What is overlapped operation?

What is overlapped operation?

Overlapped operations enable a thread to perform a time-consuming I/O operation in the background, leaving the thread free to perform other tasks. The system sets the state of the event object to not-signaled when a call to the I/O function returns before the operation has been completed.

What is overlapped structure?

It is a byte offset from the start of the file or file-like device, and it is specified by the user; the system will not modify these values. The calling process must set this member before passing the OVERLAPPED structure to functions that use an offset, such as the ReadFile or WriteFile (and related) functions.

What is CreateFile?

The CreateFile function can create a new file or open an existing file. You must specify the file name, creation instructions, and other attributes. When an application creates a new file, the operating system adds it to the specified directory.

What is lpOverlapped?

The lpOverlapped parameter must point to a valid and unique OVERLAPPED structure, otherwise the function can incorrectly report that the read operation is complete. The lpNumberOfBytesRead parameter should be set to NULL. Use the GetOverlappedResult function to get the actual number of bytes read.

What is Operation overlapping what is its purpose?

Overlapping operations occurs when the transportation of partial batches to a downstream work station is allowed while work proceeds to complete the batch at the upstream work station. The potential efficiencies to be gained are the following: Reduced total lead time • Reduced work-in-process inventory.

Has overlapped meaning?

verb (used with object), o·ver·lapped, o·ver·lap·ping. to lap over (something else or each other); extend over and cover a part of; imbricate. to cover and extend beyond (something else): The ends of cloth overlap the table. to coincide in part with; have in common with: two lives that overlapped each other.

Does Fopen call CreateFile?

1 Answer. fopen() calls CreateFile() . I debugged into fopen before and ended up in CreateFile .

What is Lpcvoid?

An LPCVOID is a 32-bit pointer to a constant of any type.

What is production overlap?

A product overlap strategy refers to a company’s decision to produce similar products under different brand names, through private labels or through original equipment manufacturers.

What happens when the setfilepointer function fails?

If a new file pointer is a negative value, the function fails, the file pointer is not moved, and the code returned by GetLastError is ERROR_NEGATIVE_SEEK. If lpDistanceToMoveHigh is NULL and the new file position does not fit in a 32-bit value, the function fails and returns INVALID_SET_FILE_POINTER.

Is it an error to set a file pointer beyond the end of the file?

It is not an error to set a file pointer to a position beyond the end of the file. The size of the file does not increase until you call the SetEndOfFile , WriteFile, or WriteFileEx function.

Can a non seeking device call the setfilepointer function?

The hFile parameter must refer to a file stored on a seeking device; for example, a disk volume. Calling the SetFilePointer function with a handle to a non-seeking device such as a pipe or a communications device is not supported, even though the SetFilePointer function may not return an error.

Can you use the SetFile pointerex function with a handle?

You cannot use the SetFilePointerEx function with a handle to a nonseeking device such as a pipe or a communications device. To determine the file type for hFile , use the GetFileType function. Use caution when setting the file pointer in a multithreaded application.