cascache: don't need create_cas_usage_monitor nowaevri/no_mark_run_in_subprocess

Now that we don't use mark.in_suprocess in our tests anymore, we don't
need to suppress creating _CASCacheUsageMonitor.

This was introduced in 9c2bbe3c3871db3a33f81e48987f6d473f97b136

1 files changed, 4 insertions, 10 deletions

diff --git a/src/buildstream/_cas/cascache.py b/src/buildstream/_cas/cascache.py
index 2a2313097..93f180c90 100644
--- a/src/buildstream/_cas/cascache.py
+++ b/src/buildstream/_cas/cascache.py
@@ -113,7 +113,7 @@ class CASCache():
                     self._casd_process = subprocess.Popen(
                         casd_args, cwd=path, stdout=logfile_fp, stderr=subprocess.STDOUT)
 
-            self._cache_usage_monitor = _CASCacheUsageMonitor.create_cas_usage_monitor(self)
+            self._cache_usage_monitor = _CASCacheUsageMonitor(self)
         else:
             self._casd_process = None
 
@@ -1047,6 +1047,9 @@ class CASCache():
     #     (CASCacheUsage): The current status
     #
     def get_cache_usage(self):
+        if not self._cache_usage_monitor:
+            self._cache_usage_monitor = _CASCacheUsageMonitor(self)
+
         return self._cache_usage_monitor.get_cache_usage()
 
     # get_casd_process()
@@ -1099,15 +1102,6 @@ class _CASCacheUsage():
 # buildbox-casd.
 #
 class _CASCacheUsageMonitor:
-
-    #  FIXME: SemaphoreTracker crashes when triggered via spawn and used in
-    #  tests using fork.
-    @classmethod
-    def create_cas_usage_monitor(cls, cas):
-        if multiprocessing.get_start_method() == 'spawn':
-            return None
-        return cls(cas)
-
     def __init__(self, cas):
         self.cas = cas