New pthread rwlock that is more scalable.

This replaces the pthread rwlock with a new implementation that uses a
more scalable algorithm (primarily through not using a critical section
anymore to make state changes).  The fast path for rdlock acquisition and
release is now basically a single atomic read-modify write or CAS and a few
branches.  See nptl/pthread_rwlock_common.c for details.

	* nptl/DESIGN-rwlock.txt: Remove.
	* nptl/lowlevelrwlock.sym: Remove.
	* nptl/Makefile: Add new tests.
	* nptl/pthread_rwlock_common.c: New file.  Contains the new rwlock.
	* nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove.
	(PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED,
	PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT,
	PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER,
	PTHREAD_RWLOCK_FUTEX_USED): New.
	* nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new
	implementation.
	* nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove.
	(__pthread_rwlock_rdlock): Adapt.
	* nptl/pthread_rwlock_timedrdlock.c
	(pthread_rwlock_timedrdlock): Adapt.
	* nptl/pthread_rwlock_timedwrlock.c
	(pthread_rwlock_timedwrlock): Adapt.
	* nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt.
	* nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt.
	* nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt.
	* nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove.
	(__pthread_rwlock_wrlock): Adapt.
	* nptl/tst-rwlock10.c: Adapt.
	* nptl/tst-rwlock11.c: Adapt.
	* nptl/tst-rwlock17.c: New file.
	* nptl/tst-rwlock18.c: New file.
	* nptl/tst-rwlock19.c: New file.
	* nptl/tst-rwlock2b.c: New file.
	* nptl/tst-rwlock8.c: Adapt.
	* nptl/tst-rwlock9.c: Adapt.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* nptl/nptl-printers.py (): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-rwlock-printers.py: Adapt.
	* nptl/test-rwlockattr-printers.c: Adapt.
	* nptl/test-rwlockattr-printers.py: Adapt.

1 files changed, 6 insertions, 5 deletions

diff --git a/nptl/Makefile b/nptl/Makefile
index 36dbdbb54c..9d5738f270 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -237,10 +237,11 @@ tests = tst-typesizes \
 	tst-robust6 tst-robust7 tst-robust8 tst-robust9 \
 	tst-robustpi1 tst-robustpi2 tst-robustpi3 tst-robustpi4 tst-robustpi5 \
 	tst-robustpi6 tst-robustpi7 tst-robustpi8 tst-robustpi9 \
-	tst-rwlock1 tst-rwlock2 tst-rwlock2a tst-rwlock3 tst-rwlock4 \
-	tst-rwlock5 tst-rwlock6 tst-rwlock7 tst-rwlock8 tst-rwlock9 \
-	tst-rwlock10 tst-rwlock11 tst-rwlock12 tst-rwlock13 tst-rwlock14 \
-	tst-rwlock15 tst-rwlock16 \
+	tst-rwlock1 tst-rwlock2 tst-rwlock2a tst-rwlock2b tst-rwlock3 \
+	tst-rwlock4 tst-rwlock5 tst-rwlock6 tst-rwlock7 tst-rwlock8 \
+	tst-rwlock9 tst-rwlock10 tst-rwlock11 tst-rwlock12 tst-rwlock13 \
+	tst-rwlock14 tst-rwlock15 tst-rwlock16 tst-rwlock17 tst-rwlock18 \
+	tst-rwlock19 \
 	tst-once1 tst-once2 tst-once3 tst-once4 tst-once5 \
 	tst-key1 tst-key2 tst-key3 tst-key4 \
 	tst-sem1 tst-sem2 tst-sem3 tst-sem4 tst-sem5 tst-sem6 tst-sem7 \
@@ -306,7 +307,7 @@ test-xfail-tst-once5 = yes
 # Files which must not be linked with libpthread.
 tests-nolibpthread = tst-unload
 
-gen-as-const-headers = pthread-errnos.sym lowlevelrwlock.sym \
+gen-as-const-headers = pthread-errnos.sym \
 		       unwindbuf.sym \
 		       lowlevelrobustlock.sym pthread-pi-defines.sym