1 /*
2  * This file is part of the MicroPython project, http://micropython.org/
3  *
4  * The MIT License (MIT)
5  *
6  * Copyright (c) 2016 Damien P. George on behalf of Pycom Ltd
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #include <stdio.h>
28 #include <string.h>
29 
30 #include "py/runtime.h"
31 #include "py/stackctrl.h"
32 
33 #if MICROPY_PY_THREAD
34 
35 #include "py/mpthread.h"
36 
37 #if MICROPY_DEBUG_VERBOSE // print debugging info
38 #define DEBUG_PRINT (1)
39 #define DEBUG_printf DEBUG_printf
40 #else // don't print debugging info
41 #define DEBUG_PRINT (0)
42 #define DEBUG_printf(...) (void)0
43 #endif
44 
45 /****************************************************************/
46 // Lock object
47 
48 STATIC const mp_obj_type_t mp_type_thread_lock;
49 
50 typedef struct _mp_obj_thread_lock_t {
51     mp_obj_base_t base;
52     mp_thread_mutex_t mutex;
53     volatile bool locked;
54 } mp_obj_thread_lock_t;
55 
mp_obj_new_thread_lock(void)56 STATIC mp_obj_thread_lock_t *mp_obj_new_thread_lock(void) {
57     mp_obj_thread_lock_t *self = m_new_obj(mp_obj_thread_lock_t);
58     self->base.type = &mp_type_thread_lock;
59     mp_thread_mutex_init(&self->mutex);
60     self->locked = false;
61     return self;
62 }
63 
thread_lock_acquire(size_t n_args,const mp_obj_t * args)64 STATIC mp_obj_t thread_lock_acquire(size_t n_args, const mp_obj_t *args) {
65     mp_obj_thread_lock_t *self = MP_OBJ_TO_PTR(args[0]);
66     bool wait = true;
67     if (n_args > 1) {
68         wait = mp_obj_get_int(args[1]);
69         // TODO support timeout arg
70     }
71     MP_THREAD_GIL_EXIT();
72     int ret = mp_thread_mutex_lock(&self->mutex, wait);
73     MP_THREAD_GIL_ENTER();
74     if (ret == 0) {
75         return mp_const_false;
76     } else if (ret == 1) {
77         self->locked = true;
78         return mp_const_true;
79     } else {
80         mp_raise_OSError(-ret);
81     }
82 }
83 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(thread_lock_acquire_obj, 1, 3, thread_lock_acquire);
84 
thread_lock_release(mp_obj_t self_in)85 STATIC mp_obj_t thread_lock_release(mp_obj_t self_in) {
86     mp_obj_thread_lock_t *self = MP_OBJ_TO_PTR(self_in);
87     if (!self->locked) {
88         mp_raise_msg(&mp_type_RuntimeError, NULL);
89     }
90     self->locked = false;
91     MP_THREAD_GIL_EXIT();
92     mp_thread_mutex_unlock(&self->mutex);
93     MP_THREAD_GIL_ENTER();
94     return mp_const_none;
95 }
96 STATIC MP_DEFINE_CONST_FUN_OBJ_1(thread_lock_release_obj, thread_lock_release);
97 
thread_lock_locked(mp_obj_t self_in)98 STATIC mp_obj_t thread_lock_locked(mp_obj_t self_in) {
99     mp_obj_thread_lock_t *self = MP_OBJ_TO_PTR(self_in);
100     return mp_obj_new_bool(self->locked);
101 }
102 STATIC MP_DEFINE_CONST_FUN_OBJ_1(thread_lock_locked_obj, thread_lock_locked);
103 
thread_lock___exit__(size_t n_args,const mp_obj_t * args)104 STATIC mp_obj_t thread_lock___exit__(size_t n_args, const mp_obj_t *args) {
105     (void)n_args; // unused
106     return thread_lock_release(args[0]);
107 }
108 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(thread_lock___exit___obj, 4, 4, thread_lock___exit__);
109 
110 STATIC const mp_rom_map_elem_t thread_lock_locals_dict_table[] = {
111     { MP_ROM_QSTR(MP_QSTR_acquire), MP_ROM_PTR(&thread_lock_acquire_obj) },
112     { MP_ROM_QSTR(MP_QSTR_release), MP_ROM_PTR(&thread_lock_release_obj) },
113     { MP_ROM_QSTR(MP_QSTR_locked), MP_ROM_PTR(&thread_lock_locked_obj) },
114     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&thread_lock_acquire_obj) },
115     { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&thread_lock___exit___obj) },
116 };
117 
118 STATIC MP_DEFINE_CONST_DICT(thread_lock_locals_dict, thread_lock_locals_dict_table);
119 
120 STATIC const mp_obj_type_t mp_type_thread_lock = {
121     { &mp_type_type },
122     .name = MP_QSTR_lock,
123     .locals_dict = (mp_obj_dict_t *)&thread_lock_locals_dict,
124 };
125 
126 /****************************************************************/
127 // _thread module
128 
129 STATIC size_t thread_stack_size = 0;
130 
mod_thread_get_ident(void)131 STATIC mp_obj_t mod_thread_get_ident(void) {
132     return mp_obj_new_int_from_uint((uintptr_t)mp_thread_get_state());
133 }
134 STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_thread_get_ident_obj, mod_thread_get_ident);
135 
mod_thread_stack_size(size_t n_args,const mp_obj_t * args)136 STATIC mp_obj_t mod_thread_stack_size(size_t n_args, const mp_obj_t *args) {
137     mp_obj_t ret = mp_obj_new_int_from_uint(thread_stack_size);
138     if (n_args == 0) {
139         thread_stack_size = 0;
140     } else {
141         thread_stack_size = mp_obj_get_int(args[0]);
142     }
143     return ret;
144 }
145 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_thread_stack_size_obj, 0, 1, mod_thread_stack_size);
146 
147 typedef struct _thread_entry_args_t {
148     mp_obj_dict_t *dict_locals;
149     mp_obj_dict_t *dict_globals;
150     size_t stack_size;
151     mp_obj_t fun;
152     size_t n_args;
153     size_t n_kw;
154     mp_obj_t args[];
155 } thread_entry_args_t;
156 
thread_entry(void * args_in)157 STATIC void *thread_entry(void *args_in) {
158     // Execution begins here for a new thread.  We do not have the GIL.
159 
160     thread_entry_args_t *args = (thread_entry_args_t *)args_in;
161 
162     mp_state_thread_t ts;
163     mp_thread_set_state(&ts);
164 
165     mp_stack_set_top(&ts + 1); // need to include ts in root-pointer scan
166     mp_stack_set_limit(args->stack_size);
167 
168     #if MICROPY_ENABLE_PYSTACK
169     // TODO threading and pystack is not fully supported, for now just make a small stack
170     mp_obj_t mini_pystack[128];
171     mp_pystack_init(mini_pystack, &mini_pystack[128]);
172     #endif
173 
174     // The GC starts off unlocked on this thread.
175 
176     // ts.gc_lock_depth = 0;
177 
178     ts.mp_pending_exception = MP_OBJ_NULL;
179 
180     // set locals and globals from the calling context
181     mp_locals_set(args->dict_locals);
182     mp_globals_set(args->dict_globals);
183 
184     MP_THREAD_GIL_ENTER();
185 
186     // signal that we are set up and running
187     mp_thread_start();
188 
189     // TODO set more thread-specific state here:
190     //  cur_exception (root pointer)
191 
192     DEBUG_printf("[thread] start ts=%p args=%p stack=%p\n", &ts, &args, MP_STATE_THREAD(stack_top));
193 
194     nlr_buf_t nlr;
195     if (nlr_push(&nlr) == 0) {
196         mp_call_function_n_kw(args->fun, args->n_args, args->n_kw, args->args);
197         nlr_pop();
198     } else {
199         // uncaught exception
200         // check for SystemExit
201         mp_obj_base_t *exc = (mp_obj_base_t *)nlr.ret_val;
202         if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
203             // swallow exception silently
204         } else {
205             // print exception out
206             mp_printf(MICROPY_ERROR_PRINTER, "Unhandled exception in thread started by ");
207             mp_obj_print_helper(MICROPY_ERROR_PRINTER, args->fun, PRINT_REPR);
208             mp_printf(MICROPY_ERROR_PRINTER, "\n");
209             mp_obj_print_exception(MICROPY_ERROR_PRINTER, MP_OBJ_FROM_PTR(exc));
210         }
211     }
212 
213     DEBUG_printf("[thread] finish ts=%p\n", &ts);
214 
215     // signal that we are finished
216     mp_thread_finish();
217 
218     MP_THREAD_GIL_EXIT();
219 
220     return NULL;
221 }
222 
mod_thread_start_new_thread(size_t n_args,const mp_obj_t * args)223 STATIC mp_obj_t mod_thread_start_new_thread(size_t n_args, const mp_obj_t *args) {
224     // This structure holds the Python function and arguments for thread entry.
225     // We copy all arguments into this structure to keep ownership of them.
226     // We must be very careful about root pointers because this pointer may
227     // disappear from our address space before the thread is created.
228     thread_entry_args_t *th_args;
229 
230     // get positional arguments
231     size_t pos_args_len;
232     mp_obj_t *pos_args_items;
233     mp_obj_get_array(args[1], &pos_args_len, &pos_args_items);
234 
235     // check for keyword arguments
236     if (n_args == 2) {
237         // just position arguments
238         th_args = m_new_obj_var(thread_entry_args_t, mp_obj_t, pos_args_len);
239         th_args->n_kw = 0;
240     } else {
241         // positional and keyword arguments
242         if (mp_obj_get_type(args[2]) != &mp_type_dict) {
243             mp_raise_TypeError(MP_ERROR_TEXT("expecting a dict for keyword args"));
244         }
245         mp_map_t *map = &((mp_obj_dict_t *)MP_OBJ_TO_PTR(args[2]))->map;
246         th_args = m_new_obj_var(thread_entry_args_t, mp_obj_t, pos_args_len + 2 * map->used);
247         th_args->n_kw = map->used;
248         // copy across the keyword arguments
249         for (size_t i = 0, n = pos_args_len; i < map->alloc; ++i) {
250             if (mp_map_slot_is_filled(map, i)) {
251                 th_args->args[n++] = map->table[i].key;
252                 th_args->args[n++] = map->table[i].value;
253             }
254         }
255     }
256 
257     // copy across the positional arguments
258     th_args->n_args = pos_args_len;
259     memcpy(th_args->args, pos_args_items, pos_args_len * sizeof(mp_obj_t));
260 
261     // pass our locals and globals into the new thread
262     th_args->dict_locals = mp_locals_get();
263     th_args->dict_globals = mp_globals_get();
264 
265     // set the stack size to use
266     th_args->stack_size = thread_stack_size;
267 
268     // set the function for thread entry
269     th_args->fun = args[0];
270 
271     // spawn the thread!
272     mp_thread_create(thread_entry, th_args, &th_args->stack_size);
273 
274     return mp_const_none;
275 }
276 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_thread_start_new_thread_obj, 2, 3, mod_thread_start_new_thread);
277 
mod_thread_exit(void)278 STATIC mp_obj_t mod_thread_exit(void) {
279     mp_raise_type(&mp_type_SystemExit);
280 }
281 STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_thread_exit_obj, mod_thread_exit);
282 
mod_thread_allocate_lock(void)283 STATIC mp_obj_t mod_thread_allocate_lock(void) {
284     return MP_OBJ_FROM_PTR(mp_obj_new_thread_lock());
285 }
286 STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_thread_allocate_lock_obj, mod_thread_allocate_lock);
287 
288 STATIC const mp_rom_map_elem_t mp_module_thread_globals_table[] = {
289     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR__thread) },
290     { MP_ROM_QSTR(MP_QSTR_LockType), MP_ROM_PTR(&mp_type_thread_lock) },
291     { MP_ROM_QSTR(MP_QSTR_get_ident), MP_ROM_PTR(&mod_thread_get_ident_obj) },
292     { MP_ROM_QSTR(MP_QSTR_stack_size), MP_ROM_PTR(&mod_thread_stack_size_obj) },
293     { MP_ROM_QSTR(MP_QSTR_start_new_thread), MP_ROM_PTR(&mod_thread_start_new_thread_obj) },
294     { MP_ROM_QSTR(MP_QSTR_exit), MP_ROM_PTR(&mod_thread_exit_obj) },
295     { MP_ROM_QSTR(MP_QSTR_allocate_lock), MP_ROM_PTR(&mod_thread_allocate_lock_obj) },
296 };
297 
298 STATIC MP_DEFINE_CONST_DICT(mp_module_thread_globals, mp_module_thread_globals_table);
299 
300 const mp_obj_module_t mp_module_thread = {
301     .base = { &mp_type_module },
302     .globals = (mp_obj_dict_t *)&mp_module_thread_globals,
303 };
304 
305 #endif // MICROPY_PY_THREAD
306