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NAME
erpc - Enhanced Remote Procedure Call
DESCRIPTION
This module provide services similar to Remote Procedure Calls. A remote procedure call is a method to
call a function on a remote node and collect the answer. It is used for collecting information on a
remote node, or for running a function with some specific side effects on the remote node.
This is an enhanced subset of the operations provided by the rpc module. Enhanced in the sense that it
makes it possible to distinguish between returned value, raised exceptions, and other errors. erpc also
has better performance and scalability than the original rpc implementation. However, current rpc module
will utilize erpc in order to also provide these properties when possible.
In order for an erpc operation to succeed, the remote node also needs to support erpc. Typically only
ordinary Erlang nodes as of OTP 23 have erpc support.
Note that it is up to the user to ensure that correct code to execute via erpc is available on the
involved nodes.
DATA TYPES
request_id()
An opaque request identifier. For more information see send_request/4.
request_id_collection()
An opaque collection of request identifiers (request_id()) where each request identifier can be
associated with a label chosen by the user. For more information see reqids_new/0.
timeout_time() = 0..4294967295 | infinity | {abs, integer()}
0..4294967295:
Timeout relative to current time in milliseconds.
infinity:
Infinite timeout. That is, the operation will never time out.
{abs, Timeout}:
An absolute Erlang monotonic time timeout in milliseconds. That is, the operation will time
out when erlang:monotonic_time(millisecond) returns a value larger than or equal to Timeout.
Timeout is not allowed to identify a time further into the future than 4294967295
milliseconds. Identifying the timeout using an absolute timeout value is especially handy when
you have a deadline for responses corresponding to a complete collection of requests
(request_id_collection()) , since you do not have to recalculate the relative time until the
deadline over and over again.
EXPORTS
call(Node, Fun) -> Result
call(Node, Fun, Timeout) -> Result
Types:
Node = node()
Fun = function()
Timeout = timeout_time()
Result = term()
The same as calling erpc:call(Node, erlang, apply, [Fun,[]], Timeout). May raise all the same
exceptions as call/5 plus an {erpc, badarg} error exception if Fun is not a fun of zero arity.
The call erpc:call(Node,Fun) is the same as the call erpc:call(Node,Fun,infinity).
call(Node, Module, Function, Args) -> Result
call(Node, Module, Function, Args, Timeout) -> Result
Types:
Node = node()
Module = Function = atom()
Args = [term()]
Timeout = timeout_time()
Result = term()
Evaluates apply(Module, Function, Args) on node Node and returns the corresponding value Result.
Timeout sets an upper time limit for the call operation to complete.
The call erpc:call(Node, Module, Function, Args) is equivalent to the call erpc:call(Node, Module,
Function, Args, infinity)
The call() function only returns if the applied function successfully returned without raising any
uncaught exceptions, the operation did not time out, and no failures occurred. In all other cases
an exception is raised. The following exceptions, listed by exception class, can currently be
raised by call():
throw:
The applied function called throw(Value) and did not catch this exception. The exception
reason Value equals the argument passed to throw/1.
exit:
Exception reason:
{exception, ExitReason}:
The applied function called exit(ExitReason) and did not catch this exception. The exit
reason ExitReason equals the argument passed to exit/1.
{signal, ExitReason}:
The process that applied the function received an exit signal and terminated due to this
signal. The process terminated with exit reason ExitReason.
error:
Exception reason:
{exception, ErrorReason, StackTrace}:
A runtime error occurred which raised an error exception while applying the function, and
the applied function did not catch the exception. The error reason ErrorReason indicates the
type of error that occurred. StackTrace is formatted as when caught in a try/catch
construct. The StackTrace is limited to the applied function and functions called by it.
{erpc, ERpcErrorReason}:
The erpc operation failed. The following ERpcErrorReasons are the most common ones:
badarg:
If any one of these are true:
* Node is not an atom.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client
side.
* Timeout is invalid.
noconnection:
The connection to Node was lost or could not be established. The function may or may not
be applied.
system_limit:
The erpc operation failed due to some system limit being reached. This typically due to
failure to create a process on the remote node Node, but can be other things as well.
timeout:
The erpc operation timed out. The function may or may not be applied.
notsup:
The remote node Node does not support this erpc operation.
If the erpc operation fails, but it is unknown if the function is/will be applied (that is, a
timeout or a connection loss), the caller will not receive any further information about the
result if/when the applied function completes. If the applied function explicitly communicates
with the calling process, such communication may, of course, reach the calling process.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be the
calling process itself, a server, or a freshly spawned process.
cast(Node, Fun) -> ok
Types:
Node = node()
Fun = function()
The same as calling erpc:cast(Node,erlang,apply,[Fun,[]]).
cast/2 fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Fun is not a a fun of zero arity.
cast(Node, Module, Function, Args) -> ok
Types:
Node = node()
Module = Function = atom()
Args = [term()]
Evaluates apply(Module, Function, Args) on node Node. No response is delivered to the calling
process. cast() returns immediately after the cast request has been sent. Any failures beside bad
arguments are silently ignored.
cast/4 fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client side.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
check_response(Message, RequestId) ->
{response, Result} | no_response
Types:
Message = term()
RequestId = request_id()
Result = term()
Check if a message is a response to a call request previously made by the calling process using
send_request/4. RequestId should be the value returned from the previously made send_request/4
call, and the corresponding response should not already have been received and handled to
completion by check_response/2, receive_response/2, or wait_response/2. Message is the message to
check.
If Message does not correspond to the response, the atom no_response is returned. If Message
corresponds to the response, the call operation is completed and either the result is returned as
{response, Result} where Result corresponds to the value returned from the applied function or an
exception is raised. The exceptions that can be raised corresponds to the same exceptions as can
be raised by call/4. That is, no {erpc, timeout} error exception can be raised. check_response()
will fail with an {erpc, badarg} exception if/when an invalid RequestId is detected.
If the erpc operation fails, but it is unknown if the function is/will be applied (that is, a
connection loss), the caller will not receive any further information about the result if/when the
applied function completes. If the applied function explicitly communicates with the calling
process, such communication may, of course, reach the calling process.
check_response(Message, RequestIdCollection, Delete) ->
{{response, Result},
Label, NewRequestIdCollection} |
no_response | no_request
Types:
Message = term()
RequestIdCollection = request_id_collection()
Delete = boolean()
Result = Label = term()
NewRequestIdCollection = request_id_collection()
Check if a message is a response to a call request corresponding to a request identifier saved in
RequestIdCollection. All request identifiers of RequestIdCollection must correspond to requests
that have been made using send_request/4 or send_request/6, and all requests must have been made
by the process calling this function.
Label is the label associated with the request identifier of the request that the response
corresponds to. A request identifier is associated with a label when adding a request identifier
in a request identifier collection, or when sending the request using send_request/6.
Compared to check_response/2, the returned result associated with a specific request identifier or
an exception associated with a specific request identifier will be wrapped in a 3-tuple. The first
element of this tuple equals the value that would have been produced by check_response/2, the
second element equals the Label associated with the specific request identifier, and the third
element NewRequestIdCollection is a possibly modified request identifier collection. The error
exception {erpc, badarg} is not associated with any specific request identifier, and will hence
not be wrapped.
If RequestIdCollection is empty, the atom no_request will be returned. If Message does not
correspond to any of the request identifiers in RequestIdCollection, the atom no_response is
returned.
If Delete equals true, the association with Label will have been deleted from RequestIdCollection
in the resulting NewRequestIdCollection. If Delete equals false, NewRequestIdCollection will equal
RequestIdCollection. Note that deleting an association is not for free and that a collection
containing already handled requests can still be used by subsequent calls to check_response/3,
receive_response/3, and wait_response/3. However, without deleting handled associations, the above
calls will not be able to detect when there are no more outstanding requests to handle, so you
will have to keep track of this some other way than relying on a no_request return. Note that if
you pass a collection only containing associations of already handled or abandoned requests to
check_response/3, it will always return no_response.
Note that a response might have been consumed uppon an {erpc, badarg} exception and if so, will be
lost for ever.
multicall(Nodes, Fun) -> Result
multicall(Nodes, Fun, Timeout) -> Result
Types:
Nodes = [atom()]
Fun = function()
Timeout = timeout_time()
Result = term()
The same as calling erpc:multicall(Nodes, erlang, apply, [Fun,[]], Timeout). May raise all the
same exceptions as multicall/5 plus an {erpc, badarg} error exception if Fun is not a fun of zero
arity.
The call erpc:multicall(Nodes,Fun) is the same as the call erpc:multicall(Nodes,Fun, infinity).
multicall(Nodes, Module, Function, Args) -> Result
multicall(Nodes, Module, Function, Args, Timeout) -> Result
Types:
Nodes = [atom()]
Module = Function = atom()
Args = [term()]
Timeout = timeout_time()
Result =
[{ok, ReturnValue :: term()} | caught_call_exception()]
caught_call_exception() =
{throw, Throw :: term()} |
{exit, {exception, Reason :: term()}} |
{error,
{exception, Reason :: term(), StackTrace :: [stack_item()]}} |
{exit, {signal, Reason :: term()}} |
{error, {erpc, Reason :: term()}}
stack_item() =
{Module :: atom(),
Function :: atom(),
Arity :: arity() | (Args :: [term()]),
Location ::
[{file, Filename :: string()} |
{line, Line :: integer() >= 1}]}
Performs multiple call operations in parallel on multiple nodes. That is, evaluates apply(Module,
Function, Args) on the nodes Nodes in parallel. Timeout sets an upper time limit for all call
operations to complete. The result is returned as a list where the result from each node is placed
at the same position as the node name is placed in Nodes. Each item in the resulting list is
formatted as either:
{ok, Result}:
The call operation for this specific node returned Result.
{Class, ExceptionReason}:
The call operation for this specific node raised an exception of class Class with exception
reason ExceptionReason. These correspond to the exceptions that call/5 can raise.
multicall/5 fails with an {erpc, badarg} error exception if:
* Nodes is not a proper list of atoms. Note that some requests may already have been sent when
the failure occurs. That is, the function may or may not be applied on some nodes.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client side.
The call erpc:multicall(Nodes, Module, Function, Args) is equivalent to the call
erpc:multicall(Nodes, Module, Function, Args, infinity). These calls are also equivalent to
calling my_multicall(Nodes, Module, Function, Args) below if one disregard performance and failure
behavior. multicall() can utilize a selective receive optimization which removes the need to scan
the message queue from the beginning in order to find a matching message. The
send_request()/receive_response() combination can, however, not utilize this optimization.
my_multicall(Nodes, Module, Function, Args) ->
ReqIds = lists:map(fun (Node) ->
erpc:send_request(Node, Module, Function, Args)
end,
Nodes),
lists:map(fun (ReqId) ->
try
{ok, erpc:receive_response(ReqId, infinity)}
catch
Class:Reason ->
{Class, Reason}
end
end,
ReqIds).
If an erpc operation fails, but it is unknown if the function is/will be applied (that is, a
timeout, connection loss, or an improper Nodes list), the caller will not receive any further
information about the result if/when the applied function completes. If the applied function
communicates with the calling process, such communication may, of course, reach the calling
process.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be the
calling process itself, a server, or a freshly spawned process.
multicast(Nodes, Fun) -> ok
Types:
Nodes = [node()]
Fun = function()
The same as calling erpc:multicast(Nodes,erlang,apply,[Fun,[]]).
multicast/2 fails with an {erpc, badarg} error exception if:
* Nodes is not a proper list of atoms.
* Fun is not a a fun of zero arity.
multicast(Nodes, Module, Function, Args) -> ok
Types:
Nodes = [node()]
Module = Function = atom()
Args = [term()]
Evaluates apply(Module, Function, Args) on the nodes Nodes. No response is delivered to the
calling process. multicast() returns immediately after the cast requests have been sent. Any
failures beside bad arguments are silently ignored.
multicast/4 fails with an {erpc, badarg} error exception if:
* Nodes is not a proper list of atoms. Note that some requests may already have been sent when
the failure occurs. That is, the function may or may not be applied on some nodes.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client side.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
receive_response(RequestId) -> Result
Types:
RequestId = request_id()
Result = term()
The same as calling erpc:receive_response(RequestId, infinity).
receive_response(RequestId, Timeout) -> Result
Types:
RequestId = request_id()
Timeout = timeout_time()
Result = term()
Receive a response to a call request previously made by the calling process using send_request/4.
RequestId should be the value returned from the previously made send_request/4 call, and the
corresponding response should not already have been received and handled to completion by
receive_response(), check_response/4, or wait_response/4.
Timeout sets an upper time limit on how long to wait for a response. If the operation times out,
the request identified by RequestId will be abandoned, then an {erpc, timeout} error exception
will be raised. That is, no response corresponding to the request will ever be received after a
timeout. If a response is received, the call operation is completed and either the result is
returned or an exception is raised. The exceptions that can be raised corresponds to the same
exceptions as can be raised by call/5. receive_response/2 will fail with an {erpc, badarg}
exception if/when an invalid RequestId is detected or if an invalid Timeout is passed.
A call to the function my_call(Node, Module, Function, Args, Timeout) below is equivalent to the
call erpc:call(Node, Module, Function, Args, Timeout) if one disregards performance. call() can
utilize a selective receive optimization which removes the need to scan the message queue from the
beginning in order to find a matching message. The send_request()/receive_response() combination
can, however, not utilize this optimization.
my_call(Node, Module, Function, Args, Timeout) ->
RequestId = erpc:send_request(Node, Module, Function, Args),
erpc:receive_response(RequestId, Timeout).
If the erpc operation fails, but it is unknown if the function is/will be applied (that is, a
timeout, or a connection loss), the caller will not receive any further information about the
result if/when the applied function completes. If the applied function explicitly communicates
with the calling process, such communication may, of course, reach the calling process.
receive_response(RequestIdCollection, Timeout, Delete) ->
{Result, Label, NewRequestIdCollection} |
no_request
Types:
RequestIdCollection = request_id_collection()
Timeout = timeout_time()
Delete = boolean()
Result = Label = term()
NewRequestIdCollection = request_id_collection()
Receive a response to a call request corresponding to a request identifier saved in
RequestIdCollection. All request identifiers of RequestIdCollection must correspond to requests
that have been made using send_request/4 or send_request/6, and all requests must have been made
by the process calling this function.
Label is the label associated with the request identifier of the request that the response
corresponds to. A request identifier is associated with a label when adding a request identifier
in a request identifier collection, or when sending the request using send_request/6.
Compared to receive_response/2, the returned result associated with a specific request identifier
or an exception associated with a specific request identifier will be wrapped in a 3-tuple. The
first element of this tuple equals the value that would have been produced by receive_response/2,
the second element equals the Label associated with the specific request identifier, and the third
element NewRequestIdCollection is a possibly modified request identifier collection. The error
exceptions {erpc, badarg} and {erpc, timeout} are not associated with any specific request
identifiers, and will hence not be wrapped.
If RequestIdCollection is empty, the atom no_request will be returned.
If the operation times out, all requests identified by RequestIdCollection will be abandoned, then
an {erpc, timeout} error exception will be raised. That is, no responses corresponding to any of
the request identifiers in RequestIdCollection will ever be received after a timeout. The
difference between receive_response/3 and wait_response/3 is that receive_response/3 abandons the
requests at timeout so that any potential future responses are ignored, while wait_response/3 does
not.
If Delete equals true, the association with Label will have been deleted from RequestIdCollection
in the resulting NewRequestIdCollection. If Delete equals false, NewRequestIdCollection will equal
RequestIdCollection. Note that deleting an association is not for free and that a collection
containing already handled requests can still be used by subsequent calls to receive_response/3,
check_response/3, and wait_response/3. However, without deleting handled associations, the above
calls will not be able to detect when there are no more outstanding requests to handle, so you
will have to keep track of this some other way than relying on a no_request return. Note that if
you pass a collection only containing associations of already handled or abandoned requests to
receive_response/3, it will always block until a timeout determined by Timeout is triggered.
Note that a response might have been consumed uppon an {erpc, badarg} exception and if so, will be
lost for ever.
reqids_add(RequestId :: request_id(),
Label :: term(),
RequestIdCollection :: request_id_collection()) ->
NewRequestIdCollection :: request_id_collection()
Saves RequestId and associates a Label with the request identifier by adding this information to
RequestIdCollection and returning the resulting request identifier collection.
reqids_new() -> NewRequestIdCollection :: request_id_collection()
Returns a new empty request identifier collection. A request identifier collection can be utilized
in order the handle multiple outstanding requests.
Request identifiers of requests made by send_request/4 can be saved in a request identifier
collection using reqids_add/3. Such a collection of request identifiers can later be used in order
to get one response corresponding to a request in the collection by passing the collection as
argument to check_response/3, receive_response/3, and wait_response/3.
reqids_size/1 can be used to determine the amount of request identifiers in a request identifier
collection.
reqids_size(RequestIdCollection :: request_id_collection()) ->
integer() >= 0
Returns the amount of request identifiers saved in RequestIdCollection.
reqids_to_list(RequestIdCollection :: request_id_collection()) ->
[{RequestId :: request_id(), Label :: term()}]
Returns a list of {RequestId, Label} tuples which corresponds to all request identifiers with
their associated labels present in the RequestIdCollection collection.
send_request(Node, Fun) -> RequestId
Types:
Node = node()
Fun = function()
RequestId = request_id()
The same as calling erpc:send_request(Node, erlang, apply, [Fun, []]).
Fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Fun is not a fun of zero arity.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
send_request(Node, Module, Function, Args) -> RequestId
Types:
Node = node()
Module = Function = atom()
Args = [term()]
RequestId = request_id()
Send an asynchronous call request to the node Node. send_request/4 returns a request identifier
that later is to be passed to either receive_response/2, wait_response/2, or, check_response/2 in
order to get the response of the call request. Besides passing the request identifier directly to
these functions, it can also be added in a request identifier collection using reqids_add/3. Such
a collection of request identifiers can later be used in order to get one response corresponding
to a request in the collection by passing the collection as argument to receive_response/3,
wait_response/3, or, check_response/3. If you are about to save the request identifier in a
request identifier collection, you may want to consider using send_request/6 instead.
A call to the function my_call(Node, Module, Function, Args, Timeout) below is equivalent to the
call erpc:call(Node, Module, Function, Args, Timeout) if one disregards performance. call() can
utilize a selective receive optimization which removes the need to scan the message queue from the
beginning in order to find a matching message. The send_request()/receive_response() combination
can, however, not utilize this optimization.
my_call(Node, Module, Function, Args, Timeout) ->
RequestId = erpc:send_request(Node, Module, Function, Args),
erpc:receive_response(RequestId, Timeout).
Fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client side.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
send_request(Node, Fun, Label, RequestIdCollection) ->
NewRequestIdCollection
Types:
Node = node()
Fun = function()
Label = term()
RequestIdCollection = NewRequestIdCollection = request_id_collection()
The same as calling erpc:send_request(Node, erlang, apply, [Fun,[]]), Label, RequestIdCollection).
Fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Fun is not a fun of zero arity.
* RequestIdCollection is detected not to be request identifier collection.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
send_request(Node, Module, Function, Args, Label,
RequestIdCollection) ->
NewRequestIdCollection
Types:
Node = node()
Module = Function = atom()
Args = [term()]
Label = term()
RequestIdCollection = NewRequestIdCollection = request_id_collection()
Send an asynchronous call request to the node Node. The Label will be associated with the request
identifier of the operation and added to the returned request identifier collection
NewRequestIdCollection. The collection can later be used in order to get one response
corresponding to a request in the collection by passing the collection as argument to
receive_response/3, wait_response/3, or, check_response/3.
The same as calling erpc:reqids_add(erpc:send_request(Node, Module, Function, Args), Label,
RequestIdCollection), but calling send_request/6 is slightly more efficient.
Fails with an {erpc, badarg} error exception if:
* Node is not an atom.
* Module is not an atom.
* Function is not an atom.
* Args is not a list. Note that the list is not verified to be a proper list at the client side.
* RequestIdCollection is detected not to be request identifier collection.
Note:
You cannot make any assumptions about the process that will perform the apply(). It may be a
server, or a freshly spawned process.
wait_response(RequestId) -> {response, Result} | no_response
Types:
RequestId = request_id()
Result = term()
The same as calling erpc:wait_response(RequestId, 0). That is, poll for a response message to a
call request previously made by the calling process.
wait_response(RequestId, WaitTime) ->
{response, Result} | no_response
Types:
RequestId = request_id()
WaitTime = timeout_time()
Result = term()
Wait or poll for a response message to a call request previously made by the calling process using
send_request/4. RequestId should be the value returned from the previously made send_request()
call, and the corresponding response should not already have been received and handled to
completion by check_response/2, receive_response/2, or wait_response().
WaitTime sets an upper time limit on how long to wait for a response. If no response is received
before the WaitTime timeout has triggered, the atom no_response is returned. It is valid to
continue waiting for a response as many times as needed up until a response has been received and
completed by check_response(), receive_response(), or wait_response(). If a response is received,
the call operation is completed and either the result is returned as {response, Result} where
Result corresponds to the value returned from the applied function or an exception is raised. The
exceptions that can be raised corresponds to the same exceptions as can be raised by call/4. That
is, no {erpc, timeout} error exception can be raised. wait_response/2 will fail with an {erpc,
badarg} exception if/when an invalid RequestId is detected or if an invalid WaitTime is passed.
If the erpc operation fails, but it is unknown if the function is/will be applied (that is, a too
large wait time value, or a connection loss), the caller will not receive any further information
about the result if/when the applied function completes. If the applied function explicitly
communicates with the calling process, such communication may, of course, reach the calling
process.
wait_response(RequestIdCollection, WaitTime, Delete) ->
{{response, Result},
Label, NewRequestIdCollection} |
no_response | no_request
Types:
RequestIdCollection = request_id_collection()
WaitTime = timeout_time()
Delete = boolean()
Label = term()
NewRequestIdCollection = request_id_collection()
Result = term()
Wait or poll for a response to a call request corresponding to a request identifier saved in
RequestIdCollection. All request identifiers of RequestIdCollection must correspond to requests
that have been made using send_request/4 or send_request/6, and all requests must have been made
by the process calling this function.
Label is the label associated with the request identifier of the request that the response
corresponds to. A request identifier is associated with a label when adding a request identifier
in a request identifier collection, or when sending the request using send_request/6.
Compared to wait_response/2, the returned result associated with a specific request identifier or
an exception associated with a specific request identifier will be wrapped in a 3-tuple. The first
element of this tuple equals the value that would have been produced by wait_response/2, the
second element equals the Label associated with the specific request identifier, and the third
element NewRequestIdCollection is a possibly modified request identifier collection. The error
exception {erpc, badarg} is not associated with any specific request identifier, and will hence
not be wrapped.
If RequestIdCollection is empty, no_request will be returned. If no response is received before
the WaitTime timeout has triggered, the atom no_response is returned. It is valid to continue
waiting for a response as many times as needed up until a response has been received and completed
by check_response(), receive_response(), or wait_response(). The difference between
receive_response/3 and wait_response/3 is that receive_response/3 abandons requests at timeout so
that any potential future responses are ignored, while wait_response/3 does not.
If Delete equals true, the association with Label will have been deleted from RequestIdCollection
in the resulting NewRequestIdCollection. If Delete equals false, NewRequestIdCollection will equal
RequestIdCollection. Note that deleting an association is not for free and that a collection
containing already handled requests can still be used by subsequent calls to wait_response/3,
check_response/3, and receive_response/3. However, without deleting handled associations, the
above calls will not be able to detect when there are no more outstanding requests to handle, so
you will have to keep track of this some other way than relying on a no_request return. Note that
if you pass a collection only containing associations of already handled or abandoned requests to
wait_response/3, it will always block until a timeout determined by WaitTime is triggered and then
return no_response.
Note that a response might have been consumed uppon an {erpc, badarg} exception and if so, will be
lost for ever.
Ericsson AB kernel 8.5.4.2 erpc(3erl)