From 56e4d8fb0cbbcd1b1036b361758ff84a40d2cb01 Mon Sep 17 00:00:00 2001 From: Quincey Koziol Date: Tue, 4 Jun 2002 12:27:13 -0500 Subject: [svn-r5529] Purpose: Code improvement Description: Now that the metadata accumulator is working correctly, the buffer size tends to get rather large and stay there. Solution: Put a throttle on the accumulator buffer to reduce its size back down when it isn't needed. Platforms tested: Solaris 2.7 (arabica) w/FORTRAN & FreeBSD 4.5 (sleipnir) w/C++ --- src/H5FD.c | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/src/H5FD.c b/src/H5FD.c index 03e9194..55c8847 100644 --- a/src/H5FD.c +++ b/src/H5FD.c @@ -38,6 +38,10 @@ static haddr_t H5FD_real_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size); /* Declare a PQ free list to manage the metadata accumulator buffer */ H5FL_BLK_DEFINE_STATIC(meta_accum); +/* Local macro definitions */ +#define H5FD_ACCUM_THROTTLE 8 +#define H5FD_ACCUM_THRESHOLD 2048 + /* Static local variables */ /* Global count of the number of H5FD_t's handed out. This is used as a @@ -2230,15 +2234,29 @@ H5FD_read(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t siz } /* end if */ /* Cache the new piece of metadata */ - /* Check if we need to reallocate the buffer */ + /* Check if we need to resize the buffer */ if(size>file->accum_buf_size) { - /* Reallocate the metadata accumulator buffer */ + /* Grow the metadata accumulator buffer */ if ((file->meta_accum=H5FL_BLK_REALLOC(meta_accum,file->meta_accum,size))==NULL) HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate metadata accumulator buffer"); /* Note the new buffer size */ file->accum_buf_size=size; } /* end if */ + else { + /* Check if we should shrink the accumulator buffer */ + if(size<(file->accum_buf_size/H5FD_ACCUM_THROTTLE) && + file->accum_buf_size>H5FD_ACCUM_THRESHOLD) { + size_t new_size=(file->accum_buf_size/H5FD_ACCUM_THROTTLE); /* New size of accumulator buffer */ + + /* Shrink the accumulator buffer */ + if ((file->meta_accum=H5FL_BLK_REALLOC(meta_accum,file->meta_accum,new_size))==NULL) + HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate metadata accumulator buffer"); + + /* Note the new buffer size */ + file->accum_buf_size=new_size; + } /* end if */ + } /* end else */ /* Update accumulator information */ file->accum_loc=addr; @@ -2484,15 +2502,29 @@ H5FD_write(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t si } /* end if */ /* Cache the new piece of metadata */ - /* Check if we need to reallocate the buffer */ + /* Check if we need to resize the buffer */ if(size>file->accum_buf_size) { - /* Reallocate the metadata accumulator buffer */ + /* Grow the metadata accumulator buffer */ if ((file->meta_accum=H5FL_BLK_REALLOC(meta_accum,file->meta_accum,size))==NULL) HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate metadata accumulator buffer"); /* Note the new buffer size */ file->accum_buf_size=size; } /* end if */ + else { + /* Check if we should shrink the accumulator buffer */ + if(size<(file->accum_buf_size/H5FD_ACCUM_THROTTLE) && + file->accum_buf_size>H5FD_ACCUM_THRESHOLD) { + size_t new_size=(file->accum_buf_size/H5FD_ACCUM_THROTTLE); /* New size of accumulator buffer */ + + /* Shrink the accumulator buffer */ + if ((file->meta_accum=H5FL_BLK_REALLOC(meta_accum,file->meta_accum,new_size))==NULL) + HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate metadata accumulator buffer"); + + /* Note the new buffer size */ + file->accum_buf_size=new_size; + } /* end if */ + } /* end else */ /* Update the metadata accumulator information */ file->accum_loc=addr; -- cgit v0.12