System.MemInfo

Implements printmem, a command that computes the memory usage of some processes

Implement printmem

getChoices :: IO Choices

Parses the command line arguments.

printProcs :: Choices -> IO ()

Print a report to stdout displaying the memory usage of the programs specified by Choices

Read MemUsage

readForOnePid :: ProcessID -> IO (Either NotRun (ProcName, MemUsage))

Load the MemUsage of a program specified by its ProcessID

readMemUsage' :: Ord a => ProcNamer -> Indexer a -> ReportBud -> IO (Either LostPid (Map a MemUsage))

Loads the MemUsage specified by a ReportBud

Fails if

• the system does not have the expected /proc filesystem memory records
• any of the processes specified by ReportBud are missing or inaccessible

readMemUsage :: ReportBud -> IO (Either LostPid (Map ProcName MemUsage))

Like readMemUsage' but uses the default ProcNamer and Indexer

data NotRun

Represents errors that prevent a report from being generated

Constructors

PidLost LostPid

MissingPids (NonEmpty ProcessID)

NeedsRoot

OddKernel

NoRecords

Instances

Show NotRun

Defined in System.MemInfo

Methods

showsPrec :: Int -> NotRun -> ShowS

show :: NotRun -> String

showList :: [NotRun] -> ShowS

Eq NotRun

Defined in System.MemInfo

Methods

(==) :: NotRun -> NotRun -> Bool

(/=) :: NotRun -> NotRun -> Bool

data LostPid

Represents reasons a specified pid may not have memory records.

Constructors

NoExeFile ProcessID

NoStatusCmd ProcessID

NoStatusParent ProcessID

NoCmdLine ProcessID

BadStatm ProcessID

NoProc ProcessID

Instances

Show LostPid

Defined in System.MemInfo

Methods

showsPrec :: Int -> LostPid -> ShowS

show :: LostPid -> String

showList :: [LostPid] -> ShowS

Eq LostPid

Defined in System.MemInfo

Methods

(==) :: LostPid -> LostPid -> Bool

(/=) :: LostPid -> LostPid -> Bool

Stream MemUsage periodically

unfoldMemUsage :: Ord a => ProcNamer -> Indexer a -> ReportBud -> IO (Either [ProcessID] ((Map a MemUsage, [ProcessID]), ReportBud))

Unfold MemUsages specified by a ReportBud

The ProcessID of stopped processes are reported, both as part of intermediate invocations (via the [ProcessID] in the Right), and in the final one (as the value of the Left).

unfoldMemUsageAfter' :: (Ord a, AsCmdName a, Integral seconds) => ProcNamer -> Indexer a -> seconds -> ReportBud -> IO (Either [ProcessID] ((Map a MemUsage, [ProcessID]), ReportBud))

Like unfoldMemUsage but computes the MemUsages after a delay

unfoldMemUsageAfter :: Integral seconds => seconds -> ReportBud -> IO (Either [ProcessID] ((Map ProcName MemUsage, [ProcessID]), ReportBud))

Like unfoldMemUsageAfter', but uses the default ProcNamer and Indexer

Obtain the process/program name

type ProcNamer = ProcessID -> IO (Either LostPid ProcName)

Functions that obtain a process name given its pid

nameFromExeOnly :: ProcNamer

Obtain the ProcName by examining the path linked by {proc_root}/pid/exe

nameFor :: ProcNamer

Obtain the ProcName by examining the path linked by {proc_root}/pid/exe or its parent's name if that is a better match

nameAsFullCmd :: ProcNamer

Obtain the ProcName as the full cmd path

Index by pid or name

type ProcName = Text

The name of a process or program in the memory report.

type Indexer index = (ProcessID, ProcName, ProcUsage) -> (index, ProcUsage)

Functions that generate the report index

dropId :: Indexer ProcName

Index a ProcUsage using just the program name

ProcUsage's with the same ProcName will be merged when added to a MemUsage

withPid :: Indexer (ProcessID, ProcName)

Index a ProcUsage using the program name and process ID.

Each ProcUsage remains distinct when added to a MemUsage

Print MemUsage

printUsage' :: AsCmdName a => (a, MemUsage) -> Bool -> IO ()

Print the program name and memory usage, optionally hiding the swap size

printUsage :: AsCmdName a => (a, MemUsage) -> IO ()

Like printUsage', but alway shows the swap size

Convenient re-exports

mkReportBud :: NonEmpty ProcessID -> IO (Maybe ReportBud)

Construct a ReportBud from some ProcessIDs

Generates values for the other fields by inspecting the system

The result is Nothing only when the KernelVersion cannot be determined

type ProcessID = CPid

class AsCmdName a where

Identifies a type as a label to use to index programs in the report output

The label is also used to group related processes under a single program

Minimal complete definition

asCmdName, cmdWithCount, hdrHasPid

Methods

asCmdName :: a -> Text

Instances

AsCmdName Text

Defined in System.MemInfo.Print

Methods

asCmdName :: Text -> Text

cmdWithCount :: Text -> Int -> Text

hdrHasPid :: Proxy Text -> Bool

AsCmdName (ProcessID, Text)

Defined in System.MemInfo.Print

Methods

asCmdName :: (ProcessID, Text) -> Text

cmdWithCount :: (ProcessID, Text) -> Int -> Text

hdrHasPid :: Proxy (ProcessID, Text) -> Bool