A bug in a multithreaded process where the code of thread A relies on thread B to complete some action, but where there is no synchronization between the two threads. The process works if thread B wins the race by completing its action before thread A needs it, but the process fails if thread A wins the race. See also process,thread.
radial
A line drawn from the center of an ellipse to a point on the ellipse. See also ellipse.
radio button
A round button operated by the user to choose from a set of related but mutually exclusive options. The check mark for a radio button is a black dot. A radio button can assume two states: checked (dot) or unchecked (no dot). In automatic radio buttons, the system is responsible for changing the state of the radio button.
raster device
A device that creates text and graphics output by highlighting rows and columns of pixels (in the case of video displays) or rows and columns of dots (in the case of printers). See also pixel.
rasterizer
A Windows dynamic-link library that converts the graphics commands and hints for TrueType glyphs into actual bitmaps that are drawn on a video display or page of paper. See also bitmap,glyph,dynamic-link library (DLL).
rectangular region
A region with the shape of a rectangle. See also region.
A color format that identifies a given color with a red, green, blue (RGB) triplet. This format is used by video displays.
reference count
The number of times a string has been added to or deleted from an atom table. The AddAtom or GlobalAddAtom function increments the count; the DeleteAtom or GlobalDeleteAtom function decrements the count. See also atom table.
reference device
The device where the original picture was created.
reference device context (DC)
The device context associated with the reference device.
reflection
A transformation that creates a mirror image of an object.
region
A rectangle, polygon, ellipse (or a combination of two or more of these shapes) used by Windows-based applications to define a part of the client area to be painted, inverted, filled with output, framed, or used for hit testing. See also ellipse,hit testing,polygon.
region operation
A procedure such as inverting, painting, clipping, or hit testing. See also clipping,hit testing.
registered clipboard format
A clipboard format registered by an application, as opposed to a standard clipboard format.
registry
The database in which configuration information is registered. This database takes the place of most configuration and initialization files for Windows and new Windows-based applications.
regular curve
A curve that defines the perimeter of a conic section.
relative identifier (RID)
The portion of a security identifier (SID) that identifies a user or group in relation to the authority that issued the SID. See also security identifier (SID).
render
To make data available in a specific clipboard format. See also clipboard format.
Replace common dialog box
A common dialog box that displays two edit controls where the user can type strings: The first string identifies a word or value that the application should replace, and the second string identifies the replacement word or value. See also common dialog box,edit control.
reserved page
A page of memory in a process's virtual address space that has been set aside for future use. The page is not accessible and has no physical storage associated with it. A reserve page reserves a range of virtual addresses that cannot be used subsequently by other allocation operations.
resolution
(1) For joysticks, the minimum and maximum intervals between joystick messages sent for a captured joystick.
(2) For timers, the accuracy of the timer event. A resolution value of zero means that the event must occur at the exact time requested; a resolution value of ten means that the event must occur within ten milliseconds of the requested time.
resource
Binary data the resource compiler or developer adds to an application's executable file. Windows resources include icons, cursors, menus, dialog boxes, bitmaps, fonts, keyboard-accelerator tables, message-table entries, string-table entries, version data, and user-defined data.
resource compiler
An application that creates a binary resource file based on the resource-definition file. The resource compiler can also append binary resource data to an executable file and create a resource table in the executable file's header. See also resource table.
resource-definition file
A text file containing descriptions of an application's resources. The resource compiler creates a binary resource file based on the contents of the resource-definition file. Resource-definition files usually have a .RC extension.
resource file
A binary file created by the resource compiler that contains an application's resource data. Resource files usually have a .RES extension. See also resource compiler.
Resource Interchange File Format (RIFF)
A tagged-file specification used to define standard formats for multimedia files. Tagged-file structure helps prevent compatibility problems that often occur when file-format definitions change over time. Because each piece of data in the file is identified by a standard header, an application that does not recognize a given data element can skip over the unknown information. See also tagged file format.
resource object
An object file that consists of the resource file and the resource table. The linker links the resource object to the executable file. See also resource file.
resource table
Data the resource compiler adds to the header of an application's executable file. This data includes the location, name, type, language, and so on, of each resource in the executable file. See also resource compiler.
restore box
A bitmap that, when clicked, restores the window to its previous size and position.
restored window
A window that does not have the WS_MAXIMIZE or WS_MINIMIZE style.
RGB color space
A color space type thatrepresents colors as red, green and blue coordinates by mapping the color components onto a Cartesian coordinate system in three or more dimensions. red, green, and blue each have a numeric color value; their intensity and hue can be changed by adding to or subtracting from those values. All three coordinates are needed for the calculation of any color.
A chunk with chunk identifier Resource Interchange File Format (RIFF) that includes an identifying code and zero or more subchunks, the contents of which depend on the form type.
RIFF file
A file whose format complies with one of the published Resource Interchange File Format (RIFF) forms. Examples of RIFF files include WAVE files for waveform audio data, RMID files for Musical Instrument Digital Interface (MIDI) sequences, and RDIB files for device-independent bitmaps.
The topmost directory on a volume. Files and directories on a volume are organized in a tree structure whose entry point is the root directory. The root directory is referenced in a path by a single backslash (\\) or a leading backslash in a longer path (\\MYDIR\\MYFILE.TXT). See also directory,path,volume.
root volume
A directory hosted by a server running Windows NT Server 4.0 and later that is unique to one Dfs tree structure. There can be multiple Dfs trees on one network, but a server can have only one share that serves as a Dfs root. See also Distributed File System (Dfs), junction point, leaf volume.
rotation
A transformation that rotates an object with respect to the coordinate-space origin.
run-time linking
Dynamic linking that occurs when the LoadLibrary and GetProcAddress functions are used to get the starting address of a dynamic-link library (DLL) function.