diff --git a/lib/std/Build/Watch.zig b/lib/std/Build/Watch.zig index 13540a2b36cf..ade31f628e72 100644 --- a/lib/std/Build/Watch.zig +++ b/lib/std/Build/Watch.zig @@ -33,9 +33,12 @@ const Os = switch (builtin.os.tag) { /// Keyed differently but indexes correspond 1:1 with `dir_table`. handle_table: HandleTable, - poll_fds: [1]posix.pollfd, + /// fanotify file descriptors are keyed by mount id since marks + /// are limited to a single filesystem. + poll_fds: std.AutoArrayHashMapUnmanaged(MountId, posix.pollfd), - const HandleTable = std.ArrayHashMapUnmanaged(FileHandle, ReactionSet, FileHandle.Adapter, false); + const MountId = i32; + const HandleTable = std.ArrayHashMapUnmanaged(FileHandle, struct { mount_id: MountId, reaction_set: ReactionSet }, FileHandle.Adapter, false); const fan_mask: std.os.linux.fanotify.MarkMask = .{ .CLOSE_WRITE = true, @@ -92,30 +95,12 @@ const Os = switch (builtin.os.tag) { }; fn init() !Watch { - const fan_fd = std.posix.fanotify_init(.{ - .CLASS = .NOTIF, - .CLOEXEC = true, - .NONBLOCK = true, - .REPORT_NAME = true, - .REPORT_DIR_FID = true, - .REPORT_FID = true, - .REPORT_TARGET_FID = true, - }, 0) catch |err| switch (err) { - error.UnsupportedFlags => fatal("fanotify_init failed due to old kernel; requires 5.17+", .{}), - else => |e| return e, - }; return .{ .dir_table = .{}, .os = switch (builtin.os.tag) { .linux => .{ .handle_table = .{}, - .poll_fds = .{ - .{ - .fd = fan_fd, - .events = std.posix.POLL.IN, - .revents = undefined, - }, - }, + .poll_fds = .{}, }, else => {}, }, @@ -123,22 +108,20 @@ const Os = switch (builtin.os.tag) { }; } - fn getDirHandle(gpa: Allocator, path: std.Build.Cache.Path) !FileHandle { + fn getDirHandle(gpa: Allocator, path: std.Build.Cache.Path, mount_id: *MountId) !FileHandle { var file_handle_buffer: [@sizeOf(std.os.linux.file_handle) + 128]u8 align(@alignOf(std.os.linux.file_handle)) = undefined; - var mount_id: i32 = undefined; var buf: [std.fs.max_path_bytes]u8 = undefined; const adjusted_path = if (path.sub_path.len == 0) "./" else std.fmt.bufPrint(&buf, "{s}/", .{ path.sub_path, }) catch return error.NameTooLong; const stack_ptr: *std.os.linux.file_handle = @ptrCast(&file_handle_buffer); stack_ptr.handle_bytes = file_handle_buffer.len - @sizeOf(std.os.linux.file_handle); - try posix.name_to_handle_at(path.root_dir.handle.fd, adjusted_path, stack_ptr, &mount_id, std.os.linux.AT.HANDLE_FID); + try posix.name_to_handle_at(path.root_dir.handle.fd, adjusted_path, stack_ptr, mount_id, std.os.linux.AT.HANDLE_FID); const stack_lfh: FileHandle = .{ .handle = stack_ptr }; return stack_lfh.clone(gpa); } - fn markDirtySteps(w: *Watch, gpa: Allocator) !bool { - const fan_fd = w.os.getFanFd(); + fn markDirtySteps(w: *Watch, gpa: Allocator, fan_fd: posix.fd_t) !bool { const fanotify = std.os.linux.fanotify; const M = fanotify.event_metadata; var events_buf: [256 + 4096]u8 = undefined; @@ -167,10 +150,10 @@ const Os = switch (builtin.os.tag) { const file_name_z: [*:0]u8 = @ptrCast((&file_handle.f_handle).ptr + file_handle.handle_bytes); const file_name = std.mem.span(file_name_z); const lfh: FileHandle = .{ .handle = file_handle }; - if (w.os.handle_table.getPtr(lfh)) |reaction_set| { - if (reaction_set.getPtr(".")) |glob_set| + if (w.os.handle_table.getPtr(lfh)) |value| { + if (value.reaction_set.getPtr(".")) |glob_set| any_dirty = markStepSetDirty(gpa, glob_set, any_dirty); - if (reaction_set.getPtr(file_name)) |step_set| + if (value.reaction_set.getPtr(file_name)) |step_set| any_dirty = markStepSetDirty(gpa, step_set, any_dirty); } }, @@ -180,19 +163,38 @@ const Os = switch (builtin.os.tag) { } } - fn getFanFd(os: *const @This()) posix.fd_t { - return os.poll_fds[0].fd; - } - fn update(w: *Watch, gpa: Allocator, steps: []const *Step) !void { - const fan_fd = w.os.getFanFd(); // Add missing marks and note persisted ones. for (steps) |step| { for (step.inputs.table.keys(), step.inputs.table.values()) |path, *files| { const reaction_set = rs: { const gop = try w.dir_table.getOrPut(gpa, path); if (!gop.found_existing) { - const dir_handle = try Os.getDirHandle(gpa, path); + var mount_id: MountId = undefined; + const dir_handle = try Os.getDirHandle(gpa, path, &mount_id); + const fan_fd = blk: { + const fd_gop = try w.os.poll_fds.getOrPut(gpa, mount_id); + if (!fd_gop.found_existing) { + const fan_fd = std.posix.fanotify_init(.{ + .CLASS = .NOTIF, + .CLOEXEC = true, + .NONBLOCK = true, + .REPORT_NAME = true, + .REPORT_DIR_FID = true, + .REPORT_FID = true, + .REPORT_TARGET_FID = true, + }, 0) catch |err| switch (err) { + error.UnsupportedFlags => fatal("fanotify_init failed due to old kernel; requires 5.17+", .{}), + else => |e| return e, + }; + fd_gop.value_ptr.* = .{ + .fd = fan_fd, + .events = std.posix.POLL.IN, + .revents = undefined, + }; + } + break :blk fd_gop.value_ptr.*.fd; + }; // `dir_handle` may already be present in the table in // the case that we have multiple Cache.Path instances // that compare inequal but ultimately point to the same @@ -204,7 +206,7 @@ const Os = switch (builtin.os.tag) { _ = w.dir_table.pop(); } else { assert(dh_gop.index == gop.index); - dh_gop.value_ptr.* = .{}; + dh_gop.value_ptr.* = .{ .mount_id = mount_id, .reaction_set = .{} }; posix.fanotify_mark(fan_fd, .{ .ADD = true, .ONLYDIR = true, @@ -212,9 +214,9 @@ const Os = switch (builtin.os.tag) { fatal("unable to watch {}: {s}", .{ path, @errorName(err) }); }; } - break :rs dh_gop.value_ptr; + break :rs &dh_gop.value_ptr.reaction_set; } - break :rs &w.os.handle_table.values()[gop.index]; + break :rs &w.os.handle_table.values()[gop.index].reaction_set; }; for (files.items) |basename| { const gop = try reaction_set.getOrPut(gpa, basename); @@ -229,7 +231,7 @@ const Os = switch (builtin.os.tag) { var i: usize = 0; while (i < w.os.handle_table.entries.len) { { - const reaction_set = &w.os.handle_table.values()[i]; + const reaction_set = &w.os.handle_table.values()[i].reaction_set; var step_set_i: usize = 0; while (step_set_i < reaction_set.entries.len) { const step_set = &reaction_set.values()[step_set_i]; @@ -256,6 +258,8 @@ const Os = switch (builtin.os.tag) { const path = w.dir_table.keys()[i]; + const mount_id = w.os.handle_table.values()[i].mount_id; + const fan_fd = w.os.poll_fds.getEntry(mount_id).?.value_ptr.fd; posix.fanotify_mark(fan_fd, .{ .REMOVE = true, .ONLYDIR = true, @@ -272,13 +276,14 @@ const Os = switch (builtin.os.tag) { } fn wait(w: *Watch, gpa: Allocator, timeout: Timeout) !WaitResult { - const events_len = try std.posix.poll(&w.os.poll_fds, timeout.to_i32_ms()); - return if (events_len == 0) - .timeout - else if (try Os.markDirtySteps(w, gpa)) - .dirty - else - .clean; + const events_len = try std.posix.poll(w.os.poll_fds.values(), timeout.to_i32_ms()); + if (events_len == 0) + return .timeout; + for (w.os.poll_fds.values()) |poll_fd| { + if (poll_fd.revents & std.posix.POLL.IN == std.posix.POLL.IN and try Os.markDirtySteps(w, gpa, poll_fd.fd)) + return .dirty; + } + return .clean; } }, .windows => struct { @@ -838,7 +843,11 @@ pub const Match = struct { }; fn markAllFilesDirty(w: *Watch, gpa: Allocator) void { - for (w.os.handle_table.values()) |reaction_set| { + for (w.os.handle_table.values()) |value| { + const reaction_set = switch (builtin.os.tag) { + .linux => value.reaction_set, + else => value, + }; for (reaction_set.values()) |step_set| { for (step_set.keys()) |step| { step.recursiveReset(gpa);