Cleanup GC

zlw · Dec 29, 2024 · 09d26a7 · 09d26a7
1 parent 90cb09c
commit 09d26a7
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Showing 2 changed files with 55 additions and 60 deletions.
diff --git a/src/memory.zig b/src/memory.zig
@@ -21,20 +21,12 @@ const GrayObjects = DynamicArray(*Object);
 
 pub const GCAllocator = struct {
     parent_allocator: Allocator,
-    vm: *Vm,
-    grayObjects: GrayObjects,
-    bytesAllocated: usize = 0,
-    nextGC: usize = GC_DEFAULT_NEXT_GC,
+    collector: GarbageCollector,
 
     const Self = @This();
 
-    pub fn init(parent_allocator: Allocator, vm: *Vm) Self {
-        return .{ .parent_allocator = parent_allocator, .vm = vm, .grayObjects = GrayObjects.init(parent_allocator) };
-    }
-
-    pub fn deinit(self: *Self) void {
-        self.grayObjects.deinit();
-        self.freeObjects();
+    pub fn init(parent_allocator: Allocator, collector: GarbageCollector) Self {
+        return .{ .parent_allocator = parent_allocator, .collector = collector };
     }
 
     pub fn allocator(self: *Self) Allocator {
@@ -49,51 +41,55 @@ pub const GCAllocator = struct {
     fn alloc(ctx: *anyopaque, len: usize, ptr_align: u8, ret_addr: usize) ?[*]u8 {
         const self: *Self = @ptrCast(@alignCast(ctx));
 
-        if ((self.bytesAllocated > self.nextGC)) {
-            try self.collectGarbage();
-        }
-
-        if (self.parent_allocator.rawAlloc(len, ptr_align, ret_addr)) |out| {
-            self.bytesAllocated += len;
-            return out;
-        } else {
-            return null;
-        }
+        return self.parent_allocator.rawAlloc(len, ptr_align, ret_addr);
     }
 
-    fn resize(ctx: *anyopaque, buf: []u8, log2_buf_align: u8, new_len: usize, ret_addr: usize) bool {
+    fn resize(ctx: *anyopaque, buf: []u8, buf_align: u8, new_len: usize, ret_addr: usize) bool {
         const self: *Self = @ptrCast(@alignCast(ctx));
 
-        // if (new_len > buf.len) {
-        //     if ((self.bytesAllocated + (new_len - buf.len) > self.nextGC) or stress_gc) {
-        //         try self.collectGarbage();
-        //     }
-        // }
-
-        if ((self.bytesAllocated > self.nextGC)) {
-            try self.collectGarbage();
-        }
-
-       if (self.parent_allocator.rawResize(buf, log2_buf_align, new_len, ret_addr)) {
-            if (new_len > buf.len) {
-                self.bytesAllocated += new_len - buf.len;
-            } else {
-                self.bytesAllocated -= buf.len - new_len;
-            }
-            return true;
-        } else {
-            return false;
-        }
+        return self.parent_allocator.rawResize(buf, buf_align, new_len, ret_addr);
     }
 
     fn free(ctx: *anyopaque, buf: []u8, buf_align: u8, ret_addr: usize) void {
         const self: *Self = @ptrCast(@alignCast(ctx));
 
         self.parent_allocator.rawFree(buf, buf_align, ret_addr);
-        self.bytesAllocated -= buf.len;
     }
+};
 
-    // end: Allocator interface
+pub const GarbageCollector = struct {
+    const Self = @This();
+
+    vm: *Vm,
+    grayObjects: GrayObjects = undefined,
+    bytesAllocated: usize = 0,
+    nextGC: usize = GC_DEFAULT_NEXT_GC,
+    parent_allocator: Allocator,
+
+    pub fn init(parent_allocator: Allocator, vm: *Vm) Self {
+        return Self{ .vm = vm, .parent_allocator = parent_allocator };
+    }
+
+    pub fn allocator(self: *Self) Allocator {
+        var gc = GCAllocator.init(self.parent_allocator, self.*);
+        return gc.allocator();
+    }
+
+    pub fn deinit(self: *Self) void {
+        self.grayObjects.deinit();
+    }
+
+    fn bytesAllocatedIncreased(self: *Self, size: usize) void {
+        self.bytesAllocated += size;
+    }
+
+    fn bytesAllocatedDecreased(self: *Self, size: usize) void {
+        self.bytesAllocated -= size;
+    }
+
+    fn shouldCollect(self: *Self) bool {
+        return self.bytesAllocated > self.nextGC;
+    }
 
     fn collectGarbage(self: *Self) !void {
         const before = self.bytesAllocated;
@@ -119,9 +115,9 @@ pub const GCAllocator = struct {
         var i: usize = undefined;
 
         // mark Object in Values sitting on the stack
-        i = 0;
-        while (i < self.vm.stack_top) : (i += 1) {
-            self.markValue(&self.vm.stack[i]);
+        var slot: [*]Value = @ptrCast(&self.vm.stack[0]);
+        while (@intFromPtr(slot) < @intFromPtr(self.vm.stack_top)) : (slot += 1) {
+            self.markValue(&slot[0]);
         }
 
         // mark Object.Closure in CallFrames

diff --git a/src/vm.zig b/src/vm.zig
@@ -14,7 +14,7 @@ const compile = @import("./compiler.zig").compile;
 
 const native = @import("./native.zig");
 
-const GCAllocator = @import("./memory.zig").GCAllocator;
+const GarbageCollector = @import("./memory.zig").GarbageCollector;
 const Parser = @import("./compiler.zig").Parser;
 
 const debug_trace_execution = debug.debug_trace_execution;
@@ -41,26 +41,24 @@ pub const Vm = struct {
     framesCount: usize = 0,
     stack: [stack_max]Value = undefined,
     stack_top: [*]Value = undefined,
-    strings: Table,
+    strings: Table = undefined,
     initString: ?*Object.String = null,
-    globals: Table,
+    globals: Table = undefined,
     objects: ?*Object = null,
     openUpvalues: ?*Object.Upvalue = null,
-    allocator: Allocator,
+    allocator: Allocator = undefined,
+    collector: *GarbageCollector = undefined,
     parser: ?*Parser = null,
 
     pub fn init(parent_allocator: Allocator) Self {
-        // var vm = Self{ .allocator = undefined, .strings = undefined, .globals = undefined };
-        // var gc = GCAllocator.init(parent_allocator, &vm);
-        // var allocator = gc.allocator();
-        // _ = allocator;
+        var vm = Self{};
 
-        // vm.allocator = parent_allocator;
-        // vm.strings = Table.init(parent_allocator);
-        // vm.globals = Table.init(parent_allocator);
-
-        var vm = Self{ .allocator = parent_allocator, .strings = Table.init(parent_allocator), .globals = Table.init(parent_allocator) };
+        var gc = GarbageCollector.init(parent_allocator, &vm);
+        vm.collector = @constCast(&gc);
+        vm.allocator = parent_allocator;
 
+        vm.strings = Table.init(vm.allocator);
+        vm.globals = Table.init(vm.allocator);
         vm.stack_top = vm.stack[0..];
         vm.initString = Object.String.copy(&vm, "init");
         vm.defineNative("clock", native.clockNative);
@@ -73,6 +71,7 @@ pub const Vm = struct {
         self.strings.deinit();
         self.initString = null;
         self.freeObjects();
+        self.collector.deinit();
     }
 
     fn freeObjects(self: *Self) void {