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db_include/storage/barrier.h

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+/*-------------------------------------------------------------------------
+ *
+ * barrier.h
+ *	  Barriers for synchronizing cooperating processes.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/barrier.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef BARRIER_H
+#define BARRIER_H
+
+/*
+ * For the header previously known as "barrier.h", please include
+ * "port/atomics.h", which deals with atomics, compiler barriers and memory
+ * barriers.
+ */
+
+#include "storage/condition_variable.h"
+#include "storage/spin.h"
+
+typedef struct Barrier
+{
+	slock_t		mutex;
+	int			phase;			/* phase counter */
+	int			participants;	/* the number of participants attached */
+	int			arrived;		/* the number of participants that have
+								 * arrived */
+	int			elected;		/* highest phase elected */
+	bool		static_party;	/* used only for assertions */
+	ConditionVariable condition_variable;
+} Barrier;
+
+extern void BarrierInit(Barrier *barrier, int num_workers);
+extern bool BarrierArriveAndWait(Barrier *barrier, uint32 wait_event_info);
+extern bool BarrierArriveAndDetach(Barrier *barrier);
+extern bool BarrierArriveAndDetachExceptLast(Barrier *barrier);
+extern int	BarrierAttach(Barrier *barrier);
+extern bool BarrierDetach(Barrier *barrier);
+extern int	BarrierPhase(Barrier *barrier);
+extern int	BarrierParticipants(Barrier *barrier);
+
+#endif							/* BARRIER_H */