1 files changed, 100 insertions, 0 deletions
diff --git a/contrib/userlock/user_locks.c b/contrib/userlock/user_locks.c
new file mode 100644
index 00000000000..efc9b0a4644
--- /dev/null
+++ b/contrib/userlock/user_locks.c
@@ -0,0 +1,100 @@
+/*
+ * user_locks.c --
+ *
+ * This loadable module, together with my user-lock.patch applied to the
+ * backend, provides support for user-level long-term cooperative locks.
+ *
+ * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "postgres.h"
+#include "miscadmin.h"
+#include "storage/lock.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "storage/block.h"
+#include "storage/multilev.h"
+#include "utils/elog.h"
+
+#include "user_locks.h"
+
+#define USER_LOCKS_TABLE_ID	0
+
+extern Oid MyDatabaseId;
+
+int
+user_lock(unsigned int id1, unsigned int id2, LOCKT lockt)
+{
+    LOCKTAG tag;
+
+    memset(&tag,0,sizeof(LOCKTAG));
+    tag.relId = 0;
+    tag.dbId = MyDatabaseId;
+    tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
+    tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
+    tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
+
+    return LockAcquire(USER_LOCKS_TABLE_ID, &tag, lockt);
+}
+
+int
+user_unlock(unsigned int id1, unsigned int id2, LOCKT lockt)
+{
+    LOCKTAG tag;
+
+    memset(&tag, 0,sizeof(LOCKTAG));
+    tag.relId = 0;
+    tag.dbId = MyDatabaseId;
+    tag.tupleId.ip_blkid.bi_hi = id2 >> 16;
+    tag.tupleId.ip_blkid.bi_lo = id2 & 0xffff;
+    tag.tupleId.ip_posid = (unsigned short) (id1 & 0xffff);
+    
+    return LockRelease(USER_LOCKS_TABLE_ID, &tag, lockt);
+}
+
+int
+user_write_lock(unsigned int id1, unsigned int id2)
+{
+    return user_lock(id1, id2, WRITE_LOCK);
+}
+
+
+int
+user_write_unlock(unsigned int id1, unsigned int id2)
+{
+    return user_unlock(id1, id2, WRITE_LOCK);
+}
+
+int
+user_write_lock_oid(Oid oid)
+{
+    return user_lock(0, oid, WRITE_LOCK);
+}
+
+int
+user_write_unlock_oid(Oid oid)
+{
+    return user_unlock(0, oid, WRITE_LOCK);
+}
+
+int
+user_unlock_all()
+{
+    PROC	*proc;
+    SHMEM_OFFSET location;
+
+    ShmemPIDLookup(getpid(),&location);
+    if (location == INVALID_OFFSET) {
+	elog(NOTICE, "UserUnlockAll: unable to get proc ptr");
+	return -1;
+    }
+
+    proc = (PROC *) MAKE_PTR(location);
+    return LockReleaseAll(USER_LOCKS_TABLE_ID, &proc->lockQueue);
+}
+
+/* end of file */