
Description of the Page Tracing Modification
--------------------------------------------

In accordance with IPL sec. 3.3, this file describes the modification made
to Firebird to allow it to optionally trace page allocations, deallocations
and page splitting.

The modification makes changes to following files:

	builds\win32\msvc7\engine_embed.vcproj
	src\jrd\btr.cpp
	src\jrd\cch.cpp
	src\jrd\cch_proto.h
	src\jrd\dpm.epp
	src\jrd\dpm_proto.h
	src\jrd\pag.cpp
	src\jrd\pag_proto.h

and it adds two new files:

	src\jrd\Tracer.cpp
	src\jrd\Tracer.h

The modification adds a wait-free queue and a separate logging thread - the
idea is to avoid influencing the execution of the traced code.

The tracing can be enabled by setting 

	"HKLM\SOFTWARE\Firebird Project\Firebird Server\Instances\PageTrace" 

to 1. 

The log appears in the file "firebird-pg.log" in the same directory where
fbembed.dll resides.
