Open non-blocking regular files as overlapped on Windows (#14921)

spec/std/file/tempfile_spec.cr

@@ -200,7 +200,7 @@ describe Crystal::System::File do
         fd, path = Crystal::System::File.mktemp("A", "Z", dir: tempdir, random: TestRNG.new([7, 8, 9, 10, 11, 12, 13, 14]))
         path.should eq Path[tempdir, "A789abcdeZ"].to_s
       ensure
-        File.from_fd(path, fd).close if fd && path
+        IO::FileDescriptor.new(fd).close if fd
       end
     end
 
@@ -212,7 +212,7 @@ describe Crystal::System::File do
         fd, path = Crystal::System::File.mktemp("A", "Z", dir: tempdir, random: TestRNG.new([7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22]))
         path.should eq File.join(tempdir, "AfghijklmZ")
       ensure
-        File.from_fd(path, fd).close if fd && path
+        IO::FileDescriptor.new(fd).close if fd
       end
     end
 
@@ -223,7 +223,7 @@ describe Crystal::System::File do
         expect_raises(File::AlreadyExistsError, "Error creating temporary file") do
           fd, path = Crystal::System::File.mktemp("A", "Z", dir: tempdir, random: TestRNG.new([7, 8, 9, 10, 11, 12, 13, 14]))
         ensure
-          File.from_fd(path, fd).close if fd && path
+          IO::FileDescriptor.new(fd).close if fd
         end
       end
     end

spec/std/file_spec.cr

@@ -71,6 +71,14 @@ describe "File" do
       end
     end
 
+    it "opens regular file as non-blocking" do
+      with_tempfile("regular") do |path|
+        File.open(path, "w", blocking: false) do |file|
+          file.blocking.should be_false
+        end
+      end
+    end
+
     {% if flag?(:unix) %}
       if File.exists?("/dev/tty")
         it "opens character device" do

src/crystal/system/file.cr

@@ -65,7 +65,7 @@ module Crystal::System::File
         io << suffix
       end
 
-      handle, errno = open(path, mode, perm)
+      handle, errno = open(path, mode, perm, blocking: true)
 
       if error_is_none?(errno)
         return {handle, path}

src/crystal/system/unix/file.cr

@@ -3,10 +3,10 @@ require "file/error"
 
 # :nodoc:
 module Crystal::System::File
-  def self.open(filename : String, mode : String, perm : Int32 | ::File::Permissions)
+  def self.open(filename : String, mode : String, perm : Int32 | ::File::Permissions, blocking)
     perm = ::File::Permissions.new(perm) if perm.is_a? Int32
 
-    fd, errno = open(filename, open_flag(mode), perm)
+    fd, errno = open(filename, open_flag(mode), perm, blocking)
 
     unless errno.none?
       raise ::File::Error.from_os_error("Error opening file with mode '#{mode}'", errno, file: filename)
@@ -15,7 +15,7 @@ module Crystal::System::File
     fd
   end
 
-  def self.open(filename : String, flags : Int32, perm : ::File::Permissions) : {LibC::Int, Errno}
+  def self.open(filename : String, flags : Int32, perm : ::File::Permissions, blocking _blocking) : {LibC::Int, Errno}
     filename.check_no_null_byte
     flags |= LibC::O_CLOEXEC
 

src/crystal/system/win32/file.cr

@@ -14,7 +14,7 @@ module Crystal::System::File
   # write at the end of the file.
   @system_append = false
 
-  def self.open(filename : String, mode : String, perm : Int32 | ::File::Permissions) : FileDescriptor::Handle
+  def self.open(filename : String, mode : String, perm : Int32 | ::File::Permissions, blocking : Bool?) : FileDescriptor::Handle
     perm = ::File::Permissions.new(perm) if perm.is_a? Int32
     # Only the owner writable bit is used, since windows only supports
     # the read only attribute.
@@ -24,16 +24,16 @@ module Crystal::System::File
       perm = LibC::S_IREAD
     end
 
-    handle, error = open(filename, open_flag(mode), ::File::Permissions.new(perm))
+    handle, error = open(filename, open_flag(mode), ::File::Permissions.new(perm), blocking != false)
     unless error.error_success?
       raise ::File::Error.from_os_error("Error opening file with mode '#{mode}'", error, file: filename)
     end
 
     handle
   end
 
-  def self.open(filename : String, flags : Int32, perm : ::File::Permissions) : {FileDescriptor::Handle, WinError}
-    access, disposition, attributes = self.posix_to_open_opts flags, perm
+  def self.open(filename : String, flags : Int32, perm : ::File::Permissions, blocking : Bool) : {FileDescriptor::Handle, WinError}
+    access, disposition, attributes = self.posix_to_open_opts flags, perm, blocking
 
     handle = LibC.CreateFileW(
       System.to_wstr(filename),
@@ -48,7 +48,7 @@ module Crystal::System::File
     {handle.address, handle == LibC::INVALID_HANDLE_VALUE ? WinError.value : WinError::ERROR_SUCCESS}
   end
 
-  private def self.posix_to_open_opts(flags : Int32, perm : ::File::Permissions)
+  private def self.posix_to_open_opts(flags : Int32, perm : ::File::Permissions, blocking : Bool)
     access = if flags.bits_set? LibC::O_WRONLY
                LibC::FILE_GENERIC_WRITE
              elsif flags.bits_set? LibC::O_RDWR
@@ -77,7 +77,7 @@ module Crystal::System::File
       disposition = LibC::OPEN_EXISTING
     end
 
-    attributes = LibC::FILE_ATTRIBUTE_NORMAL
+    attributes = 0
     unless perm.owner_write?
       attributes |= LibC::FILE_ATTRIBUTE_READONLY
     end
@@ -97,6 +97,10 @@ module Crystal::System::File
       attributes |= LibC::FILE_FLAG_RANDOM_ACCESS
     end
 
+    unless blocking
+      attributes |= LibC::FILE_FLAG_OVERLAPPED
+    end
+
     {access, disposition, attributes}
   end
 

src/crystal/system/win32/file_descriptor.cr

@@ -89,6 +89,7 @@ module Crystal::System::FileDescriptor
 
   private def system_blocking_init(value)
     @system_blocking = value
+    Crystal::EventLoop.current.create_completion_port(windows_handle) unless value
   end
 
   private def system_close_on_exec?
@@ -264,13 +265,11 @@ module Crystal::System::FileDescriptor
     w_pipe_flags |= LibC::FILE_FLAG_OVERLAPPED unless write_blocking
     w_pipe = LibC.CreateNamedPipeA(pipe_name, w_pipe_flags, pipe_mode, 1, PIPE_BUFFER_SIZE, PIPE_BUFFER_SIZE, 0, nil)
     raise IO::Error.from_winerror("CreateNamedPipeA") if w_pipe == LibC::INVALID_HANDLE_VALUE
-    Crystal::EventLoop.current.create_completion_port(w_pipe) unless write_blocking
 
     r_pipe_flags = LibC::FILE_FLAG_NO_BUFFERING
     r_pipe_flags |= LibC::FILE_FLAG_OVERLAPPED unless read_blocking
     r_pipe = LibC.CreateFileW(System.to_wstr(pipe_name), LibC::GENERIC_READ | LibC::FILE_WRITE_ATTRIBUTES, 0, nil, LibC::OPEN_EXISTING, r_pipe_flags, nil)
     raise IO::Error.from_winerror("CreateFileW") if r_pipe == LibC::INVALID_HANDLE_VALUE
-    Crystal::EventLoop.current.create_completion_port(r_pipe) unless read_blocking
 
     r = IO::FileDescriptor.new(r_pipe.address, read_blocking)
     w = IO::FileDescriptor.new(w_pipe.address, write_blocking)

src/file.cr

@@ -172,7 +172,7 @@ class File < IO::FileDescriptor
   # additional syscall.
   def self.new(filename : Path | String, mode = "r", perm = DEFAULT_CREATE_PERMISSIONS, encoding = nil, invalid = nil, blocking = true)
     filename = filename.to_s
-    fd = Crystal::System::File.open(filename, mode, perm: perm)
+    fd = Crystal::System::File.open(filename, mode, perm: perm, blocking: blocking)
     new(filename, fd, blocking: blocking, encoding: encoding, invalid: invalid).tap { |f| f.system_set_mode(mode) }
   end