| // Copyright 2021 The Pigweed Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| // use this file except in compliance with the License. You may obtain a copy of |
| // the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| // License for the specific language governing permissions and limitations under |
| // the License. |
| |
| #include "pw_sync/interrupt_spin_lock.h" |
| |
| #include "RTOS.h" |
| #include "pw_assert/check.h" |
| |
| namespace pw::sync { |
| |
| void InterruptSpinLock::lock() { |
| // Mask interrupts. |
| OS_IncDI(); |
| |
| // Disable task switching to ensure kernel APIs cannot switch to other tasks |
| // which could then end up deadlocking recursively on this same lock. |
| OS_SuspendAllTasks(); |
| |
| // We can't deadlock here so crash instead. |
| PW_DCHECK(!native_type_.locked, |
| "Recursive InterruptSpinLock::lock() detected"); |
| native_type_.locked = true; |
| } |
| |
| void InterruptSpinLock::unlock() { |
| native_type_.locked = false; |
| OS_ResumeAllSuspendedTasks(); // Restore task switching. |
| OS_DecRI(); // Restore interrupts. |
| } |
| |
| } // namespace pw::sync |