| // 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. |
| #pragma once |
| |
| #include "RTOS.h" |
| #include "pw_assert/assert.h" |
| #include "pw_chrono/system_clock.h" |
| #include "pw_chrono_embos/system_clock_constants.h" |
| #include "pw_interrupt/context.h" |
| #include "pw_sync/counting_semaphore.h" |
| |
| namespace pw::sync { |
| |
| inline CountingSemaphore::CountingSemaphore() : native_type_() { |
| OS_CreateCSema(&native_type_, 0); |
| } |
| |
| inline CountingSemaphore::~CountingSemaphore() { |
| OS_DeleteCSema(&native_type_); |
| } |
| |
| inline void CountingSemaphore::acquire() { |
| // Enforce the pw::sync::CountingSemaphore IRQ contract. |
| PW_DASSERT(!interrupt::InInterruptContext()); |
| OS_WaitCSema(&native_type_); |
| } |
| |
| inline bool CountingSemaphore::try_acquire() noexcept { |
| return OS_CSemaRequest(&native_type_) != 0; |
| } |
| |
| inline bool CountingSemaphore::try_acquire_until( |
| chrono::SystemClock::time_point deadline) { |
| // Note that if this deadline is in the future, it will get rounded up by |
| // one whole tick due to how try_acquire_for is implemented. |
| return try_acquire_for(deadline - chrono::SystemClock::now()); |
| } |
| |
| inline CountingSemaphore::native_handle_type |
| CountingSemaphore::native_handle() { |
| return native_type_; |
| } |
| |
| } // namespace pw::sync |