remove libpwq

remove libpwq from gitsubmodules.
remove support for building libpwq when building dispatch

Author: dgrove-oss

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "libpwq"]
-	path = libpwq
-	url = https://github.com/mheily/libpwq.git

Makefile.am

@@ -4,17 +4,12 @@
 
 ACLOCAL_AMFLAGS = -I m4
 
-if BUILD_OWN_PTHREAD_WORKQUEUES
-  MAYBE_PTHREAD_WORKQUEUES = libpwq
-endif
-
 if BUILD_TESTS
   MAYBE_TESTS = tests
 endif
 
 SUBDIRS=						\
 	dispatch					\
-	$(MAYBE_PTHREAD_WORKQUEUES)	\
 	man							\
 	os							\
 	private						\

configure.ac

@@ -320,7 +320,7 @@ AS_IF([test -n "$apple_libpthread_source_path" -a -n "$apple_xnu_source_osfmk_pa
 AC_CHECK_HEADERS([pthread_machdep.h pthread/qos.h])
 
 # pthread_workqueues.
-# Look for own version first, then for libpwq in our source tree, finally system version.
+# Look for own version first, than see if there is a system version.
 AC_ARG_ENABLE([internal-libpwq],
   [AS_HELP_STRING([--enable-internal-libpwq],
     [Use libdispatch's own implementation of pthread workqueues.])],,
@@ -336,26 +336,15 @@ AS_IF([test "x$enable_internal_libpwq" = "xyes"],
   [AC_DEFINE(DISPATCH_USE_INTERNAL_WORKQUEUE, 1, [Use libdispatch's own implementation of pthread_workqueue API])
    AC_DEFINE(HAVE_PTHREAD_WORKQUEUES, 1, [Define if pthread work queues are present])
    dispatch_use_internal_workqueue=true
-   have_pthread_workqueues=true
-   build_own_pthread_workqueues=false],
+   have_pthread_workqueues=true],
   [dispatch_use_internal_workqueue=false
-   AS_IF([test -f $srcdir/libpwq/configure.ac],
-     [AC_DEFINE(BUILD_OWN_PTHREAD_WORKQUEUES, 1, [Define if building pthread work queues from source])
-      ac_configure_args="--disable-libpwq-install $ac_configure_args"
-      AC_CONFIG_SUBDIRS([libpwq])
-      build_own_pthread_workqueues=true
-      AC_DEFINE(HAVE_PTHREAD_WORKQUEUES, 1, [Define if pthread work queues are present])
+   AC_CHECK_HEADERS([pthread/workqueue_private.h pthread_workqueue.h],
+     [AC_DEFINE(HAVE_PTHREAD_WORKQUEUES, 1, [Define if pthread work queues are present])
       have_pthread_workqueues=true],
-     [build_own_pthread_workqueues=false
-      AC_CHECK_HEADERS([pthread/workqueue_private.h pthread_workqueue.h],
-        [AC_DEFINE(HAVE_PTHREAD_WORKQUEUES, 1, [Define if pthread work queues are present])
-         have_pthread_workqueues=true],
-        [have_pthread_workqueues=false]
-      )]
+     [have_pthread_workqueues=false]
   )]
 )
 AM_CONDITIONAL(DISPATCH_USE_INTERNAL_WORKQUEUE, $dispatch_use_internal_workqueue)
-AM_CONDITIONAL(BUILD_OWN_PTHREAD_WORKQUEUES, $build_own_pthread_workqueues)
 AM_CONDITIONAL(HAVE_PTHREAD_WORKQUEUES, $have_pthread_workqueues)
 
 AC_CHECK_HEADERS([libproc_internal.h], [], [], [#include <mach/mach.h>])

libpwq

@@ -88,16 +88,11 @@ if DISPATCH_USE_INTERNAL_WORKQUEUE
   PTHREAD_WORKQUEUE_LIBS=
   PTHREAD_WORKQUEUE_CFLAGS=
 else
-if BUILD_OWN_PTHREAD_WORKQUEUES
-  PTHREAD_WORKQUEUE_LIBS=$(top_builddir)/libpwq/libpthread_workqueue.la
-  PTHREAD_WORKQUEUE_CFLAGS=-I$(top_srcdir)/libpwq/include
-else
 if HAVE_PTHREAD_WORKQUEUES
   PTHREAD_WORKQUEUE_LIBS=-lpthread_workqueue
   PTHREAD_WORKQUEUE_CFLAGS=
 endif
 endif
-endif
 
 if BUILD_OWN_BLOCKS_RUNTIME
 libdispatch_la_SOURCES+= BlocksRuntime/data.c BlocksRuntime/runtime.c

src/Makefile.am

@@ -84,6 +84,7 @@ _dispatch_workq_worker_register(dispatch_queue_t root_q, int priority)
 {
 	dispatch_once_f(&_dispatch_workq_init_once_pred, NULL, &_dispatch_workq_init_once);
 
+#if HAVE_DISPATCH_WORKQ_MONITORING
 	dispatch_workq_monitor_t mon = &_dispatch_workq_monitors[priority];
 	dispatch_assert(mon->dq == root_q);
 	dispatch_tid tid = _dispatch_thread_getspecific(tid);
@@ -92,11 +93,13 @@ _dispatch_workq_worker_register(dispatch_queue_t root_q, int priority)
 	int worker_id = mon->num_registered_tids++;
 	mon->registered_tids[worker_id] = tid;
 	_dispatch_unfair_lock_unlock(&mon->registered_tid_lock);
+#endif // HAVE_DISPATCH_WORKQ_MONITORING
 }
 
 void
 _dispatch_workq_worker_unregister(dispatch_queue_t root_q, int priority)
 {
+#if HAVE_DISPATCH_WORKQ_MONITORING
 	dispatch_workq_monitor_t mon = &_dispatch_workq_monitors[priority];
 	dispatch_tid tid = _dispatch_thread_getspecific(tid);
 	_dispatch_unfair_lock_lock(&mon->registered_tid_lock);
@@ -110,9 +113,12 @@ _dispatch_workq_worker_unregister(dispatch_queue_t root_q, int priority)
 		}
 	}
 	_dispatch_unfair_lock_unlock(&mon->registered_tid_lock);
+#endif // HAVE_DISPATCH_WORKQ_MONITORING
 }
 
 
+#if HAVE_DISPATCH_WORKQ_MONITORING
+#if defined(__linux__)
 /*
  * For each pid that is a registered worker, read /proc/[pid]/stat
  * to get a count of the number of them that are actually runnable.
@@ -164,6 +170,9 @@ _dispatch_workq_count_runnable_workers(dispatch_workq_monitor_t mon)
 
 	_dispatch_unfair_lock_unlock(&mon->registered_tid_lock);
 }
+#else
+#error must define _dispatch_workq_count_runnable_workers
+#endif
 
 static void
 _dispatch_workq_monitor_pools(void *context DISPATCH_UNUSED)
@@ -212,6 +221,8 @@ _dispatch_workq_monitor_pools(void *context DISPATCH_UNUSED)
 		}
 	}
 }
+#endif // HAVE_DISPATCH_WORKQ_MONITORING
+
 
 // temporary until we switch over to QoS based interface.
 static dispatch_queue_t
@@ -238,6 +249,7 @@ get_root_queue_from_legacy_priority(int priority)
 static void
 _dispatch_workq_init_once(void *context DISPATCH_UNUSED)
 {
+#if HAVE_DISPATCH_WORKQ_MONITORING
 	int target_runnable = dispatch_hw_config(active_cpus);
 	for (int i = 0; i < WORKQ_NUM_PRIORITIES; i++) {
 		dispatch_workq_monitor_t mon = &_dispatch_workq_monitors[i];
@@ -255,6 +267,7 @@ _dispatch_workq_init_once(void *context DISPATCH_UNUSED)
 	dispatch_source_set_event_handler_f(ds, _dispatch_workq_monitor_pools);
 	dispatch_set_context(ds, ds); // avoid appearing as leaked
 	dispatch_activate(ds);
+#endif // HAVE_DISPATCH_WORKQ_MONITORING
 }
 
 #endif // DISPATCH_USE_INTERNAL_WORKQUEUE

src/event/workqueue.c

@@ -42,5 +42,11 @@
 void _dispatch_workq_worker_register(dispatch_queue_t root_q, int priority);
 void _dispatch_workq_worker_unregister(dispatch_queue_t root_q, int priority);
 
+#if defined(__linux__)
+#define HAVE_DISPATCH_WORKQ_MONITORING 1
+#else
+#define HAVE_DISPATCH_WORKQ_MONITORING 0
+#endif
+
 #endif /* __DISPATCH_WORKQUEUE_INTERNAL__ */
 

src/event/workqueue_internal.h

@@ -727,7 +727,7 @@ _dispatch_root_queues_init_once(void *context DISPATCH_UNUSED)
 		size_t i;
 		for (i = 0; i < DISPATCH_ROOT_QUEUE_COUNT; i++) {
 			bool overcommit = true;
-#if TARGET_OS_EMBEDDED || DISPATCH_USE_INTERNAL_WORKQUEUE
+#if TARGET_OS_EMBEDDED || (DISPATCH_USE_INTERNAL_WORKQUEUE && HAVE_DISPATCH_WORKQ_MONITORING)
 			// some software hangs if the non-overcommitting queues do not
 			// overcommit when threads block. Someday, this behavior should
 			// apply to all platforms

src/queue.c

@@ -88,13 +88,11 @@ AM_OBJCFLAGS=$(DISPATCH_TESTS_CFLAGS) $(CBLOCKS_FLAGS)
 AM_CXXFLAGS=$(DISPATCH_TESTS_CFLAGS) $(CXXBLOCKS_FLAGS) $(BSD_OVERLAY_CFLAGS)
 AM_OBJCXXFLAGS=$(DISPATCH_TESTS_CFLAGS) $(CXXBLOCKS_FLAGS)
 
-if !BUILD_OWN_PTHREAD_WORKQUEUES
 if !DISPATCH_USE_INTERNAL_WORKQUEUE
 if HAVE_PTHREAD_WORKQUEUES
   PTHREAD_WORKQUEUE_LIBS=-lpthread_workqueue
 endif
 endif
-endif
 
 if BUILD_OWN_BLOCKS_RUNTIME
 CBLOCKS_FLAGS+= -I$(top_srcdir)/src/BlocksRuntime