Hello everybody:
I am Trying to add a new Server request to PVFS2. I was reading the
documentation about it, and found a file explaining it.
My problem is in the sixth step:
- Update the request scheduler.
The file says that in the function PINT_req_sched_target_handle() in the
source file request_scheduler.c this update must be do it.
The problem is that this function is not included in this source file.
My questions are:
- Where i can include the new request to the server scheduler?
- Is there another file with this information?
Thanks for yours answers.
Erik.
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This are the steps that i am following:
Steps in adding a request to the server:
1) select a request name and number
src/proto/pvfs2-req-proto.h
2) add a request and response struct
src/proto/pvfs2-req-proto.h
add entry to unions: PVFS_server_req and PVFS_server_resp
2a) add endecode functions if needed
src/proto/endecode-funcs.h
for each of these you add or modify you must also
add a stub in include/pvfs2-encode-stubs.h
2b) update the protocol version number
src/proto/pvfs2-req-proto.h
increment PVFS2_PROTO_MINOR, assuming that the
addition of this new request does not break backwards
compatibility for other request types
3) add entries to decode/encode functions
src/proto/PINT-le-bytefield.c
lebf_initialize() - need code here to set up a request so
it
can be encoded and expression for extra message size
if any
lebf_encode_req()
lebf_encode_resp()
lebf_decode_req()
lebf_decode_resp()
lebf_decode_rel() (2 places)
In this last entry, we free any resources allocated
during
decode - specifically array items
This does not free resources allocated by SM code
4) add request specific scratch space to PINT_server_op
src/server/pvfs2-server.h
PINT_server_op -- only if required
5) write state machine -- se details below
src/server/<reqname>.sm
each state machine added must have a delcaration in
src/server/pvfs2-server.h
6) update request scheduler
src/server/request-scheduler/request-scheduler.c
PINT_req_sched_target_handle()
7) add entry to server operation parameters table
src/server/pvfs2-server.c
init_req_table -- see src/server/prelude.sm
prelude_perm_check()
8) add entry in final response state machine
src/server/final-response.sm
s_req_resp_type_map
Writing State Machines
Every state machine passes a PINT_server_op in to each state function.
state machine initialized in src/server/pvfs2-server.c
server_state_machine_start
gets the s_op set up
decodes request message
sets s_op->req, s_op->resp
Each state machine must first run the pvfs2_prelude_sm
reads the attribs of the target object, if appropriate to s_op->attr
does basic permission checking
posts request to the scheduler
State machines typically submit jobs, defined in
src/io/job/job.h
Each state machine must run the pvfs2_final_response_sm
releases request from the scheduler
sends response to the client
s_op->resp must be filled in
return status in js_p->error_code
Cleanup must free any memory allocated by SM code
State functions return 0 or 1 on error-free completion,
0 indicates an asynchronous call has been made and must be waited for
1 indicates no async call was made and should proceed to next state
<0 indicates an error - use PVFS_EXXX codes defined in
include/pvfs2-types.h
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