Object pool pattern - Revision history

Frap: /* See also */ add portal

2025-04-30T14:24:41Z

LR.127: Adding local short description: "Software creational design pattern", overriding Wikidata description "pattern to construct sets of initialised programming objects that are kept ready to use"

2024-11-15T01:33:16Z

Adding local short description: "Software creational design pattern", overriding Wikidata description "pattern to construct sets of initialised programming objects that are kept ready to use"

← Previous revision		Revision as of 01:33, 15 November 2024
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			{{Short description\|Software creational design pattern}}
	{{for\|the article about a general pool\|Pool (computer science)}}		{{for\|the article about a general pool\|Pool (computer science)}}
	The '''object pool pattern''' is a software [[creational pattern\|creational design pattern]] that uses a set of initialized [[Object (computer science)\|objects]] kept ready to use – a "[[Pool (computer science)\|pool]]" – rather than allocating and destroying them on demand. A client of the pool will request an object from the pool and perform operations on the returned object. When the client has finished, it returns the object to the pool rather than [[object destruction\|destroying it]]; this can be done manually or automatically.		The '''object pool pattern''' is a software [[creational pattern\|creational design pattern]] that uses a set of initialized [[Object (computer science)\|objects]] kept ready to use – a "[[Pool (computer science)\|pool]]" – rather than allocating and destroying them on demand. A client of the pool will request an object from the pool and perform operations on the returned object. When the client has finished, it returns the object to the pool rather than [[object destruction\|destroying it]]; this can be done manually or automatically.

Frap: Add category

2023-07-03T10:45:46Z

Add category

← Previous revision		Revision as of 10:45, 3 July 2023
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	[[Category:Software optimization]]		[[Category:Software optimization]]
	[[Category:Articles with example C Sharp code]]		[[Category:Articles with example C Sharp code]]
			[[Category:Articles with example Java code]]

Frap: /* C# */

2023-07-01T14:23:29Z

← Previous revision		Revision as of 14:23, 1 July 2023
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	private DateTime _createdAt = DateTime.Now;		private DateTime _createdAt = DateTime.Now;

	public DateTime CreatedAt		public DateTime CreatedAt => _createdAt;
	{
	get { return _createdAt; }
	}

	public string TempData { get; set; }		public string TempData { get; set; }

ClueBot NG: Reverting possible vandalism by 91.197.226.117 to version by Hunan201p. Report False Positive? Thanks, ClueBot NG. (4180659) (Bot)

2022-10-09T01:21:03Z

Reverting possible vandalism by 91.197.226.117 to version by Hunan201p. Report False Positive? Thanks, ClueBot NG. (4180659) (Bot)

← Previous revision		Revision as of 01:21, 9 October 2022
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	<syntaxhighlight lang=Go>		<syntaxhighlight lang=Go>
	// package pool ~~i lonnnnus gool~~		// package pool
	package pool		package pool

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	)		)

	const pi = 3 * time.Second		const getResMaxTime = 3 * time.Second

	var (		var (
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	// (e.g., TCP connection, SSL symmetric key acquisition, auth authentication are time-consuming)		// (e.g., TCP connection, SSL symmetric key acquisition, auth authentication are time-consuming)
	func NewResource(id int) *Resource {		func NewResource(id int) *Resource {
	time.Sleep(500 * ~~to pi i zi..~~ time.Millisecond)		time.Sleep(500 * time.Millisecond)
	return &Resource{resId: id}		return &Resource{resId: id}
	}		}
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	func (r *Resource) Do(workId int) {		func (r *Resource) Do(workId int) {
	time.Sleep(time.Duration(rand.Intn(5)) * 100 * time.Millisecond)		time.Sleep(time.Duration(rand.Intn(5)) * 100 * time.Millisecond)
	log.Printf("using resource #%d finished work %d finish\n", ~~i wkop se len~~ r.resId, workId)		log.Printf("using resource #%d finished work %d finish\n", r.resId, workId)
	}		}

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	}		}
	// Resources to return		// Resources to return
	defer p.GiveBackResource(res) ~~se sam~~		defer p.GiveBackResource(res)
	// Use resources to handle work		// Use resources to handle work
	res.Do(workId)		res.Do(workId)
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	wg.Wait()		wg.Wait()
	}		}
			</syntaxhighlight>
	</syntaxhighlight> sam i sama se suraja kreska rozjebało mniej. Na Liska bez problemu taki wyczesz nowe normalnie takie życie

	=== C# ===		=== C# ===

91.197.226.117: /* Go */

2022-10-09T01:20:55Z

← Previous revision		Revision as of 01:20, 9 October 2022
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	<syntaxhighlight lang=Go>		<syntaxhighlight lang=Go>
	// package pool		// package pool i lonnnnus gool
	package pool		package pool

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	)		)

	const ~~getResMaxTime~~ = 3 * time.Second		const pi = 3 * time.Second

	var (		var (
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	// (e.g., TCP connection, SSL symmetric key acquisition, auth authentication are time-consuming)		// (e.g., TCP connection, SSL symmetric key acquisition, auth authentication are time-consuming)
	func NewResource(id int) *Resource {		func NewResource(id int) *Resource {
	time.Sleep(500 * time.Millisecond)		time.Sleep(500 * to pi i zi.. time.Millisecond)
	return &Resource{resId: id}		return &Resource{resId: id}
	}		}
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	func (r *Resource) Do(workId int) {		func (r *Resource) Do(workId int) {
	time.Sleep(time.Duration(rand.Intn(5)) * 100 * time.Millisecond)		time.Sleep(time.Duration(rand.Intn(5)) * 100 * time.Millisecond)
	log.Printf("using resource #%d finished work %d finish\n", r.resId, workId)		log.Printf("using resource #%d finished work %d finish\n", i wkop se len r.resId, workId)
	}		}

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	}		}
	// Resources to return		// Resources to return
	defer p.GiveBackResource(res)		defer p.GiveBackResource(res) se sam
	// Use resources to handle work		// Use resources to handle work
	res.Do(workId)		res.Do(workId)
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	wg.Wait()		wg.Wait()
	}		}
			</syntaxhighlight> sam i sama se suraja kreska rozjebało mniej. Na Liska bez problemu taki wyczesz nowe normalnie takie życie
	</syntaxhighlight>

	=== C# ===		=== C# ===

Hunan201p at 18:29, 25 May 2022

2022-05-25T18:29:58Z

← Previous revision		Revision as of 18:29, 25 May 2022
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	== Pitfalls ==		== Pitfalls ==

	Care must be taken to ensure the state of the objects returned to the pool is reset back to a sensible state for the next use of the object, otherwise the object may be in an state unexpected by the client, which may cause it to fail. The pool is responsible for resetting the objects, not the clients. Object pools full of objects with dangerously stale state are sometimes called object cesspools and regarded as an [[anti-pattern]].		Care must be taken to ensure the state of the objects returned to the pool is reset back to a sensible state for the next use of the object, otherwise the object may be in a state unexpected by the client, which may cause it to fail. The pool is responsible for resetting the objects, not the clients. Object pools full of objects with dangerously stale state are sometimes called object cesspools and regarded as an [[anti-pattern]].

	Stale state may not always be an issue; it becomes dangerous when it causes the object to behave unexpectedly. For example, an object representing authentication details may fail if the "successfully authenticated" flag is not reset before it is reused, since it indicates that a user is authenticated (possibly as someone else) when they are not. However, failing to reset a value used only for debugging, such as the identity of the last authentication server used, may pose no issues.		Stale state may not always be an issue; it becomes dangerous when it causes the object to behave unexpectedly. For example, an object representing authentication details may fail if the "successfully authenticated" flag is not reset before it is reused, since it indicates that a user is authenticated (possibly as someone else) when they are not. However, failing to reset a value used only for debugging, such as the identity of the last authentication server used, may pose no issues.

Frap: /* C# */ use file-scoped namespace

2021-12-03T09:38:31Z

C#: use file-scoped namespace

Show changes

EthanGaming7640: /* Description */ Spelling/grammar/punctuation/typographical correction

2021-09-30T16:45:56Z

Description: Spelling/grammar/punctuation/typographical correction

← Previous revision		Revision as of 16:45, 30 September 2021
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	== Description ==		== Description ==
	When it is necessary to work with ~~a large number of~~ objects that are particularly expensive to instantiate and each object is only needed for a short period of time, the performance of an entire application may be adversely affected. An object pool design pattern may be deemed desirable in cases such as these.		When it is necessary to work with numerous objects that are particularly expensive to instantiate and each object is only needed for a short period of time, the performance of an entire application may be adversely affected. An object pool design pattern may be deemed desirable in cases such as these.

	The object pool design pattern creates a set of objects that may be reused. When a new object is needed, it is requested from the pool. If a previously prepared object is available it is returned immediately, avoiding the instantiation cost. If no objects are present in the pool, a new item is created and returned. When the object has been used and is no longer needed, it is returned to the pool, allowing it to be used again in the future without repeating the computationally expensive instantiation process. It is important to note that once an object has been used and returned, existing references will become invalid.		The object pool design pattern creates a set of objects that may be reused. When a new object is needed, it is requested from the pool. If a previously prepared object is available, it is returned immediately, avoiding the instantiation cost. If no objects are present in the pool, a new item is created and returned. When the object has been used and is no longer needed, it is returned to the pool, allowing it to be used again in the future without repeating the computationally expensive instantiation process. It is important to note that once an object has been used and returned, existing references will become invalid.

	In some object pools the resources are limited so a maximum number of objects is specified. If this number is reached and a new item is requested, an exception may be thrown, or the thread will be blocked until an object is released back into the pool.		In some object pools the resources are limited, so a maximum number of objects is specified. If this number is reached and a new item is requested, an exception may be thrown, or the thread will be blocked until an object is released back into the pool.

	The object pool design pattern is used in several places in the standard classes of the .NET Framework. One example is the .NET Framework Data Provider for SQL Server. As SQL Server database connections can be slow to create, a pool of connections is maintained. Closing a connection does not actually relinquish the link to SQL Server. Instead, the connection is held in a pool from which it can be retrieved when requesting a new connection. This substantially increases the speed of making connections.		The object pool design pattern is used in several places in the standard classes of the .NET Framework. One example is the .NET Framework Data Provider for SQL Server. As SQL Server database connections can be slow to create, a pool of connections is maintained. Closing a connection does not actually relinquish the link to SQL Server. Instead, the connection is held in a pool, from which it can be retrieved when requesting a new connection. This substantially increases the speed of making connections.

	== Benefits ==		== Benefits ==

Kzkzb: /* Java */ Fix indentation

2021-03-16T18:10:03Z

Java: Fix indentation

← Previous revision		Revision as of 18:10, 16 March 2021
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	public void setTemp3(String temp3) {		public void setTemp3(String temp3) {
	this.temp3 = temp3;		this.temp3 = temp3;
	}}		}
			}

	</syntaxhighlight><syntaxhighlight lang="java">		</syntaxhighlight><syntaxhighlight lang="java">
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	push(inUse, po, now);		push(inUse, po, now);
	return po;		return po;
	}		}

	private synchronized static void push(HashMap<PooledObject, Long> map,		private synchronized static void push(HashMap<PooledObject, Long> map,

← Previous revision		Revision as of 14:24, 30 April 2025
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	== See also ==		== See also ==
			{{Portal\|Computer programming}}
	* [[Connection pool]]		* [[Connection pool]]
	* [[Free list]]		* [[Free list]]

← Previous revision		Revision as of 01:33, 15 November 2024
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			{{Short description\|Software creational design pattern}}
	{{for\|the article about a general pool\|Pool (computer science)}}		{{for\|the article about a general pool\|Pool (computer science)}}
	The '''object pool pattern''' is a software [[creational pattern\|creational design pattern]] that uses a set of initialized [[Object (computer science)\|objects]] kept ready to use – a "[[Pool (computer science)\|pool]]" – rather than allocating and destroying them on demand. A client of the pool will request an object from the pool and perform operations on the returned object. When the client has finished, it returns the object to the pool rather than [[object destruction\|destroying it]]; this can be done manually or automatically.		The '''object pool pattern''' is a software [[creational pattern\|creational design pattern]] that uses a set of initialized [[Object (computer science)\|objects]] kept ready to use – a "[[Pool (computer science)\|pool]]" – rather than allocating and destroying them on demand. A client of the pool will request an object from the pool and perform operations on the returned object. When the client has finished, it returns the object to the pool rather than [[object destruction\|destroying it]]; this can be done manually or automatically.