g0

package
v0.4.168 Latest Latest
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 Go to latest Published: May 10, 2024 License: ISC Imports: 17 Imported by: 1

Documentation

Overview

Package g0 provides Go threads and thread-groups

Index

Constants

View Source 
const (
	ThreadDataEmpty = "[empty]"
	ThreadDataNil   = "threadData:nil"
)

Variables

View Source 
var GoGroupFactory parl.GoFactory = &goGroupFactory{}
View Source 
var NoAddErr parl.AddError

for Reader

View Source 
var NoLog parl.PrintfFunc

for Reader

View Source 
var NoShouldTerm *atomic.Bool

for Reader

Functions

func NewGoError 

func NewGoError(err error, errContext parl.GoErrorContext, g0 parl.Go) (goError parl.GoError)

NewGoError creates a GoError based on an error

func NewGoGroup added in v0.4.19 

func NewGoGroup(ctx context.Context, onFirstFatal ...parl.GoFatalCallback) (g0 parl.GoGroup)

NewGoGroup returns a stand-alone thread-group with its own error channel. Thread-safe.

  • ctx is not canceled by the thread-group
  • ctx may initiate thread-group Cancel
  • a stand-alone GoGroup thread-group has goGroupParent nil
  • non-fatal and fatal errors from the thread-group’s threads are sent on the GoGroup’s error channel
  • the GoGroup processes Go invocations and thread-exits from its own threads and the threads of its subordinate thread-groups wait-group and that of its parent
  • cancel of the GoGroup’s context signals termination to its own threads and all threads of its subordinate thread-groups
  • the GoGroup’s context is canceled when its provided parent context is canceled or any of its threads invoke the GoGroup’s Cancel method
  • the GoGroup terminates when its error channel closes from all threads in its own thread-group and that of any subordinate thread-groups have exited.

func Reader added in v0.4.147 

func Reader(shouldTerminate *atomic.Bool, addError parl.AddError, log parl.PrintfFunc, goGroup parl.GoGroup, g parl.GoResult)

Reader thread reads the error channel of a GoGroup or [SubGroup]

  • shouldTerminate is an optional pointer that an application’s most important goroutine sets to true prior to exit, causing graceful shutdown
  • addError receives fatal thread-exits. If not present, those are logged. typically github.com/haraldrudell/parl/mains.Executable.AddErr
  • log outputs warnings and more, default parl.Log standard error
  • g is from parl.NewGoResult or parl.NewGoResult2 making Reader awaitable
  • a GoGroup’s or SubGroup’s error channel is unbound buffer so Reader is only required for:
  • — real-time warning output
  • — terminating the process while additional goroutines are still running:
  • — on fatal thread exit or
  • — on exit of a primary goroutine
  • —
  • because reading of the threadgroup’s error channel must not stop, it is done in this separate thread.
  • reading continues until:
  • — the threadGroup context is canceled by eg. GoGroup.Cancel
  • — the last thread exits
  • — a thread exits with error
  • — on thread exit, shouldTerminate is true

Usage: 

func main() {
  var err error
  defer mains.MinimalRecovery(&err)
  var goGroup = g0.NewGoGroup(context.Background())
  defer goGroup.Wait()
  var goResult = parl.NewGoResult()
  defer goResult.ReceiveError(&err)
  go g0.Reader(g0.NoSholdTerm, g0.NoAddErr, g0.NoLog, goGroup, goResult)
  defer goGroup.Cancel()
  go someGoroutine(goGroup.Go())

func Shorts added in v0.4.43 

func Shorts(threads []parl.ThreadData) (s string)

Shorts retruns a string of Short descriptions of all threads in the slice

  • string is never empty

Types

type Go added in v0.4.21 

type Go struct {
	// contains filtered or unexported fields
}

Go supports a goroutine executing part of a thread-group. Thread-safe.

  • Register allows to name the thread and collects information on the new thread
  • AddError processes non-fatal errors
  • Done handles thread termination and fatal errors and is deferrable. The Go thread terminates on Done invocation.
  • Go creates a sibling thread object to be provided in a go statement
  • SubGo creates a subordinate thread-group managed by the parent thread group. The SubGo can be independently terminated or terminated prior to thread exit.
  • SubGroup creates a subordinate thread-group with its own error channel. Fatal-error thread-exits in SubGroup can be recovered locally in that thread-group

func (*Go) AddError added in v0.4.21 

func (g *Go) AddError(err error)

AddError emits a non-fatal errors

func (*Go) Creator added in v0.4.92 

func (g *Go) Creator() (threadID parl.ThreadID, createLocation *pruntime.CodeLocation)

func (*Go) Done added in v0.4.21 

func (g *Go) Done(errp *error)

Done handles thread exit. Deferrable

  • *errp contains possible fatalk thread error
  • errp can be nil

func (*Go) EntityID added in v0.4.117 

func (i *Go) EntityID() (id parl.GoEntityID)

EntityID returns GoEntityID, an internal unique idntifier

func (*Go) Go added in v0.4.78 

func (g *Go) Go() (g00 parl.Go)

func (*Go) GoID added in v0.4.48 

func (g *Go) GoID() (threadID parl.ThreadID)

func (*Go) GoRoutine added in v0.4.92 

func (g *Go) GoRoutine() (threadID parl.ThreadID, goFunction *pruntime.CodeLocation)

func (*Go) Register added in v0.4.21 

func (g *Go) Register(label ...string) (g00 parl.Go)

func (*Go) String added in v0.4.29 

func (g *Go) String() (s string)

g1ID:4:g0.(*g1WaitGroup).Go-g1-thread-group.go:63

func (*Go) SubGo added in v0.4.21 

func (g *Go) SubGo(onFirstFatal ...parl.GoFatalCallback) (subGo parl.SubGo)

func (*Go) SubGroup added in v0.4.29 

func (g *Go) SubGroup(onFirstFatal ...parl.GoFatalCallback) (subGroup parl.SubGroup)

func (*Go) ThreadInfo added in v0.4.29 

func (g *Go) ThreadInfo() (threadData parl.ThreadData)

func (*Go) Wait added in v0.4.29 

func (g *Go) Wait()

func (*Go) WaitCh added in v0.4.117 

func (g *Go) WaitCh() (ch parl.AwaitableCh)

type GoError added in v0.4.29 

type GoError struct {
	// contains filtered or unexported fields
}

GoError is a wrapper around an error associating it with a Go goroutine and the situation in which this error occurred

func (*GoError) Err added in v0.4.29 

func (e *GoError) Err() (err error)

Err returns the underlying error

func (*GoError) ErrContext added in v0.4.29 

func (e *GoError) ErrContext() (errContext parl.GoErrorContext)

func (*GoError) ErrString added in v0.4.147 

func (e *GoError) ErrString() (errString string)

ErrString returns string representation of error

  • if no error “OK”
  • if not debug or panic, short error with location
  • otherwise error with stack trace

func (*GoError) Error added in v0.4.29 

func (e *GoError) Error() (message string)

Error returns a human-readable error message making GoError implement error

  • for nil errors, empty string is returned

func (*GoError) Go added in v0.4.29 

func (e *GoError) Go() (g0 parl.Go)

func (*GoError) IsFatal added in v0.4.29 

func (e *GoError) IsFatal() (isThreadExit bool)

func (*GoError) IsThreadExit added in v0.4.29 

func (e *GoError) IsThreadExit() (isThreadExit bool)

func (*GoError) String added in v0.4.29 

func (e *GoError) String() (s string)

func (*GoError) Time added in v0.4.29 

func (e *GoError) Time() (when time.Time)

Time returns when the GoError was created

type GoGroup added in v0.4.19 

type GoGroup struct {
	// contains filtered or unexported fields
}

GoGroup is a Go thread-group. Thread-safe.

  • GoGroup has its own error channel and waitgroup and no parent thread-group.
  • thread exits are processed by G1Done and the g1WaitGroup
  • the thread-group terminates when its erropr channel closes
  • non-fatal erors are processed by ConsumeError and the error channel
  • new Go threads are handled by the g1WaitGroup
  • SubGroup creates a subordinate thread-group using this threadgroup’s error channel

func (*GoGroup) Add added in v0.4.19 

func (g *GoGroup) Add(goEntityID parl.GoEntityID, threadData *ThreadData)

Add processes a thread from this or a subordinate thread-group

func (*GoGroup) Cancel added in v0.4.28 

func (g *GoGroup) Cancel()

Cancel signals shutdown to all threads of a thread-group.

func (*GoGroup) CascadeEnableTermination added in v0.4.69 

func (g *GoGroup) CascadeEnableTermination(delta int)

CascadeEnableTermination manipulates wait groups of this goGroup and those of its parents to allow or prevent termination

func (*GoGroup) Ch added in v0.4.20 

func (g *GoGroup) Ch() (ch <-chan parl.GoError)

Ch returns a channel sending the all fatal termination errors when the FailChannel option is present, or only the first when both FailChannel and StoreSubsequentFail options are present.

func (*GoGroup) ConsumeError added in v0.4.29 

func (g *GoGroup) ConsumeError(goError parl.GoError)

ConsumeError receives non-fatal errors from a Go thread.

  • Go.AddError delegates to this method

func (*GoGroup) Context added in v0.4.28 

func (c *GoGroup) Context() (ctx context.Context)

Context returns the context of this cancelAndContext.

  • Context is used to detect cancel using the receive channel Context.Done.
  • Context cancellation has happened when Context.Err is non-nil.

func (*GoGroup) EnableTermination added in v0.4.43 

func (g *GoGroup) EnableTermination(allowTermination ...bool) (mayTerminate bool)

EnableTermination controls whether the thread-droup is allowed to terminate

  • true is default
  • period of false prevents terminating even if child-object count reaches zero
  • invoking with true while child-object count is zero, terminates the thread-group regardless of previous enableTermination state. This is used prior to Wait when a thread-group was not used. Using the alternative Cancel would signal to threads to exit.

func (*GoGroup) FirstFatal added in v0.4.29 

func (g *GoGroup) FirstFatal() (firstFatal *parl.OnceWaiterRO)

FirstFatal allows to await or inspect the first thread terminating with error. it is valid if this SubGo has LocalSubGo or LocalChannel options. To wait for first fatal error using multiple-semaphore mechanic: 

firstFatal := g0.FirstFatal()
for {
  select {
  case <-firstFatal.Ch():
  …

To inspect first fatal: 

if firstFatal.DidOccur() …

func (*GoGroup) FromGoGo added in v0.4.92 

func (g *GoGroup) FromGoGo() (g2 parl.Go)

FromGoGo returns a parl.Go thread-features object invoked from another parl.Go object

  • the Go return value is to be used as a function argument in a go-statement function-call launching a goroutine thread

func (*GoGroup) FromGoSubGo added in v0.4.92 

func (g *GoGroup) FromGoSubGo(onFirstFatal ...parl.GoFatalCallback) (g1 parl.SubGo)

FromGoSubGo returns a subordinate thread-group witthout an error channel. Thread-safe.

func (*GoGroup) FromGoSubGroup added in v0.4.92 

func (g *GoGroup) FromGoSubGroup(onFirstFatal ...parl.GoFatalCallback) (g2 parl.SubGroup)

FromGoSubGroup returns a subordinate thread-group with an error channel handling fatal errors only. Thread-safe.

func (*GoGroup) Go added in v0.4.29 

func (g *GoGroup) Go() (g2 parl.Go)

Go returns a parl.Go thread-features object

  • Go is invoked by a g0-package consumer
  • the Go return value is to be used as a function argument in a go-statement function-call launching a goroutine thread

func (*GoGroup) GoDone added in v0.4.29 

func (g *GoGroup) GoDone(thread parl.Go, err error)

Done receives thread exits from threads in subordinate thread-groups

func (*GoGroup) Internals added in v0.4.131 

func (g *GoGroup) Internals() (
	isEnd func() bool,
	isAggregateThreads *atomic.Bool,
	setCancelListener func(f func()),
	endCh <-chan struct{},
)

Internals returns methods used by [g0debug.ThreadLogger]

func (*GoGroup) NamedThreads added in v0.4.43 

func (g *GoGroup) NamedThreads() (threads []parl.ThreadData)

threads that have been named ordered by name

func (*GoGroup) SetDebug added in v0.4.43 

func (g *GoGroup) SetDebug(debug parl.GoDebug, log ...parl.PrintfFunc)

SetDebug enables debug logging on this particular instance

  • parl.NoDebug
  • parl.DebugPrint
  • parl.AggregateThread

func (*GoGroup) String added in v0.4.20 

func (g *GoGroup) String() (s string)

g1Group#3threads:1(1)g0.TestNewG1Group-g1-group_test.go:60

func (*GoGroup) SubGo added in v0.4.29 

func (g *GoGroup) SubGo(onFirstFatal ...parl.GoFatalCallback) (g2 parl.SubGo)

newSubGo returns a subordinate thread-group witthout an error channel. Thread-safe.

  • a SubGo has goGroupParent non-nil and isSubGo true
  • the SubGo thread’s fatal and non-fatal errors are forwarded to its parent
  • SubGo has FirstFatal mechanic but no error channel of its own.
  • the SubGo’s Go invocations and thread-exits are processed by the SubGo’s wait-group and the thread-group of its parent
  • cancel of the SubGo’s context signals termination to its own threads and all threads of its subordinate thread-groups
  • the SubGo’s context is canceled when its parent’s context is canceled or any of its threads invoke the SubGo’s Cancel method
  • the SubGo thread-group terminates when all threads in its own thread-group and that of any subordinate thread-groups have exited.

func (*GoGroup) SubGroup added in v0.4.29 

func (g *GoGroup) SubGroup(onFirstFatal ...parl.GoFatalCallback) (g2 parl.SubGroup)

newSubGroup returns a subordinate thread-group with an error channel handling fatal errors only. Thread-safe.

  • a SubGroup has goGroupParent non-nil and isSubGo false
  • fatal errors from the SubGroup’s threads are sent on its own error channel
  • non-fatal errors from the SubGroup’s threads are forwarded to the parent
  • the SubGroup’s Go invocations and thread-exits are processed in the SubGroup’s wait-group and that of its parent
  • cancel of the SubGroup’s context signals termination to its own threads and all threads of its subordinate thread-groups
  • the SubGroup’s context is canceled when its parent’s context is canceled or any of its threads invoke the SubGroup’s Cancel method
  • SubGroup thread-group terminates when its error channel closes after all of its threads and threads of its subordinate thread-groups have exited.

func (*GoGroup) Threads added in v0.4.43 

func (g *GoGroup) Threads() (threads []parl.ThreadData)

the available data for all threads

func (*GoGroup) ThreadsInternal added in v0.4.93 

func (g *GoGroup) ThreadsInternal() (m parli.ThreadSafeMap[parl.GoEntityID, *ThreadData])

ThreadsInternal returns values with the internal parl.GoEntityID key

func (*GoGroup) UpdateThread added in v0.4.29 

func (g *GoGroup) UpdateThread(goEntityID parl.GoEntityID, threadData *ThreadData)

UpdateThread recursively updates thread information for a parl.Go object invoked when that Go fiorst obtains the information

func (*GoGroup) Wait added in v0.4.19 

func (g *GoGroup) Wait()

Wait waits for all threads of this thread-group to terminate.

func (*GoGroup) WaitCh added in v0.4.112 

func (g *GoGroup) WaitCh() (ch parl.AwaitableCh)

returns a channel that closes on subGo end similar to Wait

type ThreadData added in v0.4.29 

type ThreadData struct {
	// contains filtered or unexported fields
}

ThreadData contains identifiable information about a running thread.

  • ThreadData does not have initialization

func (*ThreadData) Create added in v0.4.43 

func (t *ThreadData) Create() (createLocation *pruntime.CodeLocation)

func (*ThreadData) Func added in v0.4.43 

func (t *ThreadData) Func() (funcLocation *pruntime.CodeLocation)

func (*ThreadData) Get added in v0.4.29 

func (t *ThreadData) Get() (threadID parl.ThreadID, createLocation pruntime.CodeLocation,
	funcLocation pruntime.CodeLocation, label string)

func (*ThreadData) LabeledString added in v0.4.92 

func (t *ThreadData) LabeledString() (s string)

func (*ThreadData) Name added in v0.4.43 

func (t *ThreadData) Name() (label string)

func (*ThreadData) SetCreator added in v0.4.29 

func (t *ThreadData) SetCreator(cl *pruntime.CodeLocation)

SetCreator gets preliminary Go identifier: the line invoking Go()

func (*ThreadData) Short added in v0.4.43 

func (t *ThreadData) Short() (s string)

"myThreadName:4"

func (*ThreadData) String added in v0.4.43 

func (t *ThreadData) String() (s string)

"myThreadName:4_func:testing.tRunner()-testing.go:1446_cre:testing.(*T).Run()-testing.go:1493"

func (*ThreadData) ThreadID added in v0.4.29 

func (t *ThreadData) ThreadID() (threadID parl.ThreadID)

threadID is the ID of the running thread

func (*ThreadData) Update added in v0.4.29 

func (t *ThreadData) Update(
	threadID parl.ThreadID,
	createInvocation, goFunction *pruntime.CodeLocation,
	label string)

Update populates this object from a stack trace.

type ThreadSafeThreadData added in v0.4.37 

type ThreadSafeThreadData struct {
	// contains filtered or unexported fields
}

ThreadSafeThreadData controls access to a ThreadData object making it thread-safe.

  • ThreadSafeThreadData does not have initialization
  • haveThreadID indicates whether data is present

func NewThreadSafeThreadData added in v0.4.117 

func NewThreadSafeThreadData() (t *ThreadSafeThreadData)

func (*ThreadSafeThreadData) Get added in v0.4.37 

func (tw *ThreadSafeThreadData) Get() (thread *ThreadData)

Get returns a clone of the wrapped ThreadData object.

func (*ThreadSafeThreadData) HaveThreadID added in v0.4.37 

func (tw *ThreadSafeThreadData) HaveThreadID() (haveThreadID bool)

HaveThreadID indicates whether Update has been invoked on this ThreadDataWrap object.

func (*ThreadSafeThreadData) SetCreator added in v0.4.37 

func (tw *ThreadSafeThreadData) SetCreator(cl *pruntime.CodeLocation)

SetCreator gets preliminary Go identifier: the line invoking Go().

func (*ThreadSafeThreadData) ThreadID added in v0.4.37 

func (tw *ThreadSafeThreadData) ThreadID() (threadID parl.ThreadID)

ThreadID returns the thread id of the running thread or zero if thread ID is missing.

func (*ThreadSafeThreadData) Update added in v0.4.37 

func (tw *ThreadSafeThreadData) Update(
	threadID parl.ThreadID,
	createInvocation *pruntime.CodeLocation,
	goFunction *pruntime.CodeLocation,
	label string,
)

Update populates the wrapped ThreadData from the stack trace.

Source Files

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Directories

Path Synopsis
Package g0debug provides troubleshooting types for Go threads and thread-groups
 Package g0debug provides troubleshooting types for Go threads and thread-groups

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