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Added EvalSession way of controlling all coroutines started from a script

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This commit is contained in:
Sergey Chernov 2026-04-02 02:05:04 +03:00
parent 446c8d9a6e
commit fc01016a74
13 changed files with 482 additions and 94 deletions
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53
README.md
View File

@ -93,42 +93,49 @@ import net.sergeych.lyng.*
// we need a coroutine to start, as Lyng
// is a coroutine based language, async topdown
runBlocking {
assert(5 == eval(""" 3*3 - 4 """).toInt())
eval(""" println("Hello, Lyng!") """)
val session = EvalSession()
assert(5 == session.eval(""" 3*3 - 4 """).toInt())
session.eval(""" println("Hello, Lyng!") """)
}
```
### Exchanging information
Script is executed over some `Scope`. Create instance,
add your specific vars and functions to it, and call:
The preferred host runtime is `EvalSession`. It owns the script scope and any coroutines
started with `launch { ... }`. Create a session, grab its scope when you need low-level
binding APIs, then execute scripts through the session:
```kotlin
import net.sergeych.lyng.*
// simple function
val scope = Script.newScope().apply {
addFn("sumOf") {
var sum = 0.0
for (a in args) sum += a.toDouble()
ObjReal(sum)
}
addConst("LIGHT_SPEED", ObjReal(299_792_458.0))
runBlocking {
val session = EvalSession()
val scope = session.getScope().apply {
// simple function
addFn("sumOf") {
var sum = 0.0
for (a in args) sum += a.toDouble()
ObjReal(sum)
}
addConst("LIGHT_SPEED", ObjReal(299_792_458.0))
// callback back to kotlin to some suspend fn, for example::
// suspend fun doSomeWork(text: String): Int
addFn("doSomeWork") {
// this _is_ a suspend lambda, we can call suspend function,
// and it won't consume the thread.
// note that in kotlin handler, `args` is a list of `Obj` arguments
// and return value from this lambda should be Obj too:
doSomeWork(args[0]).toObj()
// callback back to kotlin to some suspend fn, for example::
// suspend fun doSomeWork(text: String): Int
addFn("doSomeWork") {
// this _is_ a suspend lambda, we can call suspend function,
// and it won't consume the thread.
// note that in kotlin handler, `args` is a list of `Obj` arguments
// and return value from this lambda should be Obj too:
doSomeWork(args[0]).toObj()
}
}
// execute through the session:
session.eval("sumOf(1,2,3)") // <- 6
}
// adding constant:
scope.eval("sumOf(1,2,3)") // <- 6
```
Note that the scope stores all changes in it so you can make calls on a single scope to preserve state between calls.
Note that the session reuses one scope, so state persists across `session.eval(...)` calls.
Use raw `Scope.eval(...)` only when you intentionally want low-level control without session-owned coroutine lifecycle.
## IntelliJ IDEA plugin: Lightweight autocompletion (experimental)

4
docs/Decimal.md
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@ -80,11 +80,11 @@ If you already have an ionspin `BigDecimal` on the host side, the simplest suppo
```kotlin
import com.ionspin.kotlin.bignum.decimal.BigDecimal
import net.sergeych.lyng.Script
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.asFacade
import net.sergeych.lyng.newDecimal
val scope = Script.newScope()
val scope = EvalSession().getScope()
val decimal = scope.asFacade().newDecimal(BigDecimal.parseStringWithMode("12.34"))
```

117
docs/embedding.md
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@ -36,21 +36,60 @@ dependencies {
If you use Kotlin Multiplatform, add the dependency in the `commonMain` source set (and platform‑specific sets if you need platform APIs).
### 2) Create a runtime (Scope) and execute scripts
### 2) Preferred runtime: `EvalSession`
The easiest way to get a ready‑to‑use scope with standard packages is via `Script.newScope()`.
For host applications, prefer `EvalSession` as the main way to run scripts.
It owns one reusable Lyng scope, serializes `eval(...)` calls, and governs coroutines started from Lyng `launch { ... }`.
Main entrypoints:
- `session.eval(code)` / `session.eval(source)`
- `session.getScope()` when you need low-level binding APIs
- `session.cancel()` to cancel active session-owned coroutines
- `session.join()` to wait for active session-owned coroutines
```kotlin
fun main() = kotlinx.coroutines.runBlocking {
val session = EvalSession()
// Evaluate a one‑liner
val result = session.eval("1 + 2 * 3")
println("Lyng result: $result") // ObjReal/ObjInt etc.
// Optional lifecycle management
session.join()
}
```
The session creates its underlying scope lazily. If you need raw low-level APIs, get the scope explicitly:
```kotlin
val session = EvalSession()
val scope = session.getScope()
```
Use `cancel()` / `join()` to govern async work started by scripts:
```kotlin
val session = EvalSession()
session.eval("""launch { delay(1000); println("done") }""")
session.cancel()
session.join()
```
### 2.1) Low-level runtime: `Scope`
Use `Scope` directly when you intentionally want lower-level control.
```kotlin
fun main() = kotlinx.coroutines.runBlocking {
val scope = Script.newScope() // suspends on first init
// Evaluate a one‑liner
val result = scope.eval("1 + 2 * 3")
println("Lyng result: $result") // ObjReal/ObjInt etc.
println("Lyng result: $result")
}
```
You can also pre‑compile a script and execute it multiple times:
You can also pre‑compile a script and execute it multiple times on the same scope:
```kotlin
val script = Compiler.compile("""
@ -63,7 +102,8 @@ val run1 = script.execute(scope)
val run2 = script.execute(scope)
```
`Scope.eval("...")` is a shortcut that compiles and executes on the given scope.
`Scope.eval("...")` is the low-level shortcut that compiles and executes on the given scope.
For most embedding use cases, prefer `session.eval("...")`.
### 3) Preferred: bind extern globals from Kotlin
@ -85,6 +125,8 @@ import net.sergeych.lyng.bridge.*
import net.sergeych.lyng.obj.ObjInt
import net.sergeych.lyng.obj.ObjString
val session = EvalSession()
val scope = session.getScope()
val im = Script.defaultImportManager.copy()
im.addPackage("my.api") { module ->
module.eval("""
@ -149,6 +191,9 @@ binder.bindGlobalFunRaw("echoRaw") { _, args ->
Use this when you intentionally want raw `Scope` APIs. For most module APIs, prefer section 3.
```kotlin
val session = EvalSession()
val scope = session.getScope()
// A function returning value
scope.addFn<ObjInt>("inc") {
val x = args.firstAndOnly() as ObjInt
@ -167,7 +212,7 @@ scope.addVoidFn("log") {
// }
// Call them from Lyng
scope.eval("val y = inc(41); log('Answer:', y)")
session.eval("val y = inc(41); log('Answer:', y)")
```
You can register multiple names (aliases) at once: `addFn<ObjInt>("inc", "increment") { ... }`.
@ -254,6 +299,8 @@ If you want multi-axis slicing semantics, decode that list yourself in `getAt`.
If you need a simple field (with a value) instead of a computed property, use `createField`. This adds a field to the class that will be present in all its instances.
```kotlin
val session = EvalSession()
val scope = session.getScope()
val myClass = ObjClass("MyClass")
// Add a read-only field (constant)
@ -281,6 +328,8 @@ println(instance.count) // -> 5
Properties in Lyng are pure accessors (getters and setters) and do not have automatic backing fields. You can add them to a class using `addProperty`.
```kotlin
val session = EvalSession()
val scope = session.getScope()
val myClass = ObjClass("MyClass")
var internalValue: Long = 10
@ -447,8 +496,9 @@ For Kotlin code that needs dynamic access to Lyng variables, functions, or membe
It provides explicit, cached handles and predictable lookup rules.
```kotlin
val scope = Script.newScope()
scope.eval("""
val session = EvalSession()
val scope = session.getScope()
session.eval("""
val x = 40
fun add(a, b) = a + b
class Box { var value = 1 }
@ -463,7 +513,7 @@ val x = resolver.resolveVal("x").get(scope)
val sum = (resolver as BridgeCallByName).callByName(scope, "add", Arguments(ObjInt(1), ObjInt(2)))
// Member access
val box = scope.eval("Box()")
val box = session.eval("Box()")
val valueHandle = resolver.resolveMemberVar(box, "value")
valueHandle.set(scope, ObjInt(10))
val value = valueHandle.get(scope)
@ -474,12 +524,14 @@ val value = valueHandle.get(scope)
The simplest approach: evaluate an expression that yields the value and convert it.
```kotlin
val kotlinAnswer = scope.eval("(1 + 2) * 3").toKotlin(scope) // -> 9 (Int)
val session = EvalSession()
val scope = session.getScope()
val kotlinAnswer = session.eval("(1 + 2) * 3").toKotlin(scope) // -> 9 (Int)
// After scripts manipulate your vars:
scope.addOrUpdateItem("name", ObjString("Lyng"))
scope.eval("name = name + ' rocks!'")
val kotlinName = scope.eval("name").toKotlin(scope) // -> "Lyng rocks!"
session.eval("name = name + ' rocks!'")
val kotlinName = session.eval("name").toKotlin(scope) // -> "Lyng rocks!"
```
Advanced: you can also grab a variable record directly via `scope.get(name)` and work with its `Obj` value, but evaluating `"name"` is often clearer and enforces Lyng semantics consistently.
@ -492,16 +544,20 @@ There are two convenient patterns.
```kotlin
// Suppose Lyng defines: fun add(a, b) = a + b
scope.eval("fun add(a, b) = a + b")
val session = EvalSession()
val scope = session.getScope()
session.eval("fun add(a, b) = a + b")
val sum = scope.eval("add(20, 22)").toKotlin(scope) // -> 42
val sum = session.eval("add(20, 22)").toKotlin(scope) // -> 42
```
2) Call a Lyng function by name via a prepared call scope:
```kotlin
// Ensure the function exists in the scope
scope.eval("fun add(a, b) = a + b")
val session = EvalSession()
val scope = session.getScope()
session.eval("fun add(a, b) = a + b")
// Look up the function object
val addFn = scope.get("add")!!.value as Statement
@ -532,7 +588,8 @@ Register a Kotlin‑built package:
import net.sergeych.lyng.bridge.*
import net.sergeych.lyng.obj.ObjInt
val scope = Script.newScope()
val session = EvalSession()
val scope = session.getScope()
// Access the import manager behind this scope
val im: ImportManager = scope.importManager
@ -563,12 +620,12 @@ im.addPackage("my.tools") { module: ModuleScope ->
}
// Use it from Lyng
scope.eval("""
session.eval("""
import my.tools.*
val v = triple(14)
status = "busy"
""")
val v = scope.eval("v").toKotlin(scope) // -> 42
val v = session.eval("v").toKotlin(scope) // -> 42
```
Register a package from Lyng source text:
@ -582,24 +639,27 @@ val pkgText = """
scope.importManager.addTextPackages(pkgText)
scope.eval("""
session.eval("""
import math.extra.*
val s = sqr(12)
""")
val s = scope.eval("s").toKotlin(scope) // -> 144
val s = session.eval("s").toKotlin(scope) // -> 144
```
You can also register from parsed `Source` instances via `addSourcePackages(source)`.
### 10) Executing from files, security, and isolation
- To run code from a file, read it and pass to `scope.eval(text)` or compile with `Compiler.compile(Source(fileName, text))`.
- To run code from a file, read it and pass to `session.eval(text)` or compile with `Compiler.compile(Source(fileName, text))`.
- `ImportManager` takes an optional `SecurityManager` if you need to restrict what packages or operations are available. By default, `Script.defaultImportManager` allows everything suitable for embedded use; clamp it down in sandboxed environments.
- For isolation, create fresh modules/scopes via `Scope.new()` or `Script.newScope()` when you need a clean environment per request.
- For isolation, prefer a fresh `EvalSession()` per request. Use `Scope.new()` / `Script.newScope()` when you specifically need low-level raw scopes or modules.
```kotlin
// Fresh module based on the default manager, without the standard prelude
val isolated = net.sergeych.lyng.Scope.new()
// Preferred per-request runtime:
val isolatedSession = EvalSession()
// Low-level fresh module based on the default manager, without the standard prelude:
val isolatedScope = net.sergeych.lyng.Scope.new()
```
### 11) Tips and troubleshooting
@ -634,8 +694,11 @@ To simplify handling these objects from Kotlin, several extension methods are pr
You can serialize Lyng exception objects using `Lynon` to transmit them across boundaries and then rethrow them.
```kotlin
val session = EvalSession()
val scope = session.getScope()
try {
scope.eval("throw MyUserException(404, \"Not Found\")")
session.eval("throw MyUserException(404, \"Not Found\")")
} catch (e: ExecutionError) {
// 1. Serialize the Lyng exception object
val encoded: UByteArray = lynonEncodeAny(scope, e.errorObject)

7
docs/json_and_kotlin_serialization.md
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@ -122,7 +122,8 @@ data class TestJson2(
@Test
fun deserializeMapWithJsonTest() = runTest {
val x = eval("""
val session = EvalSession()
val x = session.eval("""
import lyng.serialization
{ value: 1, inner: { "foo": 1, "bar": 2 }}
""".trimIndent()).decodeSerializable<TestJson2>()
@ -143,7 +144,8 @@ data class TestJson3(
)
@Test
fun deserializeAnyMapWithJsonTest() = runTest {
val x = eval("""
val session = EvalSession()
val x = session.eval("""
import lyng.serialization
{ value: 12, inner: { "foo": 1, "bar": "two" }}
""".trimIndent()).decodeSerializable<TestJson3>()
@ -175,4 +177,3 @@ on [Instant](time.md), see `Instant.truncateTo...` functions.
(3)
: Map keys must be strings, map values may be any objects serializable to Json.

5
docs/lyng.io.console.md
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@ -9,12 +9,13 @@
#### Install in host
```kotlin
import net.sergeych.lyng.Script
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.io.console.createConsoleModule
import net.sergeych.lyngio.console.security.PermitAllConsoleAccessPolicy
suspend fun initScope() {
val scope = Script.newScope()
val session = EvalSession()
val scope = session.getScope()
createConsoleModule(PermitAllConsoleAccessPolicy, scope)
}
```

20
docs/lyng.io.fs.md
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@ -39,23 +39,27 @@ This brings in:
---
#### Install the module into a Lyng Scope
#### Install the module into a Lyng session
The filesystem module is not installed automatically. You must explicitly register it in the scope’s `ImportManager` using the installer. You can customize access control via `FsAccessPolicy`.
The filesystem module is not installed automatically. The preferred host runtime is `EvalSession`: create the session, get its underlying scope, install the module there, and execute scripts through the session. You can customize access control via `FsAccessPolicy`.
Kotlin (host) bootstrap example:
```kotlin
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.Scope
import net.sergeych.lyng.io.fs.createFs
import net.sergeych.lyngio.fs.security.PermitAllAccessPolicy
val scope: Scope = Scope.new()
val installed: Boolean = createFs(PermitAllAccessPolicy, scope)
// installed == true on first registration in this ImportManager, false on repeats
suspend fun bootstrapFs() {
val session = EvalSession()
val scope: Scope = session.getScope()
val installed: Boolean = createFs(PermitAllAccessPolicy, scope)
// installed == true on first registration in this ImportManager, false on repeats
// In scripts (or via scope.eval), import the module to use its symbols:
scope.eval("import lyng.io.fs")
// In scripts (or via session.eval), import the module to use its symbols:
session.eval("import lyng.io.fs")
}
```
You can install with a custom policy too (see Access policy below).
@ -185,7 +189,7 @@ val denyWrites = object : FsAccessPolicy {
}
createFs(denyWrites, scope)
scope.eval("import lyng.io.fs")
session.eval("import lyng.io.fs")
```
Composite operations like `copy` and `move` are checked as a set of primitives (e.g., `OpenRead(src)` + `Delete(dst)` if overwriting + `CreateFile(dst)` + `OpenWrite(dst)`).

18
docs/lyng.io.process.md
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@ -20,24 +20,26 @@ For external projects, ensure you have the appropriate Maven repository configur
---
#### Install the module into a Lyng Scope
#### Install the module into a Lyng session
The process module is not installed automatically. You must explicitly register it in the scope’s `ImportManager` using `createProcessModule`. You can customize access control via `ProcessAccessPolicy`.
The process module is not installed automatically. The preferred host runtime is `EvalSession`: create the session, get its underlying scope, install the module there, and execute scripts through the session. You can customize access control via `ProcessAccessPolicy`.
Kotlin (host) bootstrap example:
```kotlin
import net.sergeych.lyng.Scope
import net.sergeych.lyng.Script
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.io.process.createProcessModule
import net.sergeych.lyngio.process.security.PermitAllProcessAccessPolicy
// ... inside a suspend function or runBlocking
val scope: Scope = Script.newScope()
createProcessModule(PermitAllProcessAccessPolicy, scope)
suspend fun bootstrapProcess() {
val session = EvalSession()
val scope: Scope = session.getScope()
createProcessModule(PermitAllProcessAccessPolicy, scope)
// In scripts (or via scope.eval), import the module:
scope.eval("import lyng.io.process")
// In scripts (or via session.eval), import the module:
session.eval("import lyng.io.process")
}
```
---

7
docs/lyngio.md
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@ -37,7 +37,7 @@ dependencies {
To use `lyngio` modules in your scripts, you must install them into your Lyng scope and provide a security policy.
```kotlin
import net.sergeych.lyng.Script
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.io.fs.createFs
import net.sergeych.lyng.io.process.createProcessModule
import net.sergeych.lyng.io.console.createConsoleModule
@ -46,7 +46,8 @@ import net.sergeych.lyngio.process.security.PermitAllProcessAccessPolicy
import net.sergeych.lyngio.console.security.PermitAllConsoleAccessPolicy
suspend fun runMyScript() {
val scope = Script.newScope()
val session = EvalSession()
val scope = session.getScope()
// Install modules with policies
createFs(PermitAllAccessPolicy, scope)
@ -54,7 +55,7 @@ suspend fun runMyScript() {
createConsoleModule(PermitAllConsoleAccessPolicy, scope)
// Now scripts can import them
scope.eval("""
session.eval("""
import lyng.io.fs
import lyng.io.process
import lyng.io.console

11
docs/perf_guide.md
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@ -114,10 +114,12 @@ When running end‑to‑end “book” workloads or heavier benches, you can ena
Flags are mutable at runtime, e.g.:
```kotlin
PerfFlags.ARG_BUILDER = false
val r1 = (Scope().eval(script) as ObjInt).value
PerfFlags.ARG_BUILDER = true
val r2 = (Scope().eval(script) as ObjInt).value
runTest {
PerfFlags.ARG_BUILDER = false
val r1 = (EvalSession(Scope()).eval(script) as ObjInt).value
PerfFlags.ARG_BUILDER = true
val r2 = (EvalSession(Scope()).eval(script) as ObjInt).value
}
```
Reset flags at the end of a test to avoid impacting other tests.
@ -619,4 +621,3 @@ Reproduce
Notes
- Negative caches are installed only after a real miss throws (cache‑after‑miss), preserving error semantics and invalidation on `layoutVersion` changes.
- IndexRef PIC augments the existing direct path and uses move‑to‑front promotion; it is keyed on `(classId, layoutVersion)` like other PICs.

129
lynglib/src/commonMain/kotlin/net/sergeych/lyng/EvalSession.kt Normal file
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@ -0,0 +1,129 @@
/*
* Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package net.sergeych.lyng
import kotlinx.coroutines.*
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.filter
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.flow.update
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
import net.sergeych.lyng.obj.Obj
import kotlin.coroutines.AbstractCoroutineContextElement
import kotlin.coroutines.CoroutineContext
/**
* Host-managed lifetime owner for coroutines started from Lyng scripts.
*
* The session reuses a single [Scope] across eval calls and tracks async work launched by
* `launch { ... }` and active flow producers created from these evals.
*/
class EvalSession(initialScope: Scope? = null) {
private val ownerJob = SupervisorJob()
private val evalMutex = Mutex()
private val scopeMutex = Mutex()
private val activeJobs = MutableStateFlow(0)
private var _scope: Scope? = initialScope
val scope: Scope? get() = _scope
val isActive: Boolean get() = ownerJob.isActive
val isCancelled: Boolean get() = ownerJob.isCancelled
suspend fun getScope(): Scope = ensureScope()
suspend fun eval(code: String): Obj = eval(code.toSource())
suspend fun eval(source: Source): Obj = evalMutex.withLock {
throwIfCancelled()
val scope = ensureScope()
withEvalSession(this@EvalSession) {
scope.eval(source)
}
}
fun cancel(cause: String? = null) {
ownerJob.cancel(ScriptSessionCancelled(cause ?: "EvalSession cancelled"))
}
suspend fun join() {
activeJobs.filter { it == 0 }.first()
}
suspend fun cancelAndJoin() {
cancel()
join()
}
internal suspend fun <T> launchTrackedDeferred(block: suspend CoroutineScope.() -> T): Deferred<T> {
throwIfCancelled()
val deferred = CoroutineScope(currentTrackedCoroutineContext()).async(block = block)
track(deferred)
return deferred
}
internal suspend fun launchTrackedJob(block: suspend CoroutineScope.() -> Unit): Job {
throwIfCancelled()
val job = CoroutineScope(currentTrackedCoroutineContext()).launch(block = block)
track(job)
return job
}
private suspend fun currentTrackedCoroutineContext(): CoroutineContext {
val base = currentCoroutineContext()
return base.minusKey(Job) + ownerJob + EvalSessionElement(this)
}
private suspend fun ensureScope(): Scope {
_scope?.let { return it }
return scopeMutex.withLock {
_scope ?: Script.newScope().also { _scope = it }
}
}
private fun track(job: Job) {
activeJobs.update { it + 1 }
job.invokeOnCompletion {
activeJobs.update { count -> if (count > 0) count - 1 else 0 }
}
}
internal fun throwIfCancelled() {
if (ownerJob.isCancelled) {
throw ScriptSessionCancelled("EvalSession cancelled")
}
}
companion object {
suspend fun currentOrNull(): EvalSession? = currentCoroutineContext()[EvalSessionElement]?.session
}
}
internal class EvalSessionElement(val session: EvalSession) :
AbstractCoroutineContextElement(EvalSessionElement) {
companion object Key : CoroutineContext.Key<EvalSessionElement>
}
internal suspend fun <T> withEvalSession(session: EvalSession, block: suspend () -> T): T {
return kotlinx.coroutines.withContext(EvalSessionElement(session)) {
block()
}
}
class ScriptSessionCancelled(message: String) : CancellationException(message)

16
lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt
View File

@ -636,9 +636,17 @@ class Script(
addFn("launch") {
val callable = requireOnlyArg<Obj>()
val captured = this
ObjDeferred(globalDefer {
captured.call(callable)
})
val session = EvalSession.currentOrNull()
val deferred = if (session != null) {
session.launchTrackedDeferred {
captured.call(callable)
}
} else {
globalDefer {
captured.call(callable)
}
}
ObjDeferred(deferred)
}
addFn("yield") {
@ -649,7 +657,7 @@ class Script(
addFn("flow", callSignature = CallSignature(tailBlockReceiverType = "FlowBuilder")) {
// important is: current context contains closure often used in call;
// we'll need it for the producer
ObjFlow(requireOnlyArg<Obj>(), requireScope())
ObjFlow(requireOnlyArg<Obj>(), requireScope(), EvalSession.currentOrNull())
}
val pi = ObjReal(PI)

29
lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjFlow.kt
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@ -17,6 +17,7 @@
package net.sergeych.lyng.obj
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.channels.ChannelResult
@ -24,6 +25,7 @@ import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.SendChannel
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.Scope
import net.sergeych.lyng.ScriptFlowIsNoMoreCollected
import net.sergeych.lyng.miniast.ParamDoc
@ -72,25 +74,34 @@ class ObjFlowBuilder(val output: SendChannel<Obj>) : Obj() {
}
}
private fun createLyngFlowInput(scope: Scope, producer: Obj): ReceiveChannel<Obj> {
private suspend fun createLyngFlowInput(scope: Scope, producer: Obj, ownerSession: EvalSession?): ReceiveChannel<Obj> {
val channel = Channel<Obj>(Channel.RENDEZVOUS)
val builder = ObjFlowBuilder(channel)
val builderScope = scope.createChildScope(newThisObj = builder)
globalLaunch {
val runProducer: suspend CoroutineScope.() -> Unit = {
var failure: Throwable? = null
try {
producer.callOn(builderScope)
} catch (x: ScriptFlowIsNoMoreCollected) {
// premature flow closing, OK
} catch (x: Throwable) {
channel.close(x)
return@globalLaunch
failure = x
}
channel.close()
if (failure != null) {
channel.close(failure)
} else {
channel.close()
}
}
if (ownerSession != null) {
ownerSession.launchTrackedJob(runProducer)
} else {
globalLaunch(block = runProducer)
}
return channel
}
class ObjFlow(val producer: Obj, val scope: Scope) : Obj() {
class ObjFlow(val producer: Obj, val scope: Scope, val ownerSession: EvalSession? = null) : Obj() {
override val objClass get() = type
@ -109,14 +120,14 @@ class ObjFlow(val producer: Obj, val scope: Scope) : Obj() {
val objFlow = thisAs<ObjFlow>()
ObjFlowIterator(ObjExternCallable.fromBridge {
call(objFlow.producer)
})
}, objFlow.ownerSession)
}
}
}
}
class ObjFlowIterator(val producer: Obj) : Obj() {
class ObjFlowIterator(val producer: Obj, val ownerSession: EvalSession? = null) : Obj() {
override val objClass: ObjClass get() = type
@ -134,7 +145,7 @@ class ObjFlowIterator(val producer: Obj) : Obj() {
suspend fun hasNext(scope: Scope): ObjBool {
checkNotCancelled(scope)
// cold start:
if (channel == null) channel = createLyngFlowInput(scope, producer)
if (channel == null) channel = createLyngFlowInput(scope, producer, ownerSession)
if (nextItem == null) nextItem = channel!!.receiveCatching()
nextItem?.exceptionOrNull()?.let { throw it }
return ObjBool(nextItem!!.isSuccess)

160
lynglib/src/commonTest/kotlin/EvalSessionTest.kt Normal file
View File

@ -0,0 +1,160 @@
/*
* Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
import kotlinx.coroutines.async
import kotlinx.coroutines.launch
import kotlinx.coroutines.test.advanceTimeBy
import kotlinx.coroutines.test.runTest
import net.sergeych.lyng.EvalSession
import net.sergeych.lyng.Scope
import net.sergeych.lyng.obj.ObjBool
import net.sergeych.lyng.obj.ObjFlow
import net.sergeych.lyng.obj.ObjInt
import net.sergeych.lyng.obj.ObjList
import kotlin.test.*
class EvalSessionTest {
@Test
fun sessionCreatesAndReusesScope() = runTest {
val session = EvalSession()
assertEquals(null, session.scope)
assertEquals(10L, (session.eval("var x = 10; x") as ObjInt).value)
assertNotNull(session.scope)
assertEquals(session.scope, session.getScope())
assertEquals(15L, (session.eval("x += 5; x") as ObjInt).value)
}
@Test
fun sessionCancelStopsLaunchedCoroutines() = runTest {
val scope = Scope()
val session = EvalSession(scope)
session.eval(
"""
var touched = false
launch {
delay(100)
touched = true
}
"""
.trimIndent()
)
session.cancel()
session.join()
advanceTimeBy(150)
assertFalse((scope.eval("touched") as ObjBool).value)
}
@Test
fun joinObservesWorkStartedByLaterEval() = runTest {
val session = EvalSession(Scope())
session.eval("launch { delay(100) }")
var joined = false
val waiter = launch {
session.join()
joined = true
}
advanceTimeBy(50)
assertFalse(joined)
session.eval("launch { delay(100) }")
advanceTimeBy(60)
assertFalse(joined)
advanceTimeBy(50)
waiter.join()
assertTrue(joined)
}
@Test
fun concurrentEvalCallsAreSerialized() = runTest {
val session = EvalSession(Scope())
session.eval("var counter = 0")
val first = async {
session.eval(
"""
delay(100)
counter += 1
counter
"""
.trimIndent()
) as ObjInt
}
val second = async {
session.eval(
"""
counter += 10
counter
"""
.trimIndent()
) as ObjInt
}
advanceTimeBy(150)
assertEquals(1L, first.await().value)
assertEquals(11L, second.await().value)
assertEquals(11L, (session.eval("counter") as ObjInt).value)
}
@Test
fun joinWaitsForActiveFlowProducer() = runTest {
val scope = Scope()
val session = EvalSession(scope)
val flow = session.eval(
"""
flow {
delay(100)
emit(1)
delay(100)
emit(2)
}
"""
.trimIndent()
) as ObjFlow
var joined = false
var collected: ObjList? = null
val collector = launch {
collected = flow.callMethod(scope, "toList")
}
val waiter = launch {
session.join()
joined = true
}
advanceTimeBy(150)
assertFalse(joined)
advanceTimeBy(100)
collector.join()
waiter.join()
assertTrue(joined)
assertEquals(listOf(1L, 2L), collected!!.list.map { (it as ObjInt).value })
}
}