micropython/ports/rp2/mutex_extra.c

31 lines
1.0 KiB
C

/*
* Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include "mutex_extra.h"
// These functions are taken from lib/pico-sdk/src/common/pico_sync/mutex.c and modified
// so that they atomically obtain the mutex and disable interrupts.
uint32_t __time_critical_func(mutex_enter_blocking_and_disable_interrupts)(mutex_t * mtx) {
lock_owner_id_t caller = lock_get_caller_owner_id();
do {
uint32_t save = spin_lock_blocking(mtx->core.spin_lock);
if (!lock_is_owner_id_valid(mtx->owner)) {
mtx->owner = caller;
spin_unlock_unsafe(mtx->core.spin_lock);
return save;
}
lock_internal_spin_unlock_with_wait(&mtx->core, save);
} while (true);
}
void __time_critical_func(mutex_exit_and_restore_interrupts)(mutex_t * mtx, uint32_t save) {
spin_lock_unsafe_blocking(mtx->core.spin_lock);
assert(lock_is_owner_id_valid(mtx->owner));
mtx->owner = LOCK_INVALID_OWNER_ID;
lock_internal_spin_unlock_with_notify(&mtx->core, save);
}