3 files changed, 62 insertions, 1 deletions
diff --git a/src/include/storage/buffile.h b/src/include/storage/buffile.h
index 640908717d9..c3d7a61b64c 100644
--- a/src/include/storage/buffile.h
+++ b/src/include/storage/buffile.h
@@ -26,6 +26,8 @@
 #ifndef BUFFILE_H
 #define BUFFILE_H
 
+#include "storage/sharedfileset.h"
+
 /* BufFile is an opaque type whose details are not known outside buffile.c. */
 
 typedef struct BufFile BufFile;
@@ -42,4 +44,9 @@ extern int	BufFileSeek(BufFile *file, int fileno, off_t offset, int whence);
 extern void BufFileTell(BufFile *file, int *fileno, off_t *offset);
 extern int	BufFileSeekBlock(BufFile *file, long blknum);
 
+extern BufFile *BufFileCreateShared(SharedFileSet *fileset, const char *name);
+extern void BufFileExportShared(BufFile *file);
+extern BufFile *BufFileOpenShared(SharedFileSet *fileset, const char *name);
+extern void BufFileDeleteShared(SharedFileSet *fileset, const char *name);
+
 #endif							/* BUFFILE_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6ea26e63b84..98292815092 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -79,6 +79,14 @@ extern int	FileGetRawDesc(File file);
 extern int	FileGetRawFlags(File file);
 extern mode_t FileGetRawMode(File file);
 
+/* Operations used for sharing named temporary files */
+extern File PathNameCreateTemporaryFile(const char *name, bool error_on_failure);
+extern File PathNameOpenTemporaryFile(const char *name);
+extern bool PathNameDeleteTemporaryFile(const char *name, bool error_on_failure);
+extern void PathNameCreateTemporaryDir(const char *base, const char *name);
+extern void PathNameDeleteTemporaryDir(const char *name);
+extern void TempTablespacePath(char *path, Oid tablespace);
+
 /* Operations that allow use of regular stdio --- USE WITH CAUTION */
 extern FILE *AllocateFile(const char *name, const char *mode);
 extern int	FreeFile(FILE *file);
@@ -107,6 +115,7 @@ extern void set_max_safe_fds(void);
 extern void closeAllVfds(void);
 extern void SetTempTablespaces(Oid *tableSpaces, int numSpaces);
 extern bool TempTablespacesAreSet(void);
+extern int	GetTempTablespaces(Oid *tableSpaces, int numSpaces);
 extern Oid	GetNextTempTableSpace(void);
 extern void AtEOXact_Files(void);
 extern void AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
@@ -124,7 +133,7 @@ extern int	durable_unlink(const char *fname, int loglevel);
 extern int	durable_link_or_rename(const char *oldfile, const char *newfile, int loglevel);
 extern void SyncDataDirectory(void);
 
-/* Filename components for OpenTemporaryFile */
+/* Filename components */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"
 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
 
diff --git a/src/include/storage/sharedfileset.h b/src/include/storage/sharedfileset.h
new file mode 100644
index 00000000000..20651bb93b6
--- /dev/null
+++ b/src/include/storage/sharedfileset.h
@@ -0,0 +1,45 @@
+/*-------------------------------------------------------------------------
+ *
+ * sharedfileset.h
+ *	  Shared temporary file management.
+ *
+ *
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/sharedfilespace.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SHAREDFILESET_H
+#define SHAREDFILESET_H
+
+#include "storage/dsm.h"
+#include "storage/fd.h"
+#include "storage/spin.h"
+
+/*
+ * A set of temporary files that can be shared by multiple backends.
+ */
+typedef struct SharedFileSet
+{
+	pid_t		creator_pid;	/* PID of the creating process */
+	uint32		number;			/* per-PID identifier */
+	slock_t		mutex;			/* mutex protecting the reference count */
+	int			refcnt;			/* number of attached backends */
+	int			ntablespaces;	/* number of tablespaces to use */
+	Oid			tablespaces[8]; /* OIDs of tablespaces to use. Assumes that
+								 * it's rare that there more than temp
+								 * tablespaces. */
+} SharedFileSet;
+
+extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
+extern void SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg);
+extern File SharedFileSetCreate(SharedFileSet *fileset, const char *name);
+extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name);
+extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
+					bool error_on_failure);
+extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
+
+#endif