sljit_src/sljitUtils.c

   1 /*
   2  *    Stack-less Just-In-Time compiler
   3  *
   4  *    Copyright Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without modification, are
   7  * permitted provided that the following conditions are met:
   8  *
   9  *   1. Redistributions of source code must retain the above copyright notice, this list of
  10  *      conditions and the following disclaimer.
  11  *
  12  *   2. Redistributions in binary form must reproduce the above copyright notice, this list
  13  *      of conditions and the following disclaimer in the documentation and/or other materials
  14  *      provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  19  * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  21  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  22  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  24  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 /* ------------------------------------------------------------------------ */
  28 /*  Locks                                                                   */
  29 /* ------------------------------------------------------------------------ */
  30
  31 /* Executable Allocator */
  32
  33 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) \
  34         && !(defined SLJIT_WX_EXECUTABLE_ALLOCATOR && SLJIT_WX_EXECUTABLE_ALLOCATOR)
  35 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
  36 #define SLJIT_ALLOCATOR_LOCK()
  37 #define SLJIT_ALLOCATOR_UNLOCK()
  38 #elif !(defined _WIN32)
  39 #include <pthread.h>
  40
  41 static pthread_mutex_t allocator_lock = PTHREAD_MUTEX_INITIALIZER;
  42
  43 #define SLJIT_ALLOCATOR_LOCK() pthread_mutex_lock(&allocator_lock)
  44 #define SLJIT_ALLOCATOR_UNLOCK() pthread_mutex_unlock(&allocator_lock)
  45 #else /* windows */
  46 static HANDLE allocator_lock;
  47
  48 static SLJIT_INLINE void allocator_grab_lock(void)
  49 {
  50         HANDLE lock;
  51         if (SLJIT_UNLIKELY(!InterlockedCompareExchangePointer(&allocator_lock, NULL, NULL))) {
  52                 lock = CreateMutex(NULL, FALSE, NULL);
  53                 if (InterlockedCompareExchangePointer(&allocator_lock, lock, NULL))
  54                         CloseHandle(lock);
  55         }
  56         WaitForSingleObject(allocator_lock, INFINITE);
  57 }
  58
  59 #define SLJIT_ALLOCATOR_LOCK() allocator_grab_lock()
  60 #define SLJIT_ALLOCATOR_UNLOCK() ReleaseMutex(allocator_lock)
  61 #endif /* thread implementation */
  62 #endif /* SLJIT_EXECUTABLE_ALLOCATOR && !SLJIT_WX_EXECUTABLE_ALLOCATOR */
  63
  64 /* ------------------------------------------------------------------------ */
  65 /*  Stack                                                                   */
  66 /* ------------------------------------------------------------------------ */
  67
  68 #if ((defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) \
  69         && !(defined SLJIT_UTIL_SIMPLE_STACK_ALLOCATION && SLJIT_UTIL_SIMPLE_STACK_ALLOCATION)) \
  70         || ((defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) \
  71         && !((defined SLJIT_PROT_EXECUTABLE_ALLOCATOR && SLJIT_PROT_EXECUTABLE_ALLOCATOR) \
  72         || (defined SLJIT_WX_EXECUTABLE_ALLOCATOR && SLJIT_WX_EXECUTABLE_ALLOCATOR)))
  73
  74 #ifndef _WIN32
  75 /* Provides mmap function. */
  76 #include <sys/types.h>
  77 #include <sys/mman.h>
  78
  79 #ifndef MAP_ANON
  80 #ifdef MAP_ANONYMOUS
  81 #define MAP_ANON MAP_ANONYMOUS
  82 #endif /* MAP_ANONYMOUS */
  83 #endif /* !MAP_ANON */
  84
  85 #ifndef MAP_ANON
  86
  87 #include <fcntl.h>
  88
  89 #ifdef O_CLOEXEC
  90 #define SLJIT_CLOEXEC   O_CLOEXEC
  91 #else /* !O_CLOEXEC */
  92 #define SLJIT_CLOEXEC   0
  93 #endif /* O_CLOEXEC */
  94
  95 /* Some old systems do not have MAP_ANON. */
  96 static int dev_zero = -1;
  97
  98 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
  99
 100 static SLJIT_INLINE int open_dev_zero(void)
 101 {
 102         dev_zero = open("/dev/zero", O_RDWR | SLJIT_CLOEXEC);
 103
 104         return dev_zero < 0;
 105 }
 106
 107 #else /* !SLJIT_SINGLE_THREADED */
 108
 109 #include <pthread.h>
 110
 111 static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;
 112
 113 static SLJIT_INLINE int open_dev_zero(void)
 114 {
 115         pthread_mutex_lock(&dev_zero_mutex);
 116         if (SLJIT_UNLIKELY(dev_zero < 0))
 117                 dev_zero = open("/dev/zero", O_RDWR | SLJIT_CLOEXEC);
 118
 119         pthread_mutex_unlock(&dev_zero_mutex);
 120         return dev_zero < 0;
 121 }
 122
 123 #endif /* SLJIT_SINGLE_THREADED */
 124 #undef SLJIT_CLOEXEC
 125 #endif /* !MAP_ANON */
 126 #endif /* !_WIN32 */
 127 #endif /* open_dev_zero */
 128
 129 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) \
 130         || (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
 131
 132 #ifdef _WIN32
 133
 134 static SLJIT_INLINE sljit_sw get_page_alignment(void) {
 135         SYSTEM_INFO si;
 136         static sljit_sw sljit_page_align;
 137         if (!sljit_page_align) {
 138                 GetSystemInfo(&si);
 139                 sljit_page_align = si.dwPageSize - 1;
 140         }
 141         return sljit_page_align;
 142 }
 143
 144 #else
 145
 146 #include <unistd.h>
 147
 148 static SLJIT_INLINE sljit_sw get_page_alignment(void) {
 149         static sljit_sw sljit_page_align = -1;
 150         if (sljit_page_align < 0) {
 151 #ifdef _SC_PAGESIZE
 152                 sljit_page_align = sysconf(_SC_PAGESIZE);
 153 #else
 154                 sljit_page_align = getpagesize();
 155 #endif
 156                 /* Should never happen. */
 157                 if (sljit_page_align < 0)
 158                         sljit_page_align = 4096;
 159                 sljit_page_align--;
 160         }
 161         return sljit_page_align;
 162 }
 163
 164 #endif /* _WIN32 */
 165
 166 #endif /* get_page_alignment() */
 167
 168 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK)
 169
 170 #if (defined SLJIT_UTIL_SIMPLE_STACK_ALLOCATION && SLJIT_UTIL_SIMPLE_STACK_ALLOCATION)
 171
 172 SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_FUNC sljit_allocate_stack(sljit_uw start_size, sljit_uw max_size, void *allocator_data)
 173 {
 174         struct sljit_stack *stack;
 175         void *ptr;
 176
 177         SLJIT_UNUSED_ARG(allocator_data);
 178
 179         if (start_size > max_size || start_size < 1)
 180                 return NULL;
 181
 182         stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack), allocator_data);
 183         if (stack == NULL)
 184                 return NULL;
 185
 186         ptr = SLJIT_MALLOC(max_size, allocator_data);
 187         if (ptr == NULL) {
 188                 SLJIT_FREE(stack, allocator_data);
 189                 return NULL;
 190         }
 191
 192         stack->min_start = (sljit_u8 *)ptr;
 193         stack->end = stack->min_start + max_size;
 194         stack->start = stack->end - start_size;
 195         stack->top = stack->end;
 196         return stack;
 197 }
 198
 199 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
 200 {
 201         SLJIT_UNUSED_ARG(allocator_data);
 202         SLJIT_FREE((void*)stack->min_start, allocator_data);
 203         SLJIT_FREE(stack, allocator_data);
 204 }
 205
 206 SLJIT_API_FUNC_ATTRIBUTE sljit_u8 *SLJIT_FUNC sljit_stack_resize(struct sljit_stack *stack, sljit_u8 *new_start)
 207 {
 208         if ((new_start < stack->min_start) || (new_start >= stack->end))
 209                 return NULL;
 210         stack->start = new_start;
 211         return new_start;
 212 }
 213
 214 #else /* !SLJIT_UTIL_SIMPLE_STACK_ALLOCATION */
 215
 216 #ifdef _WIN32
 217
 218 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
 219 {
 220         SLJIT_UNUSED_ARG(allocator_data);
 221         VirtualFree((void*)stack->min_start, 0, MEM_RELEASE);
 222         SLJIT_FREE(stack, allocator_data);
 223 }
 224
 225 #else /* !_WIN32 */
 226
 227 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_free_stack(struct sljit_stack *stack, void *allocator_data)
 228 {
 229         SLJIT_UNUSED_ARG(allocator_data);
 230         munmap((void*)stack->min_start, stack->end - stack->min_start);
 231         SLJIT_FREE(stack, allocator_data);
 232 }
 233
 234 #endif /* _WIN32 */
 235
 236 SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_FUNC sljit_allocate_stack(sljit_uw start_size, sljit_uw max_size, void *allocator_data)
 237 {
 238         struct sljit_stack *stack;
 239         void *ptr;
 240         sljit_sw page_align;
 241
 242         SLJIT_UNUSED_ARG(allocator_data);
 243
 244         if (start_size > max_size || start_size < 1)
 245                 return NULL;
 246
 247         stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack), allocator_data);
 248         if (stack == NULL)
 249                 return NULL;
 250
 251         /* Align max_size. */
 252         page_align = get_page_alignment();
 253         max_size = (max_size + page_align) & ~page_align;
 254
 255 #ifdef _WIN32
 256         ptr = VirtualAlloc(NULL, max_size, MEM_RESERVE, PAGE_READWRITE);
 257         if (!ptr) {
 258                 SLJIT_FREE(stack, allocator_data);
 259                 return NULL;
 260         }
 261
 262         stack->min_start = (sljit_u8 *)ptr;
 263         stack->end = stack->min_start + max_size;
 264         stack->start = stack->end;
 265
 266         if (sljit_stack_resize(stack, stack->end - start_size) == NULL) {
 267                 sljit_free_stack(stack, allocator_data);
 268                 return NULL;
 269         }
 270 #else /* !_WIN32 */
 271 #ifdef MAP_ANON
 272         ptr = mmap(NULL, max_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
 273 #else /* !MAP_ANON */
 274         if (SLJIT_UNLIKELY((dev_zero < 0) && open_dev_zero())) {
 275                 SLJIT_FREE(stack, allocator_data);
 276                 return NULL;
 277         }
 278         ptr = mmap(NULL, max_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, dev_zero, 0);
 279 #endif /* MAP_ANON */
 280         if (ptr == MAP_FAILED) {
 281                 SLJIT_FREE(stack, allocator_data);
 282                 return NULL;
 283         }
 284         stack->min_start = (sljit_u8 *)ptr;
 285         stack->end = stack->min_start + max_size;
 286         stack->start = stack->end - start_size;
 287 #endif /* _WIN32 */
 288
 289         stack->top = stack->end;
 290         return stack;
 291 }
 292
 293 SLJIT_API_FUNC_ATTRIBUTE sljit_u8 *SLJIT_FUNC sljit_stack_resize(struct sljit_stack *stack, sljit_u8 *new_start)
 294 {
 295 #if defined _WIN32 || defined(POSIX_MADV_DONTNEED)
 296         sljit_uw aligned_old_start;
 297         sljit_uw aligned_new_start;
 298         sljit_sw page_align;
 299 #endif
 300
 301         if ((new_start < stack->min_start) || (new_start >= stack->end))
 302                 return NULL;
 303
 304 #ifdef _WIN32
 305         page_align = get_page_alignment();
 306
 307         aligned_new_start = (sljit_uw)new_start & ~page_align;
 308         aligned_old_start = ((sljit_uw)stack->start) & ~page_align;
 309         if (aligned_new_start != aligned_old_start) {
 310                 if (aligned_new_start < aligned_old_start) {
 311                         if (!VirtualAlloc((void*)aligned_new_start, aligned_old_start - aligned_new_start, MEM_COMMIT, PAGE_READWRITE))
 312                                 return NULL;
 313                 }
 314                 else {
 315                         if (!VirtualFree((void*)aligned_old_start, aligned_new_start - aligned_old_start, MEM_DECOMMIT))
 316                                 return NULL;
 317                 }
 318         }
 319 #elif defined(POSIX_MADV_DONTNEED)
 320         if (stack->start < new_start) {
 321                 page_align = get_page_alignment();
 322
 323                 aligned_new_start = (sljit_uw)new_start & ~page_align;
 324                 aligned_old_start = ((sljit_uw)stack->start) & ~page_align;
 325
 326                 if (aligned_new_start > aligned_old_start) {
 327                         posix_madvise((void*)aligned_old_start, aligned_new_start - aligned_old_start, POSIX_MADV_DONTNEED);
 328 #ifdef MADV_FREE
 329                         madvise((void*)aligned_old_start, aligned_new_start - aligned_old_start, MADV_FREE);
 330 #endif /* MADV_FREE */
 331                 }
 332         }
 333 #endif /* _WIN32 */
 334
 335         stack->start = new_start;
 336         return new_start;
 337 }
 338
 339 #endif /* SLJIT_UTIL_SIMPLE_STACK_ALLOCATION */
 340
 341 #endif /* SLJIT_UTIL_STACK */