Files
mgmt/lang/core/test/oneinstance.go
James Shubin 790b7199ca lang: New function engine
This mega patch primarily introduces a new function engine. The main
reasons for this new engine are:

1) Massively improved performance with lock-contended graphs.

Certain large function graphs could have very high lock-contention which
turned out to be much slower than I would have liked. This new algorithm
happens to be basically lock-free, so that's another helpful
improvement.

2) Glitch-free function graphs.

The function graphs could "glitch" (an FRP term) which could be
undesirable in theory. In practice this was never really an issue, and
I've not explicitly guaranteed that the new graphs are provably
glitch-free, but in practice things are a lot more consistent.

3) Simpler graph shape.

The new graphs don't require the private channels. This makes
understanding the graphs a lot easier.

4) Branched graphs only run half.

Previously we would run two pure side of an if statement, and while this
was mostly meant as an early experiment, it stayed in for far too long
and now was the right time to remove this. This also means our graphs
are much smaller and more efficient too.

Note that this changed the function API slightly. Everything has been
ported. It's possible that we introduce a new API in the future, but it
is unexpected to cause removal of the two current APIs.

In addition, we finally split out the "schedule" aspect from
world.schedule(). The "pick me" aspects now happen in a separate
resource, rather than as a yucky side-effect in the function. This also
lets us more precisely choose when we're scheduled, and we can observe
without being chosen too.

As usual many thanks to Sam for helping through some of the algorithmic
graph shape issues!
2025-09-11 23:19:45 -04:00

276 lines
8.2 KiB
Go

// Mgmt
// Copyright (C) James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//
// Additional permission under GNU GPL version 3 section 7
//
// If you modify this program, or any covered work, by linking or combining it
// with embedded mcl code and modules (and that the embedded mcl code and
// modules which link with this program, contain a copy of their source code in
// the authoritative form) containing parts covered by the terms of any other
// license, the licensors of this program grant you additional permission to
// convey the resulting work. Furthermore, the licensors of this program grant
// the original author, James Shubin, additional permission to update this
// additional permission if he deems it necessary to achieve the goals of this
// additional permission.
package coretest
import (
"context"
"sync"
"github.com/purpleidea/mgmt/lang/funcs"
"github.com/purpleidea/mgmt/lang/funcs/simple"
"github.com/purpleidea/mgmt/lang/interfaces"
"github.com/purpleidea/mgmt/lang/types"
)
const (
// OneInstanceAFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceAFuncName = "one_instance_a"
// OneInstanceBFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceBFuncName = "one_instance_b"
// OneInstanceCFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceCFuncName = "one_instance_c"
// OneInstanceDFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceDFuncName = "one_instance_d"
// OneInstanceEFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceEFuncName = "one_instance_e"
// OneInstanceFFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceFFuncName = "one_instance_f"
// OneInstanceGFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceGFuncName = "one_instance_g"
// OneInstanceHFuncName is the name this fact is registered as. It's
// still a Func Name because this is the name space the fact is actually
// using.
OneInstanceHFuncName = "one_instance_h"
msg = "hello"
)
func init() {
oneInstanceAMutex = &sync.Mutex{}
oneInstanceBMutex = &sync.Mutex{}
oneInstanceCMutex = &sync.Mutex{}
oneInstanceDMutex = &sync.Mutex{}
oneInstanceEMutex = &sync.Mutex{}
oneInstanceFMutex = &sync.Mutex{}
oneInstanceGMutex = &sync.Mutex{}
oneInstanceHMutex = &sync.Mutex{}
funcs.ModuleRegister(ModuleName, OneInstanceAFuncName, func() interfaces.Func {
return &OneInstance{
Name: OneInstanceAFuncName,
Mutex: oneInstanceAMutex,
Flag: &oneInstanceAFlag,
}
}) // must register the fact and name
funcs.ModuleRegister(ModuleName, OneInstanceCFuncName, func() interfaces.Func {
return &OneInstance{
Name: OneInstanceCFuncName,
Mutex: oneInstanceCMutex,
Flag: &oneInstanceCFlag,
}
})
funcs.ModuleRegister(ModuleName, OneInstanceEFuncName, func() interfaces.Func {
return &OneInstance{
Name: OneInstanceEFuncName,
Mutex: oneInstanceEMutex,
Flag: &oneInstanceEFlag,
}
})
funcs.ModuleRegister(ModuleName, OneInstanceGFuncName, func() interfaces.Func {
return &OneInstance{
Name: OneInstanceGFuncName,
Mutex: oneInstanceGMutex,
Flag: &oneInstanceGFlag,
}
})
simple.ModuleRegister(ModuleName, OneInstanceBFuncName, &simple.Scaffold{
I: &simple.Info{
Pure: true,
Memo: true,
Fast: true,
Spec: false, // don't break tests
},
T: types.NewType("func() str"),
F: func(context.Context, []types.Value) (types.Value, error) {
oneInstanceBMutex.Lock()
if oneInstanceBFlag {
panic("should not get called twice")
}
oneInstanceBFlag = true
oneInstanceBMutex.Unlock()
return &types.StrValue{V: msg}, nil
},
D: &OneInstance{},
})
simple.ModuleRegister(ModuleName, OneInstanceDFuncName, &simple.Scaffold{
I: &simple.Info{
Pure: true,
Memo: true,
Fast: true,
Spec: false, // don't break tests
},
T: types.NewType("func() str"),
F: func(context.Context, []types.Value) (types.Value, error) {
oneInstanceDMutex.Lock()
if oneInstanceDFlag {
panic("should not get called twice")
}
oneInstanceDFlag = true
oneInstanceDMutex.Unlock()
return &types.StrValue{V: msg}, nil
},
D: &OneInstance{},
})
simple.ModuleRegister(ModuleName, OneInstanceFFuncName, &simple.Scaffold{
I: &simple.Info{
Pure: true,
Memo: true,
Fast: true,
Spec: false, // don't break tests
},
T: types.NewType("func() str"),
F: func(context.Context, []types.Value) (types.Value, error) {
oneInstanceFMutex.Lock()
if oneInstanceFFlag {
panic("should not get called twice")
}
oneInstanceFFlag = true
oneInstanceFMutex.Unlock()
return &types.StrValue{V: msg}, nil
},
D: &OneInstance{},
})
simple.ModuleRegister(ModuleName, OneInstanceHFuncName, &simple.Scaffold{
I: &simple.Info{
Pure: true,
Memo: true,
Fast: true,
Spec: false, // don't break tests
},
T: types.NewType("func() str"),
F: func(context.Context, []types.Value) (types.Value, error) {
oneInstanceHMutex.Lock()
if oneInstanceHFlag {
panic("should not get called twice")
}
oneInstanceHFlag = true
oneInstanceHMutex.Unlock()
return &types.StrValue{V: msg}, nil
},
D: &OneInstance{},
})
}
var (
oneInstanceAFlag bool
oneInstanceBFlag bool
oneInstanceCFlag bool
oneInstanceDFlag bool
oneInstanceEFlag bool
oneInstanceFFlag bool
oneInstanceGFlag bool
oneInstanceHFlag bool
oneInstanceAMutex *sync.Mutex
oneInstanceBMutex *sync.Mutex
oneInstanceCMutex *sync.Mutex
oneInstanceDMutex *sync.Mutex
oneInstanceEMutex *sync.Mutex
oneInstanceFMutex *sync.Mutex
oneInstanceGMutex *sync.Mutex
oneInstanceHMutex *sync.Mutex
)
// OneInstance is a fact which flips a bool repeatedly. This is an example fact
// and is not meant for serious computing. This would be better served by a flip
// function which you could specify an interval for.
type OneInstance struct {
init *interfaces.Init
Name string
Mutex *sync.Mutex
Flag *bool
}
// String returns a simple name for this fact. This is needed so this struct can
// satisfy the pgraph.Vertex interface.
func (obj *OneInstance) String() string {
return obj.Name
}
// Validate makes sure we've built our struct properly.
func (obj *OneInstance) Validate() error {
return nil
}
// Info returns some static info about itself.
func (obj *OneInstance) Info() *interfaces.Info {
return &interfaces.Info{
Pure: false, // non-constant facts can't be pure!
Memo: false,
Fast: false,
Spec: false,
Sig: types.NewType("func() str"),
}
}
// Init runs some startup code for this fact.
func (obj *OneInstance) Init(init *interfaces.Init) error {
obj.init = init
obj.init.Logf("Init of `%s` @ %p", obj.Name, obj)
obj.Mutex.Lock()
if *obj.Flag {
panic("should not get called twice")
}
b := true
obj.Flag = &b
obj.Mutex.Unlock()
return nil
}
// Call this fact and return the value if it is possible to do so at this time.
func (obj *OneInstance) Call(ctx context.Context, args []types.Value) (types.Value, error) {
return &types.StrValue{
V: msg,
}, nil
}