Merge pull request #23 from hyenasky/main

defer disabled interrupts rather than dropping them
fox32-arch · Aug 1, 2024 · 1c98337 · 1c98337
2 parents b5f2f03 + d9d83cf
commit 1c98337
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Showing 2 changed files with 37 additions and 0 deletions.
diff --git a/src/cpu.c b/src/cpu.c
@@ -372,6 +372,11 @@ static void vm_init(vm_t *vm) {
     vm->io_user = NULL;
     vm->io_read = io_read_default;
     vm->io_write = io_write_default;
+    vm->deferred_interrupt_count = 0;
+
+    for (int i = 0; i < 256; i++) {
+        vm->pending_vectors[i] = 0;
+    }
 }
 
 static noreturn void vm_panic(vm_t *vm, err_t err) {
@@ -1028,12 +1033,36 @@ static void vm_execute(vm_t *vm) {
             if (vm->flag_swap_sp) {
                 vm->pointer_stack = vm_pop32(vm);
             }
+            if (vm->flag_interrupt && vm->deferred_interrupt_count != 0) {
+                for (int i = 0; i < 256; i++) {
+                    if (vm->pending_vectors[i]) {
+                        vm->deferred_interrupt_count--;
+                        vm->pending_vectors[i] = 0;
+                        vm->pointer_instr = vm->pointer_instr_mut;
+                        fox32_raise(vm, i);
+                        vm->pointer_instr_mut = vm->pointer_instr;
+                        break;
+                    }
+                }
+            }
             break;
         };
 
         case OP(SZ_WORD, OP_ISE): {
             VM_PRELUDE_0();
             vm->flag_interrupt = true;
+            if (vm->deferred_interrupt_count != 0) {
+                for (int i = 0; i < 256; i++) {
+                    if (vm->pending_vectors[i]) {
+                        vm->deferred_interrupt_count--;
+                        vm->pending_vectors[i] = 0;
+                        vm->pointer_instr = vm->pointer_instr_mut;
+                        fox32_raise(vm, i);
+                        vm->pointer_instr_mut = vm->pointer_instr;
+                        break;
+                    }
+                }
+            }
             break;
         };
         case OP(SZ_WORD, OP_ICL): {
@@ -1219,6 +1248,11 @@ static err_t vm_resume(vm_t *vm, uint32_t count, uint32_t *executed) {
 
 static fox32_err_t vm_raise(vm_t *vm, uint16_t vector) {
     if (!vm->flag_interrupt && vector < 256) {
+        if (vm->pending_vectors[vector] == 0) {
+            vm->pending_vectors[vector] = 1;
+            vm->deferred_interrupt_count++;
+        }
+
         return FOX32_ERR_NOINTERRUPTS;
     }
     if (setjmp(vm->panic_jmp) != 0) {

diff --git a/src/cpu.h b/src/cpu.h
@@ -72,6 +72,9 @@ typedef struct {
     fox32_io_read_t *io_read;
     fox32_io_write_t *io_write;
 
+    uint16_t deferred_interrupt_count;
+
+    uint8_t pending_vectors[256];
     uint8_t memory_ram[FOX32_MEMORY_RAM];
     uint8_t memory_rom[FOX32_MEMORY_ROM];
 } fox32_vm_t;