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Reentrant
Reentrant or re-entrant can refer to: *Re-entrant (landform), the low ground formed between two hill spurs. *Reentrancy (computing) in computer programming *Reentrant mutex in computer science *Reentry (neural circuitry) in neuroscience *Salients, re-entrants and pockets in military tactics *Reentrant tuning in music *Concave polygon, AKA reentrant polygon See also * Reentry Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ... * Reentrant dysrhythmia, a type of cardiac arrhythmia {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reentrancy (computing)
In computing, a computer program or subroutine is called reentrant if multiple invocations can safely run concurrently on multiple processors, or on a single processor system, where a reentrant procedure can be interrupted in the middle of its execution and then safely be called again ("re-entered") before its previous invocations complete execution. The interruption could be caused by an internal action such as a jump or call, or by an external action such as an interrupt or signal, unlike recursion, where new invocations can only be caused by internal call. This definition originates from multiprogramming environments where multiple processes may be active concurrently and where the flow of control could be interrupted by an interrupt and transferred to an interrupt service routine (ISR) or "handler" subroutine. Any subroutine used by the handler that could potentially have been executing when the interrupt was triggered should be reentrant. Similarly, code shared by two process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reentrant Mutex
In computer science, the reentrant mutex (recursive mutex, recursive lock) is a particular type of mutual exclusion (mutex) device that may be locked multiple times by the same process/thread, without causing a deadlock. While any attempt to perform the "lock" operation on an ordinary mutex (lock) would either fail or block when the mutex is already locked, on a recursive mutex this operation will succeed if and only if the locking thread is the one that already holds the lock. Typically, a recursive mutex tracks the number of times it has been locked, and requires equally many unlock operations to be performed before other threads may lock it. Motivation Recursive mutexes solve the problem of non-reentrancy with regular mutexes: if a function that takes a lock and executes a callback is itself called by the callback, deadlock ensues. In pseudocode, that is the following situation: var m : Mutex // A non-recursive mutex, initially unlocked. function lock_and_call(i : Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reentrant Tuning
On a stringed instrument, a break in an otherwise ascending (or descending) order of string pitches is known as a re-entry. A re-entrant tuning, therefore, is a tuning where the strings (or more properly the courses) are not all ordered from the lowest pitch to the highest pitch (or vice versa). Most common re-entrant tunings have only one re-entry. In the case of the ukulele, for example, the re-entry is between the third and fourth strings, while in the case of the Venezuelan cuatro it is between the first and second strings. Instruments Instruments usually tuned in this way include: * Baroque (5-course) guitar * Five-string banjo * Charango * Cittern * Venezuelan Cuatro * Laouto * Lirone * Mexican Guitarrón * Mexican vihuela * Rajão * Sitar * Theorbo * Tonkori * Soprano and concert ukuleles * Tres Cubano/Cuban Tres Instruments often (but not always) re-entrantly tuned include: * Tenor guitar * Ten string classical guitar * Tenor and Baritone (occasionally) ukuleles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Re-entrant (landform)
A re-entrant (international) or draw or is a terrain feature formed by two parallel ridges or spurs with low ground in between them. The area of low ground itself is the draw, and it is defined by the spurs surrounding it. Re-entrants are similar to valleys on a smaller scale; however, while valleys are by nature parallel to a ridgeline, a re-entrant is perpendicular to the ridge, and rises with the surrounding ground, disappearing up-slope. It is usually etched in a hillside by water flow, is usually dry, but many contain an ephemeral stream or loose rocks from eroded rockfall. In a re-entrant or draw the ground always slopes downward in only one direction, and upward in the other three. The slope on a draw is generally quite sharp, with a clearly established fall line A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is typically prominent where rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reentry (neural Circuitry)
Reentry is a neural structuring of the brain, which is characterized by the ongoing bidirectional exchange of signals along reciprocal axonal fibers linking two or more brain areas. It is hypothesized to allow for widely distributed groups of neurons to achieve integrated and synchronized firing, which is proposed to be a requirement for consciousness, as outlined by Gerald Edelman and Giulio Tononi in their book ''A Universe of Consciousness''.. See also *Embodied philosophy *Neural Darwinism *Primary consciousness *Secondary consciousness Secondary consciousness is an individual's accessibility to their history and plans. The ability allows its possessors to go beyond the limits of the remembered present of primary consciousness.Edelman, G. M. (2003). Naturalizing consciousness: a ... References Neural circuits Neurophysiology {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salients, Re-entrants And Pockets
A salient, also known as a bulge, is a battlefield feature that projects into enemy territory. The salient is surrounded by the enemy on multiple sides, making the troops occupying the salient vulnerable. The opponent's front line that borders a salient is referred to as a re-entrant – that is, an angle pointing inwards. A deep salient is vulnerable to being "pinched off" through the base, and this will result in a pocket in which the forces in the salient become isolated and without a supply line. On the other hand, a breakout of the forces within the salient through its tip can threaten the rear areas of the opposing forces outside it, leaving them open to an attack from behind. Implementation Salients can be formed in a number of ways. An attacker can produce a salient in the defender's line by either intentionally making a pincer movement around the military flanks of a strongpoint, which becomes the tip of the salient, or by making a broad, frontal attack which is held u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concave Polygon
A simple polygon that is not convex is called concave, non-convex or reentrant. A concave polygon will always have at least one reflex interior angle—that is, an angle with a measure that is between 180 degrees and 360 degrees exclusive. Polygon Some lines containing interior points of a concave polygon intersect its boundary at more than two points. Some diagonals of a concave polygon lie partly or wholly outside the polygon. Some sidelines of a concave polygon fail to divide the plane into two half-planes one of which entirely contains the polygon. None of these three statements holds for a convex polygon. As with any simple polygon, the sum of the internal angles of a concave polygon is ×(''n'' − 2) radians, equivalently 180×(''n'' − 2) degrees (°), where ''n'' is the number of sides. It is always possible to partition a concave polygon into a set of convex polygons. A polynomial-time algorithm for finding a decomposition into as few convex polyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reentry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speeds be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
