uDeviceX consists of units. They are implemented in /src/u/.

1. Build and run

Compile unit A: from /src directory

u.conf0 ./u/A
u.make -j

2. Update make file fragments

From /src

u.u u/A

updates hw/make/*.mk files

3. Create a new unit

From /src

mkdir -p hw/make

Add two file: hw/make/i and hw/make/e. The files are used by u.u to create a list of unit source files. i is a script which returns a list of [i]ncluded files. e returns a list of [e]xcluded files. The i list "minus" e list is used as a source. e file is optional. In other words e "black lists" files returned by i.

For i and e the variable $U is set to u/hw/hst.

Run

u.u u/hw/hst

Add u/hw/hst/make/dep.mk u/hw/hst/make/obj.mk u/hw/hstmake/dir.mk u/hw/hst/make/rule.mk to git.

4. list of units

4.1. comm unit

a send/recv unit with the 26 neighbors using comm module

4.2. error unit

a unit to test error handling UC, CC and MC (see utils)

4.2.1. compile

from /src/ directory:

u.conf0 u/error
u.make -j

4.2.2. usage

ERR_KIND=<kind> ./udx

where <kind> must be:

  • 0 for rasing an error from host code

  • 1 for testing MC on a failing MPI call

  • 2 for testing CC on a failing cuda API call

The output should result in an error message, location of the error and a backtrace

4.3. hw unit

a "Hello World!" unit with kernel launch.

4.4. hw unit

a "Hello World!" unit. This serves as a base for creating new units

4.5. linal unit

a unit to test linear algebra functions

4.5.1. compile

Run from src/

u.conf0 u/linal

4.5.2. run

Invert symmetric 3x3 matrix

u.run ./udx -- 2 1 5   3 4   -2
2.857143e-01 -2.857143e-01 1.428571e-01 3.766234e-01 3.896104e-02 -6.493507e-02

compare to 'octave/matlab'

>> C = [2,1,5;1,3,4;5,4,-2]
>> C^(-1)
ans =

   0.285714  -0.285714   0.142857
  -0.285714   0.376623   0.038961
   0.142857   0.038961  -0.064935

4.6. mesh bb unit

4.6.1. intro

Bounce back on triangulated mesh

4.6.2. params

if MESHBB_LOG_ROOTS is defined logs coeficeints of cubic polynomials and roots to meshbb.roots.

4.7. MPI error

Units triggers mpi error. A test for MC macro.

4.8. pair unit

4.8.1. Intro

It is for test pair interactions.

4.8.2. Compile

Run from src/

u.conf0 u/pair

or from other directorie

s=<path to src>
echo run | u.conf $s u/pair $s/conf/test.h

4.8.3. Build

u.make -j

4.8.4. Run

Particles coordinates, velocities, kinds, and colors are provided via stdin. An example is in src/data/pair/2. If RND is set it is used as a scale of random force for all pairs.

s=<path to src>
./udx        < $s/data/pair/2
RND=42 ./udx < $s/data/pair/2

Returns force between two particles

-2.4 0 0

4.8.5. Source

u/pair/imp/main.h

4.8.6. Test

u.test test/pair

4.9. RBC forces

Dumps internal RBC forces.

4.10. RBC

Runs RBC without solvent and contact forces.

See also src/test/rbc/u/main

4.11. RBC random

Dumps random numbers generated by src/rbc/rnd

4.12. scan unit

a unit to test scan algorithm (exclusive prefix sum , see e.g. https://en.wikipedia.org/wiki/Prefix_sum) on host and device.

4.13. signed distance function (sdf) unit

a unit to test sdf field.

4.13.1. compile

u.conf0 u/sdf
u.make -j

4.13.2. run

Copy sdf file

u.cp.sdf cyl1/cyl sdf.dat

cyl1/cyl along z and center at the domain center and radius lx/4.

Pass coordinates as arguments

x=2.5 y=0 z=0
u.run ./udx $x $y $z

Returns

0 0 2.5 1.45547

4.14. x unit

standard uDeviceX code