# sm_create

Definition: | include builtins\ipc.e atom pSharedMem = sm_create(string name, integer nbytes)
Description: | Allocates a contiguous block of shared memory, nbytes in length, that will be uniquely identified by name. Returns: the address of the newly created block of memory. If a block of memory that is identified by name already exists, or the memory cannot be allocated, then sm_create() returns one of the predefined error values.
pwa/p2js: | Not supported
Comments: | Before attempting to create a new block of memory, sm_open() can be called to find out if the name already exists. Each application must call sm_close() to close its handle to the shared memory. A block of shared memory will continue to exist until all handles to it have been closed.
Example: |
    include builtins\ipc.e
    include builtins\serialize.e
    sequence s = {"Pete",{-1,0,1},PI,-PI},
             enc_s = serialize(s)
    integer len = length(enc_s)
    atom pMem = sm_create("test",len+4)
    poke4(pMem,len)
    poke(pMem+4,enc_s)

    --atom pMem = sm_open("test") -- (if a separate process)
    ?deserialize(peek({pMem+4,peek4s(pMem)}))
    -- shows {"Pete",{-1,0,1},3.141592654,-3.141592654}
    sm_close(pMem)
Obviously, in a client/server scenario, the sm_close() corresponding to an sm_create() in the server should not occur before the sm_open() in the client, but otherwise, if there are two, it does not matter which sm_close() happens first.
See Also: | sm_open sm_close serialize deserialize