[PATCH 3/9] Add external interface changes: new lock types for pthread_mutex_t

[Andi Kleen <andi at firstfloor dot org>]

From: Andi Kleen <ak@linux.intel.com>

Add a new PTHREAD_MUTEX_INIT_NP() macro that allows to set generic
mutex type/flags combinations. Expose PTHREAD_MUTEX_ELISION_NP
and PTHREAD_MUTEX_NO_ELISION_NP flags. In addition also expose
the existing PTHREAD_MUTEX_PSHARED_NP flag.

Similar flags are defined for the rwlocks.

This allows programs to set elision in a fine grained matter.
See the manual for more details.

recursive/pi/error checking mutexes do not elide.
Recursive could be implemented at some point, but are not currently.
The initializer allows to set illegal combinations currently.

2013-05-02  Andi Kleen  <ak@linux.intel.com>

	* pthreadP.h: Add elision types.
          (PTHREAD_MUTEX_TYPE_EL): Add.
	* sysdeps/pthread/pthread.h: Add elision initializers.
	  (PTHREAD_MUTEX_ELISION_NP, PTHREAD_MUTEX_NO_ELISION_NP,
	   PTHREAD_MUTEX_PSHARED_NP): Add new flags.
          (__PTHREAD_SPINS): Add.
	  Update mutex initializers.
	  (PTHREAD_RWLOCK_ELISION_NP, PTHREAD_RWLOCK_NO_ELISION_NP): Add.
---
 nptl/pthreadP.h                |   17 +++++++++++-
 nptl/sysdeps/pthread/pthread.h |   51 ++++++++++++++++++++++++++++++++--------
 2 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index 31cae86..50196e4 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -60,7 +60,7 @@
 /* Internal mutex type value.  */
 enum
 {
-  PTHREAD_MUTEX_KIND_MASK_NP = 3,
+  PTHREAD_MUTEX_KIND_MASK_NP = 7,
   PTHREAD_MUTEX_ROBUST_NORMAL_NP = 16,
   PTHREAD_MUTEX_ROBUST_RECURSIVE_NP
   = PTHREAD_MUTEX_ROBUST_NORMAL_NP | PTHREAD_MUTEX_RECURSIVE_NP,
@@ -93,12 +93,25 @@ enum
   PTHREAD_MUTEX_PP_ERRORCHECK_NP
   = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ERRORCHECK_NP,
   PTHREAD_MUTEX_PP_ADAPTIVE_NP
-  = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ADAPTIVE_NP
+  = PTHREAD_MUTEX_PRIO_PROTECT_NP | PTHREAD_MUTEX_ADAPTIVE_NP,
+  PTHREAD_MUTEX_ELISION_FLAGS_NP
+  = PTHREAD_MUTEX_ELISION_NP | PTHREAD_MUTEX_NO_ELISION_NP,
+
+  PTHREAD_MUTEX_TIMED_ELISION_NP =
+	  PTHREAD_MUTEX_TIMED_NP | PTHREAD_MUTEX_ELISION_NP,
+  PTHREAD_MUTEX_TIMED_NO_ELISION_NP =
+	  PTHREAD_MUTEX_TIMED_NP | PTHREAD_MUTEX_NO_ELISION_NP,
+  PTHREAD_MUTEX_ADAPTIVE_ELISION_NP =
+	  PTHREAD_MUTEX_ADAPTIVE_NP | PTHREAD_MUTEX_ELISION_NP,
+  PTHREAD_MUTEX_ADAPTIVE_NO_ELISION_NP =
+	  PTHREAD_MUTEX_ADAPTIVE_NP | PTHREAD_MUTEX_NO_ELISION_NP
 };
 #define PTHREAD_MUTEX_PSHARED_BIT 128
 
 #define PTHREAD_MUTEX_TYPE(m) \
   ((m)->__data.__kind & 127)
+#define PTHREAD_MUTEX_TYPE_EL(m) \
+  ((m)->__data.__kind & (127|PTHREAD_MUTEX_ELISION_FLAGS_NP))
 
 #if LLL_PRIVATE == 0 && LLL_SHARED == 128
 # define PTHREAD_MUTEX_PSHARED(m) \
diff --git a/nptl/sysdeps/pthread/pthread.h b/nptl/sysdeps/pthread/pthread.h
index 10bcb80..5afadaa 100644
--- a/nptl/sysdeps/pthread/pthread.h
+++ b/nptl/sysdeps/pthread/pthread.h
@@ -44,7 +44,12 @@ enum
   PTHREAD_MUTEX_TIMED_NP,
   PTHREAD_MUTEX_RECURSIVE_NP,
   PTHREAD_MUTEX_ERRORCHECK_NP,
-  PTHREAD_MUTEX_ADAPTIVE_NP
+  PTHREAD_MUTEX_ADAPTIVE_NP,
+
+  PTHREAD_MUTEX_ELISION_NP    = 1024,
+  PTHREAD_MUTEX_NO_ELISION_NP = 2048,
+  PTHREAD_MUTEX_PSHARED_NP    = 128
+
 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
   ,
   PTHREAD_MUTEX_NORMAL = PTHREAD_MUTEX_TIMED_NP,
@@ -83,27 +88,50 @@ enum
 
 
 /* Mutex initializers.  */
+#if __PTHREAD_MUTEX_HAVE_ELISION == 1
+#define __PTHREAD_SPINS 0, 0
+#elif __PTHREAD_MUTEX_HAVE_ELISION == 2
+#define __PTHREAD_SPINS { 0, 0 }
+#else
+#define __PTHREAD_SPINS 0
+#endif
+
 #ifdef __PTHREAD_MUTEX_HAVE_PREV
 # define PTHREAD_MUTEX_INITIALIZER \
-  { { 0, 0, 0, 0, 0, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, 0, __PTHREAD_SPINS, { 0, 0 } } }
 # ifdef __USE_GNU
 #  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
 #  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, __PTHREAD_SPINS, { 0, 0 } } }
+#  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
 #  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0, 0 } } }
+  { { 0, 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, __PTHREAD_SPINS, { 0, 0 } } }
+
+/* Generic initializer allowing to specify type and additional flags.
+   Valid types are
+   PTHREAD_MUTEX_TIMED_NP, PTHREAD_MUTEX_ADAPTIVE_NP, ...
+   Valid flags are 
+   PTHREAD_MUTEX_PSHARED_NP, PTHREAD_MUTEX_ELISION_NP, PTHREAD_MUTEX_NO_ELISION_NP.
+   Both are or'ed together. Some combinations are not legal. */
+#  define PTHREAD_MUTEX_INIT_NP(type) \
+   { { 0, 0, 0, 0, (type), __PTHREAD_SPINS, { 0, 0 } } }
 # endif
 #else
 # define PTHREAD_MUTEX_INITIALIZER \
-  { { 0, 0, 0, 0, 0, { 0 } } }
+  { { 0, 0, 0, 0, 0, { __PTHREAD_SPINS } } }
 # ifdef __USE_GNU
 #  define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_RECURSIVE_NP, 0, { __PTHREAD_SPINS } } }
 #  define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_ERRORCHECK_NP, 0, { __PTHREAD_SPINS } } }
 #  define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP \
-  { { 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { 0 } } }
+  { { 0, 0, 0, PTHREAD_MUTEX_ADAPTIVE_NP, 0, { __PTHREAD_SPINS } } }
+/* Generic initializer allowing to specify type and additional flags. */
+#  define PTHREAD_MUTEX_INIT_NP(type) \
+  { { 0, 0, 0, (type), 0, { __PTHREAD_SPINS } } }
+
 # endif
 #endif
 
@@ -115,7 +143,10 @@ enum
   PTHREAD_RWLOCK_PREFER_READER_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,
-  PTHREAD_RWLOCK_DEFAULT_NP = PTHREAD_RWLOCK_PREFER_READER_NP
+  PTHREAD_RWLOCK_DEFAULT_NP = PTHREAD_RWLOCK_PREFER_READER_NP,
+
+  PTHREAD_RWLOCK_ELISION_NP = (1U << 7),
+  PTHREAD_RWLOCK_NO_ELISION_NP = (1U << 8)
 };
 
 /* Define __PTHREAD_RWLOCK_INT_FLAGS_SHARED to 1 if pthread_rwlock_t
-- 
1.7.7.6