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Diffstat (limited to 'winsup/cygwin/heap.cc')
| -rw-r--r-- | winsup/cygwin/heap.cc | 276 |
1 files changed, 0 insertions, 276 deletions
diff --git a/winsup/cygwin/heap.cc b/winsup/cygwin/heap.cc deleted file mode 100644 index 433628e06..000000000 --- a/winsup/cygwin/heap.cc +++ /dev/null @@ -1,276 +0,0 @@ -/* heap.cc: Cygwin heap manager. - - Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, - 2006, 2007, 2008, 2009, 2010, 2011 Red Hat, Inc. - -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 "cygerrno.h" -#include "shared_info.h" -#include "path.h" -#include "fhandler.h" -#include "dtable.h" -#include "cygheap.h" -#include "child_info.h" -#include "ntdll.h" -#include <sys/param.h> - -#define assert(x) - -static unsigned page_const; - -#define MINHEAP_SIZE (4 * 1024 * 1024) - -static uintptr_t -eval_start_address () -{ - /* Starting with Vista, Windows performs heap ASLR. This spoils the entire - region below 0x20000000 for us, because that region is used by Windows - to randomize heap and stack addresses. Therefore we put our heap into a - safe region starting at 0x20000000. This should work right from the start - in 99% of the cases. */ - uintptr_t start_address = 0x20000000L; - if ((uintptr_t) NtCurrentTeb () >= 0xbf000000L) - { - /* However, if we're running on a /3GB enabled 32 bit system or on - a 64 bit system, and the executable is large address aware, then - we know that we have spare 1 Gig (32 bit) or even 2 Gigs (64 bit) - virtual address space. This memory region is practically unused - by Windows, only PEB and TEBs are allocated top-down here. We use - the current TEB address as very simple test that this is a large - address aware executable. - The above test for an address beyond 0xbf000000 is supposed to - make sure that we really have 3GB on a 32 bit system. XP and - later support smaller large address regions, but then it's not - that interesting for us to use it for the heap. - If the region is big enough, the heap gets allocated at its - start. What we get are 0.999 or 1.999 Gigs of free contiguous - memory for heap, thread stacks, and shared memory regions. */ - start_address = 0x80000000L; - } - return start_address; -} - -static unsigned -eval_initial_heap_size () -{ - PIMAGE_DOS_HEADER dosheader; - PIMAGE_NT_HEADERS32 ntheader; - unsigned size; - - dosheader = (PIMAGE_DOS_HEADER) GetModuleHandle (NULL); - ntheader = (PIMAGE_NT_HEADERS32) ((PBYTE) dosheader + dosheader->e_lfanew); - /* LoaderFlags is an obsolete DWORD member of the PE/COFF file header. - It's value is ignored by the loader, so we're free to use it for - Cygwin. If it's 0, we default to the usual 384 Megs. Otherwise, - we use it as the default initial heap size in megabyte. Valid values - are between 4 and 2048 Megs. */ - size = ntheader->OptionalHeader.LoaderFlags; - if (size == 0) - size = 384; - else if (size < 4) - size = 4; - else if (size > 2048) - size = 2048; - return size << 20; -} - -/* Initialize the heap at process start up. */ -void -heap_init () -{ - const DWORD alloctype = MEM_RESERVE; - /* If we're the forkee, we must allocate the heap at exactly the same place - as our parent. If not, we (almost) don't care where it ends up. */ - - page_const = wincap.page_size (); - if (!cygheap->user_heap.base) - { - uintptr_t start_address = eval_start_address (); - PVOID largest_found = NULL; - size_t largest_found_size = 0; - SIZE_T ret; - MEMORY_BASIC_INFORMATION mbi; - - cygheap->user_heap.chunk = eval_initial_heap_size (); - do - { - cygheap->user_heap.base = VirtualAlloc ((LPVOID) start_address, - cygheap->user_heap.chunk, - alloctype, PAGE_NOACCESS); - if (cygheap->user_heap.base) - break; - - /* Ok, so we are at the 1% which didn't work with 0x20000000 out - of the box. What we do now is to search for the next free - region which matches our desired heap size. While doing that, - we keep track of the largest region we found, including the - region starting at 0x20000000. */ - while ((ret = VirtualQuery ((LPCVOID) start_address, &mbi, - sizeof mbi)) != 0) - { - if (mbi.State == MEM_FREE) - { - if (mbi.RegionSize >= cygheap->user_heap.chunk) - break; - if (mbi.RegionSize > largest_found_size) - { - largest_found = mbi.BaseAddress; - largest_found_size = mbi.RegionSize; - } - } - /* Since VirtualAlloc only reserves at allocation granularity - boundaries, we round up here, too. Otherwise we might end - up at a bogus page-aligned address. */ - start_address = roundup2 (start_address + mbi.RegionSize, - wincap.allocation_granularity ()); - } - if (!ret) - { - /* In theory this should not happen. But if it happens, we have - collected the information about the largest available region - in the above loop. So, next we squeeze the heap into that - region, unless it's smaller than the minimum size. */ - if (largest_found_size >= MINHEAP_SIZE) - { - cygheap->user_heap.chunk = largest_found_size; - cygheap->user_heap.base = - VirtualAlloc (largest_found, cygheap->user_heap.chunk, - alloctype, PAGE_NOACCESS); - } - /* Last resort (but actually we are probably broken anyway): - Use the minimal heap size and let the system decide. */ - if (!cygheap->user_heap.base) - { - cygheap->user_heap.chunk = MINHEAP_SIZE; - cygheap->user_heap.base = - VirtualAlloc (NULL, cygheap->user_heap.chunk, - alloctype, PAGE_NOACCESS); - } - } - } - while (!cygheap->user_heap.base && ret); - if (cygheap->user_heap.base == NULL) - api_fatal ("unable to allocate heap, heap_chunk_size %p, %E", - cygheap->user_heap.chunk); - cygheap->user_heap.ptr = cygheap->user_heap.top = cygheap->user_heap.base; - cygheap->user_heap.max = (char *) cygheap->user_heap.base - + cygheap->user_heap.chunk; - } - else - { - DWORD chunk = cygheap->user_heap.chunk; /* allocation chunk */ - /* total size commited in parent */ - DWORD allocsize = (char *) cygheap->user_heap.top - - (char *) cygheap->user_heap.base; - - /* Loop until we've managed to reserve an adequate amount of memory. */ - char *p; - DWORD reserve_size = chunk * ((allocsize + (chunk - 1)) / chunk); - while (1) - { - p = (char *) VirtualAlloc (cygheap->user_heap.base, reserve_size, - alloctype, PAGE_READWRITE); - if (p) - break; - if ((reserve_size -= page_const) < allocsize) - break; - } - if (!p && in_forkee && !fork_info->abort (NULL)) - api_fatal ("couldn't allocate heap, %E, base %p, top %p, " - "reserve_size %d, allocsize %d, page_const %d", - cygheap->user_heap.base, cygheap->user_heap.top, - reserve_size, allocsize, page_const); - if (p != cygheap->user_heap.base) - api_fatal ("heap allocated at wrong address %p (mapped) != %p (expected)", p, cygheap->user_heap.base); - if (allocsize && !VirtualAlloc (cygheap->user_heap.base, allocsize, MEM_COMMIT, PAGE_READWRITE)) - api_fatal ("MEM_COMMIT failed, %E"); - } - - /* CV 2012-05-21: Moved printing heap size here from strace::activate. - The value printed in strace.activate was always wrong, because at the - time it's called, cygheap points to cygheap_dummy. Above all, the heap - size has not been evaluated yet, except in a forked child. Since - heap_init is called early, the heap size is printed pretty much at the - start of the strace output, so there isn't anything lost. */ - debug_printf ("heap base %p, heap top %p, heap size %p (%u)", - cygheap->user_heap.base, cygheap->user_heap.top, - cygheap->user_heap.chunk, cygheap->user_heap.chunk); - page_const--; - // malloc_init (); -} - -#define pround(n) (((size_t)(n) + page_const) & ~page_const) - -/* FIXME: This function no longer handles "split heaps". */ - -extern "C" void * -sbrk (int n) -{ - char *newtop, *newbrk; - unsigned commitbytes, newbrksize; - - if (n == 0) - return cygheap->user_heap.ptr; /* Just wanted to find current cygheap->user_heap.ptr address */ - - newbrk = (char *) cygheap->user_heap.ptr + n; /* Where new cygheap->user_heap.ptr will be */ - newtop = (char *) pround (newbrk); /* Actual top of allocated memory - - on page boundary */ - - if (newtop == cygheap->user_heap.top) - goto good; - - if (n < 0) - { /* Freeing memory */ - assert (newtop < cygheap->user_heap.top); - n = (char *) cygheap->user_heap.top - newtop; - if (VirtualFree (newtop, n, MEM_DECOMMIT)) /* Give it back to OS */ - goto good; /* Didn't take */ - else - goto err; - } - - assert (newtop > cygheap->user_heap.top); - - /* Find the number of bytes to commit, rounded up to the nearest page. */ - commitbytes = pround (newtop - (char *) cygheap->user_heap.top); - - /* Need to grab more pages from the OS. If this fails it may be because - we have used up previously reserved memory. Or, we're just plumb out - of memory. Only attempt to commit memory that we know we've previously - reserved. */ - if (newtop <= cygheap->user_heap.max) - { - if (VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL) - goto good; - } - - /* Couldn't allocate memory. Maybe we can reserve some more. - Reserve either the maximum of the standard cygwin_shared->heap_chunk_size () - or the requested amount. Then attempt to actually allocate it. */ - if ((newbrksize = cygheap->user_heap.chunk) < commitbytes) - newbrksize = commitbytes; - - if ((VirtualAlloc (cygheap->user_heap.top, newbrksize, MEM_RESERVE, PAGE_NOACCESS) - || VirtualAlloc (cygheap->user_heap.top, newbrksize = commitbytes, MEM_RESERVE, PAGE_NOACCESS)) - && VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL) - { - cygheap->user_heap.max = (char *) cygheap->user_heap.max + pround (newbrksize); - goto good; - } - -err: - set_errno (ENOMEM); - return (void *) -1; - -good: - void *oldbrk = cygheap->user_heap.ptr; - cygheap->user_heap.ptr = newbrk; - cygheap->user_heap.top = newtop; - return oldbrk; -} |