When Is Software Engineering – That’s just coding…

Over the past couple of weeks, I’ve been thinking the following; Am I a “Software Engineer”? “Am I just a hacker?”, “What is software ‘Engineering’ exactly?”.

When I was in high school, about ready to go to college, I told my math professor that I was studying “Electrical Engineering and Computer Science”. With a puzzled look, he said “what is computer science?”. This was no dullard of a man. He was actually a wealthy man who took up teaching as his way of paying back society for the public school education he had received. He was a Berkeley grad, who had worked on the Manhattan project. He was a true “Engineer”. His question was essentially along the lines of; “I know what engineers do, and we use machines to help, and sometimes you have to program those machines, but is there really a whole “science” behind it?”

Granted, this was back in 1982, so times were a bit different with respect to computing, but this stuck in my mind.

Then, recently, I was discussing the same question with a colleague at work.  The line of reasoning we were pursuing was, “How much of our time and engineering is truly “engineering”, and how much of it is simply “coding”.  Coding is that mindless thing we do when we’re banging at our keyboards, looking up documentation on obscure functions, just trying to use some library that someone has provided.  We didn’t really consider this “engineering” because it’s basically just a translation job.  I’ve spent a fair bit of time with the Windows headers of late, and I can tell you, 90% of that time I would consider to be “coding”, but not “engineering”.

Here is one example.  I want to get the list of services that are running on my local machine and project that out to the internet as a JSON structure, so I can easily display it in a web page.  There’s a core function in Windows to get things started:

 

BOOL
EnumServicesStatusExA(
  SC_HANDLE             hSCManager,
  SC_ENUM_TYPE          InfoLevel,
  DWORD                 dwServiceType,
  DWORD                 dwServiceState,
  LPBYTE                lpServices,
  DWORD                 cbBufSize,
  LPDWORD               pcbBytesNeeded,
  LPDWORD               lpServicesReturned,
  LPDWORD               lpResumeHandle,
  LPCSTR                pszGroupName
);

 

Well, that’s a mouthful. First of all you have to discover that this call actually exists, and figure out all the parameters. Luckily MSDN documentation exists, so at least you can read about it. You might even get lucky enough to find an example laying around on the internet to help show you how to use it.

Since I’m using a scripting language, my first task is to wrap this in an ffi.cdef[[]] so that I can call it easily. In order to do that, I have to put everything into ffi.cdef[[]], the structures, enums, function call prototypes, etc. After all is said and done, I can make a call that looks like this:

local InfoLevel = ffi.C.SC_ENUM_PROCESS_INFO;
local dwServiceType = dwServiceType or ffi.C.SERVICE_TYPE_ALL;
local dwServiceState = dwServiceState or ffi.C.SERVICE_STATE_ALL;
local lpServices = nil;
local cbBufSize = 0;
local pcbBytesNeeded = ffi.new("DWORD[1]");
local lpServicesReturned = ffi.new("DWORD[1]");
local lpResumeHandle = ffi.new("DWORD[1]");
local pszGroupName = nil;

local status = service_core.EnumServicesStatusExA(
  self.Handle,
  InfoLevel,
  dwServiceType,
  dwServiceState,
  lpServices,
  cbBufSize,
  pcbBytesNeeded,
  lpServicesReturned,
  lpResumeHandle,
  pszGroupName);

That’s only the beginning. I have to call it again after allocating some space to receive the results… Although there’s a lot of little bits and pieces here, is this ‘engineering’?

If 90% of our time is “coding”, I would say at least 75% of that time is spent on this type of activity. You’re trying to use some API in some library, and you’re doing a lot of scaffolding, and boilerplate work. What is the skill involved here? Well, an experienced coder will be more familiar with the various idioms involved, such as make this call to figure out how much space to allocate, then allocate, then make the call again. They’ll also be familiar with the fact that a return value of 0 == failure in this case, and that you need to call GetLastError() to figure out what could really be wrong, if anything. I might call myself an “engineering” for having gained the wisdom and years of experience necessary to perform this particular task efficiently, but I’m not sure I’d call it “software engineering”.

But, this is only the beginning of the journey on this particular task. Ultimately I need to get this information projected out to the internet. There will be iterators, queries, and other big words involved, and somewhere along the line, I might find the dividing line where software turns into engineering.

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