Add interrupt checks to contrib/pg_prewarm.

Currently the extension's pg_prewarm() function didn't check
interrupts once it started "warming" data. Since individual calls can
take a long while it's important for them to be interruptible.

Backpatch to 9.4 where pg_prewarm was introduced.

diff --git a/contrib/pg_prewarm/pg_prewarm.c b/contrib/pg_prewarm/pg_prewarm.c
index df20e888eff08d927475d535312a114a6e0ae260..32c724e5ce2fded164be54deefaee289b16c5197 100644 (file)
--- a/contrib/pg_prewarm/pg_prewarm.c
+++ b/contrib/pg_prewarm/pg_prewarm.c
@@ -159,6 +159,7 @@ pg_prewarm(PG_FUNCTION_ARGS)
         */
        for (block = first_block; block <= last_block; ++block)
        {
+           CHECK_FOR_INTERRUPTS();
            PrefetchBuffer(rel, forkNumber, block);
            ++blocks_done;
        }
@@ -177,6 +178,7 @@ pg_prewarm(PG_FUNCTION_ARGS)
         */
        for (block = first_block; block <= last_block; ++block)
        {
+           CHECK_FOR_INTERRUPTS();
            smgrread(rel->rd_smgr, forkNumber, block, blockbuffer);
            ++blocks_done;
        }
@@ -190,6 +192,7 @@ pg_prewarm(PG_FUNCTION_ARGS)
        {
            Buffer      buf;
 
+           CHECK_FOR_INTERRUPTS();
            buf = ReadBufferExtended(rel, forkNumber, block, RBM_NORMAL, NULL);
            ReleaseBuffer(buf);
            ++blocks_done;