Revert "Revert "rts/base: Fix #9423"" and resolve issue that caused the revert.

Summary:
This reverts commit 4748f5936fe72d96edfa17b153dbfd84f2c4c053. The fix for #9423
was reverted because this commit introduced a C function setIOManagerControlFd()
(defined in Schedule.c) defined for all OS types, while the prototype
(in includes/rts/IOManager.h) was only included when mingw32_HOST_OS is
not defined. This broke Windows builds.

This commit reverts the original commit and resolves the problem by only defining
setIOManagerControlFd() when mingw32_HOST_OS is defined. Hence the missing prototype
error should not occur on Windows.

In addition, since the io_manager_control_wr_fd field of the Capability struct is only
usd by the setIOManagerControlFd, this commit includes the io_manager_control_wr_fd
field in the Capability struct only when mingw32_HOST_OS is not defined.

Test Plan: Try to compile successfully on all platforms.

Reviewers: austin

Reviewed By: austin

Subscribers: simonmar, ezyang, carter

Differential Revision: https://phabricator.haskell.org/D174

1 files changed, 19 insertions, 0 deletions

diff --git a/rts/Capability.c b/rts/Capability.c
index 29c5270416..a954006257 100644
--- a/rts/Capability.c
+++ b/rts/Capability.c
@@ -27,6 +27,10 @@
 #include "STM.h"
 #include "RtsUtils.h"
 
+#if !defined(mingw32_HOST_OS)
+#include "rts/IOManager.h" // for setIOManagerControlFd()
+#endif
+
 #include <string.h>
 
 // one global capability, this is the Capability for non-threaded
@@ -255,6 +259,9 @@ initCapability( Capability *cap, nat i )
     cap->spark_stats.converted  = 0;
     cap->spark_stats.gcd        = 0;
     cap->spark_stats.fizzled    = 0;
+#if !defined(mingw32_HOST_OS)
+    cap->io_manager_control_wr_fd = -1;
+#endif
 #endif
     cap->total_allocated        = 0;
 
@@ -1076,6 +1083,18 @@ rtsBool checkSparkCountInvariant (void)
 }
 #endif
 
+#if !defined(mingw32_HOST_OS)
+void setIOManagerControlFd(nat cap_no USED_IF_THREADS, int fd USED_IF_THREADS) {
+#if defined(THREADED_RTS)
+    if (cap_no < n_capabilities) {
+        capabilities[cap_no]->io_manager_control_wr_fd = fd;
+    } else {
+        errorBelch("warning: setIOManagerControlFd called with illegal capability number.");
+    }
+#endif
+}
+#endif
+
 // Local Variables:
 // mode: C
 // fill-column: 80