From 7956737ef1f4819190dc86e0c7b9434ba58a9390 Mon Sep 17 00:00:00 2001 From: Grzegorz Adam Hankiewicz Date: Sun, 26 Jan 2014 16:39:20 +0100 Subject: [PATCH] Adds note about manual memory handling to GC doc. --- doc/gc.txt | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/doc/gc.txt b/doc/gc.txt index 13498afaa1..18fb03b6df 100644 --- a/doc/gc.txt +++ b/doc/gc.txt @@ -107,3 +107,20 @@ that up to 100 objects are traversed and freed before it checks again. Thus ``workPackage`` affects the timing granularity and may need to be tweaked in highly specialized environments or for older hardware. + +Keeping track of memory +----------------------- + +If you need to pass around memory allocated by Nimrod to C, you can use the +procs ``GC_ref`` and ``GC_unref`` to mark objects as referenced to avoid them +being freed by the GC. Other useful procs from `system `_ you can +use to keep track of memory are: + +* getTotalMem(): returns the amount of total memory managed by the GC. +* getOccupiedMem(): bytes reserved by the GC and used by objects. +* getFreeMem(): bytes reserved by the GC and not in use. + +In addition to ``GC_ref`` and ``GC_unref`` you can avoid the GC by manually +allocating memory with procs like ``alloc``, ``allocShared``, or +``allocCStringArray``. The GC won't try to free them, you need to call their +respective *dealloc* pairs when you are done with them or they will leak.