Context Switching: Performance.Even though it's fast, context switching is expensive: 1. Time spent is 100% overhead 2. Must invalidate other processes' resources (caches, memory mappings) 3. Kernel must execute –it must be accessible in memory.Solution to #3:.keep kernel mapped in every process VAS.protect it to be inaccessible. Download Monitor Profile Switcher for free. Save and easily switch between Windows multi monitor configurations. Save monitor configurations of Windows 7 or 10 and easily switch between them with a click in a popup menu of your taskbar. The tool is designed for users with two or more monitors who in certain situations would like to quickly change their monitor setup (e.g. The ability to do context switching is an essential component for any multitasking OS. The same type of things that cause context switching in Linux would cause context switching in Windows as well. All a high thread count means is that the CPU will be forced to switch contexts more often to fulfill the processing requirements of the scheduler.
Contexts lets you switch to windows with search. Press Control-Space (or whichever keyboard shortcut you prefer) to open the Search window. Type a few characters from an app name or window title to filter the list. Press Return to switch to the selected item.
And in Contexts 3 we have taken search to a new level. Our goals were simple but ambitious: You should need as few keystrokes as possible — ideally just two for your frequently used windows; And it should be as deterministic as possible — so you can switch without even looking at the results most of the time. Here is how it works:
- Matches non-consecutive characters. You can type characters which are anywhere in the app name or window title. If an app has multiple windows open, type a couple of characters from the app name and a couple from the window title.
- Prioritizes acronym matches. Character matches at start of the app name and start of any words in the window title get a higher score. Most of the time typing the acronym of an item's title is sufficient to make it the first result.
- Creates search shortcuts. Once you type a search query and select a window (with up or down keys if necessary), typing the same query later will cause that window to be the first result. E.g. type 's', select Safari window from results and from then on that window will always be the first result for 's'.
Gemini 2: the duplicate finder 2 5 2. Fast Search. If you want to go even faster, enable Fast Search, hold down the Fn key (or whichever modifier key you prefer1) and type a one or two character query (or a longer one if you want to). The Search window will appear with the results. Just release Fn and the selected item will come to the front. Combine this with search shortcuts and you can switch to Safari with Fn-s, Notes with Fn-n, Messages with Fn-me and so on. In two or three keystrokes, that is.
1. Contexts recognizes left & right modifier keys separately. So you can set Fast Search to use, for example, only the left Option key or only the right Option key. The other modifier key will continue to work as it does by default.
Background
![Contexts 3 4 1 – fast window switcher system installation Contexts 3 4 1 – fast window switcher system installation](https://cdn.guidingtech.com/imager/assets/2019/04/221361/windows-10-tablet-mode-tips-tricks-hidden-features-11_4d470f76dc99e18ad75087b1b8410ea9.png?1554101749)
When a spacecraft is launched from Earth, its forward velocity combined with the gravitational pull of Earth cause it to travel in a curved path. As the spacecraft heads toward another planet, the gravitational pull of that planet factors in to the path the spacecraft takes. The more a spacecraft can 'coast' with engines off, the lower the cost of the mission (rocket fuel is not cheap!).
Think of a quarterback throwing a football to a receiver. The initial impulse (throw) is all the football gets as far as power is concerned. The football follows a curved path into the hands of the receiver. Likewise, the quarterback throws the football to where the receiver is going to be, not necessarily to where the receiver is currently. So, the quarterback throws the football downfield as the receiver is running in that direction. In a perfectly thrown pass, the receiver's running speed will bring him or her to the exact spot where the football arrives at hand-level.
Launching to Mars is similar to this. A spacecraft is given an initial impulse (launch) toward Mars and then shuts off its engines and coasts (obeying Newton's First Law) until it gets close to its target. Depending on the mission, the spacecraft may slow down – to get into orbit or land – by using the Martian atmosphere or retro-rockets that fire opposite to the direction of travel (obeying Newton's Third Law).
Though a spacecraft could follow a variety of curved paths from Earth to Mars, one path called the Hohmann transfer orbit uses the least energy and is thereby considered to be the most efficient.
The Hohmann transfer is an elliptical orbit with the sun at one focus of the ellipse that intersects the orbit of the target planet. Launch occurs when Earth is at Hohmann perihelion (the point of the Hohmann orbit that is closest to the sun). Arrival occurs when Mars is at Hohmann aphelion (the point of the Hohmann orbit that is farthest from the sun).
![Window Window](https://assets.hongkiat.com/uploads/android-app-switcher/swipepad.jpg)
When a spacecraft is launched from Earth, its forward velocity combined with the gravitational pull of Earth cause it to travel in a curved path. As the spacecraft heads toward another planet, the gravitational pull of that planet factors in to the path the spacecraft takes. The more a spacecraft can 'coast' with engines off, the lower the cost of the mission (rocket fuel is not cheap!).
Think of a quarterback throwing a football to a receiver. The initial impulse (throw) is all the football gets as far as power is concerned. The football follows a curved path into the hands of the receiver. Likewise, the quarterback throws the football to where the receiver is going to be, not necessarily to where the receiver is currently. So, the quarterback throws the football downfield as the receiver is running in that direction. In a perfectly thrown pass, the receiver's running speed will bring him or her to the exact spot where the football arrives at hand-level.
Launching to Mars is similar to this. A spacecraft is given an initial impulse (launch) toward Mars and then shuts off its engines and coasts (obeying Newton's First Law) until it gets close to its target. Depending on the mission, the spacecraft may slow down – to get into orbit or land – by using the Martian atmosphere or retro-rockets that fire opposite to the direction of travel (obeying Newton's Third Law).
Though a spacecraft could follow a variety of curved paths from Earth to Mars, one path called the Hohmann transfer orbit uses the least energy and is thereby considered to be the most efficient.
The Hohmann transfer is an elliptical orbit with the sun at one focus of the ellipse that intersects the orbit of the target planet. Launch occurs when Earth is at Hohmann perihelion (the point of the Hohmann orbit that is closest to the sun). Arrival occurs when Mars is at Hohmann aphelion (the point of the Hohmann orbit that is farthest from the sun).
Depending on mission objectives and spacecraft characteristics, engineers will use variations on the Hohmann transfer orbit to get spacecraft to Mars. These variations can make travel time more or less lengthy than a standard Hohmann transfer.
To make sure the spacecraft and Mars arrive at the same place at the same time, the spacecraft must launch within a particular window of time. This window is called the 'launch window' and, depending on the target, can be a few minutes or as much as a few weeks in length.
If a spacecraft is launched too early or too late, it will arrive in the planet's orbit when the planet is not there.
When launched within the proper launch window, the spacecraft will arrive in the planet's orbit just as the planet arrives at that same place. At this point, the spacecraft is positioned for either going into orbit about the planet or landing on the planet.
Contexts 3 4 1 – Fast Window Switcher System Controller
Calculating orbit trajectories and launch windows is a complex task involving a variety of parameters that may or may not be constantly changing. In order to make this task accessible to high-school students, some variable parameters have been stabilized and some assumptions have been made. This problem, with these simplifications, allows students to generate an approximation of the launch window to Mars.