blob: 244109ee93c764ace0c33e4340dd61376ca317f0 [file] [log] [blame]
// Copyright 2023 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_thread/thread.h"
#include <zephyr/kernel.h>
#include <zephyr/spinlock.h>
#include "pw_assert/check.h"
#include "pw_preprocessor/compiler.h"
#include "pw_thread/id.h"
#include "pw_thread_zephyr/config.h"
#include "pw_thread_zephyr/context.h"
#include "pw_thread_zephyr/options.h"
using pw::thread::zephyr::Context;
namespace pw::thread {
namespace {
k_spinlock global_thread_done_lock;
} // namespace
void Context::ThreadEntryPoint(void* void_context_ptr, void*, void*) {
Context& context = *static_cast<Context*>(void_context_ptr);
// Invoke the user's thread function. This may never return.
context.user_thread_entry_function_(context.user_thread_entry_arg_);
k_spinlock_key_t key = k_spin_lock(&global_thread_done_lock);
if (context.detached()) {
context.set_task_handle(nullptr);
} else {
// Defer cleanup to Thread's join() or detach().
context.set_thread_done();
}
k_spin_unlock(&global_thread_done_lock, key);
}
Thread::Thread(const thread::Options& facade_options,
ThreadRoutine entry,
void* arg)
: native_type_(nullptr) {
// Cast the generic facade options to the backend specific option of which
// only one type can exist at compile time.
auto options = static_cast<const zephyr::Options&>(facade_options);
PW_CHECK(options.static_context() != nullptr);
// Use the statically allocated context.
native_type_ = options.static_context();
// Can't use a context more than once.
PW_DCHECK_PTR_EQ(native_type_->task_handle(), nullptr);
// Reset the state of the static context in case it was re-used.
native_type_->set_detached(false);
native_type_->set_thread_done(false);
native_type_->set_thread_routine(entry, arg);
const k_tid_t task_handle =
k_thread_create(&native_type_->thread_info(),
options.static_context()->stack(),
options.static_context()->available_stack_size(),
Context::ThreadEntryPoint,
options.static_context(),
nullptr,
nullptr,
options.priority(),
options.native_options(),
K_NO_WAIT);
PW_CHECK_NOTNULL(task_handle); // Ensure it succeeded.
native_type_->set_task_handle(task_handle);
}
void Thread::detach() {
PW_CHECK(joinable());
k_spinlock_key_t key = k_spin_lock(&global_thread_done_lock);
native_type_->set_detached();
const bool thread_done = native_type_->thread_done();
if (thread_done) {
// The task finished (hit end of Context::ThreadEntryPoint) before we
// invoked detach, clean up the task handle to allow the Context reuse.
native_type_->set_task_handle(nullptr);
} else {
// We're detaching before the task finished, defer cleanup to the task at
// the end of Context::ThreadEntryPoint.
}
k_spin_unlock(&global_thread_done_lock, key);
// Update to no longer represent a thread of execution.
native_type_ = nullptr;
}
void Thread::join() {
PW_CHECK(joinable());
PW_CHECK(this_thread::get_id() != get_id());
PW_CHECK_INT_EQ(0, k_thread_join(native_type_->task_handle_, K_FOREVER));
native_type_->set_task_handle(nullptr);
// Update to no longer represent a thread of execution.
native_type_ = nullptr;
}
} // namespace pw::thread