Several environment variables affect GCL:
A positive float indicating the fraction of available memory GCL should use. Defaults to 1.0.
A positive integer bounding GCL’s heap to 1<<(n+1) bytes. Trumps GCL_MEM_MULTIPLE. Defaults to sizeof(long)-1.
A positive float indicating the minimum fraction of heap to be allocated between garbage collection (GC) cycles. Defaults to 0.05.
A positive float indicating the minimum fraction of heap to be allocated before garbage collection (GC) commences. Defaults to 0.5.
A positive float indicating the maximum fraction of heap to be allocated after which garbage collection (GC) is mandatory. Defaults to 0.75.
A string when set indicating a directory in which to place the file gcl_pool used for coordinating memory management among multiple GCL processes. This should be a local directory for performance reasons. Default is unset.
A non-negative integer indicating how many seconds to sleep before aborting on fatal error. Defaults to 0.