_Printf("block line  file                 size       \n");
        Com_Printf("----- ----- -------------------- ---------- \n");

        uint32_t totalBytes = 0;
        int j = 0;
        for (j = 0; j < MEM_HASH; j++) {
            for (i = 0, mem = best->blocks[j]; mem; mem = mem->next, i++) {
                if (i & 1)
                    Com_Printf(S_COLOR_GREEN);

                size_t const size = Mem_BlockRawSize(mem);

                Com_Printf("%5i %5i %20s " UFO_SIZE_T "B\n", i + 1, mem->allocLine, mem->allocFile, size);

                totalBytes += size;
            }
        }

        Com_Printf("----------------------------------------\n");
        Com_Printf("Total: %i blocks, %i bytes (%6.3fMB)\n", i, totalBytes, totalBytes/1048576.0f);
        return;
    }

    Com_Printf("Memory stats:\n");
    Com_Printf("    blocks size                  name\n");
    Com_Printf("--- ------ ---------- ---------- --------\n");

    uint32_t totalBlocks = 0;
    totalBytes = 0;
    uint32_t poolNum = 0;
    for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
        if (!pool->inUse)
            continue;

        poolNum++;
        if (poolNum & 1)
            Com_Printf(S_COLOR_GREEN);

        Com_Printf("#%2i %6i %9iB (%6.3fMB) %s\n", poolNum, pool->blockCount, pool->byteCount, pool->byteCount/1048576.0f, pool->name);

        totalBlocks += pool->blockCount;
        totalBytes += pool->byteCount;
    }

    Com_Printf("----------------------------------------\n");
    Com_Printf("Total: %i pools, %i blocks, %i bytes (%6.3fMB)\n", i, totalBlocks, totalBytes, totalBytes/1048576.0f);
}
#endif

void Mem_Init (void)
{
#ifdef COMPILE_UFO
    Cmd_AddCommand("mem_stats", Mem_Stats_f, "Prints out current internal memory statistics");
    Cmd_AddCommand("mem_check", Mem_Check_f, "Checks global memory integrity");
#endif

    z_lock = SDL_CreateMutex();
}

void Mem_Shutdown (void)
{
    memPool_t* pool;
    int i;

    /* don't use cvars, debug print or anything else inside of this loop
     * the mem you are trying to use here might already be wiped away */
    for (i = 0, pool = &m_poolList[0]; i < m_numPools; pool++, i++) {
        if (!pool->inUse)
            continue;
        Mem_DeletePool(pool);
    }

    SDL_DestroyMutex(z_lock);
    z_lock = nullptr;
}