Add missing pthread_barrier_t.

Supply a simple implementation of the missing pthread_barrier_t type and
functions, for macOS.

Discussion: https://postgr.es/m/20200227180100.zyvjwzcpiokfsqm2%40alap3.anarazel.de

1 files changed, 41 insertions, 0 deletions

diff --git a/src/include/port/pg_pthread.h b/src/include/port/pg_pthread.h
new file mode 100644
index 00000000000..d102ce9d6f3
--- /dev/null
+++ b/src/include/port/pg_pthread.h
@@ -0,0 +1,41 @@
+/*-------------------------------------------------------------------------
+ *
+ * Declarations for missing POSIX thread components.
+ *
+ *	  Currently this supplies an implementation of pthread_barrier_t for the
+ *	  benefit of macOS, which lacks it.  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
+
+#include <pthread.h>
+
+#ifndef HAVE_PTHREAD_BARRIER_WAIT
+
+#ifndef PTHREAD_BARRIER_SERIAL_THREAD
+#define PTHREAD_BARRIER_SERIAL_THREAD (-1)
+#endif
+
+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
+
+#endif