Cirrus Logic CS485 Manual de usuario descargar pdf (Pagina 60)

CS485G Spring 2015 60

(d) Then reclaim all allocated regions that are not marked.

3. How to know what is in use: Mark phase

(a) All global variables that point to data structures, and the struc-

tures they point to, recursively.

(b) All local variables, both for the current procedure and all its

callers, that point to data structures, recursively.

is already marked.

(d) Marking requires that the memory manager always know what

ﬁelds are pointers, and that ﬁelds are always initialized (to NULL

if necessary).

4. Variants on the basic algorithm

(a) Generational collection: most regions have a very short life; re-

gions that last after a few collections are placed in a less-frequently

collected region.

(b) Parallelized collection: Collect at the same time the program is

running, to prevent sudden stoppage.

5. Debugging memory bugs

(a) Wrapper around malloc()

(b) glibc malloc() uses the environment variable MALLOC CHECK.

purify (people seem to prefer valgrind). Very good at catching

memory bugs, but the program runs 30 times slower.

58 Networks

1. Lecture 34, 4/24/2015

2. A network is a collection of boxes (nodes) and wires (links).

(a) System-area network (SAN): a single room.

(b) Local-area network (LAN): a building or campus.

1 2 ... 55 56 57 58 59 60 61 62 63 64 65 66 67

Sin comentarios

Cirrus Logic CS485 Manual de usuario Pagina 60