examples: Add message_passing example program collection

6 files changed, 205 insertions, 0 deletions

diff --git a/examples/message_passing/.gitignore b/examples/message_passing/.gitignore
new file mode 100644
index 0000000..69b00b1
--- /dev/null
+++ b/examples/message_passing/.gitignore
@@ -0,0 +1,7 @@
+# SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
+#
+# SPDX-License-Identifier: CC0-1.0
+
+# zig cache and output
+/zig-*/
+/.zig-*/
diff --git a/examples/message_passing/build.zig b/examples/message_passing/build.zig
new file mode 100644
index 0000000..0718d3b
--- /dev/null
+++ b/examples/message_passing/build.zig
@@ -0,0 +1,102 @@
+// SPDX-FileCopyrightText: Zig contributors
+// SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
+//
+// SPDX-License-Identifier: MIT
+
+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+    const riscv64_freestanding = std.zig.CrossTarget{
+        .cpu_arch = .riscv64,
+        .os_tag = .freestanding,
+        .ofmt = .elf,
+    };
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{ .whitelist = &[_]std.zig.CrossTarget{riscv64_freestanding}, .default_target = riscv64_freestanding });
+
+    // Standard optimization options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // set a preferred release mode, allowing the user to decide how to optimize.
+    const optimize = b.standardOptimizeOption(.{});
+
+    const srvre_sys = b.dependency("srvre_sys", .{
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const exe2 = b.addExecutable(.{
+        .name = "program2",
+        .root_source_file = b.path("src/main2.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    const exe = b.addExecutable(.{
+        .name = "message_passing",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    exe.step.dependOn(&exe2.step);
+
+    exe2.root_module.addImport("srvre_sys", srvre_sys.module("srvre_sys"));
+    exe.root_module.addImport("srvre_sys", srvre_sys.module("srvre_sys"));
+
+    // This declares intent for the executable to be installed into the
+    // standard location when the user invokes the "install" step (the default
+    // step when running `zig build`).
+    b.installArtifact(exe2);
+    b.installArtifact(exe);
+
+    // This *creates* a Run step in the build graph, to be executed when another
+    // step is evaluated that depends on it. The next line below will establish
+    // such a dependency.
+    const run_cmd = b.addRunArtifact(exe);
+
+    // By making the run step depend on the install step, it will be run from the
+    // installation directory rather than directly from within the cache directory.
+    // This is not necessary, however, if the application depends on other installed
+    // files, this ensures they will be present and in the expected location.
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    // This allows the user to pass arguments to the application in the build
+    // command itself, like this: `zig build run -- arg1 arg2 etc`
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    // This creates a build step. It will be visible in the `zig build --help` menu,
+    // and can be selected like this: `zig build run`
+    // This will evaluate the `run` step rather than the default, which is "install".
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const exe2_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/main2.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    const exe_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_exe2_unit_tests = b.addRunArtifact(exe2_unit_tests);
+    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+    // Similar to creating the run step earlier, this exposes a `test` step to
+    // the `zig build --help` menu, providing a way for the user to request
+    // running the unit tests.
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&run_exe2_unit_tests.step);
+    test_step.dependOn(&run_exe_unit_tests.step);
+}
diff --git a/examples/message_passing/build.zig.zon b/examples/message_passing/build.zig.zon
new file mode 100644
index 0000000..4cff5c1
--- /dev/null
+++ b/examples/message_passing/build.zig.zon
@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: Zig contributors
+// SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
+//
+// SPDX-License-Identifier: MIT
+
+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = "message_passing",
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.0",
+
+    // This field is optional.
+    // This is currently advisory only; Zig does not yet do anything
+    // with this value.
+    //.minimum_zig_version = "0.11.0",
+
+    // This field is optional.
+    // Each dependency must either provide a `url` and `hash`, or a `path`.
+    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+    // Once all dependencies are fetched, `zig build` no longer requires
+    // internet connectivity.
+    .dependencies = .{
+        .srvre_sys = .{
+            .url = "https://codeberg.org/Himbeer/srvre_sys/archive/e1cfddc48ae3f439b898405bbe165efcde0c92e6.tar.gz",
+            .hash = "1220759f392fa652192b071a7455b033c820c013a6ad345397c7cbf7fc278c68ecce",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        // For example...
+        //"LICENSE",
+        //"README.md",
+    },
+}
diff --git a/examples/message_passing/src/main.zig b/examples/message_passing/src/main.zig
new file mode 100644
index 0000000..e637f1a
--- /dev/null
+++ b/examples/message_passing/src/main.zig
@@ -0,0 +1,33 @@
+// SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+const srvre_sys = @import("srvre_sys");
+const os = srvre_sys.os;
+
+usingnamespace srvre_sys;
+
+const program2 = @embedFile("program2");
+var program2_aligned: [program2.len]u8 = undefined;
+
+pub fn main() void {
+    _ = os.consoleWrite("Hello from program 1\r\n") catch unreachable;
+
+    os.join(0) catch unreachable;
+
+    @memcpy(program2_aligned[0..], program2);
+    _ = os.launch(@alignCast(program2_aligned[0..])) catch unreachable;
+
+    var sender: u16 = undefined;
+    var buffer: [256]u8 = undefined;
+    while (true) {
+        const n = os.receive(0, &sender, &buffer) catch continue;
+        const message = buffer[0..n];
+
+        _ = os.consoleWrite("Program 1 received message from PID ") catch unreachable;
+        _ = os.consoleWrite(&[_]u8{'0' + @as(u8, @intCast(sender))}) catch unreachable;
+        _ = os.consoleWrite(": ") catch unreachable;
+        _ = os.consoleWrite(message) catch unreachable;
+        _ = os.consoleWrite("\r\n") catch unreachable;
+    }
+}
diff --git a/examples/message_passing/src/main2.zig b/examples/message_passing/src/main2.zig
new file mode 100644
index 0000000..c56f76f
--- /dev/null
+++ b/examples/message_passing/src/main2.zig
@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: 2024 Himbeer <himbeer@disroot.org>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+const srvre_sys = @import("srvre_sys");
+const os = srvre_sys.os;
+
+usingnamespace srvre_sys;
+
+pub fn main() void {
+    _ = os.consoleWrite("Hello from program 2\r\n") catch unreachable;
+
+    os.pass(0, 0, false, "Anonymous message") catch unreachable;
+    os.pass(0, 0, true, "Identified message") catch unreachable;
+    os.pass(1, 0, false, "Mischanneled message") catch unreachable;
+    os.pass(0, 1, false, "Unicast message") catch unreachable;
+    os.pass(0, 2, false, "Misdirected message") catch unreachable;
+}
diff --git a/examples/message_passing/src/program2 b/examples/message_passing/src/program2
new file mode 120000
index 0000000..03417da
--- /dev/null
+++ b/examples/message_passing/src/program2
@@ -0,0 +1 @@
+../zig-out/bin/program2
\ No newline at end of file