ck_spinlock: Provide a default implementation.

Several users in the past have noted it was difficult for them
to decide what spinlock implementation to use. In light of this,
a light-weight greedy default is chosen (currently ck_spinlock_fas).

include/ck_spinlock.h

@@ -29,11 +29,26 @@
 
 #include <ck_backoff.h>
 #include <ck_cc.h>
+#include <ck_limits.h>
 #include <ck_md.h>
 #include <ck_pr.h>
 #include <stdbool.h>
 #include <stddef.h>
-#include <ck_limits.h>
+
+/*
+ * On tested x86, x86_64, PPC64 and SPARC64 targets,
+ * ck_spinlock_fas proved to have lowest latency
+ * in fast path testing or negligible degradation
+ * from faster but less robust implementations.
+ */
+#define CK_SPINLOCK_INITIALIZER CK_SPINLOCK_FAS_INITIALIZER
+#define ck_spinlock_t           ck_spinlock_fas_t
+#define ck_spinlock_init(x)     ck_spinlock_fas_init(x)
+#define ck_spinlock_lock(x)     ck_spinlock_fas_lock(x)
+#define ck_spinlock_lock_eb(x)  ck_spinlock_fas_lock_eb(x)
+#define ck_spinlock_unlock(x)   ck_spinlock_fas_unlock(x)
+#define ck_spinlock_locked(x)   ck_spinlock_fas_locked(x)
+#define ck_spinlock_trylock(x)  ck_spinlock_fas_trylock(x)
 
 #ifndef CK_F_SPINLOCK_ANDERSON
 #define CK_F_SPINLOCK_ANDERSON

regressions/ck_spinlock/benchmark/Makefile

@@ -8,10 +8,17 @@ OBJECTS=ck_ticket.THROUGHPUT ck_ticket.LATENCY			\
 	ck_clh.THROUGHPUT ck_clh.LATENCY			\
 	linux_spinlock.THROUGHPUT linux_spinlock.LATENCY	\
 	ck_ticket_pb.THROUGHPUT ck_ticket_pb.LATENCY		\
-	ck_anderson.THROUGHPUT ck_anderson.LATENCY
+	ck_anderson.THROUGHPUT ck_anderson.LATENCY		\
+	ck_spinlock.THROUGHPUT ck_spinlock.LATENCY
 
 all: $(OBJECTS)
 
+ck_spinlock.THROUGHPUT: ck_spinlock.c
+	$(CC) -DTHROUGHPUT $(CFLAGS) -o ck_spinlock.THROUGHPUT ck_spinlock.c
+
+ck_spinlock.LATENCY: ck_spinlock.c
+	$(CC) -DLATENCY $(CFLAGS) -o ck_spinlock.LATENCY ck_spinlock.c
+
 ck_ticket.THROUGHPUT: ck_ticket.c
 	$(CC) -DTHROUGHPUT $(CFLAGS) -o ck_ticket.THROUGHPUT ck_ticket.c
 

regressions/ck_spinlock/benchmark/ck_spinlock.c

@@ -0,0 +1,7 @@
+#include "../ck_spinlock.h"
+
+#ifdef THROUGHPUT
+#include "throughput.h"
+#elif defined(LATENCY)
+#include "latency.h"
+#endif

regressions/ck_spinlock/ck_spinlock.h

@@ -0,0 +1,5 @@
+#define LOCK_NAME "ck_spinlock"
+#define LOCK_DEFINE static ck_spinlock_t CK_CC_CACHELINE lock = CK_SPINLOCK_INITIALIZER
+#define LOCK ck_spinlock_lock_eb(&lock)
+#define UNLOCK ck_spinlock_unlock(&lock)
+

regressions/ck_spinlock/validate/Makefile

@@ -1,11 +1,14 @@
 .PHONY: clean
 
 all: ck_ticket ck_mcs ck_dec ck_cas ck_fas ck_clh linux_spinlock \
-     ck_ticket_pb ck_anderson
+     ck_ticket_pb ck_anderson ck_spinlock
 
 linux_spinlock: linux_spinlock.c
 	$(CC) $(CFLAGS) -o linux_spinlock linux_spinlock.c
 
+ck_spinlock: ck_spinlock.c
+	$(CC) $(CFLAGS) -o ck_spinlock ck_spinlock.c
+
 ck_ticket_pb: ck_ticket_pb.c
 	$(CC) $(CFLAGS) -o ck_ticket_pb ck_ticket_pb.c
 
@@ -32,7 +35,7 @@ ck_dec: ck_dec.c
 
 clean:
 	rm -rf ck_ticket ck_mcs ck_dec ck_cas ck_fas ck_clh linux_spinlock ck_ticket_pb \
-		ck_anderson test_and_set *.dSYM
+		ck_anderson ck_spinlock *.dSYM
 
 include ../../../build/regressions.build
 CFLAGS+=$(PTHREAD_CFLAGS) -D_GNU_SOURCE -lm

regressions/ck_spinlock/validate/ck_spinlock.c

@@ -0,0 +1,2 @@
+#include "../ck_spinlock.h"
+#include "validate.h"