bd25f8bee3
The `newPipeline` function, used as part of `connect`, forks a listener thread. Before this commit, the thread is forked with `forkFinally`, where the thread action is run in the same mask as the parent thread. The thread is then killed by a `killThread` when closing a connection. This is typically not a problem if the mask is “masked” (or, obviously, “unmasked”), because the listener is generally blocked on a channel at some time or other, and therefore will accept the asynchronous exception thrown by `killThread`, and terminate. However, if the mask is “masked uninterruptible”, then the listener definitely doesn't receive asynchronous exceptions, and the `killThread` calls hangs, and never returns. One should probably never call `connect` in a “masked uninterruptible” action. However, it sounds better to protect the mongoDB library against the user accidentally doing so than to add a big warning saying that calling `connect` in “masked uninterruptible” will cause the program to hang down the line. Therefore, this commit uses `forkIOWithUnmask`, in order to run the thread action always in an “unmasked” state. In which case we can be sure that we can always kill the listener thread regardless of the client code. |
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|---|---|---|
| Database | ||
| doc | ||
| test | ||
| .gitignore | ||
| .travis.yml | ||
| Benchmark.hs | ||
| CHANGELOG.md | ||
| docker-compose.yml | ||
| LICENSE | ||
| mongoDB.cabal | ||
| README.md | ||
| reattach.sh | ||
| Setup.lhs | ||
| stack-ghc80.yaml | ||
| stack-ghc82.yaml | ||
| stack-ghc84.yaml | ||
| stack-ghc86-network3.yaml | ||
| stack-ghc86.yaml | ||
This is the Haskell MongoDB driver (client). MongoDB is a free, scalable, fast, document database management system. This driver lets you connect to a MongoDB server, and update and query its data. It also lets you do adminstrative tasks, like create an index or look at performance statistics.
Documentation
Dev Environment
It's important for this library to be tested with various versions of mongodb server and with different ghc versions. In order to achieve this we use docker containers and docker-compose. This repository contains two files: docker-compose.yml and reattach.sh.
Docker compose file describes two containers.
One container is for running mongodb server. If you want a different version of mongodb server you need to change the tag of mongo image in the docker-compose.yml. In order to start your mongodb server you need to run:
docker-compose up -d mongodb
In order to stop your containers without loosing the data inside of it:
docker-compose stop mongodb
Restart:
docker-compose start mongodb
If you want to remove the mongodb container and start from scratch then:
docker-compose stop mongodb
docker-compose rm mongodb
docker-compose up -d mongodb
The other container is for compiling your code. By specifying the tag of the image you can change the version of ghc you will be using. If you never started this container then you need:
docker-compose run mongodb-haskell
It will start the container and mount your working directory to
/opt/mongodb-haskell If you exit the bash cli then the conainer will stop.
In order to reattach to an old stopped container you need to run script
reattach.sh. If you run docker-compose run again it will create another
container and all work made by cabal will be lost. reattach.sh is a
workaround for docker-compose's inability to pick up containers that exited.
When you are done with testing you need to run:
docker-compose stop mongodb
Next time you will need to do:
docker-compose start mongodb
reattach.sh
It will start your stopped container with mongodb server and pick up the stopped container with haskell.