std.Progress: include subtrees from child processes

This commit is contained in:
Andrew Kelley 2024-05-23 17:01:06 -07:00
parent f07116404a
commit df46f5af69
2 changed files with 140 additions and 26 deletions

View File

@ -83,6 +83,22 @@ pub const Node = struct {
/// Little endian.
estimated_total_count: u32,
name: [max_name_len]u8,
fn getIpcFd(s: Storage) ?posix.fd_t {
if (s.estimated_total_count != std.math.maxInt(u32))
return null;
return @bitCast(s.completed_count);
}
fn setIpcFd(s: *Storage, fd: posix.fd_t) void {
s.estimated_total_count = std.math.maxInt(u32);
s.completed_count = @bitCast(fd);
}
comptime {
assert((@sizeOf(Storage) % 4) == 0);
}
};
const Parent = enum(u16) {
@ -201,6 +217,13 @@ pub const Node = struct {
}
}
/// Posix-only. Used by `std.process.Child`.
pub fn setIpcFd(node: Node, fd: posix.fd_t) void {
const index = node.index.unwrap() orelse return;
assert(fd != -1);
storageByIndex(index).setIpcFd(fd);
}
fn storageByIndex(index: Node.Index) *Node.Storage {
return &global_progress.node_storage[@intFromEnum(index)];
}
@ -475,14 +498,8 @@ fn serialize() Serialized {
}
}
// Now we can analyze our copy of the graph without atomics, reconstructing
// children lists which do not exist in the canonical data. These are
// needed for tree traversal below.
const serialized_node_parents = serialized_node_parents_buffer[0..serialized_len];
const serialized_node_storage = serialized_node_storage_buffer[0..serialized_len];
// Remap parents to point inside serialized arrays.
for (serialized_node_parents) |*parent| {
for (serialized_node_parents_buffer[0..serialized_len]) |*parent| {
parent.* = switch (parent.*) {
.unused => unreachable,
.none => .none,
@ -490,15 +507,99 @@ fn serialize() Serialized {
};
}
// Find nodes which correspond to child processes.
var pipe_buf: [4096]u8 align(4) = undefined;
for (
serialized_node_parents_buffer[0..serialized_len],
serialized_node_storage_buffer[0..serialized_len],
0..,
) |main_parent, *main_storage, main_index| {
if (main_parent == .unused) continue;
const fd = main_storage.getIpcFd() orelse continue;
var bytes_read: usize = 0;
while (true) {
bytes_read += posix.read(fd, pipe_buf[bytes_read..]) catch |err| switch (err) {
error.WouldBlock => break,
else => |e| {
std.log.warn("failed to read child progress data: {s}", .{@errorName(e)});
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
continue;
},
};
}
// Ignore all but the last message on the pipe.
var input: []align(2) u8 = pipe_buf[0..bytes_read];
if (input.len == 0) {
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
continue;
}
const storage, const parents = while (true) {
if (input.len < 4) {
std.log.warn("short read: {d} out of 4 header bytes", .{input.len});
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
continue;
}
const subtree_len = std.mem.readInt(u32, input[0..4], .little);
const expected_bytes = 4 + subtree_len * (@sizeOf(Node.Storage) + @sizeOf(Node.Parent));
if (input.len < expected_bytes) {
std.log.warn("short read: {d} out of {d} ({d} nodes)", .{ input.len, expected_bytes, subtree_len });
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
continue;
}
if (input.len > expected_bytes) {
input = @alignCast(input[expected_bytes..]);
continue;
}
const storage_bytes = input[4..][0 .. subtree_len * @sizeOf(Node.Storage)];
const parents_bytes = input[4 + storage_bytes.len ..][0 .. subtree_len * @sizeOf(Node.Parent)];
break .{
std.mem.bytesAsSlice(Node.Storage, storage_bytes),
std.mem.bytesAsSlice(Node.Parent, parents_bytes),
};
};
// Mount the root here.
main_storage.* = storage[0];
// Copy the rest of the tree to the end.
@memcpy(serialized_node_storage_buffer[serialized_len..][0 .. storage.len - 1], storage[1..]);
// Patch up parent pointers taking into account how the subtree is mounted.
serialized_node_parents_buffer[serialized_len] = .none;
for (serialized_node_parents_buffer[serialized_len..][0 .. parents.len - 1], parents[1..]) |*dest, p| {
dest.* = switch (p) {
// Fix bad data so the rest of the code does not see `unused`.
.none, .unused => .none,
// Root node is being mounted here.
@as(Node.Parent, @enumFromInt(0)) => @enumFromInt(main_index),
// Other nodes mounted at the end.
_ => |off| @enumFromInt(serialized_len + @intFromEnum(off) - 1),
};
}
serialized_len += storage.len - 1;
}
return .{
.parents = serialized_node_parents,
.storage = serialized_node_storage,
.parents = serialized_node_parents_buffer[0..serialized_len],
.storage = serialized_node_storage_buffer[0..serialized_len],
};
}
fn computeRedraw() []u8 {
const serialized = serialize();
// Now we can analyze our copy of the graph without atomics, reconstructing
// children lists which do not exist in the canonical data. These are
// needed for tree traversal below.
var children_buffer: [default_node_storage_buffer_len]Children = undefined;
const children = children_buffer[0..serialized.parents.len];
@ -624,7 +725,8 @@ fn write(buf: []const u8) void {
fn writeIpc(fd: posix.fd_t, serialized: Serialized) void {
assert(serialized.parents.len == serialized.storage.len);
const header = std.mem.asBytes(&serialized.parents.len);
const serialized_len: u32 = @intCast(serialized.parents.len);
const header = std.mem.asBytes(&serialized_len);
const storage = std.mem.sliceAsBytes(serialized.storage);
const parents = std.mem.sliceAsBytes(serialized.parents);
@ -637,10 +739,17 @@ fn writeIpc(fd: posix.fd_t, serialized: Serialized) void {
// TODO: if big endian, byteswap
// this is needed because the parent or child process might be running in qemu
const file: std.fs.File = .{ .handle = fd };
file.writevAll(&vecs) catch |err| {
std.log.warn("failed to send progress to parent process: {s}", .{@errorName(err)});
};
// If this write would block we do not want to keep trying, but we need to
// know if a partial message was written.
if (posix.writev(fd, &vecs)) |written| {
const total = header.len + storage.len + parents.len;
if (written < total) {
std.log.warn("short write: {d} out of {d}", .{ written, total });
}
} else |err| switch (err) {
error.WouldBlock => {},
else => |e| std.log.warn("failed to send progress to parent process: {s}", .{@errorName(e)}),
}
}
fn maybeUpdateSize(resize_flag: bool) void {

View File

@ -98,7 +98,10 @@ resource_usage_statistics: ResourceUsageStatistics = .{},
/// write end of the pipe will be specified in the `ZIG_PROGRESS`
/// environment variable inside the child process. The progress reported by
/// the child will be attached to this progress node in the parent process.
parent_progress_node: std.Progress.Node = .{ .index = .none },
///
/// The child's progress tree will be grafted into the parent's progress tree,
/// by substituting this node with the child's root node.
progress_node: std.Progress.Node = .{ .index = .none },
pub const ResourceUsageStatistics = struct {
rusage: @TypeOf(rusage_init) = rusage_init,
@ -581,11 +584,11 @@ fn spawnPosix(self: *ChildProcess) SpawnError!void {
}
const prog_pipe: [2]posix.fd_t = p: {
if (self.parent_progress_node.index == .none) {
if (self.progress_node.index == .none) {
break :p .{ -1, -1 };
} else {
// No CLOEXEC because the child needs access to this file descriptor.
break :p try posix.pipe2(.{});
break :p try posix.pipe2(.{ .NONBLOCK = true });
}
};
errdefer destroyPipe(prog_pipe);
@ -685,18 +688,18 @@ fn spawnPosix(self: *ChildProcess) SpawnError!void {
// we are the parent
const pid: i32 = @intCast(pid_result);
if (self.stdin_behavior == StdIo.Pipe) {
self.stdin = File{ .handle = stdin_pipe[1] };
if (self.stdin_behavior == .Pipe) {
self.stdin = .{ .handle = stdin_pipe[1] };
} else {
self.stdin = null;
}
if (self.stdout_behavior == StdIo.Pipe) {
self.stdout = File{ .handle = stdout_pipe[0] };
if (self.stdout_behavior == .Pipe) {
self.stdout = .{ .handle = stdout_pipe[0] };
} else {
self.stdout = null;
}
if (self.stderr_behavior == StdIo.Pipe) {
self.stderr = File{ .handle = stderr_pipe[0] };
if (self.stderr_behavior == .Pipe) {
self.stderr = .{ .handle = stderr_pipe[0] };
} else {
self.stderr = null;
}
@ -705,15 +708,17 @@ fn spawnPosix(self: *ChildProcess) SpawnError!void {
self.err_pipe = err_pipe;
self.term = null;
if (self.stdin_behavior == StdIo.Pipe) {
if (self.stdin_behavior == .Pipe) {
posix.close(stdin_pipe[0]);
}
if (self.stdout_behavior == StdIo.Pipe) {
if (self.stdout_behavior == .Pipe) {
posix.close(stdout_pipe[1]);
}
if (self.stderr_behavior == StdIo.Pipe) {
if (self.stderr_behavior == .Pipe) {
posix.close(stderr_pipe[1]);
}
self.progress_node.setIpcFd(prog_pipe[0]);
}
fn spawnWindows(self: *ChildProcess) SpawnError!void {