1 files changed, 62 insertions, 0 deletions
diff --git a/src/include/storage/latch.h b/src/include/storage/latch.h
new file mode 100644
index 00000000000..2c697741e4d
--- /dev/null
+++ b/src/include/storage/latch.h
@@ -0,0 +1,62 @@
+/*-------------------------------------------------------------------------
+ *
+ * latch.h
+ *	  Routines for interprocess latches
+ *
+ *
+ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/storage/latch.h,v 1.1 2010/09/11 15:48:04 heikki Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LATCH_H
+#define LATCH_H
+
+#include <signal.h>
+
+/*
+ * Latch structure should be treated as opaque and only accessed through
+ * the public functions. It is defined here to allow embedding Latches as
+ * part of bigger structs.
+ */
+typedef struct
+{
+	sig_atomic_t	is_set;
+	bool			is_shared;
+#ifndef WIN32
+	int				owner_pid;
+#else
+	HANDLE			event;
+#endif
+} Latch;
+
+/*
+ * prototypes for functions in latch.c
+ */
+extern void InitLatch(volatile Latch *latch);
+extern void InitSharedLatch(volatile Latch *latch);
+extern void OwnLatch(volatile Latch *latch);
+extern void DisownLatch(volatile Latch *latch);
+extern bool WaitLatch(volatile Latch *latch, long timeout);
+extern int	WaitLatchOrSocket(volatile Latch *latch, pgsocket sock,
+				  long timeout);
+extern void SetLatch(volatile Latch *latch);
+extern void ResetLatch(volatile Latch *latch);
+#define TestLatch(latch) (((volatile Latch *) latch)->is_set)
+
+extern Size LatchShmemSize(void);
+extern void LatchShmemInit(void);
+
+/*
+ * Unix implementation uses SIGUSR1 for inter-process signaling, Win32 doesn't
+ * need this.
+ */
+#ifndef WIN32
+extern void latch_sigusr1_handler(void);
+#else
+#define latch_sigusr1_handler()
+#endif
+
+#endif   /* LATCH_H */