feat(ke): add generic event

src/kern/event.zig

@@ -0,0 +1,32 @@
+const ke = @import("root").ke;
+const ki = ke.private;
+
+/// Generic waitable Event, exported for use everywhere in the kernel.
+pub const Event = struct {
+    hdr: ki.wait.DispatchHeader,
+
+    const Self = @This();
+
+    pub const Type = enum {
+        /// Wake only one waiter.
+        Synchronization,
+        /// Wake all waiters.
+        Notification,
+    };
+
+    /// Initialize an event with a specified type.
+    pub fn init(self: *Self, @"type": Type) void {
+        self.hdr.init(switch (@"type") {
+            .Synchronization => .Synchronization,
+            .Notification => .Notification,
+        });
+    }
+
+    /// Signal an event, waking its waiter(s).
+    pub fn signal(self: *Self) void {
+        const ipl = self.hdr.lock.acquire();
+        self.hdr.signaled = 1;
+        ki.wait.satisfy_wait(&self.hdr);
+        self.hdr.lock.release(ipl);
+    }
+};

src/kern/root.zig

@@ -17,6 +17,7 @@ pub const Console = p.log.Console;
 pub const CpuLocal = p.cpu.CpuLocal;
 pub const ExportedCpuLocal = p.cpu.ExportedCpuLocal;
 pub const CpuMask = p.cpu.CpuMask;
+pub const Event = p.event.Event;
 
 // === Exported Interfaces ===
 pub const panic = p.panic.panic;