diff options
Diffstat (limited to 'lib/std/child_process.zig')
| -rw-r--r-- | lib/std/child_process.zig | 150 |
1 files changed, 139 insertions, 11 deletions
diff --git a/lib/std/child_process.zig b/lib/std/child_process.zig index 1cdb3ef34c..b63153e904 100644 --- a/lib/std/child_process.zig +++ b/lib/std/child_process.zig @@ -13,6 +13,7 @@ const process = std.process; const File = std.fs.File; const windows = os.windows; const mem = std.mem; +const math = std.math; const debug = std.debug; const BufMap = std.BufMap; const builtin = std.builtin; @@ -257,6 +258,79 @@ pub const ChildProcess = struct { } } + fn collectOutputWindows(child: *const ChildProcess, outs: [2]*std.ArrayList(u8), max_output_bytes: usize) !void { + const bump_amt = 512; + const handles = [_]windows.HANDLE{ + child.stdout.?.handle, + child.stderr.?.handle, + }; + + var overlapped = [_]windows.OVERLAPPED{ + mem.zeroes(windows.OVERLAPPED), + mem.zeroes(windows.OVERLAPPED), + }; + + var wait_objects: [2]windows.HANDLE = undefined; + var wait_object_count: u2 = 0; + + // we need to cancel all pending IO before returning so our OVERLAPPED values don't go out of scope + defer for (wait_objects[0..wait_object_count]) |o| { + _ = windows.kernel32.CancelIo(o); + }; + + // Windows Async IO requires an initial call to ReadFile before waiting on the handle + for ([_]u1{ 0, 1 }) |i| { + try outs[i].ensureCapacity(bump_amt); + const buf = outs[i].unusedCapacitySlice(); + _ = windows.kernel32.ReadFile(handles[i], buf.ptr, math.cast(u32, buf.len) catch maxInt(u32), null, &overlapped[i]); + wait_objects[wait_object_count] = handles[i]; + wait_object_count += 1; + } + + while (true) { + const status = windows.kernel32.WaitForMultipleObjects(wait_object_count, &wait_objects, 0, windows.INFINITE); + if (status == windows.WAIT_FAILED) { + switch (windows.kernel32.GetLastError()) { + else => |err| return windows.unexpectedError(err), + } + } + if (status < windows.WAIT_OBJECT_0 or status > windows.WAIT_OBJECT_0 + wait_object_count - 1) + unreachable; + + const wait_idx = status - windows.WAIT_OBJECT_0; + + // this extra `i` index is needed to map the wait handle back to the stdout or stderr + // values since the wait_idx can change which handle it corresponds with + const i: u1 = if (wait_objects[wait_idx] == handles[0]) 0 else 1; + + // remove completed event from the wait list + wait_object_count -= 1; + if (wait_idx == 0) + wait_objects[0] = wait_objects[1]; + + var read_bytes: u32 = undefined; + if (windows.kernel32.GetOverlappedResult(handles[i], &overlapped[i], &read_bytes, 0) == 0) { + switch (windows.kernel32.GetLastError()) { + .BROKEN_PIPE => { + if (wait_object_count == 0) + break; + continue; + }, + else => |err| return windows.unexpectedError(err), + } + } + + outs[i].items.len += read_bytes; + const new_capacity = std.math.min(outs[i].items.len + bump_amt, max_output_bytes); + try outs[i].ensureCapacity(new_capacity); + const buf = outs[i].unusedCapacitySlice(); + if (buf.len == 0) return if (i == 0) error.StdoutStreamTooLong else error.StderrStreamTooLong; + _ = windows.kernel32.ReadFile(handles[i], buf.ptr, math.cast(u32, buf.len) catch maxInt(u32), null, &overlapped[i]); + wait_objects[wait_object_count] = handles[i]; + wait_object_count += 1; + } + } + /// Spawns a child process, waits for it, collecting stdout and stderr, and then returns. /// If it succeeds, the caller owns result.stdout and result.stderr memory. pub fn exec(args: struct { @@ -306,7 +380,11 @@ pub const ChildProcess = struct { stderr.deinit(); } - try collectOutputPosix(child, &stdout, &stderr, args.max_output_bytes); + if (builtin.os.tag == .windows) { + try collectOutputWindows(child, [_]*std.ArrayList(u8){ &stdout, &stderr }, args.max_output_bytes); + } else { + try collectOutputPosix(child, &stdout, &stderr, args.max_output_bytes); + } return ExecResult{ .term = try child.wait(), @@ -644,7 +722,7 @@ pub const ChildProcess = struct { var g_hChildStd_OUT_Wr: ?windows.HANDLE = null; switch (self.stdout_behavior) { StdIo.Pipe => { - try windowsMakePipeOut(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr); + try windowsMakeAsyncPipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr); }, StdIo.Ignore => { g_hChildStd_OUT_Wr = nul_handle; @@ -664,7 +742,7 @@ pub const ChildProcess = struct { var g_hChildStd_ERR_Wr: ?windows.HANDLE = null; switch (self.stderr_behavior) { StdIo.Pipe => { - try windowsMakePipeOut(&g_hChildStd_ERR_Rd, &g_hChildStd_ERR_Wr, &saAttr); + try windowsMakeAsyncPipe(&g_hChildStd_ERR_Rd, &g_hChildStd_ERR_Wr, &saAttr); }, StdIo.Ignore => { g_hChildStd_ERR_Wr = nul_handle; @@ -907,14 +985,64 @@ fn windowsMakePipeIn(rd: *?windows.HANDLE, wr: *?windows.HANDLE, sattr: *const w wr.* = wr_h; } -fn windowsMakePipeOut(rd: *?windows.HANDLE, wr: *?windows.HANDLE, sattr: *const windows.SECURITY_ATTRIBUTES) !void { - var rd_h: windows.HANDLE = undefined; - var wr_h: windows.HANDLE = undefined; - try windows.CreatePipe(&rd_h, &wr_h, sattr); - errdefer windowsDestroyPipe(rd_h, wr_h); - try windows.SetHandleInformation(rd_h, windows.HANDLE_FLAG_INHERIT, 0); - rd.* = rd_h; - wr.* = wr_h; +var pipe_name_counter = std.atomic.Atomic(u32).init(1); + +fn windowsMakeAsyncPipe(rd: *?windows.HANDLE, wr: *?windows.HANDLE, sattr: *const windows.SECURITY_ATTRIBUTES) !void { + var tmp_bufw: [128]u16 = undefined; + + // We must make a named pipe on windows because anonymous pipes do not support async IO + const pipe_path = blk: { + var tmp_buf: [128]u8 = undefined; + // Forge a random path for the pipe. + const pipe_path = std.fmt.bufPrintZ( + &tmp_buf, + "\\\\.\\pipe\\zig-childprocess-{d}-{d}", + .{ windows.kernel32.GetCurrentProcessId(), pipe_name_counter.fetchAdd(1, .Monotonic) }, + ) catch unreachable; + const len = std.unicode.utf8ToUtf16Le(&tmp_bufw, pipe_path) catch unreachable; + tmp_bufw[len] = 0; + break :blk tmp_bufw[0..len :0]; + }; + + // Create the read handle that can be used with overlapped IO ops. + const read_handle = windows.kernel32.CreateNamedPipeW( + pipe_path.ptr, + windows.PIPE_ACCESS_INBOUND | windows.FILE_FLAG_OVERLAPPED, + windows.PIPE_TYPE_BYTE, + 1, + 4096, + 4096, + 0, + sattr, + ); + if (read_handle == windows.INVALID_HANDLE_VALUE) { + switch (windows.kernel32.GetLastError()) { + else => |err| return windows.unexpectedError(err), + } + } + errdefer os.close(read_handle); + + var sattr_copy = sattr.*; + const write_handle = windows.kernel32.CreateFileW( + pipe_path.ptr, + windows.GENERIC_WRITE, + 0, + &sattr_copy, + windows.OPEN_EXISTING, + windows.FILE_ATTRIBUTE_NORMAL, + null, + ); + if (write_handle == windows.INVALID_HANDLE_VALUE) { + switch (windows.kernel32.GetLastError()) { + else => |err| return windows.unexpectedError(err), + } + } + errdefer os.close(write_handle); + + try windows.SetHandleInformation(read_handle, windows.HANDLE_FLAG_INHERIT, 0); + + rd.* = read_handle; + wr.* = write_handle; } fn destroyPipe(pipe: [2]os.fd_t) void { |