[Qemu-devel] [PATCH v2 5/6] tcg: introduce tb_lock_recursive()

["Alex Bennée" <alex.bennee@linaro.org>]

In some cases it is useful to have a recursive lock that can be safely
taken when nested in other critical regions. Rather than make all
tb_locks() recursive having a separate function serves to notify the
reader that it explicitly a possibility in this case.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tcg/tcg.h       |  1 +
 translate-all.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/tcg/tcg.h b/tcg/tcg.h
index 66d7fc0..62e4ced 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -647,6 +647,7 @@ void tcg_pool_reset(TCGContext *s);
 void tcg_pool_delete(TCGContext *s);
 
 void tb_lock(void);
+bool tb_lock_recursive(void);
 void tb_unlock(void);
 void tb_lock_reset(void);
 
diff --git a/translate-all.c b/translate-all.c
index 97e834a..414bc7e 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -134,6 +134,17 @@ void tb_lock(void)
 #endif
 }
 
+bool tb_lock_recursive(void)
+{
+#ifdef CONFIG_USER_ONLY
+    if (have_tb_lock) {
+        return false;
+    }
+    tb_lock();
+#endif
+    return true;
+}
+
 void tb_unlock(void)
 {
 #ifdef CONFIG_USER_ONLY
-- 
2.7.4