fix: replace ThreadLocal with KMP-compatible ScratchLocal expect/actual

ThreadLocal.withInitial is a JVM-only API that doesn't compile on Kotlin/Native or iOS targets. Replace all usages in commonMain (FieldP.kt, Point.kt) with a new ScratchLocal expect/actual: - jvmMain/androidMain: delegates to java.lang.ThreadLocal (same behavior) - nativeMain: holds value directly (Kotlin/Native coroutines are cooperative, scratch buffers don't need thread isolation) https://claude.ai/code/session_01BhU63WUe9AhikZxRdw3Lpg
2026-04-06 21:05:48 +00:00
parent b60a0bcae8
commit 034c1ab2d1
6 changed files with 132 additions and 3 deletions
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.utils.secp256k1
+
+/** Android: delegates to java.lang.ThreadLocal for per-thread scratch buffers. */
+internal actual class ScratchLocal<T> actual constructor(
+    initializer: () -> T,
+) {
+    private val tl = ThreadLocal.withInitial(initializer)
+
+    actual fun get(): T = tl.get()
+}
@@ -48,11 +48,11 @@ internal object FieldP {
            -1L, // 0xFFFFFFFFFFFFFFFF
        )

-    private val wide = ThreadLocal.withInitial { LongArray(8) }
+    private val wide = ScratchLocal { LongArray(8) }

    // Pre-allocated scratch for inv/sqrt addition chains (11 field elements).
    // Avoids 11 LongArray(4) allocations per inv/sqrt call.
-    private val chainScratch = ThreadLocal.withInitial { Array(11) { LongArray(4) } }
+    private val chainScratch = ScratchLocal { Array(11) { LongArray(4) } }

    /** Get a thread-local wide buffer. Call once at the top-level entry point, then pass through. */
    fun getWide(): LongArray = wide.get()
@@ -348,7 +348,7 @@ internal object ECPoint {
        val batchZInv3 = LongArray(4)
    }

-    private val scratch = ThreadLocal.withInitial { PointScratch() }
+    private val scratch = ScratchLocal { PointScratch() }

    /** Get thread-local scratch. Call once at the top-level entry point. */
    internal fun getScratch(): PointScratch = scratch.get()
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.utils.secp256k1
+
+/**
+ * KMP-compatible thread-local storage.
+ *
+ * On JVM/Android: delegates to java.lang.ThreadLocal for true per-thread isolation.
+ * On Native: single-threaded assumption — just holds the value directly.
+ * (Kotlin/Native has its own threading model; for the secp256k1 use case,
+ * scratch buffers don't need thread isolation since coroutines are cooperative.)
+ */
+internal expect class ScratchLocal<T>(
+    initializer: () -> T,
+) {
+    fun get(): T
+}
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.utils.secp256k1
+
+/** JVM: delegates to java.lang.ThreadLocal for per-thread scratch buffers. */
+internal actual class ScratchLocal<T> actual constructor(
+    initializer: () -> T,
+) {
+    private val tl = ThreadLocal.withInitial(initializer)
+
+    actual fun get(): T = tl.get()
+}
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.utils.secp256k1
+
+/**
+ * Native: holds value directly (no thread-local needed).
+ * Kotlin/Native coroutines are cooperative — scratch buffers are safe to share
+ * within a single thread's call stack.
+ */
+internal actual class ScratchLocal<T> actual constructor(
+    initializer: () -> T,
+) {
+    private val value: T = initializer()
+
+    actual fun get(): T = value
+}