static char *
allocate_heap (void)
{
/* Try to get as much as possible of the address range from the end of
the preload heap section up to the usable address limit. Since GNU
malloc can handle gaps in the memory it gets from sbrk, we can
simply set the sbrk pointer to the base of the new heap region. */
DWORD_PTR base =
ROUND_UP ((RVA_TO_PTR (preload_heap_section->VirtualAddress)
+ preload_heap_section->Misc.VirtualSize),
get_allocation_unit ());
DWORD_PTR end = ((unsigned __int64)1) << VALBITS; /* 256MB */
void *ptr = NULL;
while (!ptr && (base < end))
{
#ifdef _WIN64
reserved_heap_size = min(end - base, 0x4000000000i64); /* Limit to 256Gb */
#else
reserved_heap_size = end - base;
#endif
ptr = VirtualAlloc ((void *) base,
get_reserved_heap_size (),
MEM_RESERVE,
PAGE_NOACCESS);
base += 0x00100000; /* 1MB increment */
}
return ptr;
}
void *
mmap_alloc (void **var, size_t nbytes)
{
void *p = NULL;
/* We implement amortized allocation. We start by reserving twice
the size requested and commit only the size requested. Then
realloc could proceed and use the reserved pages, reallocating
only if needed. Buffer shrink would happen only so that we stay
in the 2x range. This is a big win when visiting compressed
files, where the final size of the buffer is not known in
advance, and the buffer is enlarged several times as the data is
decompressed on the fly. */
if (nbytes < MAX_BUFFER_SIZE)
p = VirtualAlloc (NULL, ROUND_UP (nbytes * 2, get_allocation_unit ()),
MEM_RESERVE, PAGE_READWRITE);
/* If it fails, or if the request is above 512MB, try with the
requested size. */
if (p == NULL)
p = VirtualAlloc (NULL, ROUND_UP (nbytes, get_allocation_unit ()),
MEM_RESERVE, PAGE_READWRITE);
if (p != NULL)
{
/* Now, commit pages for NBYTES. */
*var = VirtualAlloc (p, nbytes, MEM_COMMIT, PAGE_READWRITE);
if (*var == NULL)
p = *var;
}
if (!p)
{
DWORD e = GetLastError ();
if (e == ERROR_NOT_ENOUGH_MEMORY)
errno = ENOMEM;
else
{
DebPrint (("mmap_alloc: error %ld\n", e));
errno = EINVAL;
}
}
return *var = p;
}
/* SYNOPSYS :
* int syr1_fopen_write(char *name, SYR1_FILE *file) {
* DESCRIPTION :
* Ce sous-programme gère l'ouverture d'un fichier logique en mode écriture.
* PARAMETRES :
* name : chaîne de caratère contenant le nom externe du fichier à ouvrir
* file : pointeur sur un Bloc Control Fichier (File Control Bloc)
* RESULTAT :
* 0 : ouverture réussie
* -1 : autre erreur
*/
int syr1_fopen_write(char *name, SYR1_FILE *file) {
int error = 0;
//Si le fichier existe déjà, suppression
if(search_entry(name, &(file->descriptor)) == 0)
remove_entry(name);
//initialisation du descripteur
strcpy(file->descriptor.name, name);
file->descriptor.size = 0;
file->descriptor.alloc[0] = get_allocation_unit();
//création du fichier sur disque
create_entry(name, &(file->descriptor));
//initialisation du BCF
strcpy(file->mode, "w");
file->current_block = 0;
file->file_offset = 0;
file->block_offset = 0;
file->buffer = malloc(512*sizeof(unsigned char));
return -1;
}