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Chapter 16. Understanding and Configuring the Garbage Collector

16.7. Garbage-Collection Dictionary

[Function]

gc

Description:

Causes a full GC to occur as soon as possible. Returns NIL.

[Function]

lisp-heap-gc-threshold

Description:

Returns the value of the kernel variable that specifies the amount of free space to leave in the heap after full GC.

[Function]

set-lisp-heap-gc-threshold new-threshold

Arguments and Values:

new-threshold---The requested new lisp-heap-gc-threshold.

Description:

Sets the value of the kernel variable that specifies the amount of free space to leave in the heap after full GC to new-value, which should be a non-negative fixnum. Returns the value of that kernel variable (which may be somewhat larger than what was specified).

[Function]

use-lisp-heap-gc-threshold

Description:

Tries to grow or shrink lisp's heap space, so that the free space is (approximately) equal to the current heap threshold. Returns NIL

[Function]

egc arg

Arguments and Values:

arg---a generalized boolean

Description:

Enables the EGC if arg is non-nil, disables the EGC otherwise. Returns the previous enabled status. Although this function is thread-safe (in the sense that calls to it are serialized), it doesn't make a whole lot of sense to be turning the EGC on and off from multiple threads ...

[Function]

egc-enabled-p

Description:

Returns T if the EGC was enabled at the time of the call, NIL otherwise.

[Function]

egc-active-p

Description:

Returns T if the EGC was active at the time of the call, NIL otherwise. Since this is generally a volatile piece of information, it's not clear whether this function serves a useful purpose when native threads are involved.

[Function]

egc-configuration

Description:

Returns, as multiple values, the sizes in kilobytes of the thresholds associated with the youngest ephemeral generation, the middle ephemeral generation, and the oldest ephemeral generation

[Function]

configure-egc generation-0-size generation-1-size generation-2-size

Arguments and Values:

generation-0-size---the requested threshold size of the youngest generation, in kilobytes

generation-1-size---the requested threshold size of the middle generation, in kilobytes

generation-2-size---the requested threshold size of the oldest generation, in kilobytes

Description:

Puts the indicated threshold sizes in effect. Each threshold indicates the total size that may be allocated in that and all younger generations before a GC is triggered. Disables EGC while setting the values. (The provided threshold sizes are rounded up to a multiple of 64Kbytes in CCL 0.14 and to a multiple of 32KBytes in earlier versions.)

[Function]

gc-retain-pages arg

Arguments and Values:

arg---a generalized boolean

Description:

Tries to influence the GC to retain/recycle the pages allocated between GCs if arg is true, and to release them otherwise. This is generally a tradeoff between paging and other VM considerations.

[Function]

gc-retaining-pages

Description:

Returns T if the GC tries to retain pages between full GCs and NIL if it's trying to release them to improve VM paging performance.


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