1 /*
2  *    Stack-less Just-In-Time compiler
3  *
4  *    Copyright 2009-2012 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 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) || (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)
32 
33 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
34 
35 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
36 
allocator_grab_lock(void)37 static SLJIT_INLINE void allocator_grab_lock(void)
38 {
39 	/* Always successful. */
40 }
41 
allocator_release_lock(void)42 static SLJIT_INLINE void allocator_release_lock(void)
43 {
44 	/* Always successful. */
45 }
46 
47 #endif /* SLJIT_EXECUTABLE_ALLOCATOR */
48 
49 #if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)
50 
sljit_grab_lock(void)51 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
52 {
53 	/* Always successful. */
54 }
55 
sljit_release_lock(void)56 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
57 {
58 	/* Always successful. */
59 }
60 
61 #endif /* SLJIT_UTIL_GLOBAL_LOCK */
62 
63 #elif defined(_WIN32) /* SLJIT_SINGLE_THREADED */
64 
65 #include "windows.h"
66 
67 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
68 
69 static HANDLE allocator_mutex = 0;
70 
allocator_grab_lock(void)71 static SLJIT_INLINE void allocator_grab_lock(void)
72 {
73 	/* No idea what to do if an error occures. Static mutexes should never fail... */
74 	if (!allocator_mutex)
75 		allocator_mutex = CreateMutex(NULL, TRUE, NULL);
76 	else
77 		WaitForSingleObject(allocator_mutex, INFINITE);
78 }
79 
allocator_release_lock(void)80 static SLJIT_INLINE void allocator_release_lock(void)
81 {
82 	ReleaseMutex(allocator_mutex);
83 }
84 
85 #endif /* SLJIT_EXECUTABLE_ALLOCATOR */
86 
87 #if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)
88 
89 static HANDLE global_mutex = 0;
90 
sljit_grab_lock(void)91 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
92 {
93 	/* No idea what to do if an error occures. Static mutexes should never fail... */
94 	if (!global_mutex)
95 		global_mutex = CreateMutex(NULL, TRUE, NULL);
96 	else
97 		WaitForSingleObject(global_mutex, INFINITE);
98 }
99 
sljit_release_lock(void)100 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
101 {
102 	ReleaseMutex(global_mutex);
103 }
104 
105 #endif /* SLJIT_UTIL_GLOBAL_LOCK */
106 
107 #else /* _WIN32 */
108 
109 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
110 
111 #include <pthread.h>
112 
113 static pthread_mutex_t allocator_mutex = PTHREAD_MUTEX_INITIALIZER;
114 
allocator_grab_lock(void)115 static SLJIT_INLINE void allocator_grab_lock(void)
116 {
117 	pthread_mutex_lock(&allocator_mutex);
118 }
119 
allocator_release_lock(void)120 static SLJIT_INLINE void allocator_release_lock(void)
121 {
122 	pthread_mutex_unlock(&allocator_mutex);
123 }
124 
125 #endif /* SLJIT_EXECUTABLE_ALLOCATOR */
126 
127 #if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)
128 
129 #include <pthread.h>
130 
131 static pthread_mutex_t global_mutex = PTHREAD_MUTEX_INITIALIZER;
132 
sljit_grab_lock(void)133 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
134 {
135 	pthread_mutex_lock(&global_mutex);
136 }
137 
sljit_release_lock(void)138 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
139 {
140 	pthread_mutex_unlock(&global_mutex);
141 }
142 
143 #endif /* SLJIT_UTIL_GLOBAL_LOCK */
144 
145 #endif /* _WIN32 */
146 
147 /* ------------------------------------------------------------------------ */
148 /*  Stack                                                                   */
149 /* ------------------------------------------------------------------------ */
150 
151 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) || (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
152 
153 #ifdef _WIN32
154 #include "windows.h"
155 #else
156 /* Provides mmap function. */
157 #include <sys/mman.h>
158 /* For detecting the page size. */
159 #include <unistd.h>
160 
161 #ifndef MAP_ANON
162 
163 #include <fcntl.h>
164 
165 /* Some old systems does not have MAP_ANON. */
166 static sljit_s32 dev_zero = -1;
167 
168 #if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
169 
open_dev_zero(void)170 static SLJIT_INLINE sljit_s32 open_dev_zero(void)
171 {
172 	dev_zero = open("/dev/zero", O_RDWR);
173 	return dev_zero < 0;
174 }
175 
176 #else /* SLJIT_SINGLE_THREADED */
177 
178 #include <pthread.h>
179 
180 static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;
181 
open_dev_zero(void)182 static SLJIT_INLINE sljit_s32 open_dev_zero(void)
183 {
184 	pthread_mutex_lock(&dev_zero_mutex);
185 	/* The dev_zero might be initialized by another thread during the waiting. */
186 	if (dev_zero < 0) {
187 		dev_zero = open("/dev/zero", O_RDWR);
188 	}
189 	pthread_mutex_unlock(&dev_zero_mutex);
190 	return dev_zero < 0;
191 }
192 
193 #endif /* SLJIT_SINGLE_THREADED */
194 
195 #endif
196 
197 #endif
198 
199 #endif /* SLJIT_UTIL_STACK || SLJIT_EXECUTABLE_ALLOCATOR */
200 
201 #if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK)
202 
203 /* Planning to make it even more clever in the future. */
204 static sljit_sw sljit_page_align = 0;
205 
sljit_allocate_stack(sljit_uw limit,sljit_uw max_limit,void * allocator_data)206 SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_CALL sljit_allocate_stack(sljit_uw limit, sljit_uw max_limit, void *allocator_data)
207 {
208 	struct sljit_stack *stack;
209 	union {
210 		void *ptr;
211 		sljit_uw uw;
212 	} base;
213 #ifdef _WIN32
214 	SYSTEM_INFO si;
215 #endif
216 
217 	SLJIT_UNUSED_ARG(allocator_data);
218 	if (limit > max_limit || limit < 1)
219 		return NULL;
220 
221 #ifdef _WIN32
222 	if (!sljit_page_align) {
223 		GetSystemInfo(&si);
224 		sljit_page_align = si.dwPageSize - 1;
225 	}
226 #else
227 	if (!sljit_page_align) {
228 		sljit_page_align = sysconf(_SC_PAGESIZE);
229 		/* Should never happen. */
230 		if (sljit_page_align < 0)
231 			sljit_page_align = 4096;
232 		sljit_page_align--;
233 	}
234 #endif
235 
236 	/* Align limit and max_limit. */
237 	max_limit = (max_limit + sljit_page_align) & ~sljit_page_align;
238 
239 	stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack), allocator_data);
240 	if (!stack)
241 		return NULL;
242 
243 #ifdef _WIN32
244 	base.ptr = VirtualAlloc(NULL, max_limit, MEM_RESERVE, PAGE_READWRITE);
245 	if (!base.ptr) {
246 		SLJIT_FREE(stack, allocator_data);
247 		return NULL;
248 	}
249 	stack->base = base.uw;
250 	stack->limit = stack->base;
251 	stack->max_limit = stack->base + max_limit;
252 	if (sljit_stack_resize(stack, stack->base + limit)) {
253 		sljit_free_stack(stack, allocator_data);
254 		return NULL;
255 	}
256 #else
257 #ifdef MAP_ANON
258 	base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
259 #else
260 	if (dev_zero < 0) {
261 		if (open_dev_zero()) {
262 			SLJIT_FREE(stack, allocator_data);
263 			return NULL;
264 		}
265 	}
266 	base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE, dev_zero, 0);
267 #endif
268 	if (base.ptr == MAP_FAILED) {
269 		SLJIT_FREE(stack, allocator_data);
270 		return NULL;
271 	}
272 	stack->base = base.uw;
273 	stack->limit = stack->base + limit;
274 	stack->max_limit = stack->base + max_limit;
275 #endif
276 	stack->top = stack->base;
277 	return stack;
278 }
279 
280 #undef PAGE_ALIGN
281 
sljit_free_stack(struct sljit_stack * stack,void * allocator_data)282 SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_free_stack(struct sljit_stack* stack, void *allocator_data)
283 {
284 	SLJIT_UNUSED_ARG(allocator_data);
285 #ifdef _WIN32
286 	VirtualFree((void*)stack->base, 0, MEM_RELEASE);
287 #else
288 	munmap((void*)stack->base, stack->max_limit - stack->base);
289 #endif
290 	SLJIT_FREE(stack, allocator_data);
291 }
292 
sljit_stack_resize(struct sljit_stack * stack,sljit_uw new_limit)293 SLJIT_API_FUNC_ATTRIBUTE sljit_sw SLJIT_CALL sljit_stack_resize(struct sljit_stack* stack, sljit_uw new_limit)
294 {
295 	sljit_uw aligned_old_limit;
296 	sljit_uw aligned_new_limit;
297 
298 	if ((new_limit > stack->max_limit) || (new_limit < stack->base))
299 		return -1;
300 #ifdef _WIN32
301 	aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
302 	aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
303 	if (aligned_new_limit != aligned_old_limit) {
304 		if (aligned_new_limit > aligned_old_limit) {
305 			if (!VirtualAlloc((void*)aligned_old_limit, aligned_new_limit - aligned_old_limit, MEM_COMMIT, PAGE_READWRITE))
306 				return -1;
307 		}
308 		else {
309 			if (!VirtualFree((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MEM_DECOMMIT))
310 				return -1;
311 		}
312 	}
313 	stack->limit = new_limit;
314 	return 0;
315 #else
316 	if (new_limit >= stack->limit) {
317 		stack->limit = new_limit;
318 		return 0;
319 	}
320 	aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
321 	aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
322 	/* If madvise is available, we release the unnecessary space. */
323 #if defined(MADV_DONTNEED)
324 	if (aligned_new_limit < aligned_old_limit)
325 		madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MADV_DONTNEED);
326 #elif defined(POSIX_MADV_DONTNEED)
327 	if (aligned_new_limit < aligned_old_limit)
328 		posix_madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, POSIX_MADV_DONTNEED);
329 #endif
330 	stack->limit = new_limit;
331 	return 0;
332 #endif
333 }
334 
335 #endif /* SLJIT_UTIL_STACK */
336 
337 #endif
338