The concurrent programming constructs fork and join are as below: Fork (label) which creates a new process executing from the specified label join (variable) which decrements the specified synchronization variable (by 1) and terminates the process if the new value is not 0. Show the precedence graph for S1, S2, S3, S4 and S5 of the concurrent program below.
N = 2
M = 2
fork L3
fork L4
S1
L1 : join N
S3
L2: join M
S5
L3:S2
goto L1
L4:S4
goto L2
next:

A $$1000$$ Kbyte memory is managed using variable partitions but to compaction. It currently has two partitions of sizes $$200$$ Kbytes and $$260$$ Kbytes respectively. The smallest allocation request in Kbytes that could be denied is for

A demand paged virtual memory system uses $$16$$ bit virtual address, page size of $$256$$ bytes, and has $$1$$ Kbyte of main memory. $$LRU$$ page replacement is implemented using a list, whose current status (page numbers in decimal ) is
$$\eqalign{ & \,\, \uparrow \cr & LRU\,Page \cr} $$
For each hexa decimal address in the address sequence given below,
$$00FF,$$ $$010D,$$ $$10FF,$$ $$11B0$$
Indicate,
i) The new status of the list
ii) Page faults, if any, and
iii) Page replacements, if any

A file system with a one-level directory structure is implemented on a disk with disk block size of $$4$$ K bytes. The disk is used as follows:

Disk-block $$0:$$ File Allocation Table, consisting of one $$8$$-bit entry per date block, representing the data block address of the next date block in the file:

Disk block $$1:$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Directory, with one $$32$$ bit entry per file:
Disk block $$2:$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Data block $$1;$$
Disk block $$3:$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Data block $$2;$$ etc.

(a) What is the maximum possible number of files?
(b) What is the maximum possible file size in blocks?