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
37static SLJIT_INLINE void allocator_grab_lock(void)
38{
39	/* Always successful. */
40}
41
42static 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
51SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
52{
53	/* Always successful. */
54}
55
56SLJIT_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
69static HANDLE allocator_mutex = 0;
70
71static 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
80static 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
89static HANDLE global_mutex = 0;
90
91SLJIT_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
100SLJIT_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
113static pthread_mutex_t allocator_mutex = PTHREAD_MUTEX_INITIALIZER;
114
115static SLJIT_INLINE void allocator_grab_lock(void)
116{
117	pthread_mutex_lock(&allocator_mutex);
118}
119
120static 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
131static pthread_mutex_t global_mutex = PTHREAD_MUTEX_INITIALIZER;
132
133SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
134{
135	pthread_mutex_lock(&global_mutex);
136}
137
138SLJIT_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. */
166static sljit_si dev_zero = -1;
167
168#if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)
169
170static SLJIT_INLINE sljit_si 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
180static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;
181
182static SLJIT_INLINE sljit_si open_dev_zero(void)
183{
184	pthread_mutex_lock(&dev_zero_mutex);
185	dev_zero = open("/dev/zero", O_RDWR);
186	pthread_mutex_unlock(&dev_zero_mutex);
187	return dev_zero < 0;
188}
189
190#endif /* SLJIT_SINGLE_THREADED */
191
192#endif
193
194#endif
195
196#endif /* SLJIT_UTIL_STACK || SLJIT_EXECUTABLE_ALLOCATOR */
197
198#if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK)
199
200/* Planning to make it even more clever in the future. */
201static sljit_sw sljit_page_align = 0;
202
203SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_CALL sljit_allocate_stack(sljit_uw limit, sljit_uw max_limit)
204{
205	struct sljit_stack *stack;
206	union {
207		void *ptr;
208		sljit_uw uw;
209	} base;
210#ifdef _WIN32
211	SYSTEM_INFO si;
212#endif
213
214	if (limit > max_limit || limit < 1)
215		return NULL;
216
217#ifdef _WIN32
218	if (!sljit_page_align) {
219		GetSystemInfo(&si);
220		sljit_page_align = si.dwPageSize - 1;
221	}
222#else
223	if (!sljit_page_align) {
224		sljit_page_align = sysconf(_SC_PAGESIZE);
225		/* Should never happen. */
226		if (sljit_page_align < 0)
227			sljit_page_align = 4096;
228		sljit_page_align--;
229	}
230#endif
231
232	/* Align limit and max_limit. */
233	max_limit = (max_limit + sljit_page_align) & ~sljit_page_align;
234
235	stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack));
236	if (!stack)
237		return NULL;
238
239#ifdef _WIN32
240	base.ptr = VirtualAlloc(NULL, max_limit, MEM_RESERVE, PAGE_READWRITE);
241	if (!base.ptr) {
242		SLJIT_FREE(stack);
243		return NULL;
244	}
245	stack->base = base.uw;
246	stack->limit = stack->base;
247	stack->max_limit = stack->base + max_limit;
248	if (sljit_stack_resize(stack, stack->base + limit)) {
249		sljit_free_stack(stack);
250		return NULL;
251	}
252#else
253#ifdef MAP_ANON
254	base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
255#else
256	if (dev_zero < 0) {
257		if (open_dev_zero()) {
258			SLJIT_FREE(stack);
259			return NULL;
260		}
261	}
262	base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE, dev_zero, 0);
263#endif
264	if (base.ptr == MAP_FAILED) {
265		SLJIT_FREE(stack);
266		return NULL;
267	}
268	stack->base = base.uw;
269	stack->limit = stack->base + limit;
270	stack->max_limit = stack->base + max_limit;
271#endif
272	stack->top = stack->base;
273	return stack;
274}
275
276#undef PAGE_ALIGN
277
278SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_free_stack(struct sljit_stack* stack)
279{
280#ifdef _WIN32
281	VirtualFree((void*)stack->base, 0, MEM_RELEASE);
282#else
283	munmap((void*)stack->base, stack->max_limit - stack->base);
284#endif
285	SLJIT_FREE(stack);
286}
287
288SLJIT_API_FUNC_ATTRIBUTE sljit_sw SLJIT_CALL sljit_stack_resize(struct sljit_stack* stack, sljit_uw new_limit)
289{
290	sljit_uw aligned_old_limit;
291	sljit_uw aligned_new_limit;
292
293	if ((new_limit > stack->max_limit) || (new_limit < stack->base))
294		return -1;
295#ifdef _WIN32
296	aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
297	aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
298	if (aligned_new_limit != aligned_old_limit) {
299		if (aligned_new_limit > aligned_old_limit) {
300			if (!VirtualAlloc((void*)aligned_old_limit, aligned_new_limit - aligned_old_limit, MEM_COMMIT, PAGE_READWRITE))
301				return -1;
302		}
303		else {
304			if (!VirtualFree((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MEM_DECOMMIT))
305				return -1;
306		}
307	}
308	stack->limit = new_limit;
309	return 0;
310#else
311	if (new_limit >= stack->limit) {
312		stack->limit = new_limit;
313		return 0;
314	}
315	aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
316	aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
317	/* If madvise is available, we release the unnecessary space. */
318#if defined(MADV_DONTNEED)
319	if (aligned_new_limit < aligned_old_limit)
320		madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MADV_DONTNEED);
321#elif defined(POSIX_MADV_DONTNEED)
322	if (aligned_new_limit < aligned_old_limit)
323		posix_madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, POSIX_MADV_DONTNEED);
324#endif
325	stack->limit = new_limit;
326	return 0;
327#endif
328}
329
330#endif /* SLJIT_UTIL_STACK */
331
332#endif
333