## malloctest

#### OS/161 Reference Manual

### Name

malloctest - some simple tests for userlevel malloc

### Synopsis

/testbin/malloctest [test...]

### Description

malloctest contains 7 tests, 1-7. These may be run interactively or from the command line.

Test 1 checks if all the bytes we ask for actually get allocated.

Test 2 checks if malloc gracefully handles failing requests. This test assumes that malloc will eventually fail if one keeps allocating enough memory, instead of promising memory it can't deliver and then (perhaps) killing processes when it runs out. More detail regarding this condition can be found in comments in the source code.

Test 3 also checks if malloc gracefully handles failing requests, and thus has the same restrictions as test 2.

Test 4 attempts to check if malloc coalesces the free list properly. This test is only meant for first-fit, next-fit, or best-fit allocators; anything else will most likely confuse it. Running test 4 after other tests may confuse it as well.

Tests 5-7 are a randomized stress test. Test 5 uses pseudorandom seed 0. Test 6 seeds the random generator from the random: device. Test 7 prompts you for a specific seed.

### Requirements

malloctest uses the following system calls:

- open
- read
- write
- close
- _exit

malloctest also requires a user-level malloc/free implementation.

Your system should pass all the malloctest tests, subject to the conditions described above, once your user-level malloc is complete.