Merge branch 'mr/force_cpu_number' into 'master'

Add ability to force the number of cores

See merge request it/e3-core!109

Author: Nikokrock

src/e3/env.py

@@ -123,6 +123,7 @@ def set_build(
         version: str | None = None,
         machine: str | None = None,
         mode: str | None = None,
+        cores: int | None = None,
     ) -> None:
         """Set build platform.
 
@@ -138,14 +139,16 @@ def set_build(
         :param mode: a string containing the name of the mode. This
             notion is needed on some targets such as VxWorks to switch between
             kernel mode and other modes such as rtp
+        :param cores: force a number of apparent cores. If None that number
+            is either computed (when possible) or set to 1.
 
         When calling set_build, the target and host systems are reset to the
         build one. Thus you should call set_build before calling either
         set_host or set_target.
         """
         e3.log.debug("set_build (build_name=%s, build_version=%s)", name, version)
         self.build = Platform.get(
-            platform_name=name, version=version, machine=machine, mode=mode
+            platform_name=name, version=version, machine=machine, mode=mode, cores=cores
         )
         self.host = self.build
         self.target = self.build
@@ -156,6 +159,7 @@ def set_host(
         version: str | None = None,
         machine: str | None = None,
         mode: str | None = None,
+        cores: int | None = None,
     ) -> None:
         """Set host platform.
 
@@ -170,6 +174,8 @@ def set_host(
         :param mode: a string containing the name of the mode. This
             notion is needed on some targets such as VxWorks to switch between
             kernel mode and other modes such as rtp
+        :param cores: force a number of apparent cores. If None that number
+            is either computed (when possible) or set to 1.
 
         When calling set_host, the target system is reset to the host one.
         Thus you should call set_host before set_target otherwise your call
@@ -185,7 +191,11 @@ def set_host(
             self.host = self.build
         else:
             self.host = Platform.get(
-                platform_name=name, version=version, machine=machine, mode=mode
+                platform_name=name,
+                version=version,
+                machine=machine,
+                mode=mode,
+                cores=cores,
             )
         self.target = self.host
 
@@ -195,6 +205,7 @@ def set_target(
         version: str | None = None,
         machine: str | None = None,
         mode: str | None = None,
+        cores: int | None = None,
     ) -> None:
         """Set target platform.
 
@@ -211,6 +222,8 @@ def set_target(
         :param mode: a string containing the name of the mode. This
             notion is needed on some targets such as VxWorks to switch between
             kernel mode and other modes such as rtp
+        :param cores: force a number of apparent cores. If None that number
+            is either computed (when possible) or set to 1.
 
         The target parameters are ignored if the target_name is equal to the
         host platform.
@@ -224,7 +237,11 @@ def set_target(
             self.target = self.build
         else:
             self.target = Platform.get(
-                platform_name=name, version=version, machine=machine, mode=mode
+                platform_name=name,
+                version=version,
+                machine=machine,
+                mode=mode,
+                cores=cores,
             )
 
     def set_env(

src/e3/os/platform.py

@@ -329,22 +329,31 @@ def as_dict(self) -> dict[str, Any]:
 
     @classmethod
     def get(
-        cls, name: str, endian: str | None = None, compute_cores: bool = False
+        cls,
+        name: str,
+        endian: str | None = None,
+        compute_cores: bool = False,
+        cores: int | None = None,
     ) -> CPU:
         """Initialize CPU instance.
 
         :param name: cpu name
         :param endian: if not None override endianness default settings
         :param compute_cores: if True compute the number of cores
+        :param cores: if not None force the apparent number of
+            cpu to that value.
         """
         assert name in KNOWLEDGE_BASE.cpu_info, "invalid cpu name"
         bits = KNOWLEDGE_BASE.cpu_info[name]["bits"]
-        cores = 1
 
         if endian is None:
             endian = KNOWLEDGE_BASE.cpu_info[name]["endian"]
-        if compute_cores:
-            cores = SystemInfo.core_number
+
+        if cores is None:
+            if compute_cores:
+                cores = SystemInfo.core_number
+            else:
+                cores = 1
 
         return CPU(name, bits, endian, cores)
 

src/e3/platform.py

@@ -59,6 +59,7 @@ def get(
         machine: str | None = None,
         mode: str | None = None,
         compute_default: bool = False,
+        cores: int | None = None,
     ) -> Platform:
         """Return a Platform object.
 
@@ -72,6 +73,7 @@ def get(
         :param mode: an os mode (ex: rtp for vxworks)
         :param compute_default: if True compute the default Arch for the
             current machine (this parameter is for internal purpose only).
+        :param cores: if not None force a number of apparent cores
         """
         # normalize arguments
         if not version:
@@ -112,7 +114,9 @@ def get(
         # Fill other attributes
         assert platform_name is not None
         pi = KNOWLEDGE_BASE.platform_info[platform_name]
-        cpu = e3.os.platform.CPU.get(pi["cpu"], pi.get("endian", None), is_host)
+        cpu = e3.os.platform.CPU.get(
+            pi["cpu"], pi.get("endian", None), is_host, cores=cores
+        )
         os = e3.os.platform.OS.get(pi["os"], is_host, version=version, mode=mode)
         is_hie = pi["is_hie"]
 

tests/tests_e3/env/main_test.py

@@ -260,6 +260,19 @@ def test_copy():
     assert new_e.target.platform == "arm-elf"
 
 
+def test_force_cores():
+    """Test that forcing the number of cores works in all cases."""
+    e = e3.env.BaseEnv()
+    e.set_build(cores=23)
+    assert e.build.cpu.cores == 23
+
+    e.set_build(name="x86_64-linux", cores=23)
+    assert e.build.cpu.cores == 23
+
+    e.set_build(name="x86_64-windows64", cores=23)
+    assert e.build.cpu.cores == 23
+
+
 def test_build_os_propagation():
     """Ensure that OS version is preserved when build platform is changed."""
     winenv = e3.env.BaseEnv(