[Concurrency] Enable concurrent global executor on non-Darwin platforms (swiftlang#35871)

* [Concurrency] Enable concurrent global executor on non-Darwin platforms

* Fix runtime unittest build

Author: drexin

stdlib/public/Concurrency/CMakeLists.txt

@@ -27,8 +27,8 @@ if(SWIFT_CONCURRENCY_USES_DISPATCH)
     # FIXME: we can't rely on libdispatch having been built for the
     # target at this point in the process.  Currently, we're relying
     # on soft-linking.
-    #list(APPEND swift_concurrency_link_libraries
-    #  dispatch)
+    list(APPEND swift_concurrency_link_libraries
+      dispatch)
   endif()
 endif()
 

stdlib/public/Concurrency/TaskPrivate.h

@@ -34,10 +34,6 @@ void _swift_task_alloc_destroy(AsyncTask *task);
 
 #if defined(SWIFT_STDLIB_SINGLE_THREADED_RUNTIME)
 #define SWIFT_CONCURRENCY_COOPERATIVE_GLOBAL_EXECUTOR 1
-#elif !__APPLE__
-// FIXME: this is a terrible workaround for our temporary
-// inability to link libdispatch.
-#define SWIFT_CONCURRENCY_COOPERATIVE_GLOBAL_EXECUTOR 1
 #else
 #define SWIFT_CONCURRENCY_COOPERATIVE_GLOBAL_EXECUTOR 0
 #endif

test/Concurrency/Runtime/mainactor.swift

@@ -1,28 +1,19 @@
-// RUN: %target-run-simple-swift(-parse-as-library -Xfrontend -enable-experimental-concurrency) | %FileCheck %s
+// RUN: %target-run-simple-swift(-parse-as-library -Xfrontend -enable-experimental-concurrency %import-libdispatch) | %FileCheck %s
 
 // REQUIRES: executable_test
 // REQUIRES: concurrency
+// REQUIRES: libdispatch
 
-// REQUIRES: OS=macosx || OS=ios
-// FIXME: should not require Darwin to run this test once we have async main!
-
-#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
-  import Dispatch
-#endif
+import Dispatch
 
 /// @returns true iff the expected answer is actually the case, i.e., correct.
 /// If the current queue does not match expectations, this function may return
 /// false or just crash the program with non-zero exit code, depending on SDK.
 func checkIfMainQueue(expectedAnswer expected: Bool) -> Bool {
-  // FIXME: until we start using dispatch on Linux, we only check
-  // which queue we're on with Darwin platforms.
-#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
   if #available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *) {
     dispatchPrecondition(condition: expected ? .onQueue(DispatchQueue.main) 
                                              : .notOnQueue(DispatchQueue.main))
-    
   }
-#endif
   return true
 }
 

unittests/runtime/CMakeLists.txt

@@ -69,6 +69,13 @@ if(("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "${SWIFT_PRIMARY_VARIANT_SDK}") AND
     list(APPEND PLATFORM_TARGET_LINK_LIBRARIES
       swift_Concurrency${SWIFT_PRIMARY_VARIANT_SUFFIX}
       )
+
+    if(NOT "${SWIFT_PRIMARY_VARIANT_SDK}" IN_LIST SWIFT_APPLE_PLATFORMS)
+      list(APPEND PLATFORM_TARGET_LINK_LIBRARIES
+        dispatch${SWIFT_PRIMARY_VARIANT_SUFFIX}
+        BlocksRuntime${SWIFT_PRIMARY_VARIANT_SUFFIX}
+        )
+    endif()
   endif()
 
   # Don't complain about these files not being in the sources list.