Search results
Results from the WOW.Com Content Network
A memory-mapped file is a segment of virtual memory [1] that has been assigned a direct byte-for-byte correlation with some portion of a file or file-like resource. This resource is typically a file that is physically present on disk, but can also be a device, shared memory object, or other resource that an operating system can reference through a file descriptor.
The main difference between System V shared memory (shmem) and memory mapped I/O (mmap) is that System V shared memory is persistent: unless explicitly removed by a process, it is kept in memory and remains available until the system is shut down. mmap'd memory is not persistent between application executions (unless it is backed by a file).
Drive mapping is how MS-DOS and Microsoft Windows associate a local drive letter (A-Z) with a shared storage area to another computer (often referred as a File Server) over a network. After a drive has been mapped , a software application on a client 's computer can read and write files from the shared storage area by accessing that drive, just ...
POSIX also provides the mmap API for mapping files into memory; a mapping can be shared, allowing the file's contents to be used as shared memory. Linux distributions based on the 2.6 kernel and later offer /dev/shm as shared memory in the form of a RAM disk , more specifically as a world-writable directory (a directory in which every user of ...
A process can store data in memory-mapped files on memory-backed file systems, such as the tmpfs file system or file systems on a RAM drive, and map files into and out of the address space as needed. A set of processes may still depend upon the enhanced security features page-based isolation may bring to a multitasking environment.
Instead of using standard input and output as with an anonymous pipe, processes write to and read from a named pipe, as if it were a regular file. All POSIX systems, Windows, AmigaOS 2.0+ Shared memory: Multiple processes are given access to the same block of memory, which creates a shared buffer for the processes to communicate with each other.
Shared file and printer access require an operating system on the client that supports access to resources on a server, an operating system on the server that supports access to its resources from a client, and an application layer (in the four or five layer TCP/IP reference model) file sharing protocol and transport layer protocol to provide that shared access.
DLL hell is an umbrella term for the complications that arise when one works with dynamic-link libraries (DLLs) used with older Microsoft Windows operating systems, [1] particularly legacy 16-bit editions, which all run in a single memory space.