From 207b1fa616910e24ff77f4bfd42d1b623b4ca535 Mon Sep 17 00:00:00 2001
From: Rodrigo Kumpera <kumpera@gmail.com>
Date: Thu, 16 Apr 2015 19:01:13 -0400
Subject: [PATCH] [threading] Add a global variable that is set while a global
 suspend is hapening.

This global var is meant to be used by JIT'd code to efficiently implement polling.
---
 mono/utils/mono-threads-coop.c    | 13 +++++++++++++
 mono/utils/mono-threads-coop.h    |  3 +++
 mono/utils/mono-threads-posix.c   | 10 ++++++++++
 mono/utils/mono-threads-windows.c | 10 ++++++++++
 mono/utils/mono-threads.c         |  2 ++
 mono/utils/mono-threads.h         |  3 +++
 6 files changed, 41 insertions(+)

diff --git a/mono/utils/mono-threads-coop.c b/mono/utils/mono-threads-coop.c
index f19021b5a56..b44719109ff 100644
--- a/mono/utils/mono-threads-coop.c
+++ b/mono/utils/mono-threads-coop.c
@@ -19,6 +19,7 @@
 
 #ifdef USE_COOP_BACKEND
 
+volatile size_t mono_polling_required;
 
 void
 mono_threads_state_poll (void)
@@ -249,5 +250,17 @@ mono_threads_platform_register (MonoThreadInfo *info)
 	//See the above for what's wrong here.
 }
 
+void
+mono_threads_core_begin_global_suspend (void)
+{
+	mono_polling_required = 1;
+}
+
+void
+mono_threads_core_end_global_suspend (void)
+{
+	mono_polling_required = 0;
+}
+
 
 #endif
\ No newline at end of file
diff --git a/mono/utils/mono-threads-coop.h b/mono/utils/mono-threads-coop.h
index 8626288f353..6eca0266dcf 100644
--- a/mono/utils/mono-threads-coop.h
+++ b/mono/utils/mono-threads-coop.h
@@ -58,6 +58,9 @@ void mono_threads_reset_blocking_end (void* cookie);
 void* mono_threads_try_prepare_blocking (void);
 void mono_threads_finish_try_blocking (void* cookie);
 
+/* JIT specific interface */
+extern volatile size_t mono_polling_required ;
+
 #else
 
 #define MONO_SUSPEND_CHECK do {	} while (0);
diff --git a/mono/utils/mono-threads-posix.c b/mono/utils/mono-threads-posix.c
index 94f58cdc58e..19fd8b7c12e 100644
--- a/mono/utils/mono-threads-posix.c
+++ b/mono/utils/mono-threads-posix.c
@@ -635,6 +635,16 @@ mono_threads_platform_free (MonoThreadInfo *info)
 {
 }
 
+void
+mono_threads_core_begin_global_suspend (void)
+{
+}
+
+void
+mono_threads_core_end_global_suspend (void)
+{
+}
+
 #endif /*defined (USE_POSIX_BACKEND)*/
 
 #endif
diff --git a/mono/utils/mono-threads-windows.c b/mono/utils/mono-threads-windows.c
index af7bee62097..b5008b4859e 100755
--- a/mono/utils/mono-threads-windows.c
+++ b/mono/utils/mono-threads-windows.c
@@ -407,4 +407,14 @@ mono_threads_core_clear_interruption (void)
 {
 }
 
+void
+mono_threads_core_begin_global_suspend (void)
+{
+}
+
+void
+mono_threads_core_end_global_suspend (void)
+{
+}
+
 #endif
diff --git a/mono/utils/mono-threads.c b/mono/utils/mono-threads.c
index 814a8e45754..bb9acf9103c 100644
--- a/mono/utils/mono-threads.c
+++ b/mono/utils/mono-threads.c
@@ -123,6 +123,7 @@ mono_threads_begin_global_suspend (void)
 {
 	g_assert (pending_suspends == 0);
 	THREADS_SUSPEND_DEBUG ("------ BEGIN GLOBAL OP sp %d rp %d wd %d po %d\n", suspend_posts, resume_posts, waits_done, pending_ops);
+	mono_threads_core_begin_global_suspend ();
 }
 
 void
@@ -130,6 +131,7 @@ mono_threads_end_global_suspend (void)
 {
 	g_assert (pending_suspends == 0);
 	THREADS_SUSPEND_DEBUG ("------ END GLOBAL OP sp %d rp %d wd %d po %d\n", suspend_posts, resume_posts, waits_done, pending_ops);
+	mono_threads_core_end_global_suspend ();
 }
 
 static void
diff --git a/mono/utils/mono-threads.h b/mono/utils/mono-threads.h
index a9a7b914baa..f04543cb4cf 100644
--- a/mono/utils/mono-threads.h
+++ b/mono/utils/mono-threads.h
@@ -483,6 +483,9 @@ HANDLE mono_threads_core_open_handle (void);
 HANDLE mono_threads_core_open_thread_handle (HANDLE handle, MonoNativeThreadId tid);
 void mono_threads_core_set_name (MonoNativeThreadId tid, const char *name);
 
+void mono_threads_core_begin_global_suspend (void);
+void mono_threads_core_end_global_suspend (void);
+
 /* Internal API between mono-threads and its backends. */
 
 /* Backend functions - a backend must implement all of the following */
-- 
2.11.4.GIT