A computer program (process, task, or thread) may sleep, which places it into an inactive state for a period of time. Eventually the expiration of an interval timer, or the receipt of a signal or interrupt causes the program to resume execution.
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Usage [link]
A typical sleep system call takes a time value as a parameter, specifying the minimum amount of time that the process is to sleep before resuming execution. The parameter typically specifies seconds, although some operating systems provide finer resolution, such as milliseconds or microseconds.
Windows [link]
On Windows, the Sleep() function takes a single parameter of the number of milliseconds to sleep. [1] The Sleep() function is included in kernel32.dll, but no sleep command (executable) is natively available for scripts (batch files). It can be found in collections of Windows utilities like Windows 2003 Resource Kit. [2]
Unix [link]
On Unix-like operating systems, the sleep() function is called providing a single parameter of type unsigned integer of the number of seconds to sleep. [3] (For more precise sleep times one can use the usleep() function.) [4]
C examples [link]
In Windows OS: <source lang="c"> while (myInt <= 100) {
Sleep(2*1000); // Sleep for 2 seconds
} </source>
In Unix: <source lang="c"> while (myInt <= 100) {
sleep(2); // Sleep for 2 seconds
} </source>
Low level functionality [link]
Sleep causes the thread or process to enter the Not Runnable state. This allows the CPU to suspend the thread or process and continue executing other threads or processes until the sleep has finished, and the thread or process is allowed to continue executing. On Windows systems the sleep system call is non-interruptible[dubious ], which differs from the Wait system call, which can be interrupted.[5][6] However, some functions labeled sleep() are alterable by design[7]. On Unix system signals interrupt system calls, including sleep().[8] Sleep often leads to poor code design and the wait or nanosleep functions are preferable.
Uses [link]
Some system programs that never terminate execute an event loop, going to sleep at the start of each cycle and waiting for some event to awaken them. Once an event is received, the program services the event, then returns to the beginning of the next wait cycle.
Other programs periodically poll for events by going to sleep and resuming execution after a specific interval of time. Once execution is resumed, the program polls for events or status changes, and then services any that occurred while it was asleep. After servicing the events, the program then goes to sleep again for the next time interval. Certain kinds of heartbeat events or keep-alive signals can be generated by these kinds of programs.
Uninterruptible sleep [link]
An uninterruptible sleep state is a sleep state that won't handle a signal right away. It will wake only as a result of a waited-upon resource becoming available or after a time-out occurs during that wait (if specified when put to sleep). It is mostly used by device drivers waiting for disk or network IO (input/output). When the process is sleeping uninterruptibly, signals accumulated during the sleep will be noticed when the process returns from the system call or trap.
In Unix-like systems the command 'ps -l' uses code "D" for the uninterruptible sleep state of a process.
See also [link]
References [link]
https://wn.com/Sleep_(operating_system)
Sleep (OS X)
Sleep on Macintoshes running on OS X consist of the traditional sleep, Safe Sleep, and Power Nap. In System Preferences, Safe Sleep is referred to as sleep. Since Safe Sleep also allowed state to be restored in an event of a power outage, unlike other operating systems, hibernate was never offered as an option.
In 2005, some versions of Macs running Mac OS X v10.4 began to support Safe Sleep. The feature saves the contents of volatile memory to the system hard disk each time the Mac enters Sleep mode. The Mac can instantaneously wake from sleep mode if power to the RAM has not been lost. However, if the power supply was interrupted, such as when removing batteries without an AC power connection, the Mac would wake from Safe Sleep instead, restoring memory contents from the hard drive.
Safe Sleep capability is found in Mac models starting with the October 2005 revision of the PowerBook G4 (Double-Layer SD). Mac OS X v10.4 or higher is also required. A hack enabled the feature as well on older Macs running Mac OS X v10.4.
Azure Ray (album)
Azure Ray is Azure Ray's self-titled debut. It was released January 16, 2001 on WARM.
Track listing
References
Şarkı
A şarkı is an art song in Ottoman classical music which forms one of the movements of a fasıl (suite). It is performed with an usul (metric structure). This kind of song is rarely performed today. In modern Turkish, şarkı is the common word for any song, Turkish or foreign.
ARC (file format)
ARC is a lossless data compression and archival format by System Enhancement Associates (SEA). It was very popular during the early days of networked dial-up BBS. The file format and the program were both called ARC. The ARC program made obsolete the previous use of a combination of the SQ program to compress files and the LU program to create .LBR archives, by combining both compression and archiving functions into a single program. Unlike ZIP, ARC is incapable of compressing entire directory trees. The format was subject to controversy in the 1980s—an important event in debates over what would later be known as open formats.
The .arc file extension is often used for several file archive-like file types. For example, the Internet Archive uses its own ARC format to store multiple web resources into a single file. The FreeArc archiver also uses .arc extension, but uses a completely different file format.
Nintendo uses an unrelated 'ARC' format for resources, such as MIDI, voice samples, or text, in GameCube and Wii games. Several unofficial extractors exist for this type of ARC file.
Ark (Noon Universe)
Ark (Russian: Ковчег, Kovcheg) is a fictional planet described in Space Mowgli (Малыш) by Arkady and Boris Strugatsky. This planet is a part of the so-called Noon Universe and presents a barren world very similar to Earth in all aspects except the biosphere. The latter is unbelievably poor: for example, the oceans of the planet are empty (no fish, no algae, no mammals) although quite suitable for protein life.
This planet was chosen by progressors as a refuge and a new home for the population of Pant, a planet in danger of a global natural catastrophe. The name was given after the biblical Ark built by Noah. It was initially planned to gradually change the biosphere of Ark to make it more similar to the pantian one and then transfer all Pantians to their new home. Considering the low technological advancement level of Pantians, they should not have noticed anything at all. But this plan was canceled when the non-humanoid native civilization of Ark (Megaforms) was discovered.
