Use singleton object for accessing Genode's environment.

src/mx/memory/reclamation/epoch_manager.h

@@ -63,7 +63,7 @@ public:
     EpochManager(const std::uint16_t count_channels, dynamic::Allocator &allocator,
                  util::maybe_atomic<bool> &is_running) noexcept
         :
-        Thread(*system::Environment::env, Name("EpochManager"), 8192),
+        Thread(*system::Environment::env(), Name("EpochManager"), 8192),
         _count_channels(count_channels), _is_running(is_running), _allocator(allocator)
     {
     }
@@ -159,7 +159,7 @@ private:
     std::atomic<epoch_t> _global_epoch{0U};
 
     // Genode Timer object, needed for waking up periodically
-    Timer::Connection _timer { *system::Environment::env };
+    Timer::Connection _timer { *system::Environment::env() };
 
     // Local epochs, one for every channel.
     alignas(64) std::array<LocalEpoch, tasking::config::max_cores()> _local_epochs;

src/mx/system/environment.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <base/component.h>
+#include <libc/component.h>
 
 namespace mx::system {
 /**
@@ -7,15 +7,24 @@ namespace mx::system {
  */
 class Environment
 {
-public:
-
+private:
     /**
      * @return Genode environment capability
      * 
      */
-    static Genode::Env *env;
+    Libc::Env *_env;
 
-    
+public:
+    Environment() = default;
+
+    Libc::Env *getenv() { return _env; }
+    void setenv(Libc::Env *env) { Environment::get_instance().setenv(env);  }
+
+    static Environment& get_instance() { static Environment env;
+        return env;
+    }
+
+    static Libc::Env *env() { return Environment::get_instance().getenv(); }
 
     /**
      * @return True, if NUMA balancing is enabled by the system.

src/mx/system/topology.h

@@ -36,7 +36,7 @@ public:
     /**
      * @return Number of available cores.
      */
-    static std::uint16_t count_cores() { return std::uint16_t(Environment::env->cpu().affinity_space().total());
+    static std::uint16_t count_cores() { return std::uint16_t(Environment::env()->cpu().affinity_space().total());
      }
 };
 } // namespace mx::system