Merge pull request #132 from ACCESS-Cloud-Based-InSAR/resource-compet…

…ition

Add option to control OpenMP threads

CHANGELOG.md

@@ -8,6 +8,10 @@ and uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [0.2.4]
 
+### Added
+* `++omp-num-threads` parameter to the `main()` entrypoint to limit the number of threads used by ISCE2 during
+  multiprocessing.
+
 ### Fixed
 * For Solid Earth Tide computation, use azimuth timing to calculate solid earth tide in `science/grids/imagingGeometry` reference frame using ISCE2 rdr2geo.
 * Include topsapp_iono template.

isce2_topsapp/__main__.py

@@ -339,8 +339,19 @@ def main():
         default="gunw_slc",
         help="Select the HyP3 entrypoint to use",
     )
+    parser.add_argument(
+        "++omp-num-threads",
+        type=int,
+        help=("The number of OpenMP threads to use for parallel processing in ISCE2 routines; "
+              "when running locally, this topsapp will utilize all resources, which is not recommended; "
+              "suggest to set this option to 8 - 16 so other processes on server/workstation can running.")
+    )
+
     args, unknowns = parser.parse_known_args()
 
+    if args.omp_num_threads:
+        os.environ["OMP_NUM_THREADS"] = str(args.omp_num_threads)
+
     sys.argv = [args.process, *unknowns]
     # FIXME: this gets better in python 3.10
     # (process_entry_point,) = entry_points(group='console_scripts', name=args.process)