/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */

/* Copyright (C) 2014 Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS is free software: you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/*
 * shim_malloc.c
 *
 * This file implements page allocation for the library OS-internal SLAB
 * memory allocator.  The slab allocator is in Pal/lib/slabmgr.h.  
 * 
 * When existing slabs are not sufficient, or a large (4k or greater) 
 * allocation is requested, it ends up here (__system_alloc and __system_free).
 */

#include <shim_internal.h>
#include <shim_utils.h>
#include <shim_profile.h>
#include <shim_checkpoint.h>
#include <shim_vma.h>

#include <pal.h>
#include <pal_debug.h>

#include <asm/mman.h>

static LOCKTYPE slab_mgr_lock;

#define system_lock()       lock(slab_mgr_lock)
#define system_unlock()     unlock(slab_mgr_lock)
#define PAGE_SIZE           allocsize

#ifdef SLAB_DEBUG_TRACE
# define SLAB_DEBUG
#endif

#define SLAB_CANARY
#define STARTUP_SIZE    16

#include <slabmgr.h>

static SLAB_MGR slab_mgr = NULL;

DEFINE_PROFILE_CATAGORY(memory, );

/* Returns NULL on failure */
void * __system_malloc (size_t size)
{
    size_t alloc_size = ALIGN_UP(size);
    void * addr, * ret_addr;
    int flags = MAP_PRIVATE|MAP_ANONYMOUS|VMA_INTERNAL;

    /*
     * If vmas are initialized, we need to request a free address range
     * using bkeep_unmapped_any().  The current mmap code uses this function
     * to synchronize all address allocation, via a "publication"
     * pattern.  It is not safe to just call DkVirtualMemoryAlloc directly
     * without reserving the vma region first.
     */
    addr = bkeep_unmapped_any(alloc_size, PROT_READ|PROT_WRITE, flags,
                              NULL, 0, "slab");

    if (!addr)
        return NULL;

    do {
        ret_addr = DkVirtualMemoryAlloc(addr, alloc_size, 0,
                                        PAL_PROT_WRITE|PAL_PROT_READ);

        if (!ret_addr) {
            /* If the allocation is interrupted by signal, try to handle the
             * signal and then retry the allocation. */
            if (PAL_NATIVE_ERRNO == PAL_ERROR_INTERRUPTED) {
                handle_signal(true);
                continue;
            }

            debug("failed to allocate memory (%d)\n", -PAL_ERRNO);
            bkeep_munmap(addr, alloc_size, flags);
            return NULL;
        }
    } while (!ret_addr);
    assert(addr == ret_addr);
    return addr;
}

void __system_free (void * addr, size_t size)
{
    DkVirtualMemoryFree(addr, ALIGN_UP(size));

    if (bkeep_munmap(addr, ALIGN_UP(size), VMA_INTERNAL) < 0)
        bug();
}

int init_slab (void)
{
    create_lock(slab_mgr_lock);
    slab_mgr = create_slab_mgr();
    return 0;
}

extern_alias(init_slab);

int reinit_slab (void)
{
    if (slab_mgr) {
        destroy_slab_mgr(slab_mgr);
        slab_mgr = NULL;
    }
    return 0;
}

DEFINE_PROFILE_OCCURENCE(malloc_0, memory);
DEFINE_PROFILE_OCCURENCE(malloc_1, memory);
DEFINE_PROFILE_OCCURENCE(malloc_2, memory);
DEFINE_PROFILE_OCCURENCE(malloc_3, memory);
DEFINE_PROFILE_OCCURENCE(malloc_4, memory);
DEFINE_PROFILE_OCCURENCE(malloc_5, memory);
DEFINE_PROFILE_OCCURENCE(malloc_6, memory);
DEFINE_PROFILE_OCCURENCE(malloc_7, memory);
DEFINE_PROFILE_OCCURENCE(malloc_big, memory);

#if defined(SLAB_DEBUG_PRINT) || defined(SLABD_DEBUG_TRACE)
void * __malloc_debug (size_t size, const char * file, int line)
#else
void * malloc (size_t size)
#endif
{
#ifdef PROFILE
    int i;
    int level = -1;

    for (i = 0 ; i < SLAB_LEVEL ; i++)
        if (size < slab_levels[i]) {
            level = i;
            break;
        }
    switch(level) {
    case 0:
        INC_PROFILE_OCCURENCE(malloc_0);
        break;
    case 1:
        INC_PROFILE_OCCURENCE(malloc_1);
        break;
    case 2:
        INC_PROFILE_OCCURENCE(malloc_2);
        break;
    case 3:
        INC_PROFILE_OCCURENCE(malloc_3);
        break;
    case 4:
        INC_PROFILE_OCCURENCE(malloc_4);
        break;
    case 5:
        INC_PROFILE_OCCURENCE(malloc_5);
        break;
    case 6:
        INC_PROFILE_OCCURENCE(malloc_6);
        break;
    case 7:
        INC_PROFILE_OCCURENCE(malloc_7);
        break;
    case -1:
        INC_PROFILE_OCCURENCE(malloc_big);
        break;
    }
#endif

#ifdef SLAB_DEBUG_TRACE
    void * mem = slab_alloc_debug(slab_mgr, size, file, line);
#else
    void * mem = slab_alloc(slab_mgr, size);
#endif

    if (!mem) {
        /*
         * Normally, the library OS should not run out of memory.
         * If malloc() failed internally, we cannot handle the
         * condition and must terminate the current process.
         */
        sys_printf("******** Out-of-memory in library OS ********\n");
        __abort();
    }

#ifdef SLAB_DEBUG_PRINT
    debug("malloc(%d) = %p (%s:%d)\n", size, mem, file, line);
#endif
    return mem;
}
#if !defined(SLAB_DEBUG_PRINT) && !defined(SLAB_DEBUG_TRACE)
extern_alias(malloc);
#endif

void * calloc (size_t nmemb, size_t size)
{
    // This overflow checking is not a UB, because the operands are unsigned.
    size_t total = nmemb * size;
    if (total / size != nmemb)
        return NULL;
    void *ptr = malloc(total);
    if (ptr)
        memset(ptr, 0, total);
    return ptr;
}
extern_alias(calloc);

#if 0 /* Temporarily disabling this code */
void * realloc(void * ptr, size_t new_size)
{
    /* TODO: We can't deal with this case right now */
    assert(!MEMORY_MIGRATED(ptr));

    size_t old_size = slab_get_buf_size(slab_mgr, ptr);

    /*
     * TODO: this realloc() implementation follows the GLIBC design, which
     * will avoid reallocation when the buffer is large enough. Potentially
     * this design can cause memory draining if user resizes an extremely
     * large object to much smaller.
     */
    if (old_size >= new_size)
        return ptr;

    void * new_buf = malloc(new_size);
    if (!new_buf)
        return NULL;

    memcpy(new_buf, ptr, old_size);
    /* realloc() does not zero the rest of the object */
    free(ptr);
    return new_buf;
}
extern_alias(realloc);
#endif

// Copies data from `mem` to a newly allocated buffer of a specified size.
#if defined(SLAB_DEBUG_PRINT) || defined(SLABD_DEBUG_TRACE)
void * __malloc_copy_debug (const void * mem, size_t size,
                         const char * file, int line)
#else
void * malloc_copy (const void * mem, size_t size)
#endif
{
#if defined(SLAB_DEBUG_PRINT) || defined(SLABD_DEBUG_TRACE)
    void * buff = __malloc_debug(size, file, line);
#else
    void * buff = malloc(size);
#endif
    if (buff)
        memcpy(buff, mem, size);
    return buff;
}
#if !defined(SLAB_DEBUG_PRINT) && !defined(SLABD_DEBUG_TRACE)
extern_alias(malloc_copy);
#endif

DEFINE_PROFILE_OCCURENCE(free_0, memory);
DEFINE_PROFILE_OCCURENCE(free_1, memory);
DEFINE_PROFILE_OCCURENCE(free_2, memory);
DEFINE_PROFILE_OCCURENCE(free_3, memory);
DEFINE_PROFILE_OCCURENCE(free_4, memory);
DEFINE_PROFILE_OCCURENCE(free_5, memory);
DEFINE_PROFILE_OCCURENCE(free_6, memory);
DEFINE_PROFILE_OCCURENCE(free_7, memory);
DEFINE_PROFILE_OCCURENCE(free_big, memory);
DEFINE_PROFILE_OCCURENCE(free_migrated, memory);

#if defined(SLAB_DEBUG_PRINT) || defined(SLABD_DEBUG_TRACE)
void __free_debug (void * mem, const char * file, int line)
#else
void free (void * mem)
#endif
{
    if (MEMORY_MIGRATED(mem)) {
        INC_PROFILE_OCCURENCE(free_migrated);
        return;
    }

#ifdef PROFILE
    int level = RAW_TO_LEVEL(mem);
    switch(level) {
    case 0:
        INC_PROFILE_OCCURENCE(free_0);
        break;
    case 1:
        INC_PROFILE_OCCURENCE(free_1);
        break;
    case 2:
        INC_PROFILE_OCCURENCE(free_2);
        break;
    case 3:
        INC_PROFILE_OCCURENCE(free_3);
        break;
    case 4:
        INC_PROFILE_OCCURENCE(free_4);
        break;
    case 5:
        INC_PROFILE_OCCURENCE(free_5);
        break;
    case 6:
        INC_PROFILE_OCCURENCE(free_6);
        break;
    case 7:
        INC_PROFILE_OCCURENCE(free_7);
        break;
    case -1:
    case 255:
        INC_PROFILE_OCCURENCE(free_big);
        break;
    }
#endif

#ifdef SLAB_DEBUG_PRINT
    debug("free(%p) (%s:%d)\n", mem, file, line);
#endif

#ifdef SLAB_DEBUG_TRACE
    slab_free_debug(slab_mgr, mem, file, line);
#else
    slab_free(slab_mgr, mem);
#endif
}
#if !defined(SLAB_DEBUG_PRINT) && !defined(SLABD_DEBUG_TRACE)
extern_alias(free);
#endif