diff options
| author | Andrew Leech <andrew.leech@planetinnovation.com.au> | 2019-03-21 11:52:10 +1100 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2019-03-26 16:35:42 +1100 |
| commit | 8977c7eb581f5d06500edb1ea29aea5cbda04f28 (patch) | |
| tree | 10291cc81c84a9eb0732367c613c35511be4ee48 /py/scheduler.c | |
| parent | 2befcb8a9d54f3f9c059b45eba3e9d4e5fb13514 (diff) | |
py/scheduler: Convert micropythyon.schedule() to a circular buffer.
This means the schedule operates on a first-in, first-executed manner
rather than the current last-in, first executed.
Diffstat (limited to 'py/scheduler.c')
| -rw-r--r-- | py/scheduler.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/py/scheduler.c b/py/scheduler.c index 30851a4d2..5edff45b6 100644 --- a/py/scheduler.c +++ b/py/scheduler.c @@ -30,6 +30,19 @@ #if MICROPY_ENABLE_SCHEDULER +#define IDX_MASK(i) ((i) & (MICROPY_SCHEDULER_DEPTH - 1)) + +static inline bool mp_sched_full(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() == MICROPY_SCHEDULER_DEPTH; +} + +static inline bool mp_sched_empty(void) { + return mp_sched_num_pending() == 0; +} + // A variant of this is inlined in the VM at the pending exception check void mp_handle_pending(void) { if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) { @@ -51,8 +64,10 @@ void mp_handle_pending(void) { // 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_STATE_VM(sched_sp) > 0) { - mp_sched_item_t item = MP_STATE_VM(sched_stack)[--MP_STATE_VM(sched_sp)]; + if (!mp_sched_empty()) { + mp_sched_item_t item = MP_STATE_VM(sched_stack)[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 { @@ -87,13 +102,13 @@ void mp_sched_unlock(void) { bool mp_sched_schedule(mp_obj_t function, mp_obj_t arg) { mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION(); bool ret; - if (MP_STATE_VM(sched_sp) < MICROPY_SCHEDULER_DEPTH) { + if (!mp_sched_full()) { if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) { MP_STATE_VM(sched_state) = MP_SCHED_PENDING; } - MP_STATE_VM(sched_stack)[MP_STATE_VM(sched_sp)].func = function; - MP_STATE_VM(sched_stack)[MP_STATE_VM(sched_sp)].arg = arg; - ++MP_STATE_VM(sched_sp); + uint8_t iput = IDX_MASK(MP_STATE_VM(sched_idx) + MP_STATE_VM(sched_len)++); + MP_STATE_VM(sched_stack)[iput].func = function; + MP_STATE_VM(sched_stack)[iput].arg = arg; ret = true; } else { // schedule stack is full |