tmp: progress towards unifying scheduler

src/core/Scheduler.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 
-const Bus = @import("Bus.zig");
+const nds9 = @import("nds9.zig");
+const nds7 = @import("nds7.zig");
 
 const PriorityQueue = std.PriorityQueue(Event, void, Event.lessThan);
 const Allocator = std.mem.Allocator;
@@ -19,6 +20,12 @@ pub fn push(self: *@This(), kind: Event.Kind, offset: u64) void {
     self.queue.add(.{ .kind = kind, .tick = self.tick + offset }) catch unreachable;
 }
 
+pub inline fn peek(self: *const @This()) Event {
+    @setRuntimeSafety(false);
+
+    return self.queue.items[0];
+}
+
 pub fn deinit(self: @This()) void {
     self.queue.deinit();
 }
@@ -37,18 +44,33 @@ pub fn reset(self: *@This()) void {
     self.tick = 0;
 }
 
-pub fn handle(self: *@This(), bus: *Bus) void {
+pub fn handle7(self: *@This(), bus: *nds7.Bus) void {
+    _ = bus;
+    const event = self.queue.remove();
+    // const late = self.tick - event.tick;
+
+    switch (event.kind) {
+        .nds7 => {},
+        .heat_death => unreachable,
+        .nds9 => unreachable, // handled by handle7
+    }
+}
+
+pub fn handle9(self: *@This(), bus: *nds9.Bus) void {
     const event = self.queue.remove();
     const late = self.tick - event.tick;
 
     switch (event.kind) {
-        .heat_death => unreachable,
+        .nds9 => |ev| switch (ev) {
             .draw => {
                 bus.ppu.drawScanline(bus);
                 bus.ppu.onHdrawEnd(self, late);
             },
             .hblank => bus.ppu.onHblankEnd(self, late),
             .vblank => bus.ppu.onHblankEnd(self, late),
+        },
+        .heat_death => unreachable,
+        .nds7 => unreachable, // handled by handle7
     }
 }
 
@@ -56,13 +78,20 @@ pub const Event = struct {
     tick: u64,
     kind: Kind,
 
-    pub const Kind = enum {
+    pub const Event7 = enum {};
-        heat_death,
+
+    pub const Event9 = enum {
         draw,
         hblank,
         vblank,
     };
 
+    pub const Kind = union(enum) {
+        heat_death: void,
+        nds9: Event9,
+        nds7: Event7,
+    };
+
     fn lessThan(_: void, left: @This(), right: @This()) std.math.Order {
         return std.math.order(left.tick, right.tick);
     }

src/core/emu.zig

@@ -4,6 +4,7 @@ const nds7 = @import("nds7.zig");
 
 const Header = @import("cartridge.zig").Header;
 const SharedIo = @import("io.zig").Io;
+const Scheduler = @import("Scheduler.zig");
 const Arm946es = nds9.Arm946es;
 
 const Allocator = std.mem.Allocator;
@@ -68,46 +69,82 @@ const dot_clock = 5585664; //   5.585664 Hz
 const arm7_clock = bus_clock;
 const arm9_clock = bus_clock * 2;
 
-pub fn runFrame(nds7_group: nds7.Group, nds9_group: nds9.Group) void {
+pub fn runFrame(scheduler: *Scheduler, arm7: nds7.Group, arm9: nds9.Group) void {
-    // TODO: might be more efficient to run them both in the same loop?
+    const nds9_frame_end = blk: {
-    {
-        const scheduler = nds9_group.scheduler;
-
         const cycles_per_dot = arm9_clock / dot_clock + 1;
         comptime std.debug.assert(cycles_per_dot == 12);
 
         const cycles_per_frame = 355 * 263 * cycles_per_dot;
-        const frame_end = scheduler.tick + cycles_per_frame;
+        break :blk scheduler.tick + cycles_per_frame;
+    };
 
-        const cpu = nds9_group.cpu;
+    // const nds7_frame_end = blk: {
-        const bus = nds9_group.bus;
+    //     const cycles_per_dot = arm7_clock / dot_clock + 1;
+    //     comptime std.debug.assert(cycles_per_dot == 6);
 
-        while (scheduler.tick < frame_end) {
+    //     const cycles_per_frame = 355 * 263 * cycles_per_dot;
-            cpu.step();
+    //     const frame_end = scheduler.tick + cycles_per_frame;
+    // };
 
-            if (scheduler.tick >= scheduler.next()) scheduler.handle(bus);
+    // TODO: Figure out Syncing
-        }
-    }
 
-    {
+    while (scheduler.tick < nds9_frame_end) {
-        const scheduler = nds7_group.scheduler;
+        arm7.cpu.step();
+        arm9.cpu.step();
+        arm9.cpu.step();
 
-        const cycles_per_dot = arm7_clock / dot_clock + 1;
+        const next_ev = scheduler.peek();
-        comptime std.debug.assert(cycles_per_dot == 6);
 
-        const cycles_per_frame = 355 * 263 * cycles_per_dot;
+        if (scheduler.tick >= next_ev.tick) {
-        const frame_end = scheduler.tick + cycles_per_frame;
+            switch (next_ev.kind) {
-
+                .heat_death => unreachable,
-        const cpu = nds7_group.cpu;
+                .nds9 => scheduler.handle9(arm9.bus),
-        const bus = nds7_group.bus;
+                .nds7 => scheduler.handle7(arm7.bus),
-
-        while (scheduler.tick < frame_end) {
-            cpu.step();
-
-            if (scheduler.tick >= scheduler.next()) scheduler.handle(bus);
             }
         }
     }
+}
+
+// pub fn runFrame(nds7_group: nds7.Group, nds9_group: nds9.Group) void {
+//     // TODO: might be more efficient to run them both in the same loop?
+//     {
+//         const scheduler = nds9_group.scheduler;
+
+//         const cycles_per_dot = arm9_clock / dot_clock + 1;
+//         comptime std.debug.assert(cycles_per_dot == 12);
+
+//         const cycles_per_frame = 355 * 263 * cycles_per_dot;
+//         const frame_end = scheduler.tick + cycles_per_frame;
+
+//         const cpu = nds9_group.cpu;
+//         const bus = nds9_group.bus;
+
+//         while (scheduler.tick < frame_end) {
+//             cpu.step();
+
+//             if (scheduler.tick >= scheduler.next()) scheduler.handle(bus);
+//         }
+//     }
+
+//     {
+//         const scheduler = nds7_group.scheduler;
+
+//         const cycles_per_dot = arm7_clock / dot_clock + 1;
+//         comptime std.debug.assert(cycles_per_dot == 6);
+
+//         const cycles_per_frame = 355 * 263 * cycles_per_dot;
+//         const frame_end = scheduler.tick + cycles_per_frame;
+
+//         const cpu = nds7_group.cpu;
+//         const bus = nds7_group.bus;
+
+//         while (scheduler.tick < frame_end) {
+//             cpu.step();
+
+//             if (scheduler.tick >= scheduler.next()) scheduler.handle(bus);
+//         }
+//     }
+// }
 
 // FIXME: Perf win to allocating on the stack instead?
 pub const SharedContext = struct {

src/core/nds7.zig

@@ -2,7 +2,6 @@ const std = @import("std");
 
 pub const Bus = @import("nds7/Bus.zig");
 pub const io = @import("nds7/io.zig");
-pub const Scheduler = @import("nds7/Scheduler.zig");
 pub const Arm7tdmi = @import("arm32").Arm7tdmi;
 
 const Allocator = std.mem.Allocator;
@@ -11,11 +10,9 @@ const Allocator = std.mem.Allocator;
 pub const Group = struct {
     cpu: *Arm7tdmi,
     bus: *Bus,
-    scheduler: *Scheduler,
 
     /// Responsible for deallocated the ARM7 CPU, Bus and Scheduler
     pub fn deinit(self: @This(), allocator: Allocator) void {
         self.bus.deinit(allocator);
-        self.scheduler.deinit();
     }
 };

src/core/nds7/Bus.zig

@@ -1,7 +1,7 @@
 const std = @import("std");
 const io = @import("io.zig");
 
-const Scheduler = @import("Scheduler.zig");
+const Scheduler = @import("../Scheduler.zig");
 const SharedIo = @import("../io.zig").Io;
 const SharedContext = @import("../emu.zig").SharedContext;
 const forceAlign = @import("../emu.zig").forceAlign;

src/core/nds7/Scheduler.zig

@@ -1,59 +0,0 @@
-const std = @import("std");
-
-const Bus = @import("Bus.zig");
-
-const PriorityQueue = std.PriorityQueue(Event, void, Event.lessThan);
-const Allocator = std.mem.Allocator;
-
-tick: u64 = 0,
-queue: PriorityQueue,
-
-pub fn init(allocator: Allocator) !@This() {
-    var queue = PriorityQueue.init(allocator, {});
-    try queue.add(.{ .tick = std.math.maxInt(u64), .kind = .heat_death });
-
-    return .{ .queue = queue };
-}
-
-pub fn push(self: *@This(), kind: Event.Kind, offset: u64) void {
-    self.queue.add(.{ .kind = kind, .tick = self.tick + offset }) catch unreachable;
-}
-
-pub fn deinit(self: @This()) void {
-    self.queue.deinit();
-}
-
-pub fn now(self: @This()) u64 {
-    return self.tick;
-}
-
-pub fn next(self: @This()) u64 {
-    @setRuntimeSafety(false);
-    return self.queue.items[0].tick;
-}
-
-pub fn reset(self: *@This()) void {
-    self.tick = 0;
-}
-
-pub fn handle(self: *@This(), bus: *Bus) void {
-    _ = bus;
-    const event = self.queue.remove();
-    const late = self.tick - event.tick;
-    _ = late;
-
-    switch (event.kind) {
-        .heat_death => unreachable,
-    }
-}
-
-pub const Event = struct {
-    tick: u64,
-    kind: Kind,
-
-    pub const Kind = enum { heat_death };
-
-    fn lessThan(_: void, left: @This(), right: @This()) std.math.Order {
-        return std.math.order(left.tick, right.tick);
-    }
-};

src/core/nds9.zig

@@ -3,7 +3,6 @@ const std = @import("std");
 pub const Bus = @import("nds9/Bus.zig");
 pub const Cp15 = @import("nds9/Cp15.zig");
 pub const io = @import("nds9/io.zig");
-pub const Scheduler = @import("nds9/Scheduler.zig");
 pub const Arm946es = @import("arm32").Arm946es;
 
 const Allocator = std.mem.Allocator;
@@ -12,11 +11,9 @@ const Allocator = std.mem.Allocator;
 pub const Group = struct {
     cpu: *Arm946es,
     bus: *Bus,
-    scheduler: *Scheduler,
 
     /// Responsible for deallocating the ARM9 CPU, Bus and Scheduler
     pub fn deinit(self: @This(), allocator: Allocator) void {
         self.bus.deinit(allocator);
-        self.scheduler.deinit();
     }
 };

src/core/nds9/Bus.zig

@@ -2,7 +2,7 @@ const std = @import("std");
 const io = @import("io.zig");
 
 const Ppu = @import("../ppu.zig").Ppu;
-const Scheduler = @import("Scheduler.zig");
+const Scheduler = @import("../Scheduler.zig");
 const SharedContext = @import("../emu.zig").SharedContext;
 const forceAlign = @import("../emu.zig").forceAlign;
 
@@ -27,7 +27,7 @@ pub fn init(allocator: Allocator, scheduler: *Scheduler, shared_ctx: SharedConte
     @memset(vram1_mem, 0);
 
     const dots_per_cycle = 3; // ARM946E-S runs twice as fast as the ARM7TDMI
-    scheduler.push(.draw, 256 * dots_per_cycle);
+    scheduler.push(.{ .nds9 = .draw }, 256 * dots_per_cycle);
 
     return .{
         .main = shared_ctx.main,

src/core/ppu.zig

@@ -2,6 +2,7 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 
 const nds9 = @import("nds9.zig");
+const Scheduler = @import("Scheduler.zig");
 
 pub const screen_width = 256;
 pub const screen_height = 192;
@@ -54,7 +55,7 @@ pub const Ppu = struct {
     }
 
     /// HDraw -> HBlank
-    pub fn onHdrawEnd(self: *@This(), nds9_scheduler: *nds9.Scheduler, late: u64) void {
+    pub fn onHdrawEnd(self: *@This(), scheduler: *Scheduler, late: u64) void {
         const dots_in_hblank = 99;
         std.debug.assert(self.io.dispstat.hblank.read() == false);
         std.debug.assert(self.io.dispstat.vblank.read() == false);
@@ -62,10 +63,10 @@ pub const Ppu = struct {
         // TODO: Signal HBlank IRQ
 
         self.io.dispstat.hblank.set();
-        nds9_scheduler.push(.hblank, dots_in_hblank * cycles_per_dot -| late);
+        scheduler.push(.{ .nds9 = .hblank }, dots_in_hblank * cycles_per_dot -| late);
     }
 
-    pub fn onHblankEnd(self: *@This(), nds9_scheduler: *nds9.Scheduler, late: u64) void {
+    pub fn onHblankEnd(self: *@This(), scheduler: *Scheduler, late: u64) void {
         const scanline_count = 192 + 71;
 
         const prev_scanline = self.io.vcount.scanline.read();
@@ -85,7 +86,7 @@ pub const Ppu = struct {
 
             // Draw Another Scanline
             const dots_in_hdraw = 256;
-            return nds9_scheduler.push(.draw, dots_in_hdraw * cycles_per_dot -| late);
+            return scheduler.push(.{ .nds9 = .draw }, dots_in_hdraw * cycles_per_dot -| late);
         }
 
         if (scanline == 192) {
@@ -100,7 +101,7 @@ pub const Ppu = struct {
         std.debug.assert(self.io.dispstat.vblank.read() == (scanline != 262));
 
         const dots_in_scanline = 256 + 99;
-        nds9_scheduler.push(.hblank, dots_in_scanline * cycles_per_dot -| late);
+        scheduler.push(.{ .nds9 = .hblank }, dots_in_scanline * cycles_per_dot -| late);
     }
 };
 

src/main.zig

@@ -5,6 +5,8 @@ const nds9 = @import("core/nds9.zig");
 const nds7 = @import("core/nds7.zig");
 const emu = @import("core/emu.zig");
 
+const Scheduler = @import("core/Scheduler.zig");
+
 const IBus = @import("arm32").Bus;
 const IScheduler = @import("arm32").Scheduler;
 const ICoprocessor = @import("arm32").Coprocessor;
@@ -41,23 +43,24 @@ pub fn main() !void {
     const shared_ctx = try SharedContext.init(allocator);
     defer shared_ctx.deinit(allocator);
 
+    var scheduler = try Scheduler.init(allocator);
+    defer scheduler.deinit();
+
     const nds9_group: nds9.Group = blk: {
-        var scheduler = try nds9.Scheduler.init(allocator);
         var bus = try nds9.Bus.init(allocator, &scheduler, shared_ctx);
         var cp15 = nds9.Cp15{};
 
         var arm946es = nds9.Arm946es.init(IScheduler.init(&scheduler), IBus.init(&bus), ICoprocessor.init(&cp15));
 
-        break :blk .{ .cpu = &arm946es, .bus = &bus, .scheduler = &scheduler };
+        break :blk .{ .cpu = &arm946es, .bus = &bus };
     };
     defer nds9_group.deinit(allocator);
 
     const nds7_group: nds7.Group = blk: {
-        var scheduler = try nds7.Scheduler.init(allocator);
         var bus = try nds7.Bus.init(allocator, &scheduler, shared_ctx);
         var arm7tdmi = nds7.Arm7tdmi.init(IScheduler.init(&scheduler), IBus.init(&bus));
 
-        break :blk .{ .cpu = &arm7tdmi, .bus = &bus, .scheduler = &scheduler };
+        break :blk .{ .cpu = &arm7tdmi, .bus = &bus };
     };
     defer nds7_group.deinit(allocator);
 
@@ -67,7 +70,7 @@ pub fn main() !void {
     defer ui.deinit(allocator);
 
     ui.setTitle(rom_title);
-    try ui.run(nds7_group, nds9_group);
+    try ui.run(&scheduler, nds7_group, nds9_group);
 }
 
 fn handlePositional(result: ClapResult) ![]const u8 {

src/platform.zig

@@ -11,6 +11,7 @@ const imgui = @import("ui/imgui.zig");
 const emu = @import("core/emu.zig");
 
 const KeyInput = @import("core/nds9/io.zig").KeyInput;
+const Scheduler = @import("core/Scheduler.zig");
 
 const Allocator = std.mem.Allocator;
 
@@ -86,7 +87,7 @@ pub const Ui = struct {
         return SDL.SDL_GL_GetProcAddress(proc.ptr);
     }
 
-    pub fn run(self: *Self, nds7_group: nds7.Group, nds9_group: nds9.Group) !void {
+    pub fn run(self: *Self, scheduler: *Scheduler, nds7_group: nds7.Group, nds9_group: nds9.Group) !void {
         // TODO: Sort this out please
 
         const vao_id = opengl_impl.vao();
@@ -108,7 +109,7 @@ pub const Ui = struct {
         var event: SDL.SDL_Event = undefined;
 
         emu_loop: while (true) {
-            emu.runFrame(nds7_group, nds9_group);
+            emu.runFrame(scheduler, nds7_group, nds9_group);
 
             while (SDL.SDL_PollEvent(&event) != 0) {
                 _ = zgui.backend.processEvent(&event);