implement basic time limit for PH

doc/src/hubs.rst

@@ -14,7 +14,8 @@ in a ``Config`` object) is often set to a negative number so internal
 convergence is ignored in favor of the threshhold on the gap between
 upper and lower bounds as computed by the spokes (``rel_gap`` and
 ``abs_gap`` in ``Config`` object).  Most hubs can be terminated
-based on an iteration limit (``max_iterations`` in a ``Config`` object).
+based on an iteration limit (``max_iterations`` in a ``Config`` object),
+or a time limit in seconds (``time_limit`` in a ``Config`` object).
 
 An additional gap-based termination option is supported by
 ``Config`` and ``cfg_vanilla.py``: ``max_stalled_iters``

examples/afew.py

@@ -54,8 +54,9 @@ def do_one(dirname, progname, np, argstring):
        "--solver-name={} --rel-gap=0.0 "
        " --xhatlshaped --max-solver-threads=1".format(solver_name))
 do_one("hydro", "hydro_cylinders_pysp.py", 3,
-       "--bundles-per-rank=0 --max-iterations=100 "
+       "--bundles-per-rank=0 --max-iterations=10000 "
        "--default-rho=1 --xhatshuffle --lagrangian "
+       "--abs-gap=0 --rel-gap=0 --time-limit=2 "
        "--solver-name={}".format(solver_name))
 
 if len(badguys) > 0:

mpisppy/phbase.py

@@ -821,6 +821,9 @@ def options_check(self):
         # Smoothed is optional, not required
         if "smoothed" not in self.options:
             self.options["smoothed"] = 0
+        # time_limit is optional, not required
+        if "time_limit" not in self.options:
+            self.options["time_limit"] = None
 
 
     def Iter0(self):
@@ -1001,10 +1004,15 @@ def iterk_loop(self):
                 if self.convobject.is_converged():
                     global_toc("User-supplied converger determined termination criterion reached", self.cylinder_rank == 0)
                     break
-            elif self.conv is not None:
+            if self.conv is not None:
                 if self.conv < self.options["convthresh"]:
                     global_toc("Convergence metric=%f dropped below user-supplied threshold=%f" % (self.conv, self.options["convthresh"]), self.cylinder_rank == 0)
                     break
+            if self.options["time_limit"] is not None:
+                time_to_stop = self.allreduce_or( (time.perf_counter() - self.start_time) >= self.options["time_limit"] )
+                if time_to_stop:
+                    global_toc(f"Time limit {self.options['time_limit']} seconds reached.", self.cylinder_rank == 0)
+                    break
 
             teeme = (
                 "tee-rank0-solves" in self.options

mpisppy/utils/cfg_vanilla.py

@@ -57,6 +57,7 @@ def shared_options(cfg):
         "defaultPHrho": cfg.default_rho,
         "convthresh": 0,
         "PHIterLimit": cfg.max_iterations,  # not needed by all
+        "time_limit": cfg.time_limit,  # not needed by all
         "verbose": cfg.verbose,
         "display_progress": cfg.display_progress,
         "display_convergence_detail": cfg.display_convergence_detail,

mpisppy/utils/config.py

@@ -173,10 +173,15 @@ def _common_args(self):
 
     def popular_args(self):
         self.add_to_config("max_iterations",
-                            description="hub max iiterations (default 1)",
+                            description="hub max iterations (default 1)",
                             domain=int,
                             default=1)
 
+        self.add_to_config("time_limit",
+                            description="hub time limit in seconds (default None)",
+                            domain=int,
+                            default=None)
+
         self.add_solver_specs(prefix="")
 
         self.add_to_config("seed",