ck_rwlock: Drop factor argument to trylock API.

Remove read-side recursion tests, it is an unsupported
feature to begin with.

include/ck_rwlock.h

@@ -68,26 +68,17 @@ ck_rwlock_write_downgrade(ck_rwlock_t *rw)
 }
 
 CK_CC_INLINE static bool
-ck_rwlock_write_trylock(ck_rwlock_t *rw, unsigned int factor)
+ck_rwlock_write_trylock(ck_rwlock_t *rw)
 {
-	unsigned int steps = 0;
 
-	while (ck_pr_fas_uint(&rw->writer, 1) != 0) {
-		if (++steps >= factor)
+	if (ck_pr_fas_uint(&rw->writer, 1) != 0)
 		return false;
 
-		ck_pr_stall();
-	}
-
-	while (ck_pr_load_uint(&rw->n_readers) != 0) {
-		if (++steps >= factor) {
+	if (ck_pr_load_uint(&rw->n_readers) != 0) {
 		ck_rwlock_write_unlock(rw);
 		return false;
 	}
 
-		ck_pr_stall();
-	}
-
 	ck_pr_fence_store();
 	return true;
 }
@@ -107,27 +98,19 @@ ck_rwlock_write_lock(ck_rwlock_t *rw)
 }
 
 CK_CC_INLINE static bool
-ck_rwlock_read_trylock(ck_rwlock_t *rw, unsigned int factor)
+ck_rwlock_read_trylock(ck_rwlock_t *rw)
 {
-	unsigned int steps = 0;
 
-	for (;;) {
-		while (ck_pr_load_uint(&rw->writer) != 0) {
-			if (++steps >= factor)
+	if (ck_pr_load_uint(&rw->writer) != 0)
 		return false;
 
-			ck_pr_stall();
-		}
-
 	ck_pr_inc_uint(&rw->n_readers);
 	if (ck_pr_load_uint(&rw->writer) == 0)
-			break;
+		goto leave;
 	ck_pr_dec_uint(&rw->n_readers);
-
-		if (++steps >= factor)
 	return false;
-	}
 
+leave:
 	ck_pr_fence_load();
 	return true;
 }
@@ -236,7 +219,7 @@ CK_CC_INLINE static bool
 ck_rwlock_recursive_read_trylock(ck_rwlock_recursive_t *rw)
 {
 
-	return ck_rwlock_read_trylock(&rw->rw, 1);
+	return ck_rwlock_read_trylock(&rw->rw);
 }
 
 CK_CC_INLINE static void

regressions/ck_rwlock/validate/Makefile

@@ -11,4 +11,4 @@ clean:
 	rm -rf *.dSYM *~ *.o $(OBJECTS)
 
 include ../../../build/regressions.build
-CFLAGS+=$(PTHREAD_CFLAGS) -D_GNU_SOURCE
+CFLAGS+=$(PTHREAD_CFLAGS) -D_GNU_SOURCE -g3 -O0

regressions/ck_rwlock/validate/validate.c

@@ -41,7 +41,7 @@
 #include "../../common.h"
 
 #ifndef ITERATE
-#define ITERATE 5000000
+#define ITERATE 1000000
 #endif
 
 static struct affinity a;
@@ -64,22 +64,13 @@ thread_recursive(void *null CK_CC_UNUSED)
         }
 
 	while (i--) {
-		if ((i % 10000) == 0) {
 		while (ck_rwlock_recursive_write_trylock(&r_lock, t) == false)
 			ck_pr_stall();
-		} else {
-			ck_rwlock_recursive_write_lock(&r_lock, t);
-		}
 
 		ck_rwlock_recursive_write_lock(&r_lock, t);
 		ck_rwlock_recursive_write_lock(&r_lock, t);
 		ck_rwlock_recursive_write_lock(&r_lock, t);
 
-		if (ck_rwlock_recursive_write_trylock(&r_lock, t) == false) {
-			fprintf(stderr, "ERROR: write_trylock failed.\n");
-			exit(EXIT_FAILURE);
-		}
-
 		{
 			l = ck_pr_load_uint(&locked);
 			if (l != 0) {
@@ -121,16 +112,7 @@ thread_recursive(void *null CK_CC_UNUSED)
 		ck_rwlock_recursive_write_unlock(&r_lock);
 		ck_rwlock_recursive_write_unlock(&r_lock);
 		ck_rwlock_recursive_write_unlock(&r_lock);
-		ck_rwlock_recursive_write_unlock(&r_lock);
 
-		if ((i % 10000) == 0) {
-			while (ck_rwlock_recursive_read_trylock(&r_lock) == false)
-				ck_pr_stall();
-		} else {
-			ck_rwlock_recursive_read_lock(&r_lock);
-		}
-
-		ck_rwlock_recursive_read_lock(&r_lock);
 		ck_rwlock_recursive_read_lock(&r_lock);
 		{
 			l = ck_pr_load_uint(&locked);
@@ -140,8 +122,6 @@ thread_recursive(void *null CK_CC_UNUSED)
 			}
 		}
 		ck_rwlock_recursive_read_unlock(&r_lock);
-		ck_rwlock_recursive_read_unlock(&r_lock);
-		ck_rwlock_recursive_read_unlock(&r_lock);
 	}
 
 	return (NULL);