Don't include low level locking code from frontend code.

Some frontend code like e.g. pg_xlogdump or pg_resetxlog, has to use
backend headers. Unfortunately until now that code includes most of the
locking code. It's generally not nice to expose such low level details,
but de6fd1c898 made that a hard problem. We fall back to defining
'inline' away if the compiler doesn't support it - that can cause linker
errors like on buildfarm animal pademelon if a inline function
references backend only code.

To fix that problem separate definitions from lock.h that are required
from frontend code into lockdefs.h and use it in the relevant
places. I've only removed the minimal amount of necessary definitions
for now - it might turn out that we want more for other reasons.

To avoid such details being exposed again put some checks against being
included from frontend code into atomics.h, lock.h, lwlock.h and
s_lock.h. It's otherwise fairly easy to indirectly include these
headers.

Discussion: 20150806070902.GE12214@awork2.anarazel.de

diff --git a/src/backend/utils/hash/hashfn.c b/src/backend/utils/hash/hashfn.c
index 260d8806dbb9dfca7e9c89c952f44a2028dedf07..bdd438d4cabeca494344e98a8a613d1476e95dd9 100644 (file)
--- a/src/backend/utils/hash/hashfn.c
+++ b/src/backend/utils/hash/hashfn.c
@@ -22,6 +22,7 @@
 #include "postgres.h"
 
 #include "access/hash.h"
+#include "utils/hsearch.h"
 
 
 /*

diff --git a/src/include/access/genam.h b/src/include/access/genam.h
index d86590ac111e6064c06a85b4dbc7b9979b9192b2..d9d05a08ffe1f67a4d47b4e22088e30b030efff7 100644 (file)
--- a/src/include/access/genam.h
+++ b/src/include/access/genam.h
@@ -17,7 +17,7 @@
 #include "access/sdir.h"
 #include "access/skey.h"
 #include "nodes/tidbitmap.h"
-#include "storage/lock.h"
+#include "storage/lockdefs.h"
 #include "utils/relcache.h"
 #include "utils/snapshot.h"
 

diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index 93cc8afcebc2209569fd53881d422e1fb03b645a..97cb859fa50456586eef4c0d7fc3a05e9114f20f 100644 (file)
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -24,7 +24,7 @@
 #include "fmgr.h"
 #include "lib/stringinfo.h"
 #include "storage/bufmgr.h"
-#include "storage/lock.h"
+#include "storage/lockdefs.h"
 #include "utils/relcache.h"
 
 /*

diff --git a/src/include/access/tuptoaster.h b/src/include/access/tuptoaster.h
index 7d185357714f886df52b3367c8799f9d848af4fa..77f637e90d735890b2d57cce6f96a7750dbc462e 100644 (file)
--- a/src/include/access/tuptoaster.h
+++ b/src/include/access/tuptoaster.h
@@ -14,8 +14,8 @@
 #define TUPTOASTER_H
 
 #include "access/htup_details.h"
+#include "storage/lockdefs.h"
 #include "utils/relcache.h"
-#include "storage/lock.h"
 
 /*
  * This enables de-toasting of index entries.  Needed until VACUUM is

diff --git a/src/include/catalog/objectaddress.h b/src/include/catalog/objectaddress.h
index 37808c03c6e0b7244ddbde00de7b2279b78f3089..0fc16ed717396d50a34fa28ece934f23d8345f50 100644 (file)
--- a/src/include/catalog/objectaddress.h
+++ b/src/include/catalog/objectaddress.h
@@ -14,7 +14,7 @@
 #define OBJECTADDRESS_H
 
 #include "nodes/pg_list.h"
-#include "storage/lock.h"
+#include "storage/lockdefs.h"
 #include "utils/acl.h"
 #include "utils/relcache.h"
 

diff --git a/src/include/port/atomics.h b/src/include/port/atomics.h
index bb87945088938e1414595e1b984faeab82352d8b..65cfa3f8249deb79c8b8c0b1941adcf901f66041 100644 (file)
--- a/src/include/port/atomics.h
+++ b/src/include/port/atomics.h
@@ -37,6 +37,10 @@
 #ifndef ATOMICS_H
 #define ATOMICS_H
 
+#ifdef FRONTEND
+#error "atomics.h may not be included from frontend code"
+#endif
+
 #define INSIDE_ATOMICS_H
 
 #include <limits.h>

diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index 96fe3a66ab080c8628ad7c227147e4105128cd4c..a9cd08c5276aae45b659b8c7d15532d593acacf7 100644 (file)
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -14,6 +14,11 @@
 #ifndef LOCK_H_
 #define LOCK_H_
 
+#ifdef FRONTEND
+#error "lock.h may not be included from frontend code"
+#endif
+
+#include "storage/lockdefs.h"
 #include "storage/backendid.h"
 #include "storage/lwlock.h"
 #include "storage/shmem.h"
@@ -77,15 +82,6 @@ typedef struct
        ((vxid).backendId = (proc).backendId, \
         (vxid).localTransactionId = (proc).lxid)
 
-
-/*
- * LOCKMODE is an integer (1..N) indicating a lock type.  LOCKMASK is a bit
- * mask indicating a set of held or requested lock types (the bit 1<<mode
- * corresponds to a particular lock mode).
- */
-typedef int LOCKMASK;
-typedef int LOCKMODE;
-
 /* MAX_LOCKMODES cannot be larger than the # of bits in LOCKMASK */
 #define MAX_LOCKMODES          10
 
@@ -133,28 +129,6 @@ typedef uint16 LOCKMETHODID;
 #define DEFAULT_LOCKMETHOD     1
 #define USER_LOCKMETHOD                2
 
-/*
- * These are the valid values of type LOCKMODE for all the standard lock
- * methods (both DEFAULT and USER).
- */
-
-/* NoLock is not a lock mode, but a flag value meaning "don't get a lock" */
-#define NoLock                                 0
-
-#define AccessShareLock                        1               /* SELECT */
-#define RowShareLock                   2               /* SELECT FOR UPDATE/FOR SHARE */
-#define RowExclusiveLock               3               /* INSERT, UPDATE, DELETE */
-#define ShareUpdateExclusiveLock 4             /* VACUUM (non-FULL),ANALYZE, CREATE
-                                                                                * INDEX CONCURRENTLY */
-#define ShareLock                              5               /* CREATE INDEX (WITHOUT CONCURRENTLY) */
-#define ShareRowExclusiveLock  6               /* like EXCLUSIVE MODE, but allows ROW
-                                                                                * SHARE */
-#define ExclusiveLock                  7               /* blocks ROW SHARE/SELECT...FOR
-                                                                                * UPDATE */
-#define AccessExclusiveLock            8               /* ALTER TABLE, DROP TABLE, VACUUM
-                                                                                * FULL, and unqualified LOCK TABLE */
-
-
 /*
  * LOCKTAG is the key information needed to look up a LOCK item in the
  * lock hashtable.  A LOCKTAG value uniquely identifies a lockable object.
@@ -536,13 +510,6 @@ extern void RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode);
 extern Size LockShmemSize(void);
 extern LockData *GetLockStatusData(void);
 
-typedef struct xl_standby_lock
-{
-       TransactionId xid;                      /* xid of holder of AccessExclusiveLock */
-       Oid                     dbOid;
-       Oid                     relOid;
-} xl_standby_lock;
-
 extern xl_standby_lock *GetRunningTransactionLocks(int *nlocks);
 extern const char *GetLockmodeName(LOCKMETHODID lockmethodid, LOCKMODE mode);
 

diff --git a/src/include/storage/lockdefs.h b/src/include/storage/lockdefs.h
new file mode 100644 (file)
index 0000000..bfbcdba
--- /dev/null
+++ b/src/include/storage/lockdefs.h
@@ -0,0 +1,56 @@
+/*-------------------------------------------------------------------------
+ *
+ * lockdefs.h
+ *        Frontend exposed parts of postgres' low level lock mechanism
+ *
+ * The split between lockdefs.h and lock.h is not very principled. This file
+ * contains definition that have to (indirectly) be available when included by
+ * FRONTEND code.
+ *
+ * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/lockdefs.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef LOCKDEFS_H_
+#define LOCKDEFS_H_
+
+/*
+ * LOCKMODE is an integer (1..N) indicating a lock type.  LOCKMASK is a bit
+ * mask indicating a set of held or requested lock types (the bit 1<<mode
+ * corresponds to a particular lock mode).
+ */
+typedef int LOCKMASK;
+typedef int LOCKMODE;
+
+/*
+ * These are the valid values of type LOCKMODE for all the standard lock
+ * methods (both DEFAULT and USER).
+ */
+
+/* NoLock is not a lock mode, but a flag value meaning "don't get a lock" */
+#define NoLock                                 0
+
+#define AccessShareLock                        1               /* SELECT */
+#define RowShareLock                   2               /* SELECT FOR UPDATE/FOR SHARE */
+#define RowExclusiveLock               3               /* INSERT, UPDATE, DELETE */
+#define ShareUpdateExclusiveLock 4             /* VACUUM (non-FULL),ANALYZE, CREATE
+                                                                                * INDEX CONCURRENTLY */
+#define ShareLock                              5               /* CREATE INDEX (WITHOUT CONCURRENTLY) */
+#define ShareRowExclusiveLock  6               /* like EXCLUSIVE MODE, but allows ROW
+                                                                                * SHARE */
+#define ExclusiveLock                  7               /* blocks ROW SHARE/SELECT...FOR
+                                                                                * UPDATE */
+#define AccessExclusiveLock            8               /* ALTER TABLE, DROP TABLE, VACUUM
+                                                                                * FULL, and unqualified LOCK TABLE */
+
+typedef struct xl_standby_lock
+{
+       TransactionId xid;                      /* xid of holder of AccessExclusiveLock */
+       Oid                     dbOid;
+       Oid                     relOid;
+} xl_standby_lock;
+
+#endif /* LOCKDEF_H_ */

diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index cbd63184b9b4c131afd91a7e3187da3f89a92c87..f2ff6a06f0187feb89f87e7d5b42d44645b7bdae 100644 (file)
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -14,6 +14,10 @@
 #ifndef LWLOCK_H
 #define LWLOCK_H
 
+#ifdef FRONTEND
+#error "lwlock.h may not be included from frontend code"
+#endif
+
 #include "lib/ilist.h"
 #include "storage/s_lock.h"
 #include "port/atomics.h"

diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index a9b40ed944f7e8dbb526efb05eaa2c4d75746715..834f99b9918250be994a3af49b488bc74182688b 100644 (file)
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -14,6 +14,7 @@
 #ifndef PROCARRAY_H
 #define PROCARRAY_H
 
+#include "storage/lock.h"
 #include "storage/standby.h"
 #include "utils/relcache.h"
 #include "utils/snapshot.h"

diff --git a/src/include/storage/s_lock.h b/src/include/storage/s_lock.h
index 30f28b088ab2d2985e8b3093002f666af6f9c296..c461fda251b6d593a3a3b088dd8b0d907d3580de 100644 (file)
--- a/src/include/storage/s_lock.h
+++ b/src/include/storage/s_lock.h
@@ -96,6 +96,10 @@
 #ifndef S_LOCK_H
 #define S_LOCK_H
 
+#ifdef FRONTEND
+#error "s_lock.h may not be included from frontend code"
+#endif
+
 #ifdef HAVE_SPINLOCKS  /* skip spinlocks if requested */
 
 #if defined(__GNUC__) || defined(__INTEL_COMPILER)

diff --git a/src/include/storage/standby.h b/src/include/storage/standby.h
index 7626c4c4f4bde6f3a59799fb01a6c4178e91db14..40b329b2a3c73027cbabc132ca69e927f9def886 100644 (file)
--- a/src/include/storage/standby.h
+++ b/src/include/storage/standby.h
@@ -16,7 +16,7 @@
 
 #include "access/xlogreader.h"
 #include "lib/stringinfo.h"
-#include "storage/lock.h"
+#include "storage/lockdefs.h"
 #include "storage/procsignal.h"
 #include "storage/relfilenode.h"