samples: bench: Create benchmark sample

This runs various sync primitives in a basic benchmark.  This is useful
to compare performance between native threads and work-queue based
async.  Initial results suggest that, unexpectedly, there is additional
overhead with async.

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

samples/bench/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(bench)
+
+rust_cargo_application()

samples/bench/Cargo.toml

@@ -0,0 +1,25 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+[package]
+# This must be rustapp for now.
+name = "rustapp"
+version = "0.1.0"
+edition = "2021"
+description = "A sample hello world application in Rust"
+license = "Apache-2.0 or MIT"
+
+[lib]
+crate-type = ["staticlib"]
+
+[dependencies]
+zephyr = "0.1.0"
+
+# Dependencies that are used by build.rs.
+[build-dependencies]
+zephyr-build = "0.1.0"
+
+[profile.release]
+debug-assertions = true
+overflow-checks = true
+debug = true

samples/bench/Kconfig

@@ -0,0 +1,51 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+mainmenu "Rust Dining Philosphers"
+
+source "Kconfig.zephyr"
+
+choice
+	prompt "Select Synchronization implementation"
+	default SYNC_CHANNEL
+
+	config SYNC_SYS_SEMAPHORE
+		bool "Use sys::Semaphore to synchronize forks"
+		help
+		  Use to have the dining philosophers sample use sys::Semaphore, with one per fork, to
+		  synchronize.
+
+	config SYNC_SYS_DYNAMIC_SEMAPHORE
+		bool "Use a dynamic sys::Semaphore to synchronize forks"
+		help
+		  Use to have the dining philosophers sample use sys::Semaphore, with one per fork, to
+		  synchronize.  The Semaphores will be dynamically allocated.
+
+	config SYNC_SYS_MUTEX
+		bool "Use sys::Semaphore to synchronize forks"
+		help
+		  Use to have the dining philosophers sample use sys::Mutex, with one per fork, to
+		  synchronize.
+
+	config SYNC_CONDVAR
+		bool "Use sync::Condvar and sync::Mutex to synchronize forks"
+		help
+		  Use to have the dining philosophers sample use a single data structure, protected
+		  by a sync::Mutex and coordinated with a sync::Condvar, to synchronize.
+
+	config SYNC_CHANNEL
+		bool "Use sync::channel to synchronize forks"
+		help
+		  Use to have the dining philosophers sample use a worker thread, communicating via
+		  channels to synchronize.
+
+endchoice
+
+if SYNC_CHANNEL
+	config USE_BOUNDED_CHANNELS
+	bool "Should channel sync use bounded channels?"
+	default y
+	help
+	  If set, the channel-based communication will use bounded channels with bounds calculated
+	  to not ever block.
+endif

samples/bench/boards/pimoroni_tiny_2040.conf

@@ -0,0 +1,7 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+# This board doesn't have a serial console, so use RTT.
+CONFIG_UART_CONSOLE=n
+CONFIG_RTT_CONSOLE=y
+CONFIG_USE_SEGGER_RTT=y

samples/bench/boards/rpi_pico.conf

@@ -0,0 +1,7 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+# This board doesn't have a serial console, so use RTT.
+CONFIG_UART_CONSOLE=n
+CONFIG_RTT_CONSOLE=y
+CONFIG_USE_SEGGER_RTT=y

samples/bench/build.rs

@@ -0,0 +1,9 @@
+// Copyright (c) 2023 Linaro LTD
+// SPDX-License-Identifier: Apache-2.0
+
+// This crate needs access to kconfig variables.  This is an example of how to do that.  The
+// zephyr-build must be a build dependency.
+
+fn main() {
+    zephyr_build::export_bool_kconfig();
+}

samples/bench/prj.conf

@@ -0,0 +1,17 @@
+# Copyright (c) 2024 Linaro LTD
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_RUST=y
+CONFIG_RUST_ALLOC=y
+CONFIG_MAIN_STACK_SIZE=8192
+
+CONFIG_POLL=y
+
+# CONFIG_USERSPACE=y
+
+# Some debugging
+CONFIG_THREAD_MONITOR=y
+CONFIG_THREAD_ANALYZER=y
+CONFIG_THREAD_ANALYZER_USE_PRINTK=y
+CONFIG_THREAD_ANALYZER_AUTO=n
+# CONFIG_THREAD_ANALYZER_AUTO_INTERVAL=15

samples/bench/sample.yaml

@@ -0,0 +1,46 @@
+sample:
+  description: Philosphers, in Rust
+  name: philosophers rust
+common:
+  harness: console
+  harness_config:
+    type: one_line
+    regex:
+      # Match the statistics, and make sure that each philosopher has at least 10 (two digits)
+      # meals.
+      - "c:\\[\\d{2,}, \\d{2,}, \\d{2,}, \\d{2,}, \\d{2,}, \\d{2,}\\]"
+  tags: rust
+  filter: CONFIG_RUST_SUPPORTED
+tests:
+  sample.rust.philosopher.semaphore:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_SYS_SEMAPHORE=y
+  sample.rust.philosopher.dynsemaphore:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_SYS_DYNAMIC_SEMAPHORE=y
+  sample.rust.philosopher.sysmutex:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_SYS_MUTEX=y
+  sample.rust.philosopher.condvar:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_CONDVAR=y
+  sample.rust.philosopher.channel_bounded:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_CHANNEL=y
+      - CONFIG_USE_BOUNDED_CHANNELS=y
+  sample.rust.philosopher.channel_unbounded:
+    tags: introduction
+    min_ram: 32
+    extra_configs:
+      - CONFIG_SYNC_CHANNEL=y
+      - CONFIG_USE_BOUNDED_CHANNELS=n