sylveos

commit c8b11c0d45fd9d0a3b58e2da319595c2cbef619b
parent ad00709e43bdbe9bac83c192a96839aa47eaadfc
Author: Sylvia Ivory <git@sivory.net>
Date:   Tue, 24 Feb 2026 17:33:35 -0800

Exiting works

Diffstat:
M
pi/thread.zig
 | 
6
+++++-
M
programs/threads.zig
 | 
12
++++++++++--

2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/pi/thread.zig b/pi/thread.zig
@@ -5,7 +5,7 @@ const switching = @import("./switching.zig");
 const PSR = @import("./psr.zig").PSR;
 const mem = @import("./mem.zig");
 
-pub var tid_counter: usize = 1;
+var tid_counter: usize = 1;
 var ready: bool = false;
 var threads: std.DoublyLinkedList = .{};
 var scheduler_thread: *Thread = undefined;
@@ -111,6 +111,10 @@ pub fn get_tid() usize {
     return get_current().tid;
 }
 
+pub fn is_ready() bool {
+    return ready;
+}
+
 fn thread_trampoline(func: *const fn (?*anyopaque) callconv(.c) void, arg: ?*anyopaque) callconv(.c) noreturn {
     // Won't release as next's CPSR will already reenable
     // _ = mem.enter_critical_section();
diff --git a/programs/threads.zig b/programs/threads.zig
@@ -11,6 +11,8 @@ const mem = pi.mem;
 fn thread_test(arg: ?*anyopaque) callconv(.c) void {
     _ = arg;
 
+    var count: usize = 0;
+
     while (true) {
         // Don't use format for simpler function
         const cs = mem.enter_critical_section();
@@ -19,11 +21,17 @@ fn thread_test(arg: ?*anyopaque) callconv(.c) void {
         uart.write_byte_sync(@truncate(thread.get_tid() + 48));
         uart.write_byte_sync('\n');
 
+        count += 1;
+
         cs.exit();
+
+        if (count > 1024) break;
     }
 }
 
 noinline fn tick(regs: interrupts.Registers) void {
+    if (!thread.is_ready()) return;
+
     uart.print("preempting PC=0x{X}\n", .{regs.pc});
     thread.preempt(&regs);
 }
@@ -39,7 +47,7 @@ pub fn main() !void {
     try thread.fork(thread_test, null);
     try thread.fork(thread_test, null);
 
-    uart.print("Forked threads tid={}\n", .{thread.tid_counter});
+    uart.print("Forked threads\n", .{});
 
     timer.set_tick(tick);
     uart.print("Setting tick\n", .{});
@@ -52,7 +60,7 @@ pub fn main() !void {
 
     try thread.join();
 
-    uart.print("This should be unreachable\n", .{});
+    uart.print("Done!\n", .{});
 
     while (true) {}
 }