Re: WriteBuffer return value - Mailing list pgsql-patches

On Wed, 12 Jun 2002 10:19:17 -0400, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>I'd vote for changing WriteBuffer to
>return void, and have it elog() on bad argument.

Whatever you want ...
BTW, to avoid rejected hunks this patch should be applied after the
EliminateUnused patch I posted 2002-06-10.

diff -ur ../orig/src/backend/commands/sequence.c src/backend/commands/sequence.c
--- ../orig/src/backend/commands/sequence.c    2002-06-10 15:40:46.000000000 +0200
+++ src/backend/commands/sequence.c    2002-06-13 09:32:25.000000000 +0200
@@ -468,8 +468,7 @@

     LockBuffer(buf, BUFFER_LOCK_UNLOCK);

-    if (WriteBuffer(buf) == STATUS_ERROR)
-        elog(ERROR, "%s.nextval: WriteBuffer failed", sequence->relname);
+    WriteBuffer(buf);

     relation_close(seqrel, NoLock);

@@ -581,8 +580,7 @@

     LockBuffer(buf, BUFFER_LOCK_UNLOCK);

-    if (WriteBuffer(buf) == STATUS_ERROR)
-        elog(ERROR, "%s.setval: WriteBuffer failed", sequence->relname);
+    WriteBuffer(buf);

     relation_close(seqrel, NoLock);
 }
diff -ur ../orig/src/backend/storage/buffer/bufmgr.c src/backend/storage/buffer/bufmgr.c
--- ../orig/src/backend/storage/buffer/bufmgr.c    2002-06-10 15:00:57.000000000 +0200
+++ src/backend/storage/buffer/bufmgr.c    2002-06-13 09:32:40.000000000 +0200
@@ -87,6 +87,7 @@
 static int    BufferReplace(BufferDesc *bufHdr);
 void        PrintBufferDescs(void);

+static void write_buffer(Buffer buffer, bool unpin);

 /*
  * ReadBuffer -- returns a buffer containing the requested
@@ -558,29 +559,22 @@
 }

 /*
- * WriteBuffer
- *
- *        Marks buffer contents as dirty (actual write happens later).
- *
- * Assume that buffer is pinned.  Assume that reln is
- *        valid.
- *
- * Side Effects:
- *        Pin count is decremented.
+ * write_buffer -- common functionality for
+ *                 WriteBuffer and WriteNoReleaseBuffer
  */
-
-#undef WriteBuffer
-
-int
-WriteBuffer(Buffer buffer)
+static void
+write_buffer(Buffer buffer, bool release)
 {
     BufferDesc *bufHdr;

     if (BufferIsLocal(buffer))
-        return WriteLocalBuffer(buffer, TRUE);
+    {
+        WriteLocalBuffer(buffer, release);
+        return;
+    }

     if (BAD_BUFFER_ID(buffer))
-        return FALSE;
+        elog(ERROR, "write_buffer: bad buffer %d", buffer);

     bufHdr = &BufferDescriptors[buffer - 1];

@@ -589,37 +583,39 @@

     bufHdr->flags |= (BM_DIRTY | BM_JUST_DIRTIED);

-    UnpinBuffer(bufHdr);
+    if (release)
+        UnpinBuffer(bufHdr);
     LWLockRelease(BufMgrLock);
+}

-    return TRUE;
+/*
+ * WriteBuffer
+ *
+ *        Marks buffer contents as dirty (actual write happens later).
+ *
+ * Assume that buffer is pinned.  Assume that reln is
+ *        valid.
+ *
+ * Side Effects:
+ *        Pin count is decremented.
+ */
+
+#undef WriteBuffer
+
+void
+WriteBuffer(Buffer buffer)
+{
+    write_buffer(buffer, true);
 }

 /*
  * WriteNoReleaseBuffer -- like WriteBuffer, but do not unpin the buffer
  *                           when the operation is complete.
  */
-int
+void
 WriteNoReleaseBuffer(Buffer buffer)
 {
-    BufferDesc *bufHdr;
-
-    if (BufferIsLocal(buffer))
-        return WriteLocalBuffer(buffer, FALSE);
-
-    if (BAD_BUFFER_ID(buffer))
-        return STATUS_ERROR;
-
-    bufHdr = &BufferDescriptors[buffer - 1];
-
-    LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
-    Assert(bufHdr->refcount > 0);
-
-    bufHdr->flags |= (BM_DIRTY | BM_JUST_DIRTIED);
-
-    LWLockRelease(BufMgrLock);
-
-    return STATUS_OK;
+    write_buffer(buffer, false);
 }


diff -ur ../orig/src/backend/storage/buffer/localbuf.c src/backend/storage/buffer/localbuf.c
--- ../orig/src/backend/storage/buffer/localbuf.c    2002-05-03 19:42:11.000000000 +0200
+++ src/backend/storage/buffer/localbuf.c    2002-06-13 09:23:56.000000000 +0200
@@ -155,7 +155,7 @@
  * WriteLocalBuffer -
  *      writes out a local buffer
  */
-int
+void
 WriteLocalBuffer(Buffer buffer, bool release)
 {
     int            bufid;
@@ -174,8 +174,6 @@
         Assert(LocalRefCount[bufid] > 0);
         LocalRefCount[bufid]--;
     }
-
-    return true;
 }

 /*
diff -ur ../orig/src/include/storage/buf_internals.h src/include/storage/buf_internals.h
--- ../orig/src/include/storage/buf_internals.h    2002-06-10 15:03:44.000000000 +0200
+++ src/include/storage/buf_internals.h    2002-06-13 09:23:26.000000000 +0200
@@ -176,7 +176,7 @@

 extern BufferDesc *LocalBufferAlloc(Relation reln, BlockNumber blockNum,
                  bool *foundPtr);
-extern int    WriteLocalBuffer(Buffer buffer, bool release);
+extern void    WriteLocalBuffer(Buffer buffer, bool release);
 extern int    FlushLocalBuffer(Buffer buffer, bool sync, bool release);
 extern void LocalBufferSync(void);
 extern void ResetLocalBufferPool(void);
diff -ur ../orig/src/include/storage/bufmgr.h src/include/storage/bufmgr.h
--- ../orig/src/include/storage/bufmgr.h    2002-04-16 01:47:12.000000000 +0200
+++ src/include/storage/bufmgr.h    2002-06-13 09:22:59.000000000 +0200
@@ -148,8 +148,8 @@
  */
 extern Buffer ReadBuffer(Relation reln, BlockNumber blockNum);
 extern int    ReleaseBuffer(Buffer buffer);
-extern int    WriteBuffer(Buffer buffer);
-extern int    WriteNoReleaseBuffer(Buffer buffer);
+extern void    WriteBuffer(Buffer buffer);
+extern void    WriteNoReleaseBuffer(Buffer buffer);
 extern Buffer ReleaseAndReadBuffer(Buffer buffer, Relation relation,
                      BlockNumber blockNum);
 extern int    FlushBuffer(Buffer buffer, bool sync, bool release);