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 * Copyright (c) 2017 Pycom Limited
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27
28 #include "stdio.h"
29
30 #include "py/runtime.h"
31 #include "py/gc.h"
32 #include "py/mpthread.h"
33 #include "py/mphal.h"
34 #include "mpthreadport.h"
35
36 #include "esp_task.h"
37
38 #if MICROPY_PY_THREAD
39
40 #define MP_THREAD_MIN_STACK_SIZE (4 * 1024)
41 #define MP_THREAD_DEFAULT_STACK_SIZE (MP_THREAD_MIN_STACK_SIZE + 1024)
42 #define MP_THREAD_PRIORITY (ESP_TASK_PRIO_MIN + 1)
43
44 // this structure forms a linked list, one node per active thread
45 typedef struct _thread_t {
46 TaskHandle_t id; // system id of thread
47 int ready; // whether the thread is ready and running
48 void *arg; // thread Python args, a GC root pointer
49 void *stack; // pointer to the stack
50 size_t stack_len; // number of words in the stack
51 struct _thread_t *next;
52 } thread_t;
53
54 // the mutex controls access to the linked list
55 STATIC mp_thread_mutex_t thread_mutex;
56 STATIC thread_t thread_entry0;
57 STATIC thread_t *thread = NULL; // root pointer, handled by mp_thread_gc_others
58
mp_thread_init(void * stack,uint32_t stack_len)59 void mp_thread_init(void *stack, uint32_t stack_len) {
60 mp_thread_set_state(&mp_state_ctx.thread);
61 // create the first entry in the linked list of all threads
62 thread = &thread_entry0;
63 thread->id = xTaskGetCurrentTaskHandle();
64 thread->ready = 1;
65 thread->arg = NULL;
66 thread->stack = stack;
67 thread->stack_len = stack_len;
68 thread->next = NULL;
69 mp_thread_mutex_init(&thread_mutex);
70 }
71
mp_thread_gc_others(void)72 void mp_thread_gc_others(void) {
73 mp_thread_mutex_lock(&thread_mutex, 1);
74 for (thread_t *th = thread; th != NULL; th = th->next) {
75 gc_collect_root((void **)&th, 1);
76 gc_collect_root(&th->arg, 1); // probably not needed
77 if (th->id == xTaskGetCurrentTaskHandle()) {
78 continue;
79 }
80 if (!th->ready) {
81 continue;
82 }
83 gc_collect_root(th->stack, th->stack_len);
84 }
85 mp_thread_mutex_unlock(&thread_mutex);
86 }
87
mp_thread_get_state(void)88 mp_state_thread_t *mp_thread_get_state(void) {
89 return pvTaskGetThreadLocalStoragePointer(NULL, 1);
90 }
91
mp_thread_set_state(mp_state_thread_t * state)92 void mp_thread_set_state(mp_state_thread_t *state) {
93 vTaskSetThreadLocalStoragePointer(NULL, 1, state);
94 }
95
mp_thread_start(void)96 void mp_thread_start(void) {
97 mp_thread_mutex_lock(&thread_mutex, 1);
98 for (thread_t *th = thread; th != NULL; th = th->next) {
99 if (th->id == xTaskGetCurrentTaskHandle()) {
100 th->ready = 1;
101 break;
102 }
103 }
104 mp_thread_mutex_unlock(&thread_mutex);
105 }
106
107 STATIC void *(*ext_thread_entry)(void *) = NULL;
108
freertos_entry(void * arg)109 STATIC void freertos_entry(void *arg) {
110 if (ext_thread_entry) {
111 ext_thread_entry(arg);
112 }
113 vTaskDelete(NULL);
114 for (;;) {;
115 }
116 }
117
mp_thread_create_ex(void * (* entry)(void *),void * arg,size_t * stack_size,int priority,char * name)118 void mp_thread_create_ex(void *(*entry)(void *), void *arg, size_t *stack_size, int priority, char *name) {
119 // store thread entry function into a global variable so we can access it
120 ext_thread_entry = entry;
121
122 if (*stack_size == 0) {
123 *stack_size = MP_THREAD_DEFAULT_STACK_SIZE; // default stack size
124 } else if (*stack_size < MP_THREAD_MIN_STACK_SIZE) {
125 *stack_size = MP_THREAD_MIN_STACK_SIZE; // minimum stack size
126 }
127
128 // Allocate linked-list node (must be outside thread_mutex lock)
129 thread_t *th = m_new_obj(thread_t);
130
131 mp_thread_mutex_lock(&thread_mutex, 1);
132
133 // create thread
134 BaseType_t result = xTaskCreatePinnedToCore(freertos_entry, name, *stack_size / sizeof(StackType_t), arg, priority, &th->id, MP_TASK_COREID);
135 if (result != pdPASS) {
136 mp_thread_mutex_unlock(&thread_mutex);
137 mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("can't create thread"));
138 }
139
140 // add thread to linked list of all threads
141 th->ready = 0;
142 th->arg = arg;
143 th->stack = pxTaskGetStackStart(th->id);
144 th->stack_len = *stack_size / sizeof(uintptr_t);
145 th->next = thread;
146 thread = th;
147
148 // adjust the stack_size to provide room to recover from hitting the limit
149 *stack_size -= 1024;
150
151 mp_thread_mutex_unlock(&thread_mutex);
152 }
153
mp_thread_create(void * (* entry)(void *),void * arg,size_t * stack_size)154 void mp_thread_create(void *(*entry)(void *), void *arg, size_t *stack_size) {
155 mp_thread_create_ex(entry, arg, stack_size, MP_THREAD_PRIORITY, "mp_thread");
156 }
157
mp_thread_finish(void)158 void mp_thread_finish(void) {
159 mp_thread_mutex_lock(&thread_mutex, 1);
160 for (thread_t *th = thread; th != NULL; th = th->next) {
161 if (th->id == xTaskGetCurrentTaskHandle()) {
162 th->ready = 0;
163 break;
164 }
165 }
166 mp_thread_mutex_unlock(&thread_mutex);
167 }
168
169 // This is called from the FreeRTOS idle task and is not within Python context,
170 // so MP_STATE_THREAD is not valid and it does not have the GIL.
vPortCleanUpTCB(void * tcb)171 void vPortCleanUpTCB(void *tcb) {
172 if (thread == NULL) {
173 // threading not yet initialised
174 return;
175 }
176 thread_t *prev = NULL;
177 mp_thread_mutex_lock(&thread_mutex, 1);
178 for (thread_t *th = thread; th != NULL; prev = th, th = th->next) {
179 // unlink the node from the list
180 if ((void *)th->id == tcb) {
181 if (prev != NULL) {
182 prev->next = th->next;
183 } else {
184 // move the start pointer
185 thread = th->next;
186 }
187 // The "th" memory will eventually be reclaimed by the GC.
188 break;
189 }
190 }
191 mp_thread_mutex_unlock(&thread_mutex);
192 }
193
mp_thread_mutex_init(mp_thread_mutex_t * mutex)194 void mp_thread_mutex_init(mp_thread_mutex_t *mutex) {
195 // Need a binary semaphore so a lock can be acquired on one Python thread
196 // and then released on another.
197 mutex->handle = xSemaphoreCreateBinaryStatic(&mutex->buffer);
198 xSemaphoreGive(mutex->handle);
199 }
200
mp_thread_mutex_lock(mp_thread_mutex_t * mutex,int wait)201 int mp_thread_mutex_lock(mp_thread_mutex_t *mutex, int wait) {
202 return pdTRUE == xSemaphoreTake(mutex->handle, wait ? portMAX_DELAY : 0);
203 }
204
mp_thread_mutex_unlock(mp_thread_mutex_t * mutex)205 void mp_thread_mutex_unlock(mp_thread_mutex_t *mutex) {
206 xSemaphoreGive(mutex->handle);
207 }
208
mp_thread_deinit(void)209 void mp_thread_deinit(void) {
210 for (;;) {
211 // Find a task to delete
212 TaskHandle_t id = NULL;
213 mp_thread_mutex_lock(&thread_mutex, 1);
214 for (thread_t *th = thread; th != NULL; th = th->next) {
215 // Don't delete the current task
216 if (th->id != xTaskGetCurrentTaskHandle()) {
217 id = th->id;
218 break;
219 }
220 }
221 mp_thread_mutex_unlock(&thread_mutex);
222
223 if (id == NULL) {
224 // No tasks left to delete
225 break;
226 } else {
227 // Call FreeRTOS to delete the task (it will call vPortCleanUpTCB)
228 vTaskDelete(id);
229 }
230 }
231 }
232
233 #else
234
vPortCleanUpTCB(void * tcb)235 void vPortCleanUpTCB(void *tcb) {
236 }
237
238 #endif // MICROPY_PY_THREAD
239