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diff --git a/lib/kernel/doc/src/rpc.xml b/lib/kernel/doc/src/rpc.xml index c323a84e50..032b4fb0c3 100644 --- a/lib/kernel/doc/src/rpc.xml +++ b/lib/kernel/doc/src/rpc.xml @@ -25,328 +25,407 @@ <title>rpc</title> <prepared>Claes Wikstrom</prepared> <docno>1</docno> - <date>96-09-10</date> + <date>1996-09-10</date> <rev>A</rev> </header> <module>rpc</module> - <modulesummary>Remote Procedure Call Services</modulesummary> + <modulesummary>Remote Procedure Call services.</modulesummary> <description> - <p>This module contains services which are similar to remote - procedure calls. It also contains broadcast facilities and + <p>This module contains services similar to Remote + Procedure Calls. It also contains broadcast facilities and parallel evaluators. 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.</p> </description> + <datatypes> <datatype> <name name="key"/> <desc> - <p>As returned by <seealso marker="#async_call/4"> - <c>async_call/4</c>.</seealso></p> + <p>As returned by + <seealso marker="#async_call/4"><c>async_call/4</c></seealso>.</p> </desc> </datatype> </datatypes> + <funcs> <func> - <name name="call" arity="4"/> - <fsummary>Evaluate a function call on a node</fsummary> + <name name="abcast" arity="2"/> + <fsummary>Broadcast a message asynchronously to a registered process on + all nodes.</fsummary> <desc> - <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on the node - <c><anno>Node</anno></c> and returns the corresponding value <c><anno>Res</anno></c>, or - <c>{badrpc, <anno>Reason</anno>}</c> if the call fails.</p> + <p>Equivalent to <c>abcast([node()|nodes()], <anno>Name</anno>, + <anno>Msg</anno>)</c>.</p> </desc> </func> + <func> - <name name="call" arity="5"/> - <fsummary>Evaluate a function call on a node</fsummary> + <name name="abcast" arity="3"/> + <fsummary>Broadcast a message asynchronously to a registered process on + specific nodes.</fsummary> <desc> - <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on the node - <c><anno>Node</anno></c> and returns the corresponding value <c><anno>Res</anno></c>, or - <c>{badrpc, <anno>Reason</anno>}</c> if the call fails. <c><anno>Timeout</anno></c> is - a timeout value in milliseconds. If the call times out, - <c><anno>Reason</anno></c> is <c>timeout</c>.</p> - <p>If the reply arrives after the call times out, no message - will contaminate the caller's message queue, since this - function spawns off a middleman process to act as (a void) - destination for such an orphan reply. This feature also makes - this function more expensive than <c>call/4</c> at - the caller's end.</p> + <p>Broadcasts the message <c><anno>Msg</anno></c> asynchronously to + the registered process <c><anno>Name</anno></c> on the specified + nodes.</p> </desc> </func> + + <func> + <name name="async_call" arity="4"/> + <fsummary>Evaluate a function call on a node, asynchronous + version.</fsummary> + <desc> + <p>Implements <em>call streams with promises</em>, a type of + RPC that does not suspend the caller until the result is + finished. Instead, a key is returned, which can be used + later to collect the value. The key can be viewed as a + promise to deliver the answer.</p> + <p>In this case, the key <c><anno>Key</anno></c> is returned, which + can be used in a subsequent call to + <seealso marker="#yield/1"><c>yield/1</c></seealso> or + <seealso marker="#nb_yield/1"><c>nb_yield/1,2</c></seealso> + to retrieve the value of evaluating <c>apply(<anno>Module</anno>, + <anno>Function</anno>, <anno>Args</anno>)</c> on node + <c><anno>Node</anno></c>.</p> + </desc> + </func> + <func> <name name="block_call" arity="4"/> - <fsummary>Evaluate a function call on a node in the RPC server's context</fsummary> + <fsummary>Evaluate a function call on a node in the RPC server's + context.</fsummary> <desc> - <p>Like <c>call/4</c>, but the RPC server at <c><anno>Node</anno></c> does + <p>Same as <seealso marker="#call/4"><c>call/4</c></seealso>, + but the RPC server at <c><anno>Node</anno></c> does not create a separate process to handle the call. Thus, this function can be used if the intention of the call is to block the RPC server from any other incoming requests until - the request has been handled. The function can also be used + the request has been handled. The function can also be used for efficiency reasons when very small fast functions are - evaluated, for example BIFs that are guaranteed not to + evaluated, for example, BIFs that are guaranteed not to suspend.</p> </desc> </func> + <func> <name name="block_call" arity="5"/> - <fsummary>Evaluate a function call on a node in the RPC server's context</fsummary> + <fsummary>Evaluate a function call on a node in the RPC server's + context.</fsummary> <desc> - <p>Like <c>block_call/4</c>, but with a timeout value in - the same manner as <c>call/5</c>.</p> + <p>Same as + <seealso marker="#block_call/4"><c>block_call/4</c></seealso>, + but with a time-out value in the same manner as + <seealso marker="#call/5"><c>call/5</c></seealso>.</p> </desc> </func> + <func> - <name name="async_call" arity="4"/> - <fsummary>Evaluate a function call on a node, asynchronous version</fsummary> + <name name="call" arity="4"/> + <fsummary>Evaluate a function call on a node.</fsummary> <desc> - <p>Implements <em>call streams with promises</em>, a type of - RPC which does not suspend the caller until the result is - finished. Instead, a key is returned which can be used at a - later stage to collect the value. The key can be viewed as a - promise to deliver the answer.</p> - <p>In this case, the key <c><anno>Key</anno></c> is returned, which can be - used in a subsequent call to <c>yield/1</c> or - <c>nb_yield/1,2</c> to retrieve the value of evaluating - <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on the node <c><anno>Node</anno></c>.</p> + <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c> on node <c><anno>Node</anno></c> and returns + the corresponding value <c><anno>Res</anno></c>, or + <c>{badrpc, <anno>Reason</anno>}</c> if the call fails.</p> </desc> </func> + <func> - <name name="yield" arity="1"/> - <fsummary>Deliver the result of evaluating a function call on a node (blocking)</fsummary> + <name name="call" arity="5"/> + <fsummary>Evaluate a function call on a node.</fsummary> <desc> - <p>Returns the promised answer from a previous - <c>async_call/4</c>. If the answer is available, it is - returned immediately. Otherwise, the calling process is - suspended until the answer arrives from <c>Node</c>.</p> + <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c> on node <c><anno>Node</anno></c> and returns + the corresponding value <c><anno>Res</anno></c>, or + <c>{badrpc, <anno>Reason</anno>}</c> if the call fails. + <c><anno>Timeout</anno></c> is + a time-out value in milliseconds. If the call times out, + <c><anno>Reason</anno></c> is <c>timeout</c>.</p> + <p>If the reply arrives after the call times out, no message + contaminates the caller's message queue, as this + function spawns off a middleman process to act as (a void) + destination for such an orphan reply. This feature also makes + this function more expensive than <c>call/4</c> at + the caller's end.</p> </desc> </func> + <func> - <name name="nb_yield" arity="1"/> - <fsummary>Deliver the result of evaluating a function call on a node (non-blocking)</fsummary> + <name name="cast" arity="4"/> + <fsummary>Run a function on a node ignoring the result.</fsummary> <desc> - <p>Equivalent to <c>nb_yield(<anno>Key</anno>, 0)</c>.</p> + <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c> on node + <c><anno>Node</anno></c>. No response is delivered and the calling + process is not suspended until the evaluation is complete, as + is the case with + <seealso marker="#call/4"><c>call/4,5</c></seealso>.</p> </desc> </func> + <func> - <name name="nb_yield" arity="2"/> - <fsummary>Deliver the result of evaluating a function call on a node (non-blocking)</fsummary> + <name name="eval_everywhere" arity="3"/> + <fsummary>Run a function on all nodes, ignoring the result.</fsummary> + <desc> + <p>Equivalent to <c>eval_everywhere([node()|nodes()], + <anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c>.</p> + </desc> + </func> + + <func> + <name name="eval_everywhere" arity="4"/> + <fsummary>Run a function on specific nodes, ignoring the + result.</fsummary> + <desc> + <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c> on + the specified nodes. No answers are collected.</p> + </desc> + </func> + + <func> + <name name="multi_server_call" arity="2"/> + <fsummary>Interact with the servers on a number of nodes.</fsummary> + <desc> + <p>Equivalent to <c>multi_server_call([node()|nodes()], + <anno>Name</anno>, <anno>Msg</anno>)</c>.</p> + </desc> + </func> + + <func> + <name name="multi_server_call" arity="3"/> + <fsummary>Interact with the servers on a number of nodes.</fsummary> <desc> - <p>This is a non-blocking version of <c>yield/1</c>. It returns - the tuple <c>{value, <anno>Val</anno>}</c> when the computation has - finished, or <c>timeout</c> when <c><anno>Timeout</anno></c> milliseconds - has elapsed.</p> + <p>Can be used when interacting with servers called + <c><anno>Name</anno></c> on the specified nodes. It is assumed that + the servers receive messages in the format + <c>{From, <anno>Msg</anno>}</c> and reply using + <c>From ! {<anno>Name</anno>, Node, <anno>Reply</anno>}</c>, where + <c>Node</c> is the name of the node where the server is located. + The function returns <c>{<anno>Replies</anno>, + <anno>BadNodes</anno>}</c>, where <c><anno>Replies</anno></c> is a + list of all <c><anno>Reply</anno></c> values, and + <c><anno>BadNodes</anno></c> is one of the following:</p> + <list type="bulleted"> + <item>A list of the nodes that do not exist</item> + <item>A list of the nodes where the server does not exist</item> + <item>A list of the nodes where the server terminatd before sending + any reply.</item> + </list> </desc> </func> + <func> <name name="multicall" arity="3"/> - <fsummary>Evaluate a function call on a number of nodes</fsummary> + <fsummary>Evaluate a function call on a number of nodes.</fsummary> <desc> - <p>Equivalent to <c>multicall([node()|nodes()], <anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>, infinity)</c>.</p> + <p>Equivalent to <c>multicall([node()|nodes()], <anno>Module</anno>, + <anno>Function</anno>, <anno>Args</anno>, infinity)</c>.</p> </desc> </func> + <func> <name name="multicall" arity="4" clause_i="1"/> - <fsummary>Evaluate a function call on a number of nodes</fsummary> + <fsummary>Evaluate a function call on a number of nodes.</fsummary> <desc> - <p>Equivalent to <c>multicall(<anno>Nodes</anno>, <anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>, infinity)</c>.</p> + <p>Equivalent to <c>multicall(<anno>Nodes</anno>, <anno>Module</anno>, + <anno>Function</anno>, <anno>Args</anno>, infinity)</c>.</p> </desc> </func> + <func> <name name="multicall" arity="4" clause_i="2"/> - <fsummary>Evaluate a function call on a number of nodes</fsummary> + <fsummary>Evaluate a function call on a number of nodes.</fsummary> <desc> - <p>Equivalent to <c>multicall([node()|nodes()], <anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>, <anno>Timeout</anno>)</c>.</p> + <p>Equivalent to <c>multicall([node()|nodes()], <anno>Module</anno>, + <anno>Function</anno>, <anno>Args</anno>, + <anno>Timeout</anno>)</c>.</p> </desc> </func> + <func> <name name="multicall" arity="5"/> - <fsummary>Evaluate a function call on a number of nodes</fsummary> + <fsummary>Evaluate a function call on a number of nodes.</fsummary> <desc> - <p>In contrast to an RPC, a multicall is an RPC which is sent + <p>In contrast to an RPC, a multicall is an RPC that is sent concurrently from one client to multiple servers. This is - useful for collecting some information from a set of nodes, + useful for collecting information from a set of nodes, or for calling a function on a set of nodes to achieve some side effects. It is semantically the same as iteratively making a series of RPCs on all the nodes, but the multicall - is faster as all the requests are sent at the same time + is faster, as all the requests are sent at the same time and are collected one by one as they come back.</p> - <p>The function evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> - on the specified nodes and collects the answers. It returns - <c>{<anno>ResL</anno>, <anno>BadNodes</anno>}</c>, where <c><anno>BadNodes</anno></c> is a list + <p>The function evaluates <c>apply(<anno>Module</anno>, + <anno>Function</anno>, <anno>Args</anno>)</c> + on the specified nodes and collects the answers. It returns + <c>{<anno>ResL</anno>, <anno>BadNodes</anno>}</c>, where + <c><anno>BadNodes</anno></c> is a list of the nodes that terminated or timed out during computation, and <c><anno>ResL</anno></c> is a list of the return values. <c><anno>Timeout</anno></c> is a time (integer) in milliseconds, or <c>infinity</c>.</p> <p>The following example is useful when new object code is to - be loaded on all nodes in the network, and also indicates - some side effects RPCs may produce:</p> + be loaded on all nodes in the network, and indicates + some side effects that RPCs can produce:</p> <code type="none"> -%% Find object code for module Mod -{Mod, Bin, File} = code:get_object_code(Mod), +%% Find object code for module Mod +{Mod, Bin, File} = code:get_object_code(Mod), -%% and load it on all nodes including this one +%% and load it on all nodes including this one {ResL, _} = rpc:multicall(code, load_binary, [Mod, File, Bin]), %% and then maybe check the ResL list.</code> </desc> </func> + <func> - <name name="cast" arity="4"/> - <fsummary>Run a function on a node ignoring the result</fsummary> - <desc> - <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on the node - <c><anno>Node</anno></c>. No response is delivered and the calling - process is not suspended until the evaluation is complete, as - is the case with <c>call/4,5</c>.</p> - </desc> - </func> - <func> - <name name="eval_everywhere" arity="3"/> - <fsummary>Run a function on all nodes, ignoring the result</fsummary> - <desc> - <p>Equivalent to <c>eval_everywhere([node()|nodes()], <anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c>.</p> - </desc> - </func> - <func> - <name name="eval_everywhere" arity="4"/> - <fsummary>Run a function on specific nodes, ignoring the result</fsummary> - <desc> - <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on - the specified nodes. No answers are collected.</p> - </desc> - </func> - <func> - <name name="abcast" arity="2"/> - <fsummary>Broadcast a message asynchronously to a registered process on all nodes</fsummary> - <desc> - <p>Equivalent to <c>abcast([node()|nodes()], <anno>Name</anno>, <anno>Msg</anno>)</c>.</p> - </desc> - </func> - <func> - <name name="abcast" arity="3"/> - <fsummary>Broadcast a message asynchronously to a registered process on specific nodes</fsummary> + <name name="nb_yield" arity="1"/> + <fsummary>Deliver the result of evaluating a function call on a node + (non-blocking).</fsummary> <desc> - <p>Broadcasts the message <c><anno>Msg</anno></c> asynchronously to - the registered process <c><anno>Name</anno></c> on the specified nodes.</p> + <p>Equivalent to <c>nb_yield(<anno>Key</anno>, 0)</c>.</p> </desc> </func> + <func> - <name name="sbcast" arity="2"/> - <fsummary>Broadcast a message synchronously to a registered process on all nodes</fsummary> + <name name="nb_yield" arity="2"/> + <fsummary>Deliver the result of evaluating a function call on a node + (non-blocking).</fsummary> <desc> - <p>Equivalent to <c>sbcast([node()|nodes()], <anno>Name</anno>, <anno>Msg</anno>)</c>.</p> + <p>Non-blocking version of + <seealso marker="#yield/1"><c>yield/1</c></seealso>. It returns + the tuple <c>{value, <anno>Val</anno>}</c> when the computation is + finished, or <c>timeout</c> when <c><anno>Timeout</anno></c> + milliseconds has elapsed.</p> </desc> </func> + <func> - <name name="sbcast" arity="3"/> - <fsummary>Broadcast a message synchronously to a registered process on specific nodes</fsummary> + <name name="parallel_eval" arity="1"/> + <fsummary>Evaluate many function calls on all nodes in + parallel.</fsummary> <desc> - <p>Broadcasts the message <c><anno>Msg</anno></c> synchronously to - the registered process <c><anno>Name</anno></c> on the specified nodes.</p> - <p>Returns <c>{<anno>GoodNodes</anno>, <anno>BadNodes</anno>}</c>, where <c><anno>GoodNodes</anno></c> - is the list of nodes which have <c><anno>Name</anno></c> as a registered - process.</p> - <p>The function is synchronous in the sense that it is known - that all servers have received the message when the call - returns. It is not possible to know that the servers have - actually processed the message.</p> - <p>Any further messages sent to the servers, after this - function has returned, will be received by all servers after - this message.</p> + <p>Evaluates, for every tuple in <c><anno>FuncCalls</anno></c>, + <c>apply(<anno>Module</anno>, <anno>Function</anno>, + <anno>Args</anno>)</c> on some node in + the network. Returns the list of return values, in the same + order as in <c><anno>FuncCalls</anno></c>.</p> </desc> </func> + <func> - <name name="server_call" arity="4"/> - <fsummary>Interact with a server on a node</fsummary> + <name name="pinfo" arity="1"/> + <fsummary>Information about a process.</fsummary> <desc> - <p>This function can be used when interacting with a server - called <c><anno>Name</anno></c> at node <c><anno>Node</anno></c>. It is assumed that - the server receives messages in the format - <c>{From, <anno>Msg</anno>}</c> and replies using <c>From ! {<anno>ReplyWrapper</anno>, <anno>Node</anno>, <anno>Reply</anno>}</c>. This function makes such - a server call and ensures that the entire call is packed into - an atomic transaction which either succeeds or fails. It - never hangs, unless the server itself hangs.</p> - <p>The function returns the answer <c><anno>Reply</anno></c> as produced by - the server <c><anno>Name</anno></c>, or <c>{error, <anno>Reason</anno>}</c>.</p> + <p>Location transparent version of the BIF + <seealso marker="erts:erlang#process_info/1"><c>erlang:process_info/1</c></seealso> in <c>ERTS</c>.</p> </desc> </func> + <func> - <name name="multi_server_call" arity="2"/> - <fsummary>Interact with the servers on a number of nodes</fsummary> + <name name="pinfo" arity="2"/> + <fsummary>Information about a process.</fsummary> <desc> - <p>Equivalent to <c>multi_server_call([node()|nodes()], <anno>Name</anno>, <anno>Msg</anno>)</c>.</p> + <p>Location transparent version of the BIF + <seealso marker="erts:erlang#process_info/2"><c>erlang:process_info/2</c></seealso> in <c>ERTS</c>.</p> </desc> </func> + <func> - <name name="multi_server_call" arity="3"/> - <fsummary>Interact with the servers on a number of nodes</fsummary> + <name name="pmap" arity="3"/> + <fsummary>Parallell evaluation of mapping a function over a + list.</fsummary> <desc> - <p>This function can be used when interacting with servers - called <c><anno>Name</anno></c> on the specified nodes. It is assumed that - the servers receive messages in the format <c>{From, <anno>Msg</anno>}</c> - and reply using <c>From ! {<anno>Name</anno>, Node, <anno>Reply</anno>}</c>, where - <c>Node</c> is the name of the node where the server is - located. The function returns <c>{<anno>Replies</anno>, <anno>BadNodes</anno>}</c>, - where <c><anno>Replies</anno></c> is a list of all <c><anno>Reply</anno></c> values and - <c><anno>BadNodes</anno></c> is a list of the nodes which did not exist, or - where the server did not exist, or where the server terminated - before sending any reply.</p> + <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, + [<anno>Elem</anno>|<anno>ExtraArgs</anno>])</c> for every element + <c><anno>Elem</anno></c> in <c><anno>List1</anno></c>, in parallel. + Returns the list of return values, in the same order as in + <c><anno>List1</anno></c>.</p> </desc> </func> + <func> <name name="safe_multi_server_call" arity="2"/> <name name="safe_multi_server_call" arity="3"/> - <fsummary>Interact with the servers on a number of nodes (deprecated)</fsummary> + <fsummary>Interact with the servers on a number of nodes + (deprecated).</fsummary> <desc> <warning> - <p>This function is deprecated. Use - <c>multi_server_call/2,3</c> instead.</p> + <p>Deprecated. Use + <seealso marker="#multi_server_call/2"><c>multi_server_call/2,3</c></seealso> + instead.</p> </warning> <p>In Erlang/OTP R6B and earlier releases, <c>multi_server_call/2,3</c> could not handle the case where the remote node exists, but there is no server called - <c><anno>Name</anno></c>. Instead this function had to be used. In + <c><anno>Name</anno></c>. Instead, this function had to be used. In Erlang/OTP R7B and later releases, however, the functions are - equivalent, except for this function being slightly slower.</p> + equivalent, except that this function is slightly slower.</p> </desc> </func> + <func> - <name name="parallel_eval" arity="1"/> - <fsummary>Evaluate several function calls on all nodes in parallel</fsummary> + <name name="sbcast" arity="2"/> + <fsummary>Broadcast a message synchronously to a registered process on + all nodes.</fsummary> <desc> - <p>For every tuple in <c><anno>FuncCalls</anno></c>, evaluates - <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Args</anno>)</c> on some node in - the network. Returns the list of return values, in the same - order as in <c><anno>FuncCalls</anno></c>.</p> + <p>Equivalent to <c>sbcast([node()|nodes()], <anno>Name</anno>, + <anno>Msg</anno>)</c>.</p> </desc> </func> + <func> - <name name="pmap" arity="3"/> - <fsummary>Parallell evaluation of mapping a function over a list </fsummary> + <name name="sbcast" arity="3"/> + <fsummary>Broadcast a message synchronously to a registered process on + specific nodes.</fsummary> <desc> - <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, [<anno>Elem</anno>|<anno>ExtraArgs</anno>])</c>, - for every element <c><anno>Elem</anno></c> in <c><anno>List1</anno></c>, in parallel. - Returns the list of return values, in the same order as in - <c><anno>List1</anno></c>.</p> + <p>Broadcasts the message <c><anno>Msg</anno></c> synchronously to + the registered process <c><anno>Name</anno></c> on the specified + nodes.</p> + <p>Returns <c>{<anno>GoodNodes</anno>, <anno>BadNodes</anno>}</c>, + where <c><anno>GoodNodes</anno></c> is the list of nodes that have + <c><anno>Name</anno></c> as a registered process.</p> + <p>The function is synchronous in the sense that it is known + that all servers have received the message when the call + returns. It is not possible to know that the servers have + processed the message.</p> + <p>Any further messages sent to the servers, after this + function has returned, are received by all servers after + this message.</p> </desc> </func> + <func> - <name name="pinfo" arity="1"/> - <fsummary>Information about a process</fsummary> + <name name="server_call" arity="4"/> + <fsummary>Interact with a server on a node.</fsummary> <desc> - <p>Location transparent version of the BIF - <seealso marker="erts:erlang#process_info/1"> - <c>process_info/1</c></seealso>.</p> + <p>Can be used when interacting with a server called + <c><anno>Name</anno></c> on node <c><anno>Node</anno></c>. It is + assumed that the server receives messages in the format + <c>{From, <anno>Msg</anno>}</c> and replies using + <c>From ! {<anno>ReplyWrapper</anno>, <anno>Node</anno>, + <anno>Reply</anno>}</c>. This function makes such + a server call and ensures that the entire call is packed into + an atomic transaction, which either succeeds or fails. It + never hangs, unless the server itself hangs.</p> + <p>The function returns the answer <c><anno>Reply</anno></c> as + produced by the server <c><anno>Name</anno></c>, or + <c>{error, <anno>Reason</anno>}</c>.</p> </desc> </func> + <func> - <name name="pinfo" arity="2"/> - <fsummary>Information about a process</fsummary> + <name name="yield" arity="1"/> + <fsummary>Deliver the result of evaluating a function call on a node + (blocking).</fsummary> <desc> - <p>Location transparent version of the BIF - <seealso marker="erts:erlang#process_info/2"> - <c>process_info/2</c></seealso>.</p> + <p>Returns the promised answer from a previous + <seealso marker="#async_call/4"><c>async_call/4</c></seealso>. + If the answer is available, it is + returned immediately. Otherwise, the calling process is + suspended until the answer arrives from <c>Node</c>.</p> </desc> </func> </funcs> |