SunOS man pages : rpc_svc_calls (3)
Networking Services Library Functions rpc_svc_calls(3NSL)
NAME
rpc_svc_calls, svc_dg_enablecache, svc_done, svc_exit,
svc_fdset, svc_freeargs, svc_getargs, svc_getreq_common,
svc_getreq_poll, svc_getreqset, svc_getrpccaller,
svc_max_pollfd, svc_pollfd, svc_run, svc_sendreply - library
routines for RPC servers
DESCRIPTION
These routines are part of the RPC library which allows C
language programs to make procedure calls on other machines
across the network.
These routines are associated with the server side of the
RPC mechanism. Some of them are called by the server side
dispatch function, while others (such as svc_run()) are
called when the server is initiated.
In the current implementation, the service transport handle
SVCXPRT contains a single data area for decoding arguments
and encoding results. Therefore, this structure cannot be
freely shared between threads that call functions that do
this. However, when a server is operating in the Automatic
or User MT modes, a copy of this structure is passed to the
service dispatch procedure in order to enable concurrent
request processing. Under these circumstances, some rou-
tines which would otherwise be unsafe, become safe. These
are marked as such. Also marked are routines that are
unsafe for MT applications, and are not to be used by such
applications.
Routines
#include <rpc/rpc.h>
int svc_dg_enablecache(SVCXPRT *xprt, const uint_t cache_size);
This function allocates a duplicate request cache for
the service endpoint xprt, large enough to hold
cache_size entries. Once enabled, there is no way to
disable caching. This routine returns 1 if space
necessary for a cache of the given size was success-
fully allocated, and 0 otherwise.
This function is safe in MT applications.
int svc_done(SVCXPRT *xprt);
This function frees resources allocated to service a
client request directed to the service endpoint xprt.
This call pertains only to servers executing in the
User MT mode. In the User MT mode, service procedures
must invoke this call before returning, either after a
client request has been serviced, or after an error or
abnormal condition that prevents a reply from being
sent. After svc_done() is invoked, the service
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Networking Services Library Functions rpc_svc_calls(3NSL)
endpoint xprt should not be referenced by the service
procedure. Server multithreading modes and parameters
can be set using the rpc_control() call.
This function is safe in MT applications. It will
have no effect if invoked in modes other than the User
MT mode.
void svc_exit(void);
This function when called by any of the RPC server
procedure or otherwise, destroys all services
registered by the server and causes svc_run() to
return.
If RPC server activity is to be resumed, services must
be reregistered with the RPC library either through
one of the rpc_svc_create(3NSL) functions, or using
xprt_register(3NSL).
svc_exit() has global scope and ends all RPC server
activity.
fd_set svc_fdset;
A global variable reflecting the RPC server's read
file descriptor bit mask. This is only of interest if
service implementors do not call svc_run(), but rather
do their own asynchronous event processing. This vari-
able is read-only, and it may change after calls to
svc_getreqset() or any creation routines. Do not pass
its address to select(3C)! Instead, pass the address
of a copy.
MT applications executing in either the Automatic MT
mode or the user MT mode should never read this vari-
able. They should use auxiliary threads to do asyn-
chronous event processing.
svc_fdset is limited to 1024 file descriptors and is
considered obsolete. Use of svc_pollfd is recommended
instead.
pollfd_t *svc_pollfd;
A global variable pointing to an array of pollfd_t
structures reflecting the RPC server's read file
descriptor array. This is only of interest if service
service implementors do not call svc_run() but rather
do their own asynchronous event processing. This
variable is read-only, and it may change after calls
to svc_getreg_poll() or any creation routines. Do no
pass its address to poll(2)! Instead, pass the address
of a copy.
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Networking Services Library Functions rpc_svc_calls(3NSL)
By default, svc_pollfd is limited to 1024 entries. Use
rpc_control(3NSL) to remove this limitation.
MT applications executing in either the Automatic MT
mode or the user MT mode should never be read this
variable. They should use auxiliary threads to do
asynchronous event processing.
int svc_max_pollfd;
A global variable containing the maximum length of the
svc_pollfd array. This variable is read-only, and it
may change after calls to svc_getreg_poll() or any
creation routines.
caddr_t in);
bool_t svc_freeargs(const SVCXPRT *xprt, const xdrproc_t inproc,
A function macro that frees any data allocated by the
RPC/XDR system when it decoded the arguments to a ser-
vice procedure using svc_getargs(). This routine
returns TRUE if the results were successfully freed,
and FALSE otherwise.
This function macro is safe in MT applications utiliz-
ing the Automatic or User MT modes.
caddr_t in);
bool_t svc_getargs(const SVCXPRT *xprt, const xdrproc_t inproc,
A function macro that decodes the arguments of an RPC
request associated with the RPC service transport han-
dle xprt. The parameter in is the address where the
arguments will be placed; inproc is the XDR routine
used to decode the arguments. This routine returns
TRUE if decoding succeeds, and FALSE otherwise.
This function macro is safe in MT applications utiliz-
ing the Automatic or User MT modes.
void svc_getreq_common(const int fd);
This routine is called to handle a request on the
given file descriptor.
void svc_getreq_poll(struct pollfd *pfdp, const int pollretval);
This routine is only of interest if a service imple-
mentor does not call svc_run(), but instead implements
custom asynchronous event processing. It is called
when poll(2) has determined that an RPC request has
arrived on some RPC file descriptors; pollretval is
the return value from poll(2) and pfdp is the array
of pollfd structures on which the poll(2) was done. It
is assumed to be an array large enough to contain the
maximal number of descriptors allowed.
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Networking Services Library Functions rpc_svc_calls(3NSL)
This function macro is unsafe in MT applications.
void svc_getreqset(fd_set *rdfds);
This routine is only of interest if a service imple-
mentor does not call svc_run(), but instead implements
custom asynchronous event processing. It is called
when select(3C) has determined that an RPC request has
arrived on some RPC file descriptors; rdfds is the
resultant read file descriptor bit mask. The routine
returns when all file descriptors associated with the
value of rdfds have been serviced.
This function macro is unsafe in MT applications.
struct netbuf *svc_getrpccaller(const SVCXPRT *xprt);
The approved way of getting the network address of the
caller of a procedure associated with the RPC service
transport handle xprt.
This function macro is safe in MT applications.
void svc_run(void);
This routine never returns. In single threaded mode,
it waits for RPC requests to arrive, and calls the
appropriate service procedure using svc_getreq_poll()
when one arrives. This procedure is usually waiting
for the poll(2) library call to return.
Applications executing in the Automatic or User MT
modes should invoke this function exactly once. It
the Automatic MT mode, it will create threads to ser-
vice client requests. In the User MT mode, it will
provide a framework for service developers to create
and manage their own threads for servicing client
requests.
outproc, const caddr_t out);
bool_t svc_sendreply(const SVCXPRT *xprt, const xdrproc_t
Called by an RPC service's dispatch routine to send
the results of a remote procedure call. The parameter
xprt is the request's associated transport handle;
outproc is the XDR routine which is used to encode the
results; and out is the address of the results. This
routine returns TRUE if it succeeds, FALSE otherwise.
This function macro is safe in MT applications utiliz-
ing the Automatic or User MT modes.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
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Networking Services Library Functions rpc_svc_calls(3NSL)
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| MT-Level | See NOTES below. |
|_____________________________|_____________________________|
SEE ALSO
rpcgen(1), poll(2), rpc(3NSL), rpc_control(3NSL),
rpc_svc_create(3NSL), rpc_svc_err(3NSL), rpc_svc_reg(3NSL),
select(3C), xprt_register(3NSL), attributes(5)
NOTES
svc_dg_enablecache() and svc_getrpccaller() are safe in mul-
tithreaded applications. svc_freeargs(), svc_getargs(), and
svc_sendreply() are safe in MT applications utilizing the
Automatic or User MT modes. svc_getreq_common(),
svc_getreqset(), and svc_getreq_poll() are unsafe in mul-
tithreaded applications and should be called only from the
main thread.
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