[PATCH v2 8/8] rust: workqueue: add examples

Alice Ryhl
2023-06-01T13:57:53Z

This adds two examples of how to use the workqueue. The first example
shows how to use it when you only have one `work_struct` field, and the
second example shows how to use it when you have multiple `work_struct`
fields.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/kernel/workqueue.rs | 104 +++++++++++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index c302e8b8624b..cefcf43ff40e 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -26,6 +26,110 @@
//! * The `WorkItemPointer` trait is implemented for the pointer type that points at a something
//! that implements `WorkItem`.
//!
+//! ## Example
+//!
+//! This example defines a struct that holds an integer and can be scheduled on the workqueue. When
+//! the struct is executed, it will print the integer. Since there is only one `work_struct` field,
+//! we do not need to specify ids for the fields.
+//!
+//! ```
+//! use kernel::prelude::*;
+//! use kernel::sync::Arc;
+//! use kernel::workqueue::{self, Work, WorkItem};
+//!
+//! #[pin_data]
+//! struct MyStruct {
+//! value: i32,
+//! #[pin]
+//! work: Work<MyStruct>,
+//! }
+//!
+//! impl_has_work! {
+//! impl HasWork<Self> for MyStruct { self.work }
+//! }
+//!
+//! impl MyStruct {
+//! fn new(value: i32) -> Result<Arc<Self>> {
+//! Arc::pin_init(pin_init!(MyStruct {
+//! value,
+//! work <- Work::new(),
+//! }))
+//! }
+//! }
+//!
+//! impl WorkItem for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The value is: {}", this.value);
+//! }
+//! }
+//!
+//! /// This method will enqueue the struct for execution on the system workqueue, where its value
+//! /// will be printed.
+//! fn print_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue(val);
+//! }
+//! ```
+//!
+//! The following example shows how multiple `work_struct` fields can be used:
+//!
+//! ```
+//! use kernel::prelude::*;
+//! use kernel::sync::Arc;
+//! use kernel::workqueue::{self, Work, WorkItem};
+//!
+//! #[pin_data]
+//! struct MyStruct {
+//! value_1: i32,
+//! value_2: i32,
+//! #[pin]
+//! work_1: Work<MyStruct, 1>,
+//! #[pin]
+//! work_2: Work<MyStruct, 2>,
+//! }
+//!
+//! impl_has_work! {
+//! impl HasWork<Self, 1> for MyStruct { self.work_1 }
+//! impl HasWork<Self, 2> for MyStruct { self.work_2 }
+//! }
+//!
+//! impl MyStruct {
+//! fn new(value_1: i32, value_2: i32) -> Result<Arc<Self>> {
+//! Arc::pin_init(pin_init!(MyStruct {
+//! value_1,
+//! value_2,
+//! work_1 <- Work::new(),
+//! work_2 <- Work::new(),
+//! }))
+//! }
+//! }
+//!
+//! impl WorkItem<1> for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The value is: {}", this.value_1);
+//! }
+//! }
+//!
+//! impl WorkItem<2> for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The second value is: {}", this.value_2);
+//! }
+//! }
+//!
+//! fn print_1_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue::<Arc<MyStruct>, 1>(val);
+//! }
+//!
+//! fn print_2_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue::<Arc<MyStruct>, 2>(val);
+//! }
+//! ```
+//!
//! C header: [`include/linux/workqueue.h`](../../../../include/linux/workqueue.h)

use crate::{bindings, prelude::*, sync::Arc, types::Opaque};
--
2.41.0.rc0.172.g3f132b7071-goog