py/scheduler: Add mp_sched_exception() to schedule a pending exception.

This helper is added to properly set a pending exception, to mirror
mp_sched_schedule(), which schedules a function.

Signed-off-by: Damien George <damien@micropython.org>

ports/esp32/mpconfigport.h

@@ -264,6 +264,7 @@ void *esp_native_code_commit(void *, size_t, void *);
 #endif
 
 // Functions that should go in IRAM
+#define MICROPY_WRAP_MP_SCHED_EXCEPTION(f) IRAM_ATTR f
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) IRAM_ATTR f
 
 #define UINT_FMT "%u"

ports/esp8266/mpconfigport.h

@@ -195,6 +195,7 @@ extern const struct _mp_obj_module_t mp_module_onewire;
 #define MICROPY_PY_SYS_PLATFORM "esp8266"
 
 #define MP_FASTCODE(n) __attribute__((section(".iram0.text." #n))) n
+#define MICROPY_WRAP_MP_SCHED_EXCEPTION(f) MP_FASTCODE(f)
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) MP_FASTCODE(f)
 #define MICROPY_WRAP_MP_SCHED_SCHEDULE(f) MP_FASTCODE(f)
 

py/mpconfig.h

@@ -1504,6 +1504,10 @@ typedef double mp_float_t;
 /*****************************************************************************/
 /* Hooks for a port to wrap functions with attributes                        */
 
+#ifndef MICROPY_WRAP_MP_SCHED_EXCEPTION
+#define MICROPY_WRAP_MP_SCHED_EXCEPTION(f) f
+#endif
+
 #ifndef MICROPY_WRAP_MP_KEYBOARD_INTERRUPT
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) f
 #endif

py/runtime.h

@@ -64,6 +64,7 @@ extern const byte mp_binary_op_method_name[];
 void mp_init(void);
 void mp_deinit(void);
 
+void mp_sched_exception(mp_obj_t exc);
 void mp_keyboard_interrupt(void);
 void mp_handle_pending(bool raise_exc);
 void mp_handle_pending_tail(mp_uint_t atomic_state);

py/scheduler.c

@@ -28,17 +28,21 @@
 
 #include "py/runtime.h"
 
-#if MICROPY_KBD_EXCEPTION
-// This function may be called asynchronously at any time so only do the bare minimum.
-void MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(mp_keyboard_interrupt)(void) {
-    MP_STATE_VM(mp_kbd_exception).traceback_data = NULL;
-    MP_STATE_VM(mp_pending_exception) = MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception));
+void mp_sched_exception(mp_obj_t exc) {
+    MP_STATE_VM(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_KEYBOARD_INTERRUPT(mp_keyboard_interrupt)(void) {
+    MP_STATE_VM(mp_kbd_exception).traceback_data = NULL;
+    mp_sched_exception(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception)));
+}
 #endif
 
 #if MICROPY_ENABLE_SCHEDULER