[.]

2015-01-21   Basile Starynkevitch  <basile@starynkevitch.net>
	{{merged with trunk -i.e. GCC5.0 in stage4- using
	svn merge -r209216:219879 svn+ssh://bstarynk@gcc.gnu.org/svn/gcc/trunk
	but should probably have used
	svn merge -r209216:219879 ^/trunk
	we don't use svnmerge.py anymore since our svn is version 1.8.10
	}}
	VERY UNSTABLE

2015-01-20   Basile Starynkevitch  <basile@starynkevitch.net>
	Move previous topdir ChangeLog.MELT to ChangeLog.MELT.2008-2014


[contrib/]
2015-01-21   Basile Starynkevitch  <basile@starynkevitch.net>

	* MELT-Plugin-Makefile: Able to make upgrade-melt as a
	plugin. Works for GCC 5.0. Remove GCC 4.7 old stuff.

	Move previous contrib/ChangeLog.MELT to ChangeLog.MELT.2008-2014

[gcc/]
2015-01-21   Basile Starynkevitch  <basile@starynkevitch.net>
	{{merged with trunk -i.e. GCC5.0 in stage4- using
	svn merge -r209216:219879 svn+ssh://bstarynk@gcc.gnu.org/svn/gcc/trunk
	but should probably have used
	svn merge -r209216:219879 ^/trunk

	**@@@ UNSTABLE since libmelt-ana-gimple.melt not compiling, but
	translator painfully bootstrapping!!@@@@ }}

	* toplev.c: Merged manually by keeping MELT extra stuff.
	* toplev.h: Likewise.
	* gengtype.c: Add "melt-runtime.h" in list, but merged with trunk.

	* melt-runtime.h (MELT_VERSION_STRING): Bump to "1.2-pre-merged".
	(meltgc_walk_gimple_seq): Remove.
	(gt_ggc_mx_gimple_statement_d): Same for GCC 4.9 & 5.0

	* melt-runtime.cc: Update copyright year.
	(ggc_alloc_cleared_melt_valuevector_st, melt_resize_scangcvect):
	Call ggc_internal_cleared_alloc.
	(melt_val2passflag): Skip TODO_verify_ssa, TODO_verify_flow,
	TODO_verify_stmts, TODO_verify_rtl_sharing for GCC 5.0.
	(meltgc_walkstmt_cb, meltgc_walktree_cb)
	(melt_tree_walk_frame_size, meltgc_walk_gimple_seq): Remove.
	(melt_gt_ggc_mx_gimple_seq_d): Call
	gt_ggc_mx_gimple_statement_base.
	* melt-build-script.tpl: Update copyright year. Don't symlink
	meltrunsup.h anymore.
	* melt-build-script.sh: Regenerate.

	* melt/warmelt-base.melt: Update copyright year.
	(valdesc_object, valdesc_mapobjects, valdesc_mapstrings)
	(valdesc_multiple, valdesc_closure, valdesc_routine, valdesc_hook)
	(valdesc_bucketlongs, valdesc_jsonobject, valdesc_string)
	(valdesc_strbuf, valdesc_pair, valdesc_list, valdesc_int)
	(valdesc_double, valdesc_mixint, valdesc_mixloc)
	(valdesc_mixbigint, valdesc_real, valdesc_special_data): Use
	ggc_internal_alloc & ggc_internal_cleared_alloc for GCC 5.0.
	(json_canonical_name): Use ISUPPER, ISALPHA, TOUPPER instead of
	their standard <ctype.h> lowercase macros.
	* melt/warmelt-modes.melt: Update copyright year.
	(generate_runtypesupport_forwcopy_fun): Emit both GCC 4.9 & 5.0
	compatible code.
	* melt/libmelt-ana-base.melt: Update copyright year.
	* melt/libmelt-ana-gimple.melt: TO BE IMPROVED
	* melt/generated/*: Painfully regenerated several times thru GCC
	4.9 MELT plugin.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@219975 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 84 insertions, 0 deletions

diff --git a/libsanitizer/sanitizer_common/sanitizer_mutex.h b/libsanitizer/sanitizer_common/sanitizer_mutex.h
index d78f43edaae..adc3add6008 100644
--- a/libsanitizer/sanitizer_common/sanitizer_mutex.h
+++ b/libsanitizer/sanitizer_common/sanitizer_mutex.h
@@ -81,6 +81,88 @@ class BlockingMutex {
   uptr owner_;  // for debugging
 };
 
+// Reader-writer spin mutex.
+class RWMutex {
+ public:
+  RWMutex() {
+    atomic_store(&state_, kUnlocked, memory_order_relaxed);
+  }
+
+  ~RWMutex() {
+    CHECK_EQ(atomic_load(&state_, memory_order_relaxed), kUnlocked);
+  }
+
+  void Lock() {
+    u32 cmp = kUnlocked;
+    if (atomic_compare_exchange_strong(&state_, &cmp, kWriteLock,
+                                       memory_order_acquire))
+      return;
+    LockSlow();
+  }
+
+  void Unlock() {
+    u32 prev = atomic_fetch_sub(&state_, kWriteLock, memory_order_release);
+    DCHECK_NE(prev & kWriteLock, 0);
+    (void)prev;
+  }
+
+  void ReadLock() {
+    u32 prev = atomic_fetch_add(&state_, kReadLock, memory_order_acquire);
+    if ((prev & kWriteLock) == 0)
+      return;
+    ReadLockSlow();
+  }
+
+  void ReadUnlock() {
+    u32 prev = atomic_fetch_sub(&state_, kReadLock, memory_order_release);
+    DCHECK_EQ(prev & kWriteLock, 0);
+    DCHECK_GT(prev & ~kWriteLock, 0);
+    (void)prev;
+  }
+
+  void CheckLocked() {
+    CHECK_NE(atomic_load(&state_, memory_order_relaxed), kUnlocked);
+  }
+
+ private:
+  atomic_uint32_t state_;
+
+  enum {
+    kUnlocked = 0,
+    kWriteLock = 1,
+    kReadLock = 2
+  };
+
+  void NOINLINE LockSlow() {
+    for (int i = 0;; i++) {
+      if (i < 10)
+        proc_yield(10);
+      else
+        internal_sched_yield();
+      u32 cmp = atomic_load(&state_, memory_order_relaxed);
+      if (cmp == kUnlocked &&
+          atomic_compare_exchange_weak(&state_, &cmp, kWriteLock,
+                                       memory_order_acquire))
+          return;
+    }
+  }
+
+  void NOINLINE ReadLockSlow() {
+    for (int i = 0;; i++) {
+      if (i < 10)
+        proc_yield(10);
+      else
+        internal_sched_yield();
+      u32 prev = atomic_load(&state_, memory_order_acquire);
+      if ((prev & kWriteLock) == 0)
+        return;
+    }
+  }
+
+  RWMutex(const RWMutex&);
+  void operator = (const RWMutex&);
+};
+
 template<typename MutexType>
 class GenericScopedLock {
  public:
@@ -121,6 +203,8 @@ class GenericScopedReadLock {
 
 typedef GenericScopedLock<StaticSpinMutex> SpinMutexLock;
 typedef GenericScopedLock<BlockingMutex> BlockingMutexLock;
+typedef GenericScopedLock<RWMutex> RWMutexLock;
+typedef GenericScopedReadLock<RWMutex> RWMutexReadLock;
 
 }  // namespace __sanitizer