| 1 | /* Heap management routines for GNU Emacs on the Microsoft Windows API. |
| 2 | Copyright (C) 1994, 2001-2014 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU Emacs. |
| 5 | |
| 6 | GNU Emacs is free software: you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation, either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | GNU Emacs is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | /* |
| 20 | Geoff Voelker (voelker@cs.washington.edu) 7-29-94 |
| 21 | */ |
| 22 | |
| 23 | #include <config.h> |
| 24 | #include <stdio.h> |
| 25 | |
| 26 | #include "w32common.h" |
| 27 | #include "w32heap.h" |
| 28 | #include "lisp.h" /* for VALMASK */ |
| 29 | |
| 30 | #define RVA_TO_PTR(rva) ((unsigned char *)((DWORD_PTR)(rva) + (DWORD_PTR)GetModuleHandle (NULL))) |
| 31 | |
| 32 | /* Emulate getpagesize. */ |
| 33 | int |
| 34 | getpagesize (void) |
| 35 | { |
| 36 | return sysinfo_cache.dwPageSize; |
| 37 | } |
| 38 | |
| 39 | /* Info for managing our preload heap, which is essentially a fixed size |
| 40 | data area in the executable. */ |
| 41 | PIMAGE_SECTION_HEADER preload_heap_section; |
| 42 | |
| 43 | /* Info for keeping track of our heap. */ |
| 44 | unsigned char *data_region_base = NULL; |
| 45 | unsigned char *data_region_end = NULL; |
| 46 | unsigned char *real_data_region_end = NULL; |
| 47 | size_t reserved_heap_size = 0; |
| 48 | |
| 49 | /* The start of the data segment. */ |
| 50 | unsigned char * |
| 51 | get_data_start (void) |
| 52 | { |
| 53 | return data_region_base; |
| 54 | } |
| 55 | |
| 56 | /* The end of the data segment. */ |
| 57 | unsigned char * |
| 58 | get_data_end (void) |
| 59 | { |
| 60 | return data_region_end; |
| 61 | } |
| 62 | |
| 63 | #if !USE_LSB_TAG |
| 64 | static char * |
| 65 | allocate_heap (void) |
| 66 | { |
| 67 | /* Try to get as much as possible of the address range from the end of |
| 68 | the preload heap section up to the usable address limit. Since GNU |
| 69 | malloc can handle gaps in the memory it gets from sbrk, we can |
| 70 | simply set the sbrk pointer to the base of the new heap region. */ |
| 71 | DWORD_PTR base = |
| 72 | ROUND_UP ((RVA_TO_PTR (preload_heap_section->VirtualAddress) |
| 73 | + preload_heap_section->Misc.VirtualSize), |
| 74 | get_allocation_unit ()); |
| 75 | DWORD_PTR end = ((unsigned __int64)1) << VALBITS; /* 256MB */ |
| 76 | void *ptr = NULL; |
| 77 | |
| 78 | while (!ptr && (base < end)) |
| 79 | { |
| 80 | #ifdef _WIN64 |
| 81 | reserved_heap_size = min(end - base, 0x4000000000ull); /* Limit to 256Gb */ |
| 82 | #else |
| 83 | reserved_heap_size = end - base; |
| 84 | #endif |
| 85 | ptr = VirtualAlloc ((void *) base, |
| 86 | get_reserved_heap_size (), |
| 87 | MEM_RESERVE, |
| 88 | PAGE_NOACCESS); |
| 89 | base += 0x00100000; /* 1MB increment */ |
| 90 | } |
| 91 | |
| 92 | return ptr; |
| 93 | } |
| 94 | #else /* USE_LSB_TAG */ |
| 95 | static char * |
| 96 | allocate_heap (void) |
| 97 | { |
| 98 | #ifdef _WIN64 |
| 99 | size_t size = 0x4000000000ull; /* start by asking for 32GB */ |
| 100 | #else |
| 101 | /* We used to start with 2GB here, but on Windows 7 that would leave |
| 102 | too little room in the address space for threads started by |
| 103 | Windows on our behalf, e.g. when we pop up the file selection |
| 104 | dialog. */ |
| 105 | size_t size = 0x68000000; /* start by asking for 1.7GB */ |
| 106 | #endif |
| 107 | void *ptr = NULL; |
| 108 | |
| 109 | while (!ptr && size > 0x00100000) |
| 110 | { |
| 111 | reserved_heap_size = size; |
| 112 | ptr = VirtualAlloc (NULL, |
| 113 | get_reserved_heap_size (), |
| 114 | MEM_RESERVE, |
| 115 | PAGE_NOACCESS); |
| 116 | size -= 0x00800000; /* if failed, decrease request by 8MB */ |
| 117 | } |
| 118 | |
| 119 | return ptr; |
| 120 | } |
| 121 | #endif /* USE_LSB_TAG */ |
| 122 | |
| 123 | |
| 124 | /* Emulate Unix sbrk. Note that ralloc.c expects the return value to |
| 125 | be the address of the _start_ (not end) of the new block in case of |
| 126 | success, and zero (not -1) in case of failure. */ |
| 127 | void * |
| 128 | sbrk (ptrdiff_t increment) |
| 129 | { |
| 130 | void *result; |
| 131 | ptrdiff_t size = increment; |
| 132 | |
| 133 | result = data_region_end; |
| 134 | |
| 135 | /* If size is negative, shrink the heap by decommitting pages. */ |
| 136 | if (size < 0) |
| 137 | { |
| 138 | ptrdiff_t new_size; |
| 139 | unsigned char *new_data_region_end; |
| 140 | |
| 141 | size = -size; |
| 142 | |
| 143 | /* Sanity checks. */ |
| 144 | if ((data_region_end - size) < data_region_base) |
| 145 | return NULL; |
| 146 | |
| 147 | /* We can only decommit full pages, so allow for |
| 148 | partial deallocation [cga]. */ |
| 149 | new_data_region_end = (data_region_end - size); |
| 150 | new_data_region_end = (unsigned char *) |
| 151 | ((DWORD_PTR) (new_data_region_end + syspage_mask) & ~syspage_mask); |
| 152 | new_size = real_data_region_end - new_data_region_end; |
| 153 | real_data_region_end = new_data_region_end; |
| 154 | if (new_size > 0) |
| 155 | { |
| 156 | /* Decommit size bytes from the end of the heap. */ |
| 157 | if (using_dynamic_heap |
| 158 | && !VirtualFree (real_data_region_end, new_size, MEM_DECOMMIT)) |
| 159 | return NULL; |
| 160 | } |
| 161 | |
| 162 | data_region_end -= size; |
| 163 | } |
| 164 | /* If size is positive, grow the heap by committing reserved pages. */ |
| 165 | else if (size > 0) |
| 166 | { |
| 167 | /* Sanity checks. */ |
| 168 | if ((data_region_end + size) > |
| 169 | (data_region_base + get_reserved_heap_size ())) |
| 170 | return NULL; |
| 171 | |
| 172 | /* Commit more of our heap. */ |
| 173 | if (using_dynamic_heap |
| 174 | && VirtualAlloc (data_region_end, size, MEM_COMMIT, |
| 175 | PAGE_READWRITE) == NULL) |
| 176 | return NULL; |
| 177 | data_region_end += size; |
| 178 | |
| 179 | /* We really only commit full pages, so record where |
| 180 | the real end of committed memory is [cga]. */ |
| 181 | real_data_region_end = (unsigned char *) |
| 182 | ((DWORD_PTR) (data_region_end + syspage_mask) & ~syspage_mask); |
| 183 | } |
| 184 | |
| 185 | return result; |
| 186 | } |
| 187 | |
| 188 | /* Initialize the internal heap variables used by sbrk. When running in |
| 189 | preload phase (ie. in the undumped executable), we rely entirely on a |
| 190 | fixed size heap section included in the .exe itself; this is |
| 191 | preserved during dumping, and truncated to the size actually used. |
| 192 | |
| 193 | When running in the dumped executable, we reserve as much as possible |
| 194 | of the address range that is addressable by Lisp object pointers, to |
| 195 | supplement what is left of the preload heap. Although we cannot rely |
| 196 | on the dynamically allocated arena being contiguous with the static |
| 197 | heap area, it is not a problem because sbrk can pretend that the gap |
| 198 | was allocated by something else; GNU malloc detects when there is a |
| 199 | jump in the sbrk values, and starts a new heap block. */ |
| 200 | void |
| 201 | init_heap (void) |
| 202 | { |
| 203 | PIMAGE_DOS_HEADER dos_header; |
| 204 | PIMAGE_NT_HEADERS nt_header; |
| 205 | |
| 206 | dos_header = (PIMAGE_DOS_HEADER) RVA_TO_PTR (0); |
| 207 | nt_header = (PIMAGE_NT_HEADERS) (((DWORD_PTR) dos_header) + |
| 208 | dos_header->e_lfanew); |
| 209 | preload_heap_section = find_section ("EMHEAP", nt_header); |
| 210 | |
| 211 | if (using_dynamic_heap) |
| 212 | { |
| 213 | data_region_base = allocate_heap (); |
| 214 | if (!data_region_base) |
| 215 | { |
| 216 | printf ("Error: Could not reserve dynamic heap area.\n"); |
| 217 | exit (1); |
| 218 | } |
| 219 | |
| 220 | #if !USE_LSB_TAG |
| 221 | /* Ensure that the addresses don't use the upper tag bits since |
| 222 | the Lisp type goes there. */ |
| 223 | if (((DWORD_PTR) data_region_base & ~VALMASK) != 0) |
| 224 | { |
| 225 | printf ("Error: The heap was allocated in upper memory.\n"); |
| 226 | exit (1); |
| 227 | } |
| 228 | #endif |
| 229 | data_region_end = data_region_base; |
| 230 | real_data_region_end = data_region_end; |
| 231 | } |
| 232 | else |
| 233 | { |
| 234 | data_region_base = RVA_TO_PTR (preload_heap_section->VirtualAddress); |
| 235 | data_region_end = data_region_base; |
| 236 | real_data_region_end = data_region_end; |
| 237 | reserved_heap_size = preload_heap_section->Misc.VirtualSize; |
| 238 | } |
| 239 | |
| 240 | /* Update system version information to match current system. */ |
| 241 | cache_system_info (); |
| 242 | } |
| 243 | |
| 244 | /* Round the heap up to the given alignment. */ |
| 245 | void |
| 246 | round_heap (size_t align) |
| 247 | { |
| 248 | DWORD_PTR needs_to_be; |
| 249 | DWORD_PTR need_to_alloc; |
| 250 | |
| 251 | needs_to_be = (DWORD_PTR) ROUND_UP (get_heap_end (), align); |
| 252 | need_to_alloc = needs_to_be - (DWORD_PTR) get_heap_end (); |
| 253 | |
| 254 | if (need_to_alloc) |
| 255 | sbrk (need_to_alloc); |
| 256 | } |