Major internal redesign - step 3:

* All built-in backends now implements the new FutureBackend API
* Any backends that does not support the new FutureBackend API, will use the old API

Squashed commit of the following:

commit 30c7a86
Merge: bcd382d 2fa7893
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 11:36:16 2025 -0800

    Merge branch 'feature/FutureBackend' of github.com:HenrikBengtsson/future into feature/FutureBackend

commit 2fa7893
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 11:15:19 2025 -0800

    Add internal getSocketSelectTimeout() that memoizes the 'timeout' value

commit bcd382d
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 11:05:05 2025 -0800

    REVDEP: 415 packages [ci skip]

commit 7f36deb
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 09:45:51 2025 -0800

    remove unneeded code

commit 1de0c36
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 03:29:23 2025 -0800

    GHA: typo

commit 56e7cf2
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 03:10:18 2025 -0800

    drop duplicate code

commit 5995d3a
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 03:04:16 2025 -0800

    evalFuture(): disable querying of availableCores() for now

commit f6ba839
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 02:23:20 2025 -0800

    GHA: Run future.tests also on future.mirai backends + don't test vignettes on Windows

commit c7d7d86
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 02:07:10 2025 -0800

    Make future.backend.version=2 the default; previous attempt was a mistake

commit 29b2b6d
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 02:05:54 2025 -0800

    Allow 'backend' to be a list (for backend.version=1)

commit 165b861
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 01:51:56 2025 -0800

    Give more informative error message if 'backend' is not a FutureBackend as expected

commit 2539277
Merge: 4c71d9f e8b86ce
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 01:23:20 2025 -0800

    Merge branch 'feature/FutureBackend' of github.com:futureverse/future into feature/FutureBackend

commit 4c71d9f
Author: Henrik Bengtsson <[email protected]>
Date:   Thu Feb 20 01:16:31 2025 -0800

    run() for Future does the common validation and setup now

commit 6c25fd5
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 23:19:44 2025 -0800

    Remove coerceFuture(); not really needed

commit c578170
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 22:53:44 2025 -0800

    Consolodating the help on all FutureBackend:s to one page

commit e8b86ce
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 22:53:44 2025 -0800

    Consolodating the help on all FutureBackend:s to one page

commit 688f5a7
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 21:54:18 2025 -0800

    More fixes for nested future tests on dual-cores machines [ci skip]

commit 00642db
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 20:43:39 2025 -0800

    REVDEP: 415 packages [ci skip]

commit de8670a
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 14:41:23 2025 -0800

    Making sure package passes checks also on single- and dual-core machines (emulated using R_PARALLELLY_AVAILABLECORES_SYSTEM)

commit 0c770e6
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 12:07:42 2025 -0800

    Use the FutureBackend approach by default, if the backend implements it

commit fc23ad6
Author: Henrik Bengtsson <[email protected]>
Date:   Wed Feb 19 10:52:34 2025 -0800

    ClusterFuture: clean out temporary ClusterFutureBackend0 again

commit 9e5eaa1
Author: Henrik Bengtsson <[email protected]>
Date:   Tue Feb 18 19:55:43 2025 -0800

    Make sure 'multicore' and 'multisession' with workers = 1 fall back to sequential
    Have ClusterFutureBackend "process" the 'workers' argument

commit 7d93ae1
Author: Henrik Bengtsson <[email protected]>
Date:   Tue Feb 18 17:17:27 2025 -0800

    First prototype of MulticoreFutureBackend

commit 4ff28fc
Author: Henrik Bengtsson <[email protected]>
Date:   Tue Feb 18 15:30:25 2025 -0800

    Memoize cluster timeout options related to cluster futures; this should really be done when plan() is configured

commit b3208c4
Author: Henrik Bengtsson <[email protected]>
Date:   Tue Feb 18 15:18:59 2025 -0800

    GHA: Test also with R_FUTURE_BACKEND_VERSION=2

commit 3886998
Author: Henrik Bengtsson <[email protected]>
Date:   Tue Feb 18 15:15:51 2025 -0800

    First prototype of ClusterFutureBackend and MultisessionFutureBackend classes

commit ecc8c15
Author: Henrik Bengtsson <[email protected]>
Date:   Mon Feb 17 20:46:04 2025 -0800

    First prototype of a SequentialFutureBackend class

commit 4f56b20
Author: Henrik Bengtsson <[email protected]>
Date:   Mon Feb 17 19:13:02 2025 -0800

    evalFuture(): add comments explaining that the use of availableCores() adds to the baseline processing time

Author: HenrikBengtsson

.github/workflows/R-CMD-check.yaml

@@ -28,6 +28,10 @@ jobs:
           - {os: ubuntu-latest,  r: 'oldrel-1' }
           - {os: ubuntu-latest,  r: 'oldrel-2' }
           - {os: ubuntu-latest,  r: '4.0'      }
+          
+          - {os: ubuntu-latest,  r: 'release'  , availablecores: 1, label: 'availableCores.system=1' }
+          - {os: ubuntu-latest,  r: 'release'  , availablecores: 2, label: 'availableCores.system=2' }
+          - {os: ubuntu-latest,  r: 'release'  , backend_version: 1, label: 'backend_version=1' }
           - {os: ubuntu-latest,  r: 'release'  , language: ko,    label: ko    }
           - {os: ubuntu-latest,  r: 'release'  , language: zh_CN, label: zh_CN }
           - {os: ubuntu-latest,  r: 'release'  , language: zh_TW, label: zh_TW }
@@ -53,8 +57,10 @@ jobs:
       _R_CHECK_TESTS_NLINES_: 300
       RCMDCHECK_ERROR_ON: note
       ## Specific to futures
+      R_PARALLELLY_AVAILABLECORES_SYSTEM: ${{ matrix.config.availablecores }}
       R_FUTURE_RNG_ONMISUSE: error
       R_FUTURE_GLOBALS_KEEPWHERE: ${{ matrix.config.globals_keepWhere }}
+      R_FUTURE_BACKEND_VERSION: ${{ matrix.config.backend_version }}
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/future_tests.yaml

@@ -23,12 +23,13 @@ jobs:
           - { plan: 'future.batchtools::batchtools_local' }
           - { plan: 'future.batchtools::batchtools_bash'  }
           - { plan: 'future.callr::callr'                 }
+          - { plan: 'future.mirai::mirai_multisession'    }
+          - { plan: 'future.mirai::mirai_cluster'         }
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
       ## R CMD check
-      _R_CHECK_LENGTH_1_LOGIC2_: true
       _R_CHECK_MATRIX_DATA_: true
       _R_CHECK_CRAN_INCOMING_: false
       ## Specific to futures

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: future
-Version: 1.34.0-9140
+Version: 1.34.0-9209
 Title: Unified Parallel and Distributed Processing in R for Everyone
 Imports:
     digest,

NAMESPACE

@@ -21,6 +21,10 @@ S3method(journal,Future)
 S3method(journal,FutureJournal)
 S3method(journal,FutureJournalCondition)
 S3method(journal,list)
+S3method(launchFuture,ClusterFutureBackend)
+S3method(launchFuture,FutureBackend)
+S3method(launchFuture,MulticoreFutureBackend)
+S3method(launchFuture,SequentialFutureBackend)
 S3method(mandelbrot,matrix)
 S3method(mandelbrot,numeric)
 S3method(nbrOfFreeWorkers,"NULL")
@@ -92,8 +96,10 @@ export("%seed%")
 export("%stdout%")
 export("%tweak%")
 export(ClusterFuture)
+export(ClusterFutureBackend)
 export(ConstantFuture)
 export(Future)
+export(FutureBackend)
 export(FutureCondition)
 export(FutureError)
 export(FutureGlobals)
@@ -105,12 +111,15 @@ export(GlobalEnvFutureCondition)
 export(GlobalEnvFutureError)
 export(GlobalEnvFutureWarning)
 export(MulticoreFuture)
+export(MulticoreFutureBackend)
 export(MultiprocessFuture)
 export(MultisessionFuture)
+export(MultisessionFutureBackend)
 export(RngFutureCondition)
 export(RngFutureError)
 export(RngFutureWarning)
 export(SequentialFuture)
+export(SequentialFutureBackend)
 export(UnexpectedFutureResultError)
 export(UniprocessFuture)
 export(as.FutureGlobals)
@@ -128,6 +137,7 @@ export(futureSessionInfo)
 export(futures)
 export(getExpression)
 export(getGlobalsAndPackages)
+export(launchFuture)
 export(makeClusterMPI)
 export(makeClusterPSOCK)
 export(makeNodePSOCK)