Lab: Visualizing memory allocations

Names:

Consider the output from the following program. This program makes a series of malloc/free calls based on random sizes of memory. In this question, you will visualize the execution of malloc and free based on the example from class.

$ ./memstats
Starting test..
The initial top of the heap is 0x7feffe84d010.
---------------
0
Allocating 452 bytes at index 0
Allocating 1042 bytes at index 4
Allocating 45 bytes at index 1
Freeing index 0
Allocating 68 bytes at index 0
Freeing index 1
Freeing index 0
Allocating 127 bytes at index 3
Allocating 1141 bytes at index 2
Allocating 89 bytes at index 1
The new top of the heap is 0x7feffe84db31.
Increased by 2849 (0xb21) bytes
Total blocks: 5 Free blocks: 1 Used blocks: 4
Total memory allocated: 2769 Free memory: 45 Used memory: 2724
Underutilized memory: 0.12
---------------
1
Freeing index 3
Allocating 47 bytes at index 0
Freeing index 4
Freeing index 1
Freeing index 2
Freeing index 0
Allocating 3426 bytes at index 1
Freeing index 1
Allocating 39 bytes at index 2
Allocating 163 bytes at index 4
The new top of the heap is 0x7feffe84e8a3.
Increased by 3442 (0xd72) bytes
Total blocks: 6 Free blocks: 4 Used blocks: 2
Total memory allocated: 6195 Free memory: 2317 Used memory: 3878
Underutilized memory: 0.95
---------------
2
Allocating 1658 bytes at index 3
Allocating 1812 bytes at index 0
Freeing index 3
Allocating 39 bytes at index 3
Allocating 156 bytes at index 1
Freeing index 3
Freeing index 1
Freeing index 4
Freeing index 2
Allocating 921 bytes at index 1
The new top of the heap is 0x7feffe84f651.
Increased by 3502 (0xdae) bytes
Total blocks: 8 Free blocks: 6 Used blocks: 2
Total memory allocated: 9665 Free memory: 4427 Used memory: 5238
Underutilized memory: 0.48
Time is 4.1e-05

Below, we explain the first block of memory allocations (Round 1). When the program starts, we have no buffers allocated and the free list is empty.

memstats0