| Re: [ptp-dev] How does PTP deal with large amount of output (30, 000 lines of OOB record in GDB) ? |
| Xing Yun, The typical way to do this is with a multicast reduction network. The network consists of a tree of server processes, with each server having a parent and multiple children. The number of children is called the fanout of the network. At the "root" of the tree is a single process that handles communication with a client (in this case Eclipse). The "leaves" of the tree (i.e. those servers with no children) communicate with the gdbs. The tree is bi-directional. The root-to-leaf direction is used to send commands to the gdbs in a broadcast manner. There is usually some way to prefix the command with the destinations you want it to go to, such as "all", or "1-5000", etc. The leaf-to-root direction is used to manage responses or events from the gdbs. This usually comprises some kind of reduction or aggregation process, so that at each level in the tree, only a small number of messages are passed to the parent, again prefixed in some manner that distinguishes where they have come from. Eventually the "root" receives these messages and passes them to the client. For the PTP parallel debugger, we aggregate responses from gdb by using a simple hash function. So, as each server receives messages from it's children, it computes the hash over the message, and if any hashes match, the messages are aggregated together. These aggregated messages are then passed to the parent. The PTP debugger implements this network and hashing mechanism internally, however we also have a general multicast/reduction network that can be used by any application. The application just needs to provide "filters", which are simple functions that determine how messages are passed from the parent to the children and vice versa. The debugger code is available in the debug/org.eclipse.ptp.debug.sdm plugin (written in C) and the generic framework is in tools/org.eclipse.ptp.sci (written in C++). Both of these are available from the git repo org.eclipse.ptp.git. Hope this helps. Regards, Greg On Oct 17, 2012, at 4:03 AM, 邢云 wrote:
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