License Manager Spike

This project is a spike for work to rewrite license_manager. To run it, compile the code, and in an erl shell issue the commands

test:start_link(10).
test:go().

10 is the number of voice requests to make, and can be adjusted for each test. Progress will be displayed by a series of strings. The characters in the strings have these meanings:

Character	Meaning
.	Nothing has happened yet with this request.
+	Request has been granted.
x	Request has been denied. Retry will occur in 750 ms.
-	License has been released.
A	Requested category does not exist.
B	Request was already granted.
C	Release failed because category does not exist.
D	Release "failed" because GUID is not using a license.

• A can be made to happen if the license file(s) do not contain counts for the voice category.
• B, C, and D probably won't happen at all in the testing.

Licenses expire after 15 seconds; there is no manual releasing of licenses done in this test code.

While test:go() is running, you can call lm directly, via the lm:request/2 and lm:release/2 functions. This is one way to cause the B, C, and D statuses above to occur.

test

• gen_server
• start_links lm to maintain a communication link to it.
• API
  • start up with # of requests to make start_link(Count) default: 20
  • start testing go()
• Reports progress of test, visualizing what happens because of the random timing that the test uses.

lm

• gen_server

• started by test

• start_links license_poller to maintain a communication link to it.

• API

  • request licenses request(Category, Giud)
  • release licenses release(Category, Guid)
  • get current state state()

• Messages Handled and Responses

  • state
  • {request, Category, Guid}
    • no_such_category
    • granted
    • already_granted
    • not_available
  • {release, Category, Guid}
    • no_such_category
    • released
    • guid_is_not_using_license
  • {expire, Cagetory, Guid}
  • {update_license_info, LicenseFiles}

• Reading License Files

  • All license files are read, and totals by category are summed up.
  • New max licenses available are stored in the state.

  Responses are also cast back to the parent gen_server (test). This is only for visualizing what's happening.

license_poller

• gen_server

• started by lm

• watches a folder for *.lic files

• when a change in files occurs...

  • new file
  • deleted file
  • modified file/timestamp

  sends {update_license_info, NewFiles} to its parent (lm).

License Files

• Can have any name, but must have an extension of .lic.
• All files are combined for a total license count.
• Each file contains an erlang term with this definition:

{licenses, [{CATEGORY1, COUNT},{CATEGORY2, COUNT},...]}.

CATEGORYn can be any type of license you intend to control. In the current version, this would be voice, nonvoice, or outbound, but in the future, these may be renamed or discontinued, and others will be added.