Replace a ioManagerDie call with stopIOManager

The latter is the proper hook defined in IOManager.h. The former is part
of a specific I/O manager implementation (the threaded unix one).

2 files changed, 14 insertions, 1 deletions

diff --git a/rts/Capability.c b/rts/Capability.c
index 3ef604693b..c3ef3929d9 100644
--- a/rts/Capability.c
+++ b/rts/Capability.c
@@ -1221,7 +1221,15 @@ shutdownCapability (Capability *cap USED_IF_THREADS,
             //
             // To reproduce this deadlock: run ffi002(threaded1)
             // repeatedly on a loaded machine.
-            ioManagerDie();
+            //
+            // FIXME: stopIOManager is not a per-capability action. It shuts
+            // down the I/O subsystem for all capabilities, but here we call
+            // it once per cap, so this is accidentally quadratic, but mainly
+            // it is confusing. Replace this with a per-capability stop, and
+            // perhaps make it synchronous so it works the first time and we
+            // don't have to come back and try again here.
+            //
+            stopIOManager();
             yieldThread();
             continue;
         }
diff --git a/rts/IOManager.h b/rts/IOManager.h
index 3a66760258..1059f4212e 100644
--- a/rts/IOManager.h
+++ b/rts/IOManager.h
@@ -39,6 +39,11 @@ void initIOManagerAfterFork(/* inout */ Capability **pcap);
 
 
 /* Shutdown hooks: called from hs_exit_ before and after the scheduler exits.
+ *
+ * The stopIOManager is also called many times (once per-capability) within the
+ * scheduler shutdown (but only in threaded mode). This is despite the fact that
+ * stopIOManager shuts down the I/O manager for all capabilities.
+ * FIXME: this is accidentally quadratic and confusing.
  */
 void stopIOManager(void);
 void exitIOManager(bool wait_threads);