Anonymous Shared Memory
pr_memunmap( addr ); pr_closefilemap(fm); client: ...
...pr_memunmap(addr); pr_closefilemap(fm); second protocol server: fm = pr_openanonfilemap(dirname, size, filemapprot); fmstring = pr_exportfilemapasstring( fm ); addr = pr_memmap(fm); ...
...server uses his own magic to create child pr_memunmap( addr ); pr_closefilemap(fm); client: ...
...pr_memunmap(addr); pr_closefilemap(fm); anonymous shared memory functions pr_openanonfilemap pr_processattrsetinheritablefilemap pr_getinheritedfilemap pr_exportfilemapasstring pr_importfilemapfromstring ...

PR_Unmap
syntax #include <prio.h> prstatus pr_memunmap( void *addr, pruint32 len); parameters the function has the following parameters: addr the starting address of the memory region to be unmapped.
... description pr_memunmap removes the file mapping for the memory region (addr, addr + len).

I/O Functions
pr_createfilemap pr_memmap pr_memunmap pr_closefilemap anonymous pipe function pr_createpipe polling functions this section describes two of the most important polling functions provided by nspr: pr_poll pr_getconnectstatus pollable events a pollable event is a special kind of file descriptor.

PR_MemMap
when the file-mapping memory region is no longer needed, it should be unmapped with a call to pr_memunmap.