add circuitpython code

1 files changed, 162 insertions, 0 deletions

diff --git a/circuitpython/py/scheduler.c b/circuitpython/py/scheduler.c
new file mode 100644
index 0000000..1fd5dae
--- /dev/null
+++ b/circuitpython/py/scheduler.c
@@ -0,0 +1,162 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2017 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+
+#include "py/runtime.h"
+
+// Schedules an exception on the main thread (for exceptions "thrown" by async
+// sources such as interrupts and UNIX signal handlers).
+void MICROPY_WRAP_MP_SCHED_EXCEPTION(mp_sched_exception)(mp_obj_t exc) {
+    MP_STATE_MAIN_THREAD(mp_pending_exception) = exc;
+    #if MICROPY_ENABLE_SCHEDULER
+    if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) {
+        MP_STATE_VM(sched_state) = MP_SCHED_PENDING;
+    }
+    #endif
+}
+
+#if MICROPY_KBD_EXCEPTION
+// This function may be called asynchronously at any time so only do the bare minimum.
+void MICROPY_WRAP_MP_SCHED_KEYBOARD_INTERRUPT(mp_sched_keyboard_interrupt)(void) {
+    MP_STATE_VM(mp_kbd_exception).traceback = (mp_obj_traceback_t *)&mp_const_empty_traceback_obj;
+    mp_sched_exception(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception)));
+}
+#endif
+
+#if MICROPY_ENABLE_SCHEDULER
+
+#define IDX_MASK(i) ((i) & (MICROPY_SCHEDULER_DEPTH - 1))
+
+// This is a macro so it is guaranteed to be inlined in functions like
+// mp_sched_schedule that may be located in a special memory region.
+#define mp_sched_full() (mp_sched_num_pending() == MICROPY_SCHEDULER_DEPTH)
+
+static inline bool mp_sched_empty(void) {
+    MP_STATIC_ASSERT(MICROPY_SCHEDULER_DEPTH <= 255); // MICROPY_SCHEDULER_DEPTH must fit in 8 bits
+    MP_STATIC_ASSERT((IDX_MASK(MICROPY_SCHEDULER_DEPTH) == 0)); // MICROPY_SCHEDULER_DEPTH must be a power of 2
+
+    return mp_sched_num_pending() == 0;
+}
+
+// A variant of this is inlined in the VM at the pending exception check
+void mp_handle_pending(bool raise_exc) {
+    if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) {
+        mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+        // Re-check state is still pending now that we're in the atomic section.
+        if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) {
+            mp_obj_t obj = MP_STATE_THREAD(mp_pending_exception);
+            if (obj != MP_OBJ_NULL) {
+                MP_STATE_THREAD(mp_pending_exception) = MP_OBJ_NULL;
+                if (!mp_sched_num_pending()) {
+                    MP_STATE_VM(sched_state) = MP_SCHED_IDLE;
+                }
+                if (raise_exc) {
+                    MICROPY_END_ATOMIC_SECTION(atomic_state);
+                    nlr_raise(obj);
+                }
+            }
+            mp_handle_pending_tail(atomic_state);
+        } else {
+            MICROPY_END_ATOMIC_SECTION(atomic_state);
+        }
+    }
+}
+
+// This function should only be called by mp_handle_pending,
+// or by the VM's inlined version of that function.
+void mp_handle_pending_tail(mp_uint_t atomic_state) {
+    MP_STATE_VM(sched_state) = MP_SCHED_LOCKED;
+    if (!mp_sched_empty()) {
+        mp_sched_item_t item = MP_STATE_VM(sched_queue)[MP_STATE_VM(sched_idx)];
+        MP_STATE_VM(sched_idx) = IDX_MASK(MP_STATE_VM(sched_idx) + 1);
+        --MP_STATE_VM(sched_len);
+        MICROPY_END_ATOMIC_SECTION(atomic_state);
+        mp_call_function_1_protected(item.func, item.arg);
+    } else {
+        MICROPY_END_ATOMIC_SECTION(atomic_state);
+    }
+    mp_sched_unlock();
+}
+
+void mp_sched_lock(void) {
+    mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+    if (MP_STATE_VM(sched_state) < 0) {
+        --MP_STATE_VM(sched_state);
+    } else {
+        MP_STATE_VM(sched_state) = MP_SCHED_LOCKED;
+    }
+    MICROPY_END_ATOMIC_SECTION(atomic_state);
+}
+
+void mp_sched_unlock(void) {
+    mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+    assert(MP_STATE_VM(sched_state) < 0);
+    if (++MP_STATE_VM(sched_state) == 0) {
+        // vm became unlocked
+        if (MP_STATE_THREAD(mp_pending_exception) != MP_OBJ_NULL || mp_sched_num_pending()) {
+            MP_STATE_VM(sched_state) = MP_SCHED_PENDING;
+        } else {
+            MP_STATE_VM(sched_state) = MP_SCHED_IDLE;
+        }
+    }
+    MICROPY_END_ATOMIC_SECTION(atomic_state);
+}
+
+bool MICROPY_WRAP_MP_SCHED_SCHEDULE(mp_sched_schedule)(mp_obj_t function, mp_obj_t arg) {
+    mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
+    bool ret;
+    if (!mp_sched_full()) {
+        if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) {
+            MP_STATE_VM(sched_state) = MP_SCHED_PENDING;
+        }
+        uint8_t iput = IDX_MASK(MP_STATE_VM(sched_idx) + MP_STATE_VM(sched_len)++);
+        MP_STATE_VM(sched_queue)[iput].func = function;
+        MP_STATE_VM(sched_queue)[iput].arg = arg;
+        MICROPY_SCHED_HOOK_SCHEDULED;
+        ret = true;
+    } else {
+        // schedule queue is full
+        ret = false;
+    }
+    MICROPY_END_ATOMIC_SECTION(atomic_state);
+    return ret;
+}
+
+#else // MICROPY_ENABLE_SCHEDULER
+
+// A variant of this is inlined in the VM at the pending exception check
+void mp_handle_pending(bool raise_exc) {
+    if (MP_STATE_THREAD(mp_pending_exception) != MP_OBJ_NULL) {
+        mp_obj_t obj = MP_STATE_THREAD(mp_pending_exception);
+        MP_STATE_THREAD(mp_pending_exception) = MP_OBJ_NULL;
+        if (raise_exc) {
+            nlr_raise(obj);
+        }
+    }
+}
+
+#endif // MICROPY_ENABLE_SCHEDULER