Thread safety issue in WCS 1.1 and 2.0

[Schpidi]

The usage of VSI IO in WCS 1.1 and 2.0 is non-thread safe . As you can see with below script all files are written to "/vsimem/wcsout" which is never cleaned.

#!/usr/bin/python

import mapscript
from osgeo import gdal

map = mapscript.mapObj('msautotest/wxs/wcs_simple.map')
ows_req = mapscript.OWSRequest()

ows_req.setParameter('service', 'wcs')
ows_req.setParameter('version', '2.0.0')
ows_req.setParameter('request', 'getcoverage')
ows_req.setParameter('coverageid', 'grey')
ows_req.setParameter('format', 'image/tiff')

ows_req.type = mapscript.MS_GET_REQUEST

def dispatch(i):

    format = map.getOutputFormatByName("GEOTIFF_BYTE")
    format.setOption("FILENAME","%d.tif"%i)

    mapscript.msIO_installStdoutToBuffer()
    dispatch_status = map.OWSDispatch(ows_req)
    result = mapscript.msIO_getStdoutBufferBytes()
    mapscript.msIO_resetHandlers()

    print "Length: %d" % len(result)
    print gdal.ReadDir("/vsimem/wcsout")

for i in range(2):
    dispatch(i)