clear.so

berkeley db 4.6.21的源码。berkeley db是一个简单的数据库管理系统

m4_comment([$Id: clear.so,v 1.2 2005/12/13 16:47:06 bostic Exp $])

m4_ref_title(Upgrading m4_db Applications,
    Release 4.4: DB_MPOOLFILE-__GT__set_clear_len,,
    upgrade.4.4/mutex, upgrade.4.4/lockstat)

m4_p([dnl
The meaning of a 0 "clear length" argument to the
m4_refT(memp_set_clear_len) changed in the m4_db 4.4 release.   In
previous releases, specifying a length of 0 was equivalent to the
default, and the entire created page was cleared.  Unfortunately, this
left no way to specify that no part of the page needed to be cleared.
In the 4.4 release, specifying a "clear length" argument of 0 means that
no part of the page need be cleared.])

m4_p([dnl
Applications specifying a 0 "clear length" argument to the
m4_refT(memp_set_clear_len) should simply remove the call, as the
default behavior is to clear the entire created page.])

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