* cygwin.din (pthread_spin_destroy): Export.

	(pthread_spin_init): Export.
	(pthread_spin_lock): Export.
	(pthread_spin_trylock): Export.
	(pthread_spin_unlock): Export.
	* posix.sgml (std-susv4): Add pthread_spin_destroy, pthread_spin_init,
	pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock.
	(std-notimpl): Remove pthread_spin_[...].
	* pthread.cc (pthread_spin_init): New function.
	* thread.cc (pthread_spinlock::is_good_object): New function.
	(pthread_mutex::pthread_mutex): Rearrange initializers to accommodate
	protected data in pthread_mutex.
	(pthread_spinlock::pthread_spinlock): New constructor.
	(pthread_spinlock::lock): New method.
	(pthread_spinlock::unlock): New method.
	(pthread_spinlock::init): New method.
	(pthread_spin_lock): New function.
	(pthread_spin_trylock): New function.
	(pthread_spin_unlock): New function.
	(pthread_spin_destroy): New function.
	* thread.h (PTHREAD_SPINLOCK_MAGIC): Define.
	(class pthread_mutex): Change access level of members shared with
	derived classes to protected.
	(pthread_mutex::set_shared): New protected method.
	(class pthread_spinlock): New class, derived class of pthread_mutex.
	* include/pthread.h (pthread_spin_destroy): Declare.
	(pthread_spin_init): Declare.
	(pthread_spin_lock): Declare.
	(pthread_spin_trylock): Declare.
	(pthread_spin_unlock): Declare.
	* include/cygwin/types.h (pthread_spinlock_t): New typedef.
	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.

9 files changed, 217 insertions, 13 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 0c1a61075..fc9aac203 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,40 @@
 2011-03-29  Corinna Vinschen  <corinna@vinschen.de>
 
+	* cygwin.din (pthread_spin_destroy): Export.
+	(pthread_spin_init): Export.
+	(pthread_spin_lock): Export.
+	(pthread_spin_trylock): Export.
+	(pthread_spin_unlock): Export.
+	* posix.sgml (std-susv4): Add pthread_spin_destroy, pthread_spin_init,
+	pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock.
+	(std-notimpl): Remove pthread_spin_[...].
+	* pthread.cc (pthread_spin_init): New function.
+	* thread.cc (pthread_spinlock::is_good_object): New function.
+	(pthread_mutex::pthread_mutex): Rearrange initializers to accommodate
+	protected data in pthread_mutex.
+	(pthread_spinlock::pthread_spinlock): New constructor.
+	(pthread_spinlock::lock): New method.
+	(pthread_spinlock::unlock): New method.
+	(pthread_spinlock::init): New method.
+	(pthread_spin_lock): New function.
+	(pthread_spin_trylock): New function.
+	(pthread_spin_unlock): New function.
+	(pthread_spin_destroy): New function.
+	* thread.h (PTHREAD_SPINLOCK_MAGIC): Define.
+	(class pthread_mutex): Change access level of members shared with
+	derived classes to protected.
+	(pthread_mutex::set_shared): New protected method.
+	(class pthread_spinlock): New class, derived class of pthread_mutex.
+	* include/pthread.h (pthread_spin_destroy): Declare.
+	(pthread_spin_init): Declare.
+	(pthread_spin_lock): Declare.
+	(pthread_spin_trylock): Declare.
+	(pthread_spin_unlock): Declare.
+	* include/cygwin/types.h (pthread_spinlock_t): New typedef.
+	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
+
+2011-03-29  Corinna Vinschen  <corinna@vinschen.de>
+
 	* net.cc (SIO_BASE_HANDLE): Define.
 	(fdsock): If we got an LSP handle, try to create a copy of the base
 	handle instead.  Change comment to explain.
diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din
index e1dcea75b..10565adeb 100644
--- a/winsup/cygwin/cygwin.din
+++ b/winsup/cygwin/cygwin.din
@@ -1244,6 +1244,11 @@ pthread_setschedparam SIGFE
 pthread_setspecific SIGFE
 pthread_sigmask SIGFE
 pthread_suspend SIGFE
+pthread_spin_destroy SIGFE
+pthread_spin_init SIGFE
+pthread_spin_lock SIGFE
+pthread_spin_trylock SIGFE
+pthread_spin_unlock SIGFE
 pthread_testcancel SIGFE
 pthread_yield = sched_yield SIGFE
 ptsname SIGFE
diff --git a/winsup/cygwin/include/cygwin/types.h b/winsup/cygwin/include/cygwin/types.h
index a202d958d..efc076a45 100644
--- a/winsup/cygwin/include/cygwin/types.h
+++ b/winsup/cygwin/include/cygwin/types.h
@@ -1,6 +1,6 @@
 /* types.h
 
-   Copyright 2001, 2002, 2003, 2005, 2006, 2010 Red Hat Inc.
+   Copyright 2001, 2002, 2003, 2005, 2006, 2010, 2011 Red Hat Inc.
    Written by Robert Collins <rbtcollins@hotmail.com>
 
 This file is part of Cygwin.
@@ -195,6 +195,7 @@ typedef struct
   int state;
 }
 pthread_once_t;
+typedef struct __pthread_spinlock_t {char __dummy;} *pthread_spinlock_t;
 typedef struct __pthread_rwlock_t {char __dummy;} *pthread_rwlock_t;
 typedef struct __pthread_rwlockattr_t {char __dummy;} *pthread_rwlockattr_t;
 
@@ -210,6 +211,7 @@ typedef class pthread_mutexattr *pthread_mutexattr_t;
 typedef class pthread_condattr *pthread_condattr_t;
 typedef class pthread_cond *pthread_cond_t;
 typedef class pthread_once pthread_once_t;
+typedef class pthread_spinlock *pthread_spinlock_t;
 typedef class pthread_rwlock *pthread_rwlock_t;
 typedef class pthread_rwlockattr *pthread_rwlockattr_t;
 
diff --git a/winsup/cygwin/include/cygwin/version.h b/winsup/cygwin/include/cygwin/version.h
index 91c3c53d9..58c55f6e3 100644
--- a/winsup/cygwin/include/cygwin/version.h
+++ b/winsup/cygwin/include/cygwin/version.h
@@ -401,12 +401,14 @@ details. */
       235: Export madvise.
       236: Export pthread_yield, __xpg_strerror_r.
       237: Export strchrnul.
+      238: Export pthread_spin_destroy, pthread_spin_init, pthread_spin_lock,
+	   pthread_spin_trylock, pthread_spin_unlock.
      */
 
      /* Note that we forgot to bump the api for ualarm, strtoll, strtoull */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 237
+#define CYGWIN_VERSION_API_MINOR 238
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible
diff --git a/winsup/cygwin/include/pthread.h b/winsup/cygwin/include/pthread.h
index 8e35808e1..10a53f3fd 100644
--- a/winsup/cygwin/include/pthread.h
+++ b/winsup/cygwin/include/pthread.h
@@ -162,6 +162,13 @@ int pthread_mutexattr_setprotocol (pthread_mutexattr_t *, int);
 int pthread_mutexattr_setpshared (pthread_mutexattr_t *, int);
 int pthread_mutexattr_settype (pthread_mutexattr_t *, int);
 
+/* Spinlocks */
+int pthread_spin_destroy (pthread_spinlock_t *);
+int pthread_spin_init (pthread_spinlock_t *, int);
+int pthread_spin_lock (pthread_spinlock_t *);
+int pthread_spin_trylock (pthread_spinlock_t *);
+int pthread_spin_unlock (pthread_spinlock_t *);
+
 /* RW Locks */
 int pthread_rwlock_destroy (pthread_rwlock_t *rwlock);
 int pthread_rwlock_init (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr);
diff --git a/winsup/cygwin/posix.sgml b/winsup/cygwin/posix.sgml
index 393a2bcb7..53e760633 100644
--- a/winsup/cygwin/posix.sgml
+++ b/winsup/cygwin/posix.sgml
@@ -600,6 +600,11 @@ also IEEE Std 1003.1-2008 (POSIX.1-2008).</para>
     pthread_setschedparam
     pthread_setspecific
     pthread_sigmask
+    pthread_spin_destroy
+    pthread_spin_init
+    pthread_spin_lock
+    pthread_spin_trylock
+    pthread_spin_unlock
     pthread_testcancel
     ptsname
     putc
@@ -1384,7 +1389,6 @@ also IEEE Std 1003.1-2008 (POSIX.1-2008).</para>
     pthread_rwlock_timedrdlock
     pthread_rwlock_timedwrlock
     pthread_setschedprio
-    pthread_spin_[...]
     putmsg
     reminderl
     remquol
diff --git a/winsup/cygwin/pthread.cc b/winsup/cygwin/pthread.cc
index 18f2aea5d..3dddf48b1 100644
--- a/winsup/cygwin/pthread.cc
+++ b/winsup/cygwin/pthread.cc
@@ -1,6 +1,6 @@
 /* pthread.cc: posix pthread interface for Cygwin
 
-   Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2005, 2007 Red Hat, Inc.
+   Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2005, 2007, 2011 Red Hat, Inc.
 
    Originally written by Marco Fuykschot <marco@ddi.nl>
 
@@ -91,6 +91,14 @@ pthread_mutex_init (pthread_mutex_t * mutex, const pthread_mutexattr_t * attr)
   return pthread_mutex::init (mutex, attr, NULL);
 }
 
+/* Spinlocks */
+int
+pthread_spin_init (pthread_spinlock_t *spinlock, int pshared)
+{
+  return pthread_spinlock::init (spinlock, pshared);
+}
+
+
 /* Synchronisation */
 int
 pthread_cond_init (pthread_cond_t * cond, const pthread_condattr_t * attr)
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 891b43fb9..29674d4ed 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -1,7 +1,7 @@
 /* thread.cc: Locking and threading module functions
 
    Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
-   2006, 2007, 2008, 2009, 2010 Red Hat, Inc.
+   2006, 2007, 2008, 2009, 2010, 2011 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -174,6 +174,14 @@ pthread_key::is_good_object (pthread_key_t const *key)
 }
 
 inline bool
+pthread_spinlock::is_good_object (pthread_spinlock_t const *mutex)
+{
+  if (verifyable_object_isvalid (mutex, PTHREAD_SPINLOCK_MAGIC) != VALID_OBJECT)
+    return false;
+  return true;
+}
+
+inline bool
 pthread_mutex::is_good_object (pthread_mutex_t const *mutex)
 {
   if (verifyable_object_isvalid (mutex, PTHREAD_MUTEX_MAGIC) != VALID_OBJECT)
@@ -1547,11 +1555,11 @@ pthread_mutex::init_mutex ()
 pthread_mutex::pthread_mutex (pthread_mutexattr *attr) :
   verifyable_object (0),	/* set magic to zero initially */
   lock_counter (0),
-  win32_obj_id (NULL), recursion_counter (0),
-  condwaits (0), owner (_new_mutex),
+  win32_obj_id (NULL), owner (_new_mutex),
 #ifdef DEBUGGING
   tid (0),
 #endif
+  recursion_counter (0), condwaits (0),
   type (PTHREAD_MUTEX_ERRORCHECK),
   pshared (PTHREAD_PROCESS_PRIVATE)
 {
@@ -1701,6 +1709,65 @@ pthread_mutexattr::~pthread_mutexattr ()
 {
 }
 
+/* pshared spinlocks
+
+   The infrastructure is provided by the underlying pthread_mutex class.
+   The rest is a simplification implementing spin locking. */
+
+pthread_spinlock::pthread_spinlock (int pshared) :
+  pthread_mutex (NULL)
+{
+  magic = PTHREAD_SPINLOCK_MAGIC;
+  set_type (PTHREAD_MUTEX_NORMAL);
+  set_shared (pshared);
+}
+
+int
+pthread_spinlock::lock ()
+{
+  pthread_t self = ::pthread_self ();
+  int result = -1;
+
+  do
+    {
+      if (InterlockedExchange ((long *) &lock_counter, 1) == 0)
+	{
+	  set_owner (self);
+	  result = 0;
+	}
+      else if (pthread::equal (owner, self))
+	result = EDEADLK;
+      else /* Minimal timeout to minimize CPU usage while still spinning. */
+	cancelable_wait (win32_obj_id, 1L, cw_no_cancel, cw_sig_resume);
+    }
+  while (result == -1);
+  pthread_printf ("spinlock %p, self %p, owner %p", this, self, owner);
+  return result;
+}
+
+int
+pthread_spinlock::unlock ()
+{
+  pthread_t self = ::pthread_self ();
+  int result = 0;
+
+  if (!pthread::equal (owner, self))
+    result = EPERM;
+  else
+    {
+      owner = (pthread_t) _unlocked_mutex;
+#ifdef DEBUGGING
+      tid = 0;
+#endif
+      InterlockedExchange ((long *) &lock_counter, 0);
+      ::SetEvent (win32_obj_id);
+      result = 0;
+    }
+  pthread_printf ("spinlock %p, owner %p, self %p, res %d",
+		  this, owner, self, result);
+  return result;
+}
+
 DWORD WINAPI
 pthread::thread_init_wrapper (void *arg)
 {
@@ -2768,6 +2835,63 @@ pthread_mutex_setprioceiling (pthread_mutex_t *mutex, int prioceiling,
   return ENOSYS;
 }
 
+/* Spinlocks  */
+
+int
+pthread_spinlock::init (pthread_spinlock_t *spinlock, int pshared)
+{
+  pthread_spinlock_t new_spinlock = new pthread_spinlock (pshared);
+  if (!is_good_object (&new_spinlock))
+    {
+      delete new_spinlock;
+      return EAGAIN;
+    }
+
+  myfault efault;
+  if (efault.faulted ())
+    {
+      delete new_spinlock;
+      return EINVAL;
+    }
+
+  *spinlock = new_spinlock;
+  pthread_printf ("*spinlock %p, pshared %d", *spinlock, pshared);
+
+  return 0;
+}
+
+extern "C" int
+pthread_spin_lock (pthread_spinlock_t *spinlock)
+{
+  if (!pthread_spinlock::is_good_object (spinlock))
+    return EINVAL;
+  return (*spinlock)->lock ();
+}
+
+extern "C" int
+pthread_spin_trylock (pthread_spinlock_t *spinlock)
+{
+  if (!pthread_spinlock::is_good_object (spinlock))
+    return EINVAL;
+  return (*spinlock)->trylock ();
+}
+
+extern "C" int
+pthread_spin_unlock (pthread_spinlock_t *spinlock)
+{
+  if (!pthread_spinlock::is_good_object (spinlock))
+    return EINVAL;
+  return (*spinlock)->unlock ();
+}
+
+extern "C" int
+pthread_spin_destroy (pthread_spinlock_t *spinlock)
+{
+  if (!pthread_spinlock::is_good_object (spinlock))
+    return EINVAL;
+  return (*spinlock)->destroy ();
+}
+
 /* Win32 doesn't support mutex priorities - see __pthread_mutex_getprioceiling
    for more detail */
 extern "C" int
diff --git a/winsup/cygwin/thread.h b/winsup/cygwin/thread.h
index bea8e2aa3..f96714f49 100644
--- a/winsup/cygwin/thread.h
+++ b/winsup/cygwin/thread.h
@@ -1,7 +1,7 @@
 /* thread.h: Locking and threading module definitions
 
    Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007,
-   2008, 2009, 2010 Red Hat, Inc.
+   2008, 2009, 2010, 2011 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -98,6 +98,7 @@ class pinfo;
 #define PTHREAD_ONCE_MAGIC PTHREAD_MAGIC+8
 #define PTHREAD_RWLOCK_MAGIC PTHREAD_MAGIC+9
 #define PTHREAD_RWLOCKATTR_MAGIC PTHREAD_MAGIC+10
+#define PTHREAD_SPINLOCK_MAGIC PTHREAD_MAGIC+11
 
 #define MUTEX_OWNER_ANONYMOUS ((pthread_t) -1)
 
@@ -303,18 +304,15 @@ public:
     mutexes.for_each (&pthread_mutex::_fixup_after_fork);
   }
 
-private:
+protected:
   unsigned long lock_counter;
   HANDLE win32_obj_id;
-  unsigned int recursion_counter;
-  LONG condwaits;
   pthread_t owner;
 #ifdef DEBUGGING
   DWORD tid;		/* the thread id of the owner */
 #endif
-  int type;
-  int pshared;
 
+  void set_shared (int in_shared) { pshared = in_shared; }
   void set_owner (pthread_t self)
   {
     recursion_counter = 1;
@@ -323,10 +321,17 @@ private:
     tid = GetCurrentThreadId ();
 #endif
   }
+
   static const pthread_t _new_mutex;
   static const pthread_t _unlocked_mutex;
   static const pthread_t _destroyed_mutex;
 
+private:
+  unsigned int recursion_counter;
+  LONG condwaits;
+  int type;
+  int pshared;
+
   bool no_owner ();
   void _fixup_after_fork ();
 
@@ -335,6 +340,18 @@ private:
   friend class pthread_cond;
 };
 
+class pthread_spinlock: public pthread_mutex
+{
+public:
+  static bool is_good_object (pthread_spinlock_t const *);
+  static int init (pthread_spinlock_t *, int);
+
+  int lock ();
+  int unlock ();
+
+  pthread_spinlock (int);
+};
+
 #define WAIT_CANCELED   (WAIT_OBJECT_0 + 1)
 #define WAIT_SIGNALED  (WAIT_OBJECT_0 + 2)