Commit 6bd97ab640
Changed files (3)
lib
std
atomic
lib/std/atomic/stack.zig
@@ -1,178 +0,0 @@
-const std = @import("../std.zig");
-const builtin = @import("builtin");
-const assert = std.debug.assert;
-const expect = std.testing.expect;
-
-/// Many reader, many writer, non-allocating, thread-safe.
-/// Uses a spinlock to protect `push()` and `pop()`.
-/// When building in single threaded mode, this is a simple linked list.
-pub fn Stack(comptime T: type) type {
- return struct {
- root: ?*Node,
- lock: @TypeOf(lock_init),
-
- const lock_init = if (builtin.single_threaded) {} else false;
-
- pub const Self = @This();
-
- pub const Node = struct {
- next: ?*Node,
- data: T,
- };
-
- pub fn init() Self {
- return Self{
- .root = null,
- .lock = lock_init,
- };
- }
-
- /// push operation, but only if you are the first item in the stack. if you did not succeed in
- /// being the first item in the stack, returns the other item that was there.
- pub fn pushFirst(self: *Self, node: *Node) ?*Node {
- node.next = null;
- return @cmpxchgStrong(?*Node, &self.root, null, node, .SeqCst, .SeqCst);
- }
-
- pub fn push(self: *Self, node: *Node) void {
- if (builtin.single_threaded) {
- node.next = self.root;
- self.root = node;
- } else {
- while (@atomicRmw(bool, &self.lock, .Xchg, true, .SeqCst)) {}
- defer assert(@atomicRmw(bool, &self.lock, .Xchg, false, .SeqCst));
-
- node.next = self.root;
- self.root = node;
- }
- }
-
- pub fn pop(self: *Self) ?*Node {
- if (builtin.single_threaded) {
- const root = self.root orelse return null;
- self.root = root.next;
- return root;
- } else {
- while (@atomicRmw(bool, &self.lock, .Xchg, true, .SeqCst)) {}
- defer assert(@atomicRmw(bool, &self.lock, .Xchg, false, .SeqCst));
-
- const root = self.root orelse return null;
- self.root = root.next;
- return root;
- }
- }
-
- pub fn isEmpty(self: *Self) bool {
- return @atomicLoad(?*Node, &self.root, .SeqCst) == null;
- }
- };
-}
-
-const Context = struct {
- allocator: std.mem.Allocator,
- stack: *Stack(i32),
- put_sum: isize,
- get_sum: isize,
- get_count: usize,
- puts_done: bool,
-};
-// TODO add lazy evaluated build options and then put puts_per_thread behind
-// some option such as: "AggressiveMultithreadedFuzzTest". In the AppVeyor
-// CI we would use a less aggressive setting since at 1 core, while we still
-// want this test to pass, we need a smaller value since there is so much thrashing
-// we would also use a less aggressive setting when running in valgrind
-const puts_per_thread = 500;
-const put_thread_count = 3;
-
-test "std.atomic.stack" {
- const plenty_of_memory = try std.heap.page_allocator.alloc(u8, 300 * 1024);
- defer std.heap.page_allocator.free(plenty_of_memory);
-
- var fixed_buffer_allocator = std.heap.FixedBufferAllocator.init(plenty_of_memory);
- const a = fixed_buffer_allocator.threadSafeAllocator();
-
- var stack = Stack(i32).init();
- var context = Context{
- .allocator = a,
- .stack = &stack,
- .put_sum = 0,
- .get_sum = 0,
- .puts_done = false,
- .get_count = 0,
- };
-
- if (builtin.single_threaded) {
- {
- var i: usize = 0;
- while (i < put_thread_count) : (i += 1) {
- try expect(startPuts(&context) == 0);
- }
- }
- context.puts_done = true;
- {
- var i: usize = 0;
- while (i < put_thread_count) : (i += 1) {
- try expect(startGets(&context) == 0);
- }
- }
- } else {
- var putters: [put_thread_count]std.Thread = undefined;
- for (&putters) |*t| {
- t.* = try std.Thread.spawn(.{}, startPuts, .{&context});
- }
- var getters: [put_thread_count]std.Thread = undefined;
- for (&getters) |*t| {
- t.* = try std.Thread.spawn(.{}, startGets, .{&context});
- }
-
- for (putters) |t|
- t.join();
- @atomicStore(bool, &context.puts_done, true, .SeqCst);
- for (getters) |t|
- t.join();
- }
-
- if (context.put_sum != context.get_sum) {
- std.debug.panic("failure\nput_sum:{} != get_sum:{}", .{ context.put_sum, context.get_sum });
- }
-
- if (context.get_count != puts_per_thread * put_thread_count) {
- std.debug.panic("failure\nget_count:{} != puts_per_thread:{} * put_thread_count:{}", .{
- context.get_count,
- @as(u32, puts_per_thread),
- @as(u32, put_thread_count),
- });
- }
-}
-
-fn startPuts(ctx: *Context) u8 {
- var put_count: usize = puts_per_thread;
- var prng = std.rand.DefaultPrng.init(0xdeadbeef);
- const random = prng.random();
- while (put_count != 0) : (put_count -= 1) {
- std.time.sleep(1); // let the os scheduler be our fuzz
- const x = @as(i32, @bitCast(random.int(u32)));
- const node = ctx.allocator.create(Stack(i32).Node) catch unreachable;
- node.* = Stack(i32).Node{
- .next = undefined,
- .data = x,
- };
- ctx.stack.push(node);
- _ = @atomicRmw(isize, &ctx.put_sum, .Add, x, .SeqCst);
- }
- return 0;
-}
-
-fn startGets(ctx: *Context) u8 {
- while (true) {
- const last = @atomicLoad(bool, &ctx.puts_done, .SeqCst);
-
- while (ctx.stack.pop()) |node| {
- std.time.sleep(1); // let the os scheduler be our fuzz
- _ = @atomicRmw(isize, &ctx.get_sum, .Add, node.data, .SeqCst);
- _ = @atomicRmw(usize, &ctx.get_count, .Add, 1, .SeqCst);
- }
-
- if (last) return 0;
- }
-}
lib/std/atomic.zig
@@ -1,16 +1,9 @@
const std = @import("std.zig");
const builtin = @import("builtin");
-pub const Stack = @import("atomic/stack.zig").Stack;
pub const Queue = @import("atomic/queue.zig").Queue;
pub const Atomic = @import("atomic/Atomic.zig").Atomic;
-test {
- _ = @import("atomic/stack.zig");
- _ = @import("atomic/queue.zig");
- _ = @import("atomic/Atomic.zig");
-}
-
/// Signals to the processor that the caller is inside a busy-wait spin-loop.
pub inline fn spinLoopHint() void {
switch (builtin.target.cpu.arch) {
@@ -90,3 +83,8 @@ pub const cache_line = switch (builtin.cpu.arch) {
// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_wasm.go#L7
else => 64,
};
+
+test {
+ _ = Queue;
+ _ = Atomic;
+}
CMakeLists.txt
@@ -211,7 +211,6 @@ set(ZIG_STAGE2_SOURCES
"${CMAKE_SOURCE_DIR}/lib/std/atomic.zig"
"${CMAKE_SOURCE_DIR}/lib/std/atomic/Atomic.zig"
"${CMAKE_SOURCE_DIR}/lib/std/atomic/queue.zig"
- "${CMAKE_SOURCE_DIR}/lib/std/atomic/stack.zig"
"${CMAKE_SOURCE_DIR}/lib/std/base64.zig"
"${CMAKE_SOURCE_DIR}/lib/std/BitStack.zig"
"${CMAKE_SOURCE_DIR}/lib/std/buf_map.zig"