newlib/winsup/cygwin/cygheap.cc

295 lines
6.2 KiB
C++

/* cygheap.cc: Cygwin heap manager.
Copyright 2000 Cygnus Solutions.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <errno.h>
#include <fhandler.h>
#include <assert.h>
#include "cygheap.h"
#include "heap.h"
#include "cygerrno.h"
void *cygheap = NULL;
void *cygheap_max = NULL;
inline static void
init_cheap ()
{
cygheap = VirtualAlloc (NULL, CYGHEAPSIZE, MEM_RESERVE, PAGE_NOACCESS);
if (!cygheap)
api_fatal ("Couldn't reserve space for cygwin's heap, %E");
cygheap_max = (((char **) cygheap) + 1);
}
#define pagetrunc(x) ((void *) (((DWORD) (x)) & ~(4096 - 1)))
static void *__stdcall
_csbrk (int sbs)
{
void *lastheap;
bool needalloc;
if (cygheap)
needalloc = 0;
else
{
init_cheap ();
needalloc = 1;
}
lastheap = cygheap_max;
(char *) cygheap_max += sbs;
void *heapalign = (void *) pagetrunc (lastheap);
if (!needalloc)
needalloc = sbs && ((heapalign == lastheap) || heapalign != pagetrunc (cygheap_max));
if (needalloc && !VirtualAlloc (lastheap, (DWORD) sbs, MEM_COMMIT, PAGE_READWRITE))
api_fatal ("couldn't commit memory for cygwin heap, %E");
return lastheap;
}
/* Copyright (C) 1997, 2000 DJ Delorie */
#define NBUCKETS 32
char *buckets[NBUCKETS] = {0};
int bucket2size[NBUCKETS] = {0};
static inline int
size2bucket (int size)
{
int rv = 0x1f;
int bit = ~0x10;
int i;
if (size < 4)
size = 4;
size = (size + 3) & ~3;
for (i = 0; i < 5; i++)
{
if (bucket2size[rv & bit] >= size)
rv &= bit;
bit >>= 1;
}
return rv;
}
static inline void
init_buckets ()
{
unsigned b;
for (b = 0; b < NBUCKETS; b++)
bucket2size[b] = (1 << b);
}
struct _cmalloc_entry
{
union
{
DWORD b;
char *ptr;
};
struct _cmalloc_entry *prev;
char data[0];
};
#define N0 ((_cmalloc_entry *) NULL)
#define to_cmalloc(s) ((_cmalloc_entry *) (((char *) (s)) - (int) (N0->data)))
#define cygheap_chain ((_cmalloc_entry **)cygheap)
static void *__stdcall
_cmalloc (int size)
{
_cmalloc_entry *rvc;
int b;
if (bucket2size[0] == 0)
init_buckets ();
b = size2bucket (size);
if (buckets[b])
{
rvc = (_cmalloc_entry *) buckets[b];
buckets[b] = rvc->ptr;
rvc->b = b;
return rvc->data;
}
size = bucket2size[b] + sizeof (_cmalloc_entry);
rvc = (_cmalloc_entry *) _csbrk (size);
rvc->b = b;
rvc->prev = *cygheap_chain;
*cygheap_chain = rvc;
return rvc->data;
}
static void __stdcall
_cfree (void *ptr)
{
_cmalloc_entry *rvc = to_cmalloc (ptr);
DWORD b = rvc->b;
rvc->ptr = buckets[b];
buckets[b] = (char *) rvc;
}
static void *__stdcall
_crealloc (void *ptr, int size)
{
void *newptr;
if (ptr == NULL)
newptr = _cmalloc (size);
else
{
int oldsize = bucket2size[to_cmalloc (ptr)->b];
if (size <= oldsize)
return ptr;
newptr = _cmalloc (size);
memcpy (newptr, ptr, oldsize);
_cfree (ptr);
}
return newptr;
}
/* End Copyright (C) 1997 DJ Delorie */
#define sizeof_cygheap(n) ((n) + sizeof(cygheap_entry))
struct cygheap_entry
{
int type;
struct cygheap_entry *next;
char data[0];
};
#define N ((cygheap_entry *) NULL)
#define tocygheap(s) ((cygheap_entry *) (((char *) (s)) - (int) (N->data)))
/* Called by fork or spawn to reallocate cygwin heap */
extern "C" void __stdcall
cygheap_fixup_in_child (HANDLE parent, bool execed)
{
DWORD m, n;
n = (DWORD) cygheap_max - (DWORD) cygheap;
/* Reserve cygwin heap in same spot as parent */
if (!VirtualAlloc (cygheap, CYGHEAPSIZE, MEM_RESERVE, PAGE_NOACCESS))
api_fatal ("Couldn't reserve space for cygwin's heap in child, %E");
/* Allocate same amount of memory as parent */
if (!VirtualAlloc (cygheap, n, MEM_COMMIT, PAGE_READWRITE))
api_fatal ("Couldn't allocate space for child's heap %p, size %d, %E",
cygheap, n);
/* Copy memory from the parent */
m = 0;
n = (DWORD) pagetrunc (n + 4095);
if (!ReadProcessMemory (parent, cygheap, cygheap, n, &m) ||
m != n)
api_fatal ("Couldn't read parent's cygwin heap %d bytes != %d, %E",
n, m);
if (!execed)
return; /* Forked. Nothing extra to do. */
/* Walk the allocated memory chain looking for orphaned memory from
previous execs */
for (_cmalloc_entry *rvc = *cygheap_chain; rvc; rvc = rvc->prev)
{
cygheap_entry *ce = (cygheap_entry *) rvc->data;
if (rvc->b >= NBUCKETS || ce->type <= HEAP_1_START)
continue;
else if (ce->type < HEAP_1_MAX)
ce->type += HEAP_1_MAX; /* Mark for freeing after next exec */
else
_cfree (ce); /* Marked by parent for freeing in child */
}
}
static void *__stdcall
creturn (cygheap_types x, cygheap_entry * c, int len)
{
if (!c)
{
__seterrno ();
return NULL;
}
c->type = x;
if (cygheap_max < ((char *) c + len))
cygheap_max = (char *) c + len;
return (void *) c->data;
}
extern "C" void *__stdcall
cmalloc (cygheap_types x, DWORD n)
{
cygheap_entry *c;
c = (cygheap_entry *) _cmalloc (sizeof_cygheap (n));
if (!c)
system_printf ("cmalloc returned NULL");
return creturn (x, c, n);
}
extern "C" void *__stdcall
crealloc (void *s, DWORD n)
{
if (s == NULL)
return cmalloc (HEAP_STR, n); // kludge
assert (!inheap (s));
cygheap_entry *c = tocygheap (s);
cygheap_types t = (cygheap_types) c->type;
c = (cygheap_entry *) _crealloc (c, sizeof_cygheap (n));
if (!c)
system_printf ("crealloc returned NULL");
return creturn (t, c, n);
}
extern "C" void __stdcall
cfree (void *s)
{
assert (!inheap (s));
(void) _cfree (tocygheap (s));
}
extern "C" void *__stdcall
ccalloc (cygheap_types x, DWORD n, DWORD size)
{
cygheap_entry *c;
c = (cygheap_entry *) _cmalloc (sizeof_cygheap (n * size));
if (c)
memset (c->data, 0, size);
if (!c)
system_printf ("ccalloc returned NULL");
return creturn (x, c, n);
}
extern "C" char *__stdcall
cstrdup (const char *s)
{
char *p = (char *) cmalloc (HEAP_STR, strlen (s) + 1);
if (!p)
return NULL;
strcpy (p, s);
return p;
}
extern "C" char *__stdcall
cstrdup1 (const char *s)
{
char *p = (char *) cmalloc (HEAP_1_STR, strlen (s) + 1);
if (!p)
return NULL;
strcpy (p, s);
return p;
}