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| -rw-r--r-- | doc/v8compatibility.html | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/doc/v8compatibility.html b/doc/v8compatibility.html index 4aa9be41..72bab322 100644 --- a/doc/v8compatibility.html +++ b/doc/v8compatibility.html @@ -25,6 +25,44 @@ action.writeAllMarkMessages="off" to the actions in question. changed. It is suggested to review some of the project-provided plugins for full details. In this doc, we describe the most important changes from a high level perspective. +<p><b>Multi-thread awareness required</b></p> +<p>The new engine activates one <b>worker</b>instance of output actions on +each worker thread. This means an action has now three types of data: +<ul> +<li>global +<li>action-instance - previously known pData, one for each action inside the config +<li>worker-action-instance - one for each worker thread (called pWrkrData), note +that this is specific to exactly one pData +</ul> +The plugin <b>must</b> now by multi-threading aware. It may be called by multiple +threads concurrently, but it is guaranteed that each call is for a unique +pWrkrData structure. This still permits to write plugins easily, but enables the +engine to work with much higher performance. Note that plugin developers +should assume it is the norm that multiple concurrent worker action instances +are active a the some time. + +<p><b>New required entry points</b></p> +<p>In order to support the new threading model, new entry points are required. +Most importantly, only the plugin knows which data must be present in pData and +pWrkrData, so it must created and destroy these data structures on request of +the engine. Note that pWrkrData may be destroyed at any time and new ones +re-created later. Depending on workload structure and configuration, this can happen +frequently. +<p>New entry points are: +<ul> +<li>createWrkrInstance +<li>freeWrkrInstance +</ul> + +The calling interface for these entry points has changed. Basically, +they now receive a pWrkrData object instead pData. It is assumed that +createWrkrInstance populates pWrkrData->pData appropriately. +<ul> +<li>beginTransaction +<li>doAction +<li>endTransaction +</ul> + <p><b>RS_RET_SUSPENDED is no longer supported when creating an action instance</b> <p>This means a plugin must not try to establish any connections or the like before any of its processing entry points (like beginTransaction or doAction) @@ -32,7 +70,6 @@ is called. This was generally also the case von v7, but was not enforced in all cases. In v8, creating action creation fails if anything but RS_RET_OK is returned. - <a href="http://www.rsyslog.com/g/BSD">rsyslog BSD blocks info</a> page for more information and how to upgrade your config. <p>[<a href="manual.html">manual index</a>] [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p> |