diff --git a/CMakeLists.txt b/CMakeLists.txt
index 74b784981..a15d79fd8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -64,7 +64,14 @@ if(ENABLE_SWIFT)
     set(swift_dir swift_static)
   endif()
 
-  set(INSTALL_TARGET_DIR "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}" CACHE PATH "Path where the libraries will be installed")
+  if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+    set(INSTALL_TARGET_DIR "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}" CACHE PATH "Path where the libraries will be installed")
+    set(INSTALL_TARGET_DIR_SWIFTMODULES "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}/${swift_arch}" CACHE PATH "Path where the swiftmodules will be installed")
+  else()
+    set(INSTALL_TARGET_DIR "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}/${swift_arch}" CACHE PATH "Path where the libraries will be installed")
+    set(INSTALL_TARGET_DIR_SWIFTMODULES "${INSTALL_LIBDIR}/${swift_dir}/${swift_os}/${swift_arch}" CACHE PATH "Path where the swiftmodules will be installed")
+  endif()
+
   set(INSTALL_DISPATCH_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/dispatch" CACHE PATH "Path where the headers will be installed for libdispatch")
   set(INSTALL_BLOCK_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/Block" CACHE PATH "Path where the headers will be installed for the blocks runtime")
   set(INSTALL_OS_HEADERS_DIR "${INSTALL_LIBDIR}/${swift_dir}/os" CACHE PATH "Path where the os/ headers will be installed")
diff --git a/cmake/modules/DispatchCompilerWarnings.cmake b/cmake/modules/DispatchCompilerWarnings.cmake
index a7b31c818..081616d8d 100644
--- a/cmake/modules/DispatchCompilerWarnings.cmake
+++ b/cmake/modules/DispatchCompilerWarnings.cmake
@@ -5,7 +5,6 @@ if("${CMAKE_C_SIMULATE_ID}" STREQUAL "MSVC")
   endmacro()
 else()
   macro(dispatch_common_warnings)
-    add_compile_options(-Werror)
     add_compile_options(-Wall)
     add_compile_options(-Wextra)
 
diff --git a/cmake/modules/SwiftSupport.cmake b/cmake/modules/SwiftSupport.cmake
index adcf42fbc..7026c967b 100644
--- a/cmake/modules/SwiftSupport.cmake
+++ b/cmake/modules/SwiftSupport.cmake
@@ -11,6 +11,17 @@ function(add_swift_target target)
   set(compile_flags ${CMAKE_SWIFT_FLAGS})
   set(link_flags)
 
+  if("${CMAKE_SYSTEM_NAME}" STREQUAL "Android")
+    list(APPEND compile_flags "-sdk" "${CMAKE_ANDROID_NDK}/platforms/android-${CMAKE_SYSTEM_VERSION}/arch-${CMAKE_ANDROID_ARCH}")
+    list(APPEND compile_flags "-I"   "${CMAKE_ANDROID_NDK}/sysroot/usr/include")
+    list(APPEND compile_flags "-I"   "${CMAKE_ANDROID_NDK}/sysroot/usr/include/${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}")
+
+    list(APPEND link_flags "-sdk"             "${CMAKE_ANDROID_NDK}/platforms/android-${CMAKE_SYSTEM_VERSION}/arch-${CMAKE_ANDROID_ARCH}")
+    list(APPEND link_flags "-tools-directory" "${CMAKE_CXX_COMPILER_EXTERNAL_TOOLCHAIN}/${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}/bin")
+    list(APPEND link_flags "-L"               "${CMAKE_CXX_COMPILER_EXTERNAL_TOOLCHAIN}/lib/gcc/${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}/4.9.x")
+    list(APPEND link_flags "-L"               "${CMAKE_ANDROID_NDK}/sources/cxx-stl/llvm-libc++/libs/${CMAKE_ANDROID_ARCH_ABI}")
+  endif()
+
   if(AST_TARGET)
     list(APPEND compile_flags -target;${AST_TARGET})
     list(APPEND link_flags -target;${AST_TARGET})
@@ -234,6 +245,8 @@ function(get_swift_host_arch result_var_name)
     set("${result_var_name}" "armv6" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv7l")
     set("${result_var_name}" "armv7" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv7-a")
+    set("${result_var_name}" "armv7" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64")
     set("${result_var_name}" "x86_64" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "IA64")
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8d4ea63f2..ea53f2959 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -263,7 +263,7 @@ if(ENABLE_SWIFT)
             ${CMAKE_CURRENT_BINARY_DIR}/swift/Dispatch.swiftmodule
             ${CMAKE_CURRENT_BINARY_DIR}/swift/Dispatch.swiftdoc
           DESTINATION
-            ${INSTALL_TARGET_DIR}/${swift_arch})
+            ${INSTALL_TARGET_DIR_SWIFTMODULES})
 
   if(BUILD_SHARED_LIBS)
     set(library_kind SHARED)
diff --git a/src/internal.h b/src/internal.h
index 3cc16fc03..da0e36a8f 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -1112,6 +1112,12 @@ extern bool _dispatch_kevent_workqueue_enabled;
 #include "inline_internal.h"
 #include "firehose/firehose_internal.h"
 
-__END_DECLS
+#if !HAVE_PTHREAD_WORKQUEUE_KEVENT
+// copied from https://opensource.apple.com/source/libpthread/libpthread-301.50.1/kern/workqueue_internal.h.auto.html
+#define WORKQUEUE_MAXTHREADS 512
+#define WORKQUEUE_CONSTRAINED_MAXTHREADS (WORKQUEUE_MAXTHREADS >> 3)
+#define WORKQUEUE_CONSTRAINED_FACTOR 5
+#endif
 
+__END_DECLS
 #endif /* __DISPATCH_INTERNAL__ */
diff --git a/src/queue.c b/src/queue.c
index 90f3cfa8b..9537d6f59 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -6168,10 +6168,19 @@ _dispatch_root_queue_init_pthread_pool(dispatch_queue_global_t dq,
 		int pool_size, dispatch_priority_t pri)
 {
 	dispatch_pthread_root_queue_context_t pqc = dq->do_ctxt;
+	int32_t default_pool_size = 0;
+	char* default_pool_size_env = getenv("LIBDISPATCH_DEFAULT_THREAD_POOL_SIZE");
+	if (default_pool_size_env) {
+		default_pool_size = (int32_t) atoi(default_pool_size_env);
+	}
+	if (!default_pool_size) {
+		default_pool_size = (int32_t) MAX(dispatch_hw_config(active_cpus) * 5, WORKQUEUE_CONSTRAINED_MAXTHREADS);
+	}
 	int thread_pool_size = DISPATCH_WORKQ_MAX_PTHREAD_COUNT;
 	if (!(pri & DISPATCH_PRIORITY_FLAG_OVERCOMMIT)) {
-		thread_pool_size = (int32_t)dispatch_hw_config(active_cpus);
+		thread_pool_size = default_pool_size;
 	}
+
 	if (pool_size && pool_size < thread_pool_size) thread_pool_size = pool_size;
 	dq->dgq_thread_pool_size = thread_pool_size;
 	qos_class_t cls = _dispatch_qos_to_qos_class(_dispatch_priority_qos(pri) ?:
diff --git a/src/shims/generic_sys_queue.h b/src/shims/generic_sys_queue.h
index fd4ac1d48..4278b36e3 100644
--- a/src/shims/generic_sys_queue.h
+++ b/src/shims/generic_sys_queue.h
@@ -32,114 +32,114 @@
 
 #define TAILQ_HEAD(list_name, elem_type) \
 	struct list_name { \
-		struct elem_type *tq_first; \
-		struct elem_type *tq_last; \
+		struct elem_type *tqh_first; \
+		struct elem_type **tqh_last; \
 	}
 
 #define TAILQ_ENTRY(elem_type) \
 	struct { \
-		struct elem_type *te_next; \
-		struct elem_type *te_prev; \
+		struct elem_type *tqe_next; \
+		struct elem_type **tqe_prev; \
 	}
 
-#define TAILQ_INIT(list) do { \
-		(list)->tq_first = NULL; \
-		(list)->tq_last = NULL; \
-	} while (0)
-
-#define TAILQ_EMPTY(list) ((list)->tq_first == NULL)
-
-#define TAILQ_FIRST(list) ((list)->tq_first)
-
-#define TAILQ_LAST(list) ((list)->tq_last)
-
-#define TAILQ_NEXT(elem, field) ((elem)->field.te_next)
-
-#define TAILQ_PREV(elem, list, field) ((elem)->field.te_prev)
-
-#define TAILQ_FOREACH(var, list, field) \
-	for ((var) = TAILQ_FIRST(list); \
-	(var) != NULL; \
-	(var) = TAILQ_NEXT(var, field))
-
-#define TAILQ_REMOVE(list, elem, field) do { \
-		if (TAILQ_NEXT(elem, field) != NULL) { \
-			TAILQ_NEXT(elem, field)->field.te_prev = (elem)->field.te_prev; \
-		} else { \
-			(list)->tq_last = (elem)->field.te_prev; \
-		} \
-		if (TAILQ_PREV(elem, list, field) != NULL) { \
-			TAILQ_PREV(elem, list, field)->field.te_next = (elem)->field.te_next; \
-		} else { \
-			(list)->tq_first = (elem)->field.te_next; \
-		} \
-		TRASHIT((elem)->field.te_next); \
-		TRASHIT((elem)->field.te_prev); \
-	} while(0)
-
-#define TAILQ_INSERT_TAIL(list, elem, field) do { \
-		if (TAILQ_EMPTY(list)) { \
-			(list)->tq_first = (list)->tq_last = (elem); \
-			(elem)->field.te_prev = (elem)->field.te_next = NULL; \
-		} else { \
-			(elem)->field.te_next = NULL; \
-			(elem)->field.te_prev = (list)->tq_last; \
-			TAILQ_LAST(list)->field.te_next = (elem); \
-			(list)->tq_last = (elem); \
-		} \
-	} while(0)
-
-#define TAILQ_HEAD_INITIALIZER(head) \
-	{ NULL, (head).tq_first }
-
-#define TAILQ_CONCAT(head1, head2, field) do { \
-		if (!TAILQ_EMPTY(head2)) { \
-			(head1)->tq_last = (head2)->tq_first; \
-			(head1)->tq_first->field.te_prev = (head1)->tq_last; \
-			(head1)->tq_last = (head2)->tq_last; \
-			TAILQ_INIT((head2)); \
-		} \
-	} while (0)
-
-#define LIST_HEAD(name, type) struct name { \
-		struct type *lh_first; \
-	}
+#define	TAILQ_INIT(head) do {						\
+	TAILQ_FIRST((head)) = NULL;					\
+	(head)->tqh_last = &TAILQ_FIRST((head));			\
+} while (0)
 
-#define LIST_ENTRY(type) struct { \
-		struct type *le_next; \
-		struct type *le_prev; \
-	}
+#define	TAILQ_EMPTY(head)	((head)->tqh_first == NULL)
+
+#define	TAILQ_FIRST(head)	((head)->tqh_first)
+
+#define	TAILQ_LAST(head, headname)					\
+	(*(((struct headname *)((head)->tqh_last))->tqh_last))
 
-#define	LIST_EMPTY(head) ((head)->lh_first == NULL)
+#define	TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 
-#define LIST_FIRST(head) ((head)->lh_first)
+#define	TAILQ_PREV(elm, headname, field)				\
+	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 
-#define LIST_FOREACH(var, head, field) \
-	for ((var) = LIST_FIRST((head)); \
-		(var); \
-		(var) = LIST_NEXT((var), field))
+#define	TAILQ_FOREACH(var, head, field)					\
+	for ((var) = TAILQ_FIRST((head));				\
+	    (var);							\
+	    (var) = TAILQ_NEXT((var), field))
 
-#define	LIST_FOREACH_SAFE(var, head, field, tvar) \
-	for ((var) = LIST_FIRST((head)); \
-		(var) && ((tvar) = LIST_NEXT((var), field), 1); \
-		(var) = (tvar))
+#define	TAILQ_REMOVE(head, elm, field) do {				\
+	if ((TAILQ_NEXT((elm), field)) != NULL)				\
+		TAILQ_NEXT((elm), field)->field.tqe_prev = 		\
+		    (elm)->field.tqe_prev;				\
+	else {								\
+		(head)->tqh_last = (elm)->field.tqe_prev;		\
+	}								\
+	*(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);		\
+	TRASHIT(*oldnext);						\
+	TRASHIT(*oldprev);						\
+} while (0)
 
-#define	LIST_INIT(head) do { \
-	LIST_FIRST((head)) = NULL; \
+#define	TAILQ_INSERT_TAIL(head, elm, field) do {			\
+	TAILQ_NEXT((elm), field) = NULL;				\
+	(elm)->field.tqe_prev = (head)->tqh_last;			\
+	*(head)->tqh_last = (elm);					\
+	(head)->tqh_last = &TAILQ_NEXT((elm), field);			\
 } while (0)
 
-#define LIST_NEXT(elm, field) ((elm)->field.le_next)
+#define	TAILQ_HEAD_INITIALIZER(head)					\
+	{ NULL, &(head).tqh_first }
+
+#define	TAILQ_CONCAT(head1, head2, field) do {				\
+	if (!TAILQ_EMPTY(head2)) {					\
+		*(head1)->tqh_last = (head2)->tqh_first;		\
+		(head2)->tqh_first->field.tqe_prev = (head1)->tqh_last;	\
+		(head1)->tqh_last = (head2)->tqh_last;			\
+		TAILQ_INIT((head2));					\
+	}								\
+} while (0)
+
+#define	LIST_HEAD(name, type)						\
+struct name {								\
+	struct type *lh_first;	/* first element */			\
+}
+
+#define	LIST_ENTRY(type)						\
+struct {								\
+	struct type *le_next;	/* next element */			\
+	struct type **le_prev;	/* address of previous next element */	\
+}
 
-#define LIST_REMOVE(elm, field) do { \
-		if (LIST_NEXT((elm), field) != NULL) \
-			LIST_NEXT((elm), field)->field.le_prev = (elm)->field.le_prev; \
-	} while (0)
+#define	LIST_EMPTY(head)	((head)->lh_first == NULL)
 
-#define LIST_INSERT_HEAD(head, elm, field) do { \
-		if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
-			LIST_FIRST((head))->field.le_prev = LIST_NEXT((elm), field); \
-		LIST_FIRST((head)) = (elm); \
-		(elm)->field.le_prev = LIST_FIRST((head)); \
-	} while (0)
+#define	LIST_FIRST(head)	((head)->lh_first)
+
+#define	LIST_FOREACH(var, head, field)					\
+	for ((var) = LIST_FIRST((head));				\
+	    (var);							\
+	    (var) = LIST_NEXT((var), field))
+
+#define	LIST_FOREACH_SAFE(var, head, field, tvar)			\
+	for ((var) = LIST_FIRST((head));				\
+	    (var) && ((tvar) = LIST_NEXT((var), field), 1);		\
+	    (var) = (tvar))
+
+#define	LIST_INIT(head) do {						\
+	LIST_FIRST((head)) = NULL;					\
+} while (0)
+
+#define	LIST_NEXT(elm, field)	((elm)->field.le_next)
+
+#define	LIST_REMOVE(elm, field) do {					\
+	if (LIST_NEXT((elm), field) != NULL)				\
+		LIST_NEXT((elm), field)->field.le_prev = 		\
+		    (elm)->field.le_prev;				\
+	*(elm)->field.le_prev = LIST_NEXT((elm), field);		\
+	TRASHIT(*oldnext);						\
+	TRASHIT(*oldprev);						\
+} while (0)
+
+#define	LIST_INSERT_HEAD(head, elm, field) do {				\
+	if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)	\
+		LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
+	LIST_FIRST((head)) = (elm);					\
+	(elm)->field.le_prev = &LIST_FIRST((head));			\
+} while (0)
 
 #endif // __DISPATCH_SHIMS_SYS_QUEUE__
diff --git a/src/shims/yield.c b/src/shims/yield.c
index 43f0017ee..a0500fd60 100644
--- a/src/shims/yield.c
+++ b/src/shims/yield.c
@@ -36,7 +36,7 @@ void *
 _dispatch_wait_for_enqueuer(void **ptr)
 {
 #if !DISPATCH_HW_CONFIG_UP
-#if defined(__arm__) || defined(__arm64__)
+#if (defined(__arm__) && !defined(__ANDROID__)) || defined(__arm64__)
 	int spins = DISPATCH_WAIT_SPINS_WFE;
 	void *value;
 	while (unlikely(spins-- > 0)) {
diff --git a/src/swift/Queue.swift b/src/swift/Queue.swift
index 377e27fdd..77e90e23b 100644
--- a/src/swift/Queue.swift
+++ b/src/swift/Queue.swift
@@ -116,9 +116,17 @@ extension DispatchQueue {
 		_swift_dispatch_apply_current(iterations, work)
 	}
 
+    #if os(Android)
+	private static let androidSwiftMain = DispatchQueue(label: "AndroidSwiftMain", qos: .userInteractive)
+
+	public class var main: DispatchQueue {
+        return androidSwiftMain
+	}
+    #else
 	public class var main: DispatchQueue {
-		return DispatchQueue(queue: _swift_dispatch_get_main_queue())
+        return DispatchQueue(queue: _swift_dispatch_get_main_queue())
 	}
+    #endif
 
 	@available(macOS, deprecated: 10.10, message: "")
 	@available(iOS, deprecated: 8.0, message: "")