Major update: to context creation and device selection.

Add quick setup function fclInit which selects a device from across all available platforms based on criteria and sets the default context accordingly.
Also add vendor and extensions filter to device selection criteria.
Fix device selection bug in sorting.
Update examples to use new fclInit function.

.gitignore

@@ -4,6 +4,7 @@
 *.smod
 *.a
 doc/*
+bin/*
 *fclKernels.cl
 test/testSummary
 test/test_outputs*

examples/nbody.f90

@@ -20,11 +20,11 @@ program nbody
 character(*), parameter :: cl_vendor = 'nvidia,amd,intel'     ! Vendors for which to create OpenCL context in order of preference
 
 ! ---------Program variables  ---------
-integer :: i, nBlock
+integer :: i
 integer(c_size_t) :: kern1T, kern2T
 real :: Tavg, perf
 character(:), allocatable :: kernelSrc              ! Kernel source string
-type(fclDevice), allocatable :: devices(:)          ! List of focal devices
+type(fclDevice) :: device                           ! OpenCL device on which to run
 type(fclProgram) :: prog                            ! Focal program object 
 type(fclKernel) :: kern1, kern2                     ! Focal kernel object
 type(fclEvent) :: e
@@ -40,32 +40,29 @@ program nbody
 write(*,*) ('-',i=1,72)
 write(*,*)
 
-! Create context with nvidia platform
-call fclSetDefaultContext(fclCreateContext(vendor=cl_vendor))
+! Initialise OpenCL context and select device with most cores 
+device = fclInit(vendor=cl_vendor,sortBy='cores')
 
-! Select device with most cores and create command queue
-devices = fclFindDevices(sortBy='cores')
-call fclSetDefaultCommandQ(fclCreateCommandQ(devices(1),enableProfiling=.true., &
+call fclSetDefaultCommandQ(fclCreateCommandQ(device,enableProfiling=.true., &
            outOfOrderExec=.true.,blockingWrite=.false.))
 
-write(*,*) '  Created OpenCL command queue on device: "',devices(1)%name,'"'
-write(*,'(A,I6,A,I6,A,I4,A,A,A)') '    (', devices(1)%nComputeUnits,' cores, ', &
-    devices(1)%global_memory/1024/1024,'MB, ', &
-    devices(1)%clock_freq, 'MHz, ',&
-    devices(1)%version,')'
+write(*,*) '  Created OpenCL command queue on device: "',device%name,'"'
+write(*,'(A,I6,A,I6,A,I4,A,A,A)') '    (', device%nComputeUnits,' cores, ', &
+    device%global_memory/1024/1024,'MB, ', &
+    device%clock_freq, 'MHz, ',&
+    device%version,')'
 write(*,*) ''
 
 ! Set profiler device
-profiler%device = devices(1)
+profiler%device = device
 
 ! Load kernels from file and compile
 call fclGetKernelResource(kernelSrc)
 prog = fclCompileProgram(kernelSrc)
 
 ! Get kernel objects and set local/global work sizes
-nBlock = (N+blockSize-1)/blockSize
-kern1 = fclGetProgramKernel(prog,'bodyForces',[nBlock*blockSize],[blockSize])
-kern2 = fclGetProgramKernel(prog,'integrateBodies',[nBlock*blockSize],[blockSize])
+kern1 = fclGetProgramKernel(prog,'bodyForces',[N],[blockSize])
+kern2 = fclGetProgramKernel(prog,'integrateBodies',[N],[blockSize])
 
 call fclProfilerAdd(profiler,Niter,kern1,kern2)
 

examples/platform_query.f90

@@ -37,6 +37,7 @@ program platform_query
                platforms(i)%devices(j)%global_memory/1024/1024,'MB, ', &
                platforms(i)%devices(j)%clock_freq, 'MHz, ',&
                platforms(i)%devices(j)%version
+    ! write(*,*) platforms(i)%devices(j)%extensions
 
   end do
 

examples/sum.f90

@@ -9,21 +9,20 @@ program sum
 
 integer :: i                                ! Counter variable
 character(:), allocatable :: kernelSrc      ! Kernel source string
-type(fclDevice), allocatable :: devices(:)      ! List of focal devices
+type(fclDevice) :: device                   ! OpenCL device on which to run
 type(fclProgram) :: prog                    ! Focal program object
 type(fclKernel) :: sumKernel                ! Focal kernel object
 real(c_float) :: array1(Nelem)              ! Host array 1
 real(c_float) :: array2(Nelem)              ! Host array 2
 type(fclDeviceFloat) :: array1_d            ! Device array 1
 type(fclDeviceFloat) :: array2_d            ! Device array 2
 
-! Create context with nvidia platform
-call fclSetDefaultContext(fclCreateContext(vendor='nvidia,amd,intel'))
+! Initialise OpenCL context and select device with most cores 
+device = fclInit(vendor='nvidia,amd,intel',sortBy='cores')
 
 ! Select device with most cores and create command queue
-devices = fclFindDevices(sortBy='cores') !,type='cpu')
-write(*,*) 'Using device: ',devices(1)%name
-call fclSetDefaultCommandQ(fclCreateCommandQ(devices(1),enableProfiling=.true.))
+write(*,*) 'Using device: ',device%name
+call fclSetDefaultCommandQ(fclCreateCommandQ(device,enableProfiling=.true.))
 
 ! Load kernel from file and compile
 ! call fclSourceFromFile('examples/sum.cl',kernelSrc)

src/Focal.f90

@@ -63,6 +63,11 @@ module Focal
     integer(c_int64_t) :: global_memory              !! Total global memory, bytes
     integer(c_int32_t) :: clock_freq                 !! Max clock frequency, MHz
     character(:), allocatable :: version             !! OpenCL version
+    character(:), allocatable :: extensions          !! Supported OpenCL extensions
+    type(fclPlatform), pointer :: platform           !! Pointer to containing platform
+    integer(c_intptr_t) :: cl_platform_id            !! OpenCL platform pointer
+    character(:), allocatable :: platformName        !! Name of containing platform
+    character(:), allocatable :: platformVendor      !! Vendor of containing platform
   end type fclDevice
 
   type :: fclPlatform
@@ -1008,23 +1013,99 @@ module subroutine fclSetDefaultContext(ctx)
       !! Set the global default context
       type(fclContext), intent(in) :: ctx
     end subroutine fclSetDefaultContext
+
+    module function fclFilterDevices(devices,vendor,type,nameLike,extensions,sortBy) result(deviceList)
+      !! Filter and sort list of devices based on criteria
+      type(fclDevice), intent(in) :: devices(:)
+      character(*), intent(in), optional :: vendor
+        !! Filter device list based on platform vendor.
+        !!  Specify multiple possible vendors in comma-separate list
+      character(*), intent(in), optional :: type
+        !! Filter device list based on device type.
+        !! Specify at least one of 'cpu', 'gpu', default: 'cpu,gpu' (both)
+      character(*), intent(in), optional :: nameLike
+        !! Filter devices based on device name. Look for this substring in device name.
+      character(*), intent(in), optional :: extensions
+        !! Filter devices based on supported device extensions.
+        !! Specify comma-separated list of OpenCL extension names, e.g. cl_khr_fp64.
+        !! See [clGetDeviceInfo](https://www.khronos.org/registry/OpenCL/sdk/1.2/docs/man/xhtml/clGetDeviceInfo.html)
+        !! Extensions specified are requirements: devices are filtered-out if they don't support all extensions specified.
+      character(*), intent(in), optional :: sortBy
+        !! Sort device list based on either 'memory': total global memory,
+        !!  'cores': total number of compute units, 'clock': maximum clock speed
+      type(fclDevice), allocatable :: deviceList(:)
+        !! Filtered and sorted list. Unallocated if no matching devices found.
+    end function fclFilterDevices
+
+    module function fclInit(vendor,type,nameLike,extensions,sortBy) result(device)
+      !! Quick setup helper function: find a single device based on criteria
+      !!  and set the default context accordingly.
+      !!  Raises runtime error if no matching device is found.
+      character(*), intent(in), optional :: vendor
+        !! Filter device based on platform vendor
+      !!  Specify multiple possible vendors in comma-separate list
+      character(*), intent(in), optional :: type
+        !! Filter device list based on device type.
+        !! Specify at least one of 'cpu', 'gpu', default: 'cpu,gpu' (both)
+      character(*), intent(in), optional :: nameLike
+        !! Filter devices based on device name. Look for this substring in device name.
+      character(*), intent(in), optional :: extensions
+        !! Filter devices based on supported device extensions.
+        !! Specify comma-separated list of OpenCL extension names, e.g. cl_khr_fp64.
+        !! See [clGetDeviceInfo](https://www.khronos.org/registry/OpenCL/sdk/1.2/docs/man/xhtml/clGetDeviceInfo.html)
+        !! Extensions specified are requirements: devices are filtered-out if they don't support all extensions specified.
+      character(*), intent(in), optional :: sortBy
+        !! Sort device list based on either 'memory': total global memory,
+        !!  'cores': total number of compute units, 'clock': maximum clock speed
+      type(fclDevice), allocatable :: device
+        !! The device chosen based on the user criteria
+    end function fclInit
+
   end interface
 
   interface fclFindDevices
     !! Generic interface to list devices, sorted and filtered by properties
+    !!  Raises runtime error if no matching device is found.  
 
-    module function fclFindDevices_1(ctx,type,nameLike,sortBy) result(deviceList)
+    module function fclFindDevices_1(ctx,vendor,type,nameLike,extensions,sortBy) result(deviceList)
       type(fclContext), intent(in), target :: ctx
+        !! Context containing device for command queue
+      character(*), intent(in), optional :: vendor
+        !! Filter device list based on platform vendor.
+        !!  Specify multiple possible vendors in comma-separate list
       character(*), intent(in), optional :: type
+        !! Filter device list based on device type.
+        !! Specify at least one of 'cpu', 'gpu', default: 'cpu,gpu' (both)
       character(*), intent(in), optional :: nameLike
+        !! Filter devices based on device name. Look for this substring in device name.
+      character(*), intent(in), optional :: extensions
+        !! Filter devices based on supported device extensions.
+        !! Specify comma-separated list of OpenCL extension names, e.g. cl_khr_fp64.
+        !! See [clGetDeviceInfo](https://www.khronos.org/registry/OpenCL/sdk/1.2/docs/man/xhtml/clGetDeviceInfo.html)
+        !! Extensions specified are requirements: devices are filtered-out if they don't support all extensions specified.
       character(*), intent(in), optional :: sortBy
+        !! Sort device list based on either 'memory': total global memory,
+        !!  'cores': total number of compute units, 'clock': maximum clock speed
       type(fclDevice), allocatable :: deviceList(:)
     end function fclFindDevices_1
 
-    module function fclFindDevices_2(type,nameLike,sortBy) result(deviceList)
+    module function fclFindDevices_2(vendor,type,nameLike,extensions,sortBy) result(deviceList)
+      character(*), intent(in), optional :: vendor
+        !! Filter device list based on platform vendor.
+        !!  Specify multiple possible vendors in comma-separate list
       character(*), intent(in), optional :: type
+        !! Filter device list based on device type.
+        !! Specify at least one of 'cpu', 'gpu', default: 'cpu,gpu' (both)
       character(*), intent(in), optional :: nameLike
+        !! Filter devices based on device name. Look for this substring in device name.
+      character(*), intent(in), optional :: extensions
+        !! Filter devices based on supported device extensions.
+        !! Specify comma-separated list of OpenCL extension names, e.g. cl_khr_fp64.
+        !! See [clGetDeviceInfo](https://www.khronos.org/registry/OpenCL/sdk/1.2/docs/man/xhtml/clGetDeviceInfo.html)
+        !! Extensions specified are requirements: devices are filtered-out if they don't support all extensions specified.
       character(*), intent(in), optional :: sortBy
+        !! Sort device list based on either 'memory': total global memory,
+        !!  'cores': total number of compute units, 'clock': maximum clock speed
       type(fclDevice), allocatable :: deviceList(:)
     end function fclFindDevices_2
 

src/Focal_Query.f90

@@ -274,19 +274,23 @@
                                   C_LOC(platform%cl_device_ids), int32_ret)
     call fclErrorHandler(errcode,'fclGetPlatform','clGetDeviceIDs')
 
+    ! --- Populate fclPlatform info strings ---
+    call fclGetPlatformInfo(platform,CL_PLATFORM_PROFILE,platform%profile)
+    call fclGetPlatformInfo(platform,CL_PLATFORM_VERSION,platform%version)
+    call fclGetPlatformInfo(platform,CL_PLATFORM_NAME,platform%name)
+    call fclGetPlatformInfo(platform,CL_PLATFORM_VENDOR,platform%vendor)
+    call fclGetPlatformInfo(platform,CL_PLATFORM_EXTENSIONS,platform%extensions)
+
     ! --- Populate fclDevice structure array ---
     do i=1,platform%numDevice
 
       platform%devices(i) = fclGetDevice(platform%cl_device_ids(i))
+      platform%devices(i)%platformName = platform%name
+      platform%devices(i)%platformVendor = platform%vendor
+      platform%devices(i)%cl_platform_id = platform_id
 
     end do
 
-    ! --- Populate fclPlatform info strings ---
-    call fclGetPlatformInfo(platform,CL_PLATFORM_PROFILE,platform%profile)
-    call fclGetPlatformInfo(platform,CL_PLATFORM_VERSION,platform%version)
-    call fclGetPlatformInfo(platform,CL_PLATFORM_NAME,platform%name)
-    call fclGetPlatformInfo(platform,CL_PLATFORM_VENDOR,platform%vendor)
-    call fclGetPlatformInfo(platform,CL_PLATFORM_EXTENSIONS,platform%extensions)
 
   end procedure fclGetPlatform
   ! ---------------------------------------------------------------------------
@@ -303,6 +307,7 @@
     call fclGetDeviceInfo(device,CL_DEVICE_GLOBAL_MEM_SIZE,device%global_memory)
     call fclGetDeviceInfo(device,CL_DEVICE_MAX_CLOCK_FREQUENCY,device%clock_freq)
     call fclGetDeviceInfo(device,CL_DEVICE_VERSION,device%version)
+    call fclGetDeviceInfo(device,CL_DEVICE_EXTENSIONS,device%extensions)
 
   end procedure fclGetDevice
   ! ---------------------------------------------------------------------------