[svn-r1276] H5D.c:

H5F.c:
H5Flow.c:
H5Fprivate.h:
    Joined work by Quincey, Robb and me to eliminate the initial writes
    of BOOTBLOCK when the file is first created.  Also, eliminate the
    repeatedly encoding of BOOTBLOCK in the flushing code.  Introduced
    the eof_written flag to indicate when it is not necessary to go
    do a dumb write at eof.
    (But something is not right if the userblock is not zero.)

H5Fmpio.c:
    Added code to allow setting the MPIO debug output mask via
    the environment variable H5F_mpio_Debug.

1 files changed, 12 insertions, 8 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 7c19921..cb9e9d2 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1609,6 +1609,7 @@ H5F_flush(H5F_t *f, H5F_scope_t scope, hbool_t invalidate)
 {
     uint8_t		buf[2048], *p = buf;
     haddr_t		reserved_addr;
+    uintn               firsttime_bootblock=0;
     uintn		nerrors=0, i;
     
     FUNC_ENTER(H5F_flush, FAIL);
@@ -1677,20 +1678,23 @@ H5F_flush(H5F_t *f, H5F_scope_t scope, hbool_t invalidate)
 	H5F_addr_reset(&(f->shared->hdf5_eof));
 	H5F_addr_inc(&(f->shared->hdf5_eof), (hsize_t)(p-buf));
 	H5F_low_seteof(f->shared->lf, &(f->shared->hdf5_eof));
+        firsttime_bootblock=1;
     }
     
     /* write the boot block to disk */
+    if(!firsttime_bootblock) {
 #ifdef HAVE_PARALLEL
-    H5F_mpio_tas_allsame(f->shared->lf, TRUE);	/* only p0 will write */
+        H5F_mpio_tas_allsame(f->shared->lf, TRUE);	/* only p0 will write */
 #endif
-    if (H5F_low_write(f->shared->lf, f->shared->access_parms, &H5F_xfer_dflt,
-		      &(f->shared->boot_addr), (size_t)(p-buf), buf)<0) {
-	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write header");
-    }
+	if (H5F_low_write(f->shared->lf, f->shared->access_parms, &H5F_xfer_dflt,
+			  &(f->shared->boot_addr), (size_t)(p-buf), buf)<0) {
+	    HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write header");
+	}
     
-    /* Flush file buffers to disk */
-    if (H5F_low_flush(f->shared->lf, f->shared->access_parms) < 0) {
-	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low level flush failed");
+        /* Flush file buffers to disk */
+        if (H5F_low_flush(f->shared->lf, f->shared->access_parms) < 0) {
+        	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low level flush failed");
+        }
     }
 
     /* Check flush errors for children - errors are already on the stack */