1 files changed, 113 insertions, 0 deletions
diff --git a/circuitpython/supervisor/shared/reload.c b/circuitpython/supervisor/shared/reload.c
new file mode 100644
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+++ b/circuitpython/supervisor/shared/reload.c
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+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
+ *
+ * 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 "reload.h"
+
+#include "py/mphal.h"
+#include "py/mpstate.h"
+#include "supervisor/shared/reload.h"
+#include "supervisor/shared/tick.h"
+
+supervisor_allocation *next_code_allocation;
+#include "shared-bindings/supervisor/Runtime.h"
+
+// True if user has disabled autoreload.
+static bool autoreload_enabled = false;
+
+// Non-zero if autoreload is temporarily off, due to an AUTORELOAD_SUSPEND_... reason.
+static uint32_t autoreload_suspended = 0;
+
+volatile uint32_t last_autoreload_trigger = 0;
+
+void reload_initiate(supervisor_run_reason_t run_reason) {
+    supervisor_set_run_reason(run_reason);
+
+    // Raise reload exception, in case code is running.
+    MP_STATE_THREAD(mp_pending_exception) = MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_reload_exception));
+    #if MICROPY_ENABLE_SCHEDULER
+    if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) {
+        MP_STATE_VM(sched_state) = MP_SCHED_PENDING;
+    }
+    #endif
+}
+
+void autoreload_reset() {
+    last_autoreload_trigger = 0;
+}
+
+void autoreload_enable() {
+    autoreload_enabled = true;
+    last_autoreload_trigger = 0;
+}
+
+void autoreload_disable() {
+    autoreload_enabled = false;
+}
+
+void autoreload_suspend(uint32_t suspend_reason_mask) {
+    autoreload_suspended |= suspend_reason_mask;
+}
+
+void autoreload_resume(uint32_t suspend_reason_mask) {
+    autoreload_suspended &= ~suspend_reason_mask;
+}
+
+inline bool autoreload_is_enabled() {
+    return autoreload_enabled;
+}
+
+void autoreload_trigger() {
+    if (autoreload_enabled & !autoreload_suspended) {
+        last_autoreload_trigger = supervisor_ticks_ms32();
+        // Guard against the rare time that ticks is 0;
+        if (last_autoreload_trigger == 0) {
+            last_autoreload_trigger += 1;
+        }
+        // Initiate a reload of the VM immediately. Later code will pause to
+        // wait for the autoreload to become ready. Doing the VM exit
+        // immediately is clearer for the user.
+        reload_initiate(RUN_REASON_AUTO_RELOAD);
+    }
+}
+
+bool autoreload_ready() {
+    if (last_autoreload_trigger == 0 || autoreload_suspended != 0) {
+        return false;
+    }
+    // Wait for autoreload interval before reloading
+    uint32_t now = supervisor_ticks_ms32();
+    uint32_t diff;
+    if (now >= last_autoreload_trigger) {
+        diff = now - last_autoreload_trigger;
+    } else {
+        diff = now + (0xffffffff - last_autoreload_trigger);
+    }
+    return diff > CIRCUITPY_AUTORELOAD_DELAY_MS;
+}
+
+bool autoreload_pending(void) {
+    return last_autoreload_trigger != 0;
+}