adds HDF5 I/O server functionality

[danielpeter]

setting the additional parameter HDF5_IO_NODES in the Par_file to a value >0 will turn on the I/O server. for example, with:

..
HDF5_FORMAT              = .true.
..
HDF5_ENABLED             = .true.
HDF5_FOR_MOVIES          = .true.
HDF5_IO_NODES            =  1

the solver will use NPROC + HDF5_IO_NODES mpi processes, where the last mpi process is dedicated to performing all file outputs for movie snapshots, shakemap and seismograms.

[codecov-commenter]

Codecov Report

Patch coverage: 22.01% and project coverage change: -0.12 :warning:

Comparison is base (20beb8d) 45.09% compared to head (c08576b) 44.98%.

:mega: This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## devel #1604 +/- ## ========================================== - Coverage 45.09% 44.98% -0.12% ========================================== Files 258 259 +1 Lines 57051 57211 +160 ========================================== + Hits 25727 25735 +8 - Misses 31324 31476 +152 ``` | [Impacted Files](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM) | Coverage Δ | | |---|---|---| | [src/decompose\_mesh/write\_mesh\_databases\_hdf5.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL2RlY29tcG9zZV9tZXNoL3dyaXRlX21lc2hfZGF0YWJhc2VzX2hkZjUuRjkw) | `0.00% <ø> (ø)` | | | [...c/generate\_databases/read\_partition\_files\_hdf5.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL2dlbmVyYXRlX2RhdGFiYXNlcy9yZWFkX3BhcnRpdGlvbl9maWxlc19oZGY1LkY5MA==) | `0.00% <ø> (ø)` | | | [src/generate\_databases/save\_arrays\_solver\_hdf5.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL2dlbmVyYXRlX2RhdGFiYXNlcy9zYXZlX2FycmF5c19zb2x2ZXJfaGRmNS5GOTA=) | `0.00% <ø> (ø)` | | | [src/meshfem3D/save\_databases\_hdf5.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL21lc2hmZW0zRC9zYXZlX2RhdGFiYXNlc19oZGY1LkY5MA==) | `0.00% <ø> (ø)` | | | [src/shared/exit\_mpi.f90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NoYXJlZC9leGl0X21waS5mOTA=) | `9.67% <0.00%> (-1.04%)` | :arrow_down: | | [src/shared/hdf5\_manager.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NoYXJlZC9oZGY1X21hbmFnZXIuRjkw) | `0.00% <0.00%> (ø)` | | | [src/shared/serial.f90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NoYXJlZC9zZXJpYWwuZjkw) | `38.83% <0.00%> (-6.01%)` | :arrow_down: | | [src/specfem3D/hdf5\_io\_server.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NwZWNmZW0zRC9oZGY1X2lvX3NlcnZlci5GOTA=) | `0.00% <0.00%> (ø)` | | | [src/specfem3D/iterate\_time\_undoatt.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NwZWNmZW0zRC9pdGVyYXRlX3RpbWVfdW5kb2F0dC5GOTA=) | `0.00% <0.00%> (ø)` | | | [src/specfem3D/read\_mesh\_databases\_hdf5.F90](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM#diff-c3JjL3NwZWNmZW0zRC9yZWFkX21lc2hfZGF0YWJhc2VzX2hkZjUuRjkw) | `0.00% <ø> (ø)` | | | ... and [8 more](https://app.codecov.io/gh/SPECFEM/specfem3d/pull/1604?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=SPECFEM) | |

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.