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Diffstat (limited to 'lib/pman/src/pman_buf.erl')
| -rw-r--r-- | lib/pman/src/pman_buf.erl | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/lib/pman/src/pman_buf.erl b/lib/pman/src/pman_buf.erl new file mode 100644 index 0000000000..d56ce184fa --- /dev/null +++ b/lib/pman/src/pman_buf.erl @@ -0,0 +1,117 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1997-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +%%%---------------------------------------------------------------------- +%%% Purpose : This module is the exported interface to the buffering mechanism +%%% used in PMAN to prevent the trace output to congest +%%% the system. +%%% +%%% This module depends on the modules (direct or indirectly): +%%% pman_buf.hrl +%%% pman_buf_utils.erl +%%% pman_buf_buffer.erl +%%% pman_buf_converter.erl +%%% pman_buf_printer.erl +%%% +%%%---------------------------------------------------------------------- + +-module(pman_buf). + +%%-compile(export_all). +-export([start/2,clear/3]). + + +-include("pman_buf.hrl"). + + +%% The buffering mechanism consists of three processes that +%% work in a chain to prevent the process monitor from congesting +%% output mechanism. +%% +%% Messages are buffered in the CONVERTER process before they are sent to +%% to the BUFFER process where they are formatted before they are finally +%% sent to either a file or the PRINTER process. The printer process +%% outputs the messages in the graphical user interface. +%% +%% +%% +%% --> CONVERTER --> BUFFER --> PRINTER --> gui +%% | +%% | +%% | +%% V +%% +%% file +%% + + + + + +%% ---------------------------------------------------------------- +%% The amount of data produced by a trace message may be large, and +%% cause the run time system to run out of memory. To avoid this, +%% the task of storing, cutting buffers, formating data and printing +%% it is performed by three processes: The buffer, the converter and +%% the printer. +%% +%% The converter accepts the raw data, a list +%% of {trace,Msg} tuples. Having max priority, it assures that the +%% amount of raw data stored never excedes ?BUFF_SIZE messages. +%% (With the exception of the last batch received, which assures that +%% the last trace message printed is never a buffer cut message.) +%% Whenever there is space available in the buffer process, (The +%% Buffer process stores max. ?BUFF_SIZE converted messages), +%% the buffer asks for more unconverted messages, and ?PRINT_LEN messages +%% are sent. They are converted by the buffer, and added to the list +%% of messages to be sent. + +%% The printer process requests formatted messages from the buffer, +%% and in chuncs of ?MAX_OUTPUT sends them to the buffer. If traces +%% are to be dumped on file, due to the max priority, such is handled +%% in the converter, and buffers are not cut. +%% + + +%% --------------------------------------------------------------- +%% Initializes the buffering mechanism, which consist of three +%% processes, each involved with a phase of the formattation and +%% output of data to the process windows. + +start(Editor, FileName) -> + Buffer_Pid = spawn_link(pman_buf_buffer,init,[Editor]), + Converter_Pid = + spawn_link(pman_buf_converter,init,[Buffer_Pid, FileName]), + Buffer_Pid!{converter_pid, Converter_Pid}, + #buffer{converter=Converter_Pid,buffer=Buffer_Pid}. + + + +%% --------------------------------------------------------------- +%% Kills the converter and the clears the buffer with formated data +%% starting a new converter. + +clear(Buff,String, FileName) -> + exit(Buff#buffer.converter,win_killed), + Converter_Pid=spawn_link(pman_buf_converter,init,[Buff#buffer.buffer, + FileName]), + Buff#buffer.buffer!{clear,String,Converter_Pid }, + Buff#buffer{converter = Converter_Pid}. + + + |