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2010-06-03Add declaration for exported typesKostis Sagonas
2010-06-03Add types and specs; performed some cleanups alsoKostis Sagonas
2010-02-12Merge branch 'jn/supervisor_child_count_only' into ccase/r13b04_devErlang/OTP
* jn/supervisor_child_count_only: Add count_children/1 to supervisor.erl to determine the number of OTP-8436 Added supervisor:count_children/1 to count the number of children being managed without the memory impact of which_children/1. (Thanks to Jay Nelson.)
2010-02-10Add count_children/1 to supervisor.erl to determine the number ofJay Nelson
children being managed without the memory impact of which_children/1 The function which_children/1 returns a list of the child processes currently being supervised, but it has the penalty of creating a new list thereby consuming more memory. In low memory situations it is often desirable to know which supervisor may have generated many processes, but the act of discovering the culprit should not cause the node to crash (or worse a different node if the kernel kills one randomly). The new function count_children/1 can give an indication of which supervisor is taxing resources the most without adding to the burden. Rather than creating a new list, it walks the supervisor's internal children structure using an accumulator function so that any used memory can be incrementally collected yet the resulting count can still be obtained. The return result of count_children/1 is a property list of counts containing: - {specs, Total_Num_Child_Specs} - {active, Num_Active_Child_Processes_Of_Supervisor_Or_Worker_Type} - {supervisors, Num_Supervisor_Type_Children_Including_Dead_Processes} - {workers, Num_Worker_Type_Children_Including_Dead_Processes} This patch was made in response to mailing list discussions of the problem diagnosing heavily taxed production systems. I cannot find the original request, but http://www.erlang.org/cgi-bin/ezmlm-cgi/4/35060 is my original post of the patch.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP