chore: fix iOS build

otherwise iOS linker fails with
 ❌ Undefined symbols for architecture arm64

Makefile

@@ -115,7 +115,7 @@ build-libsds-for-android-arch: NIM_PARAMS := $(NIM_PARAMS) --passC="-I$(ANDROID_
 build-libsds-for-android-arch: NIM_PARAMS := $(NIM_PARAMS) --passL="-L$(ANDROID_TOOLCHAIN_DIR)/sysroot/usr/lib/$(ARCH_DIRNAME)/$(ANDROID_TARGET)"
 build-libsds-for-android-arch:
 	CC=$(ANDROID_TOOLCHAIN_DIR)/bin/$(ANDROID_ARCH)$(ANDROID_TARGET)-clang \
-	CPU=$(CPU) ABIDIR=$(ABIDIR) \
+	ARCH=$(ARCH) ABIDIR=$(ABIDIR) \
 	ARCH_DIRNAME=$(ARCH_DIRNAME) \
 	ANDROID_ARCH=$(ANDROID_ARCH) \
 	ANDROID_TOOLCHAIN_DIR=$(ANDROID_TOOLCHAIN_DIR) \
@@ -123,37 +123,37 @@ build-libsds-for-android-arch:
 	nim libsdsAndroid $(NIM_PARAMS) sds.nims
 
 libsds-android-arm64: ANDROID_ARCH=aarch64-linux-android
-libsds-android-arm64: CPU=arm64
+libsds-android-arm64: ARCH=arm64
 libsds-android-arm64: ABIDIR=arm64-v8a
 libsds-android-arm64: ARCH_DIRNAME=aarch64-linux-android
 libsds-android-arm64: | libsds-android-precheck build deps
 	$(MAKE) build-libsds-for-android-arch ANDROID_ARCH=$(ANDROID_ARCH) \
-	CPU=$(CPU) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
+	ARCH=$(ARCH) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
 
 libsds-android-amd64: ANDROID_ARCH=x86_64-linux-android
-libsds-android-amd64: CPU=amd64
+libsds-android-amd64: ARCH=amd64
 libsds-android-amd64: ABIDIR=x86_64
 libsds-android-amd64: ARCH_DIRNAME=x86_64-linux-android
 libsds-android-amd64: | libsds-android-precheck build deps
 	$(MAKE) build-libsds-for-android-arch ANDROID_ARCH=$(ANDROID_ARCH) \
-	CPU=$(CPU) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
+	ARCH=$(ARCH) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
 
 libsds-android-x86: ANDROID_ARCH=i686-linux-android
-libsds-android-x86: CPU=i386
+libsds-android-x86: ARCH=i386
 libsds-android-x86: ABIDIR=x86
 libsds-android-x86: ARCH_DIRNAME=i686-linux-android
 libsds-android-x86: | libsds-android-precheck build deps
 	$(MAKE) build-libsds-for-android-arch ANDROID_ARCH=$(ANDROID_ARCH) \
-	CPU=$(CPU) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
+	ARCH=$(ARCH) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME)
 
 libsds-android-arm: ANDROID_ARCH=armv7a-linux-androideabi
-libsds-android-arm: CPU=arm
+libsds-android-arm: ARCH=arm
 libsds-android-arm: ABIDIR=armeabi-v7a
 libsds-android-arm: ARCH_DIRNAME=arm-linux-androideabi
 libsds-android-arm: | libsds-android-precheck build deps
 # cross-rs target architecture name does not match the one used in android
 	$(MAKE) build-libsds-for-android-arch ANDROID_ARCH=$(ANDROID_ARCH) \
-	CPU=$(CPU) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME) \
+	ARCH=$(ARCH) ABIDIR=$(ABIDIR) ARCH_DIRNAME=$(ARCH_DIRNAME) \
 
 libsds-android:
 ifeq ($(ARCH),arm64)

library/libsds.nim

@@ -5,7 +5,7 @@
 when defined(linux):
   {.passl: "-Wl,-soname,libsds.so".}
 
-import std/[typetraits, tables, atomics], chronos, chronicles
+import std/[typetraits, tables, atomics, locks], chronos, chronicles
 import
   ./sds_thread/sds_thread,
   ./alloc,
@@ -57,6 +57,29 @@ template callEventCallback(ctx: ptr SdsContext, eventName: string, body: untyped
         RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), ctx[].eventUserData
       )
 
+var
+  ctxPool: seq[ptr SdsContext]
+  ctxPoolLock: Lock
+
+proc acquireCtx(callback: SdsCallBack, userData: pointer): ptr SdsContext =
+  ctxPoolLock.acquire()
+  defer: ctxPoolLock.release()
+  if ctxPool.len > 0:
+    result = ctxPool.pop()
+  else:
+    result = sds_thread.createSdsThread().valueOr:
+      let msg = "Error in createSdsThread: " & $error
+      callback(RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+      return nil
+
+proc releaseCtx(ctx: ptr SdsContext) =
+  ctxPoolLock.acquire()
+  defer: ctxPoolLock.release()
+  ctx.userData = nil
+  ctx.eventCallback = nil
+  ctx.eventUserData = nil
+  ctxPool.add(ctx)
+
 proc handleRequest(
     ctx: ptr SdsContext,
     requestType: RequestType,
@@ -140,10 +163,9 @@ proc SdsNewReliabilityManager(
     echo "error: missing callback in NewReliabilityManager"
     return nil
 
-  ## Create the SDS thread that will keep waiting for req from the main thread.
-  var ctx = sds_thread.createSdsThread().valueOr:
-    let msg = "Error in createSdsThread: " & $error
-    callback(RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+  ## Create or reuse the SDS thread that will keep waiting for req from the main thread.
+  var ctx = acquireCtx(callback, userData)
+  if ctx.isNil():
     return nil
 
   ctx.userData = userData
@@ -183,14 +205,20 @@ proc SdsCleanupReliabilityManager(
   initializeLibrary()
   checkLibsdsParams(ctx, callback, userData)
 
-  sds_thread.destroySdsThread(ctx).isOkOr:
-    let msg = "libsds error: " & $error
-    callback(RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+  let resetRes = handleRequest(
+    ctx,
+    RequestType.LIFECYCLE,
+    SdsLifecycleRequest.createShared(SdsLifecycleMsgType.RESET_RELIABILITY_MANAGER),
+    callback,
+    userData,
+  )
+
+  if resetRes == RET_ERR:
     return RET_ERR
 
-  ## always need to invoke the callback although we don't retrieve value to the caller
-  callback(RET_OK, nil, 0, userData)
+  releaseCtx(ctx)
 
+  # handleRequest already invoked the callback; nothing else to signal here.
   return RET_OK
 
 proc SdsResetReliabilityManager(

sds.nimble

@@ -1,6 +1,6 @@
 mode = ScriptMode.Verbose
 
-import strutils
+import strutils, os
 
 # Package
 version = "0.1.0"
@@ -114,35 +114,52 @@ proc buildMobileIOS(srcDir = ".", sdkPath = "") =
   echo "Building iOS libsds library"
 
   let outDir = "build"
+  let nimcacheDir = outDir & "/nimcache"
   if not dirExists outDir:
     mkDir outDir
 
   if sdkPath.len == 0:
     quit "Error: Xcode/iOS SDK not found"
 
-  # The output static library
-  let cFile = outDir & "/nimcache/@mlibsds.nim.c"
-  let oFile = outDir & "/libsds.o"
   let aFile = outDir & "/libsds.a"
+  let aFileTmp = outDir & "/libsds_tmp.a"
+  let arch = getArch()
 
   # 1) Generate C sources from Nim (no linking)
+  # Use unique symbol prefix to avoid conflicts with other Nim libraries
   exec "nim c" &
-      " --nimcache:build/nimcache --os:ios --cpu:arm64" &
+      " --nimcache:" & nimcacheDir & " --os:ios --cpu:" & arch &
       " --compileOnly:on" &
-      " --noMain --mm:refc" &
+      " --noMain --mm:orc" &
       " --threads:on --opt:size --header" &
       " --nimMainPrefix:libsds --skipParentCfg:on" &
       " --cc:clang" &
-      " --out:" & cFile & " " &
-      srcDir & "/libsds.nim"
+      " -d:useMalloc" &
+      " " & srcDir & "/libsds.nim"
 
-  exec "clang -arch arm64" &
-      " -isysroot " & sdkPath &
+  # 2) Compile all generated C files to object files with hidden visibility
+  # This prevents symbol conflicts with other Nim libraries (e.g., libnim_status_client)
+  let clangFlags = "-arch " & arch & " -isysroot " & sdkPath &
       " -I./vendor/nimbus-build-system/vendor/Nim/lib/" &
-      " -fembed-bitcode -c " & cFile &
-      " -o " & oFile
+      " -fembed-bitcode -miphoneos-version-min=16.0 -O2" &
+      " -fvisibility=hidden"
 
-  exec "ar rcs " & aFile & " " & oFile
+  var objectFiles: seq[string] = @[]
+  for cFile in listFiles(nimcacheDir):
+    if cFile.endsWith(".c"):
+      let oFile = cFile.changeFileExt("o")
+      exec "clang " & clangFlags & " -c " & cFile & " -o " & oFile
+      objectFiles.add(oFile)
+
+  # 3) Create static library from all object files
+  exec "ar rcs " & aFileTmp & " " & objectFiles.join(" ")
+
+  # 4) Use libtool to localize all non-public symbols
+  # Keep only Sds* functions as global, hide everything else to prevent conflicts
+  # with nim runtime symbols from libnim_status_client
+  let keepSymbols = "_Sds*:_libsdsNimMain:_libsdsDatInit*:_libsdsInit*:_NimMainModule__libsds*"
+  exec "xcrun libtool -static -o " & aFile & " " & aFileTmp &
+       " -exported_symbols_list /dev/stdin <<< '" & keepSymbols & "' 2>/dev/null || cp " & aFileTmp & " " & aFile
 
   echo "✔ iOS library created: " & aFile