shmemx_session_start

Start a communication session.

Definitions

C/C++ Synopsis

void shmemx_session_start(shmem_ctx_t ctx, long options);

Arguments

ctx         A context handle specifying the context associated with this
            session.

options     The set of requested options from Table 9 for this session.
            Multiple options may be requested by combining them with a
            bitwise OR operation; otherwise, 0 can be given if no options
            are requested

Description

The shmemx_session_start routine begins a session on communication context
ctx with hints requested via options. If a session is already started on a
given context, another call to shmemx_session_start on that context
combines any new options via a bitwise OR operation. Sessions on a
communication context must be stopped with a call to shmem_session_stop on
the same context. Passing false or ambiguous options to a session should
not result in undefined behavior, but may result in the library aborting
the program.

Return Values

None.

Session Hint Options

Option	Usage hint
SHMEM_SESSION_BUNDLE	Bundle ops where the implemenation has an expectation of further operations of the same type
SHMEM_SESSION_HRP	High rate put optimizationion
SHMEM_SESSION_STAMO	This session will contain single transfer AMOs
SHMEM _SESSION_NO_CNCR_TACCESS	This session will contain single access AMOs
SHMEM_SESSION_OP_PUT	This session will contain non-blocking put and/or scalar put operations
SHMEM_SESSION_OP_AMO	This session will contain non-fetching AMOs
SHMEM_SESSION_OP_FAMO	This session will contain fetching AMOs
SHMEM_SESSION_OP_PWS	This session will contain non-blocking put-with-signal operations
SHMEM_SESSION_DC	All operations within this session will be using delivery complete semantics instead of the transmit complete default

Notes

The shmemx_session_start routine is a hint for improving performance, and
OpenSHMEM implementations are not required to apply any optimization.
Implementations are encouraged to supply users with information about the
session options being applied or ignored; for instance, when SHMEM_DEBUG is
set.