Schedular working

zig-ecs/src/process/process.zig

@@ -1,10 +1,12 @@
+/// Processes are run by the Scheduler. They use a similar pattern to Allocators in that they are created and
+/// added as fields in a parent struct, your actual process that will be run.
 pub const Process = struct {
     const State = enum(u8) {
         uninitialized, running, paused, succeeded, failed, aborted, finished
     };
 
     updateFn: fn (self: *Process) void,
-    initFn: ?fn (self: *Process) void = null,
+    startFn: ?fn (self: *Process) void = null,
     abortedFn: ?fn (self: *Process) void = null,
     failedFn: ?fn (self: *Process) void = null,
     succeededFn: ?fn (self: *Process) void = null,
@@ -12,6 +14,10 @@ pub const Process = struct {
     state: State = .uninitialized,
     stopped: bool = false,
 
+    pub fn getParent(self: *Process, comptime T: type) *T {
+        return @fieldParentPtr(T, "process", self);
+    }
+
     /// Terminates a process with success if it's still alive
     pub fn succeed(self: *Process) void {
         if (self.alive()) self.state = .succeeded;
@@ -57,11 +63,11 @@ pub const Process = struct {
         return self.stopped;
     }
 
-    /// Updates a process and its internal state if required
+    /// Updates a process and its internal state
     pub fn tick(self: *Process) void {
         switch (self.state) {
             .uninitialized => {
-                if (self.initFn) |func| func(self);
+                if (self.startFn) |func| func(self);
                 self.state = .running;
             },
             .running => {

zig-ecs/src/process/scheduler.zig

@@ -1,13 +1,23 @@
 const std = @import("std");
 const Process = @import("process.zig").Process;
 
+/// Cooperative scheduler for processes. Each process is invoked once per tick. If a process terminates, it's
+/// removed automatically from the scheduler and it's never invoked again. A process can also have a child. In
+/// this case, the process is replaced with its child when it terminates if it returns with success. In case of errors,
+/// both the process and its child are discarded. In order to invoke all scheduled processes, call the `update` member function
+/// Processes add themselves by calling `attach` and must satisfy the following conditions:
+/// - have a field `process: Process`
+/// - have a method `initialize(self: *@This(), data: var) void` that initializes all fields and takes in a the data passed to `attach`
+/// - when initializing the `process` field it ust be given an `updateFn`. All other callbacks are optional.
+/// - in any callback you can get your oiginal struct back via `process.getParent(@This())`
 pub const Scheduler = struct {
     handlers: std.ArrayList(ProcessHandler),
     allocator: *std.mem.Allocator,
 
-    fn createProcessHandler(comptime T: type) ProcessHandler {
+    /// helper to create and prepare a process and wrap it in a ProcessHandler
+    fn createProcessHandler(comptime T: type, data: var) ProcessHandler {
         var proc = std.testing.allocator.create(T) catch unreachable;
-        proc.initialize();
+        proc.initialize(data);
 
         // get a closure so that we can safely deinit this later
         var handlerDeinitFn = struct {
@@ -29,9 +39,9 @@ pub const Scheduler = struct {
             return .{ .handler = handler };
         }
 
-        // TODO: fix and return when ProcessHandler can have next be a ProcessHandler
-        pub fn next(self: *@This(), comptime T: type) void { // *@This()
-            var next_handler = createProcessHandler(T);
+        // TODO: fix and return this when ProcessHandler can have next be a ProcessHandler
+        pub fn next(self: *@This(), comptime T: type, data: var) void { // *@This()
+            var next_handler = createProcessHandler(T, data);
             self.handler.next = .{ .deinitChild = next_handler.deinitChild, .process = next_handler.process };
         }
     };
@@ -87,19 +97,17 @@ pub const Scheduler = struct {
         };
     }
 
-    pub fn deinit(self: Scheduler) void {
-        for (self.handlers.items) |handler| {
-            handler.deinit(self.allocator);
-        }
+    pub fn deinit(self: *Scheduler) void {
+        self.clear();
         self.handlers.deinit();
     }
 
     /// Schedules a process for the next tick
-    pub fn attach(self: *Scheduler, comptime T: type) Continuation {
+    pub fn attach(self: *Scheduler, comptime T: type, data: var) Continuation {
         std.debug.assert(@hasDecl(T, "initialize"));
         std.debug.assert(@hasField(T, "process"));
 
-        var handler = createProcessHandler(T);
+        var handler = createProcessHandler(T, data);
         handler.process.tick();
 
         self.handlers.append(handler) catch unreachable;
@@ -129,7 +137,7 @@ pub const Scheduler = struct {
     /// resets the scheduler to its initial state and discards all the processes
     pub fn clear(self: *Scheduler) void {
         for (self.handlers.items) |handler| {
-            handler.deinit(handler.process, self.allocator);
+            handler.deinit(self.allocator);
         }
         self.handlers.items.len = 0;
     }
@@ -142,8 +150,6 @@ pub const Scheduler = struct {
     }
 };
 
-var fart: usize = 666;
-
 test "" {
     std.debug.warn("\n", .{});
 
@@ -151,41 +157,40 @@ test "" {
         process: Process,
         fart: usize,
 
-        pub fn initialize(self: *@This()) void {
+        pub fn initialize(self: *@This(), data: var) void {
             self.process = .{
-                .initFn = init,
+                .startFn = start,
                 .updateFn = update,
                 .abortedFn = aborted,
                 .failedFn = failed,
                 .succeededFn = succeeded,
             };
-            self.fart = fart;
-            fart += 111;
+            self.fart = data;
         }
 
-        fn init(process: *Process) void {
+        fn start(process: *Process) void {
             const self = @fieldParentPtr(@This(), "process", process);
-            std.debug.warn("init {}\n", .{self.fart});
+            // std.debug.warn("start {}\n", .{self.fart});
         }
 
         fn aborted(process: *Process) void {
             const self = @fieldParentPtr(@This(), "process", process);
-            std.debug.warn("aborted {}\n", .{self.fart});
+            // std.debug.warn("aborted {}\n", .{self.fart});
         }
 
         fn failed(process: *Process) void {
             const self = @fieldParentPtr(@This(), "process", process);
-            std.debug.warn("failed {}\n", .{self.fart});
+            // std.debug.warn("failed {}\n", .{self.fart});
         }
 
         fn succeeded(process: *Process) void {
             const self = @fieldParentPtr(@This(), "process", process);
-            std.debug.warn("succeeded {}\n", .{self.fart});
+            // std.debug.warn("succeeded {}\n", .{self.fart});
         }
 
         fn update(process: *Process) void {
             const self = @fieldParentPtr(@This(), "process", process);
-            std.debug.warn("update {}\n", .{self.fart});
+            // std.debug.warn("update {}\n", .{self.fart});
             process.succeed();
         }
     };
@@ -193,8 +198,56 @@ test "" {
     var scheduler = Scheduler.init(std.testing.allocator);
     defer scheduler.deinit();
 
-    _ = scheduler.attach(Tester).next(Tester);
+    _ = scheduler.attach(Tester, 33).next(Tester, 66);
     scheduler.update();
     scheduler.update();
     scheduler.update();
 }
+
+test "scheduler.clear" {
+    const Tester = struct {
+        process: Process,
+
+        pub fn initialize(self: *@This(), data: var) void {
+            self.process = .{ .updateFn = update };
+        }
+
+        fn update(process: *Process) void {
+            std.debug.assert(false);
+        }
+    };
+
+    var scheduler = Scheduler.init(std.testing.allocator);
+    defer scheduler.deinit();
+
+    _ = scheduler.attach(Tester, {}).next(Tester, {});
+    scheduler.clear();
+    scheduler.update();
+}
+
+test "scheduler.attach.next" {
+    const Tester = struct {
+        process: Process,
+        counter: *usize,
+
+        pub fn initialize(self: *@This(), data: var) void {
+            self.process = .{ .updateFn = update };
+            self.counter = data;
+        }
+
+        fn update(process: *Process) void {
+            const self = process.getParent(@This());
+            self.counter.* += 1;
+            process.succeed();
+        }
+    };
+
+    var scheduler = Scheduler.init(std.testing.allocator);
+    defer scheduler.deinit();
+
+    var counter: usize = 0;
+    _ = scheduler.attach(Tester, &counter).next(Tester, &counter);
+    scheduler.update();
+    scheduler.update();
+    std.testing.expectEqual(counter, 2);
+}