fix(taskfiles): Improve concurrency control for external tools:

exports/taskfiles/utils/boost.yaml

@@ -2,11 +2,16 @@ version: "3"
 
 includes:
   checksum: "checksum.yaml"
+  misc: "misc.yaml"
   remote: "remote.yaml"
 
 set: ["u", "pipefail"]
 shopt: ["globstar"]
 
+# `JOBS` is a special variable name and is used for concurrency related variables to allow users to
+# override all concurrency when invoking task. Callers using these tasks should default to `JOBS` to
+# propagate any user set value.
+
 tasks:
   # Generates `GENERATE_DIR` by copying `SOURCE_DIR` and then running boost's bootstrap step.
   #
@@ -61,18 +66,16 @@ tasks:
   # @param {string} BUILD_DIR Directory in which to build boost.
   # @param {string} INSTALL_PREFIX Path prefix of where the project should be installed.
   # @param {string[]} [EXTRA_ARGS] Any additional arguments to pass to the build command.
-  # @param {int} [JOBS] The maximum number of concurrent processes to use when building. If
-  # omitted, the b2 default number is used. Before 1.76.0, the number was 1. Since 1.76.0, the
-  # default is the number of cores.
+  # @param {int} [JOBS=G_NPROCS] The maximum number of concurrent processes to use when building. If
+  # omitted, the number of cores is used.
   # @param {string} [CMAKE_SETTINGS_DIR] If set, the directory where the project's CMake settings
   # file should be stored.
   build-and-install:
     internal: true
     vars:
       EXTRA_ARGS:
         ref: "default (list) .EXTRA_ARGS"
-      JOBS: >-
-        {{default "" .JOBS}}
+      JOBS: "{{default .G_NPROCS .JOBS}}"
     requires:
       vars: ["GENERATE_DIR", "BUILD_DIR", "INSTALL_PREFIX"]
     cmds:
@@ -121,9 +124,7 @@ tasks:
   #
   # Boost build-and-install parameters
   # @param {string} [BUILD_DIR={{.WORK_DIR}}/boost-build] Directory in which to build the project.
-  # @param {int} [JOBS] The maximum number of concurrent processes to use when building. If
-  # omitted, the b2 default number is used. Before 1.76.0, the number was 1. Since 1.76.0, the
-  # default is the number of cores.
+  # @param {int} [JOBS] The maximum number of concurrent processes to use when building.
   # @param {string[]} [BUILD_AND_INSTALL_ARGS] Any additional arguments to pass to boost's build
   # and install command.
   # @param {string} [CMAKE_SETTINGS_DIR] If set, the directory where the project's CMake settings
@@ -155,8 +156,6 @@ tasks:
         {{default (printf "%s/boost-build" .WORK_DIR) .BUILD_DIR}}
       BUILD_AND_INSTALL_ARGS:
         ref: "default (list) .BUILD_AND_INSTALL_ARGS"
-      JOBS: >-
-        {{default "" .JOBS}}
       CMAKE_SETTINGS_DIR: >-
         {{default "" .CMAKE_SETTINGS_DIR}}
     requires:

exports/taskfiles/utils/cmake.yaml

@@ -7,24 +7,27 @@ includes:
 set: ["u", "pipefail"]
 shopt: ["globstar"]
 
+# `JOBS` is a special variable name and is used for concurrency related variables to allow users to
+# override all concurrency when invoking task. Callers using these tasks should default to `JOBS` to
+# propagate any user set value.
+
 tasks:
   # Runs the CMake build step for the given build directory. The caller must have previously called
   # `generate` on `BUILD_DIR` for this task to succeed. We purposely omit `sources` and `generates`
   # as we defer to `cmake` to decide whether it should perform any actions.
   #
   # @param {string} BUILD_DIR Directory containing the generated build system to use.
   # @param {string[]} [EXTRA_ARGS] Any additional arguments to pass to the build command.
-  # @param {int} [JOBS] The maximum number of concurrent processes to use when building. If
-  # omitted, the native build tool's default number is used. See `man cmake`.
+  # @param {int} [JOBS=G_NPROCS] The maximum number of concurrent processes to use when building. If
+  # omitted, the number of cores is used.
   # @param {string[]} [TARGETS] A list of specific targets to build instead of the default target.
   build:
     internal: true
     label: "{{.TASK}}:{{.BUILD_DIR}}-{{.TARGETS}}-{{.EXTRA_ARGS}}"
     vars:
       EXTRA_ARGS:
         ref: "default (list) .EXTRA_ARGS"
-      JOBS: >-
-        {{default "" .JOBS}}
+      JOBS: "{{default .G_NPROCS .JOBS}}"
       TARGETS:
         ref: "default (list) .TARGETS"
     requires:
@@ -153,8 +156,7 @@ tasks:
   # command.
   # @param {string[]} [CMAKE_INSTALL_ARGS] Any additional arguments to pass to the CMake install
   # command.
-  # @param {int} [CMAKE_JOBS] The maximum number of concurrent processes to use when building. If
-  # omitted, the native build tool's default number is used. See `man cmake`.
+  # @param {int} [CMAKE_JOBS] The maximum number of concurrent processes to use when building.
   # @param {string} [CMAKE_SETTINGS_DIR] The directory where the project's CMake settings file
   # should be stored.
   # @param {string} [CMAKE_SOURCE_DIR=.] The path, within the extraction directory, containing the
@@ -172,8 +174,7 @@ tasks:
         ref: "default (list) .CMAKE_GEN_ARGS"
       CMAKE_INSTALL_ARGS:
         ref: "default (list) .CMAKE_INSTALL_ARGS"
-      CMAKE_JOBS: >-
-        {{default "" .CMAKE_JOBS}}
+      CMAKE_JOBS: "{{default .JOBS .CMAKE_JOBS}}"
       CMAKE_SETTINGS_DIR: >-
         {{default "" .CMAKE_SETTINGS_DIR}}
       CMAKE_SOURCE_DIR: >-

exports/taskfiles/utils/misc.yaml

@@ -3,6 +3,10 @@ version: "3"
 set: ["u", "pipefail"]
 shopt: ["globstar"]
 
+vars:
+  G_NPROCS:
+    sh: "getconf _NPROCESSORS_ONLN"
+
 tasks:
   replace-text:
     desc: "Replaces some text in a file using sed."