Commit 78e2a203e3

Haze Booth <isnt@haze.cool>
2020-04-21 20:26:41
Remove std.lazyInit
1 parent aca6b70
Changed files (3)
lib
src-self-hosted
lib/std/lazy_init.zig
@@ -1,88 +0,0 @@
-const std = @import("std.zig");
-const assert = std.debug.assert;
-const testing = std.testing;
-
-/// Thread-safe initialization of global data.
-/// TODO use a mutex instead of a spinlock
-pub fn lazyInit(comptime T: type) LazyInit(T) {
-    return LazyInit(T){
-        .data = undefined,
-    };
-}
-
-fn LazyInit(comptime T: type) type {
-    return struct {
-        state: State = .NotResolved,
-        data: Data,
-
-        const State = enum(u8) {
-            NotResolved,
-            Resolving,
-            Resolved,
-        };
-
-        const Self = @This();
-
-        // TODO this isn't working for void, investigate and then remove this special case
-        const Data = if (@sizeOf(T) == 0) u8 else T;
-        const Ptr = if (T == void) void else *T;
-
-        /// Returns a usable pointer to the initialized data,
-        /// or returns null, indicating that the caller should
-        /// perform the initialization and then call resolve().
-        pub fn get(self: *Self) ?Ptr {
-            while (true) {
-                var state = @cmpxchgWeak(State, &self.state, .NotResolved, .Resolving, .SeqCst, .SeqCst) orelse return null;
-                switch (state) {
-                    .NotResolved => continue,
-                    .Resolving => {
-                        // TODO mutex instead of a spinlock
-                        continue;
-                    },
-                    .Resolved => {
-                        if (@sizeOf(T) == 0) {
-                            return @as(T, undefined);
-                        } else {
-                            return &self.data;
-                        }
-                    },
-                    else => unreachable,
-                }
-            }
-        }
-
-        pub fn resolve(self: *Self) void {
-            const prev = @atomicRmw(State, &self.state, .Xchg, .Resolved, .SeqCst);
-            assert(prev != .Resolved); // resolve() called twice
-        }
-    };
-}
-
-var global_number = lazyInit(i32);
-
-test "std.lazyInit" {
-    if (global_number.get()) |_| @panic("bad") else {
-        global_number.data = 1234;
-        global_number.resolve();
-    }
-    if (global_number.get()) |x| {
-        testing.expect(x.* == 1234);
-    } else {
-        @panic("bad");
-    }
-    if (global_number.get()) |x| {
-        testing.expect(x.* == 1234);
-    } else {
-        @panic("bad");
-    }
-}
-
-var global_void = lazyInit(void);
-
-test "std.lazyInit(void)" {
-    if (global_void.get()) |_| @panic("bad") else {
-        global_void.resolve();
-    }
-    testing.expect(global_void.get() != null);
-    testing.expect(global_void.get() != null);
-}
lib/std/std.zig
@@ -45,7 +45,6 @@ pub const heap = @import("heap.zig");
 pub const http = @import("http.zig");
 pub const io = @import("io.zig");
 pub const json = @import("json.zig");
-pub const lazyInit = @import("lazy_init.zig").lazyInit;
 pub const macho = @import("macho.zig");
 pub const math = @import("math.zig");
 pub const mem = @import("mem.zig");
src-self-hosted/compilation.zig
@@ -45,13 +45,10 @@ pub const ZigCompiler = struct {
 
     native_libc: event.Future(LibCInstallation),
 
-    var lazy_init_targets = std.lazyInit(void);
+    var lazy_init_targets = std.once(util.initializeAllTargets);
 
     pub fn init(allocator: *Allocator) !ZigCompiler {
-        lazy_init_targets.get() orelse {
-            util.initializeAllTargets();
-            lazy_init_targets.resolve();
-        };
+        lazy_init_targets.call();
 
         var seed_bytes: [@sizeOf(u64)]u8 = undefined;
         try std.crypto.randomBytes(seed_bytes[0..]);