dat_srq_resize(3dat)

1dat_srq_resize(3DAT)Direct Access Transport Library Functiondsat_srq_resize(3DAT)
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NAME

6       dat_srq_resize - modify the size of the shared receive queue
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SYNOPSIS

9       cc [ flag... ] file... -ldat [ library... ]
10       #include <dat/udat.h>
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12       DAT_RETURN
13           dat_srq_resize (
14           IN      DAT_SRQ_HANDLE      srq_handle,
15           IN      DAT_COUNT           srq_max_recv_dto
16           )
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PARAMETERS

20       srq_handle          A handle for an instance of the SRQ.
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23       srq_max_recv_dto    The  new  maximum  number  of Recv DTOs that Shared
24                           Receive Queue must hold.
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DESCRIPTION

28       The dat_srq_resize() function modifies the size of the queue of SRQ.
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31       Resizing of Shared Receive Queue should not cause any incoming messages
32       on  any  of  the EPs that use the SRQ to be lost. If the number of out‐
33       standing  Recv  buffers  on  the  SRQ  is  larger  then  the  requested
34       srq_max_recv_dto,  the  operation  returns DAT_INVALID_STATE and do not
35       change SRQ. This includes not just the buffers on the SRQ but all  out‐
36       standing Receive buffers that had been posted to the SRQ and whose com‐
37       pletions have not reaped yet. Thus, the outstanding buffers include the
38       buffers on SRQ, the buffers posted to SRQ at are at SRQ associated EPs,
39       and the buffers posted to SRQ for which completions have been generated
40       but  not  yet reaped by Consumer from recv_evds of the EPs that use the
41       SRQ.
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44       If the requested srq_max_recv_dto is below the SRQ low  watermark,  the
45       operation returns DAT_INVALID_STATE and does not change SRQ.
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RETURN VALUES

48       DAT_SUCCESS                   The operation was successful.
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51       DAT_INVALID_HANDLE            The srq_handle argument is an invalid DAT
52                                     handle.
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55       DAT_INVALID_PARAMETER         The srq_max_recv_dto argument is invalid.
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58       DAT_INSUFFICIENT_RESOURCES    The operation failed due to resource lim‐
59                                     itations.
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62       DAT_INVALID_STATE             Invalid   state.  Either  the  number  of
63                                     entries on the SRQ exceeds the  requested
64                                     SRQ  queue  length  or  the requested SRQ
65                                     queue length is smaller than the SRQ  low
66                                     watermark.
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USAGE

70       The  dat_srq_resize()  function  is  required  not to lose any buffers.
71       Thus, it cannot shrink below the outstanding number of Recv buffers  on
72       SRQ. There is no requirement to shrink the SRQ to return DAT_SUCCESS.
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75       The  quality  of  the implementation determines how closely to the Con‐
76       sumer-requested value the Provider shrinks the SRQ.  For  example,  the
77       Provider  can shrink the SRQ to the Consumer-requested value and if the
78       requested value is smaller than the outstanding buffers on SRQ,  return
79       DAT_INVALID_STATE; or the Provider can shrink to some value larger than
80       that requested by the Consumer but  below  current  SRQ  size;  or  the
81       Provider does not change the SRQ size and still returns DAT_SUCCESS.
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ATTRIBUTES

84       See attributes(5) for descriptions of the following attributes:
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89       ┌─────────────────────────────┬─────────────────────────────┐
90       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
91       ├─────────────────────────────┼─────────────────────────────┤
92       │Interface Stability          │Standard: uDAPL, 1.2         │
93       ├─────────────────────────────┼─────────────────────────────┤
94       │MT-Level                     │Unsafe                       │
95       └─────────────────────────────┴─────────────────────────────┘
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