diff --git a/configure b/configure
index e202697bbf..54c5a7963f 100755
--- a/configure
+++ b/configure
@@ -11668,6 +11668,62 @@ if test "$ac_res" != no; then :
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing pthread_barrier_wait" >&5
+$as_echo_n "checking for library containing pthread_barrier_wait... " >&6; }
+if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pthread_barrier_wait ();
+int
+main ()
+{
+return pthread_barrier_wait ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' pthread; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_pthread_barrier_wait=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+  break
+fi
+done
+if ${ac_cv_search_pthread_barrier_wait+:} false; then :
+
+else
+  ac_cv_search_pthread_barrier_wait=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_pthread_barrier_wait" >&5
+$as_echo "$ac_cv_search_pthread_barrier_wait" >&6; }
+ac_res=$ac_cv_search_pthread_barrier_wait
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
 # Solaris:
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fdatasync" >&5
 $as_echo_n "checking for library containing fdatasync... " >&6; }
@@ -15853,6 +15909,19 @@ esac
 
 fi
 
+ac_fn_c_check_func "$LINENO" "pthread_barrier_wait" "ac_cv_func_pthread_barrier_wait"
+if test "x$ac_cv_func_pthread_barrier_wait" = xyes; then :
+  $as_echo "#define HAVE_PTHREAD_BARRIER_WAIT 1" >>confdefs.h
+
+else
+  case " $LIBOBJS " in
+  *" pthread_barrier_wait.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS pthread_barrier_wait.$ac_objext"
+ ;;
+esac
+
+fi
+
 ac_fn_c_check_func "$LINENO" "pwrite" "ac_cv_func_pwrite"
 if test "x$ac_cv_func_pwrite" = xyes; then :
   $as_echo "#define HAVE_PWRITE 1" >>confdefs.h
diff --git a/configure.ac b/configure.ac
index a5ad072ee4..23ad861b27 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1152,6 +1152,7 @@ AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 AC_SEARCH_LIBS(shm_open, rt)
 AC_SEARCH_LIBS(shm_unlink, rt)
 AC_SEARCH_LIBS(clock_gettime, [rt posix4])
+AC_SEARCH_LIBS(pthread_barrier_wait, pthread)
 # Solaris:
 AC_SEARCH_LIBS(fdatasync, [rt posix4])
 # Required for thread_test.c on Solaris
@@ -1734,6 +1735,7 @@ AC_REPLACE_FUNCS(m4_normalize([
 	mkdtemp
 	pread
 	preadv
+	pthread_barrier_wait
 	pwrite
 	pwritev
 	random
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index a4a3f40048..0ac0e186ea 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -66,6 +66,7 @@
 #include "libpq-fe.h"
 #include "pgbench.h"
 #include "portability/instr_time.h"
+#include "port/pg_pthread.h"
 
 #ifndef M_PI
 #define M_PI 3.14159265358979323846
@@ -109,26 +110,6 @@ typedef struct socket_set
 
 #endif							/* POLL_USING_SELECT */
 
-/*
- * Multi-platform pthread implementations
- */
-
-#ifdef WIN32
-/* Use native win32 threads on Windows */
-typedef struct win32_pthread *pthread_t;
-typedef int pthread_attr_t;
-
-static int	pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
-static int	pthread_join(pthread_t th, void **thread_return);
-#elif defined(ENABLE_THREAD_SAFETY)
-/* Use platform-dependent pthread capability */
-#include <pthread.h>
-#else
-/* No threads implementation, use none (-j 1) */
-#define pthread_t void *
-#endif
-
-
 /********************************************************************
  * some configurable parameters */
 
@@ -6742,74 +6723,3 @@ socket_has_input(socket_set *sa, int fd, int idx)
 }
 
 #endif							/* POLL_USING_SELECT */
-
-
-/* partial pthread implementation for Windows */
-
-#ifdef WIN32
-
-typedef struct win32_pthread
-{
-	HANDLE		handle;
-	void	   *(*routine) (void *);
-	void	   *arg;
-	void	   *result;
-} win32_pthread;
-
-static unsigned __stdcall
-win32_pthread_run(void *arg)
-{
-	win32_pthread *th = (win32_pthread *) arg;
-
-	th->result = th->routine(th->arg);
-
-	return 0;
-}
-
-static int
-pthread_create(pthread_t *thread,
-			   pthread_attr_t *attr,
-			   void *(*start_routine) (void *),
-			   void *arg)
-{
-	int			save_errno;
-	win32_pthread *th;
-
-	th = (win32_pthread *) pg_malloc(sizeof(win32_pthread));
-	th->routine = start_routine;
-	th->arg = arg;
-	th->result = NULL;
-
-	th->handle = (HANDLE) _beginthreadex(NULL, 0, win32_pthread_run, th, 0, NULL);
-	if (th->handle == NULL)
-	{
-		save_errno = errno;
-		free(th);
-		return save_errno;
-	}
-
-	*thread = th;
-	return 0;
-}
-
-static int
-pthread_join(pthread_t th, void **thread_return)
-{
-	if (th == NULL || th->handle == NULL)
-		return errno = EINVAL;
-
-	if (WaitForSingleObject(th->handle, INFINITE) != WAIT_OBJECT_0)
-	{
-		_dosmaperr(GetLastError());
-		return errno;
-	}
-
-	if (thread_return)
-		*thread_return = th->result;
-
-	CloseHandle(th->handle);
-	free(th);
-	return 0;
-}
-
-#endif							/* WIN32 */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f4d9f3b408..0bc2efb2d8 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -424,6 +424,9 @@
 /* Define if you have POSIX threads libraries and header files. */
 #undef HAVE_PTHREAD
 
+/* Define to 1 if you have the `pthread_barrier_wait' function. */
+#undef HAVE_PTHREAD_BARRIER_WAIT
+
 /* Define to 1 if you have the `pthread_is_threaded_np' function. */
 #undef HAVE_PTHREAD_IS_THREADED_NP
 
diff --git a/src/include/port/pg_pthread.h b/src/include/port/pg_pthread.h
new file mode 100644
index 0000000000..90056b1242
--- /dev/null
+++ b/src/include/port/pg_pthread.h
@@ -0,0 +1,77 @@
+/*-------------------------------------------------------------------------
+ *
+ * Declarations for missing POSIX thread components.
+ *
+ *	  Currently this supplies an implementation of pthread_barrier_t for the
+ *	  benefit of macOS, which lacks it as of release 11.  These declarations
+ *	  are not in port.h, because that'd require <pthread.h> to be included by
+ *	  every translation unit.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef PG_PTHREAD_H
+#define PG_PTHREAD_H
+
+/*
+ * Multi-platform pthread implementations
+ */
+#ifdef WIN32
+
+/* Use native win32 threads on Windows */
+
+typedef struct win32_pthread *pthread_t;
+typedef int pthread_attr_t;
+typedef SYNCHRONIZATION_BARRIER pthread_barrier_t;
+
+extern int	pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
+extern int	pthread_join(pthread_t th, void **thread_return);
+
+extern int	pthread_barrier_init(pthread_barrier_t *barrier, void *unused, int nthreads);
+extern int	pthread_barrier_wait(pthread_barrier_t *barrier);
+extern int	pthread_barrier_destroy(pthread_barrier_t *barrier);
+
+#define PTHREAD_BARRIER_SERIAL_THREAD (-1)
+
+#elif defined(ENABLE_THREAD_SAFETY)
+
+/* Use platform-dependent pthread capability */
+#include <pthread.h>
+
+#ifndef PTHREAD_BARRIER_SERIAL_THREAD
+#define PTHREAD_BARRIER_SERIAL_THREAD (-1)
+#endif
+
+/* MacOS is missing pthread barriers */
+
+#if !defined(HAVE_PTHREAD_BARRIER_WAIT)
+
+typedef struct pg_pthread_barrier
+{
+	bool		sense;			/* we only need a one bit phase */
+	int			count;			/* number of threads expected */
+	int			arrived;		/* number of threads that have arrived */
+	pthread_mutex_t mutex;
+	pthread_cond_t cond;
+} pthread_barrier_t;
+
+extern int pthread_barrier_init(pthread_barrier_t *barrier,
+								const void *attr,
+								int count);
+extern int pthread_barrier_wait(pthread_barrier_t *barrier);
+extern int pthread_barrier_destroy(pthread_barrier_t *barrier);
+
+#endif /* HAVE_PTHREAD_BARRIER_WAIT */
+
+#else
+
+/* No threads implementation, use none */
+#define pthread_t void *
+#define pthread_barrier_t void *
+#define pthread_barrier_init(a, b, c) /* ignore */
+#define pthread_barrier_wait(a) /* ignore */
+#define pthread_barrier_destroy(a) /* ignore */
+
+#endif /* WIN32 / ENABLE_THREAD_SAFETY */
+
+#endif /* PG_PTHREAD_H */
diff --git a/src/port/Makefile b/src/port/Makefile
index e41b005c4f..1a4b1f3a25 100644
--- a/src/port/Makefile
+++ b/src/port/Makefile
@@ -59,7 +59,8 @@ OBJS = \
 	snprintf.o \
 	strerror.o \
 	tar.o \
-	thread.o
+	thread.o \
+	pthread.o
 
 # libpgport.a, libpgport_shlib.a, and libpgport_srv.a contain the same files
 # foo.o, foo_shlib.o, and foo_srv.o are all built from foo.c
diff --git a/src/port/pthread.c b/src/port/pthread.c
new file mode 100644
index 0000000000..224ac23d26
--- /dev/null
+++ b/src/port/pthread.c
@@ -0,0 +1,174 @@
+#include "postgres_fe.h"
+
+#include "port/pg_pthread.h"
+
+/*
+ * partial pthread and pthread_barrier implementation for Windows
+ */
+
+#ifdef WIN32
+
+typedef struct win32_pthread
+{
+	HANDLE		handle;
+	void	   *(*routine) (void *);
+	void	   *arg;
+	void	   *result;
+} win32_pthread;
+
+unsigned __stdcall
+win32_pthread_run(void *arg)
+{
+	win32_pthread *th = (win32_pthread *) arg;
+
+	th->result = th->routine(th->arg);
+
+	return 0;
+}
+
+int
+pthread_create(pthread_t *thread,
+			   pthread_attr_t *attr,
+			   void *(*start_routine) (void *),
+			   void *arg)
+{
+	int			save_errno;
+	win32_pthread *th;
+
+	th = (win32_pthread *) pg_malloc(sizeof(win32_pthread));
+	th->routine = start_routine;
+	th->arg = arg;
+	th->result = NULL;
+
+	th->handle = (HANDLE) _beginthreadex(NULL, 0, win32_pthread_run, th, 0, NULL);
+	if (th->handle == NULL)
+	{
+		save_errno = errno;
+		free(th);
+		return save_errno;
+	}
+
+	*thread = th;
+	return 0;
+}
+
+int
+pthread_join(pthread_t th, void **thread_return)
+{
+	if (th == NULL || th->handle == NULL)
+		return errno = EINVAL;
+
+	if (WaitForSingleObject(th->handle, INFINITE) != WAIT_OBJECT_0)
+	{
+		_dosmaperr(GetLastError());
+		return errno;
+	}
+
+	if (thread_return)
+		*thread_return = th->result;
+
+	CloseHandle(th->handle);
+	free(th);
+	return 0;
+}
+
+int
+pthread_barrier_init(pthread_barrier_t *barrier, void *unused, int nthreads)
+{
+	/* no spinning: threads are not expected to arrive at the barrier together */
+	bool ok = InitializeSynchronizationBarrier(barrier, nthreads, 0);
+	return 0;
+}
+
+int
+pthread_barrier_wait(pthread_barrier_t *barrier)
+{
+	bool last = EnterSynchronizationBarrier(barrier, SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY);
+	return last ? PTHREAD_BARRIER_SERIAL_THREAD : 0;
+}
+
+int
+pthread_barrier_destroy(pthread_barrier_t *barrier)
+{
+	/*
+	 * The following is coldly ignored because it requires Windows 8
+	 * or Windows Server 2012, which is a little too much.
+	 *
+	 * Also, there is a SYNCHRONIZATION_BARRIER_FLAGS_NO_DELETE flag
+	 * but it probably requires the same versions.
+	 *
+	 *  (void) DeleteSynchronizationBarrier(barrier);
+	 */
+	return 0;
+}
+
+#elif !defined(HAVE_PTHREAD_BARRIER_WAIT)
+
+/*
+ * pthread barrier implementation for MacOS
+ */
+
+int
+pthread_barrier_init(pthread_barrier_t *barrier, const void *attr, int count)
+{
+	barrier->sense = false;
+	barrier->count = count;
+	barrier->arrived = 0;
+	if (pthread_cond_init(&barrier->cond, NULL) < 0)
+		return -1;
+	if (pthread_mutex_init(&barrier->mutex, NULL) < 0)
+	{
+		int save_errno = errno;
+
+		pthread_cond_destroy(&barrier->cond);
+		errno = save_errno;
+
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+pthread_barrier_wait(pthread_barrier_t *barrier)
+{
+	bool		initial_sense;
+
+	pthread_mutex_lock(&barrier->mutex);
+
+	/* We have arrived at the barrier. */
+	barrier->arrived++;
+	Assert(barrier->arrived <= barrier->count);
+
+	/* If we were the last to arrive, release the others and return. */
+	if (barrier->arrived == barrier->count)
+	{
+		barrier->arrived = 0;
+		barrier->sense = !barrier->sense;
+		pthread_mutex_unlock(&barrier->mutex);
+		pthread_cond_broadcast(&barrier->cond);
+
+		return PTHREAD_BARRIER_SERIAL_THREAD;
+	}
+
+	/* Wait for someone else to flip the sense. */
+	initial_sense = barrier->sense;
+	do
+	{
+		pthread_cond_wait(&barrier->cond, &barrier->mutex);
+	} while (barrier->sense == initial_sense);
+
+	pthread_mutex_unlock(&barrier->mutex);
+
+	return 0;
+}
+
+int
+pthread_barrier_destroy(pthread_barrier_t *barrier)
+{
+	pthread_cond_destroy(&barrier->cond);
+	pthread_mutex_destroy(&barrier->mutex);
+	return 0;
+}
+
+#endif							/* HAVE_PTHREAD_BARRIER_WAIT / WIN32 */
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 90328db04e..cfcfe9e416 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -102,7 +102,7 @@ sub mkvcbuild
 	  pread.c preadv.c pwrite.c pwritev.c pg_bitutils.c
 	  pg_strong_random.c pgcheckdir.c pgmkdirp.c pgsleep.c pgstrcasecmp.c
 	  pqsignal.c mkdtemp.c qsort.c qsort_arg.c quotes.c system.c
-	  strerror.c tar.c thread.c
+	  strerror.c tar.c thread.c pthread.c
 	  win32env.c win32error.c win32security.c win32setlocale.c win32stat.c);
 
 	push(@pgportfiles, 'strtof.c') if ($vsVersion < '14.00');
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index 2f28de0355..f091e6a863 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -333,6 +333,7 @@ sub GenerateFiles
 		HAVE_PSTAT                  => undef,
 		HAVE_PS_STRINGS             => undef,
 		HAVE_PTHREAD                => undef,
+		HAVE_PTHREAD_BARRIER_WAIT   => undef,
 		HAVE_PTHREAD_IS_THREADED_NP => undef,
 		HAVE_PTHREAD_PRIO_INHERIT   => undef,
 		HAVE_PWRITE                 => undef,