= Specifying plan classes in C++ ==

The scheduler is linked with a function
{{{
bool app_plan(SCHEDULER_REQUEST &sreq, char* plan_class, HOST_USAGE&);
}}}
The '''sreq''' argument describes the host.
It contains:
 * in '''sreq.host''' field, a description of the host's hardware, including:
  * In p_vendor and p_model, the processor type
  * In p_features, the processor features (e.g., fpu tsc pae nx sse sse2 mmx)
  * In m_nbytes, the amount of RAM
 * in '''sreq.coprocs''', a list of the hosts's coprocessors.
 * in '''core_client_version''', the client's version number in MMmmRR form.

When called with a particular SCHEDULER_REQUEST and plan class,
the function returns true if the host's resources are sufficient for apps of that class.
If true, it populates the HOST_USAGE structure:
{{{
struct HOST_USAGE {
   double ncudas;     // number of NVIDIA GPUs used
   double natis;      // number of ATI GPUs used
   double gpu_ram;    // max amount of GPU RAM used
   double avg_ncpus;  // avg #CPUs used by app (may be fractional)
   double max_ncpus;  // max #CPUs used (not currently used for anything)
   double projected_flops;
      // an estimate of the actual FLOPS.
      // used to select versions, so make it higher for the preferred version
   double peak_flops;
      // the peak FLOPS of the devices to be used
   char cmdline[256]; // passed to the app as a cmdline argument;
                      // this can be used, e.g. to control the # of threads used
};
}}}

You are free to define your own set of plan classes,
and to link your own '''app_plan()''' function with the scheduler.
The BOINC scheduler comes with a default '''app_plan()''' (in sched/sched_customize.cpp).