ck_cohort: Added trylock support to cohort framework

include/ck_cohort.h

@@ -50,6 +50,7 @@ enum ck_cohort_state {
 #define CK_COHORT_INIT(N, C, GL, LL, P) ck_cohort_##N##_init(C, GL, LL, P)
 #define CK_COHORT_LOCK(N, C, GC, LC) ck_cohort_##N##_lock(C, GC, LC)
 #define CK_COHORT_UNLOCK(N, C, GC, LC) ck_cohort_##N##_unlock(C, GC, LC)
+#define CK_COHORT_TRYLOCK(N, C, GLC, LLC, LUC) ck_cohort_##N##_trylock(C, GLC, LLC, LUC)
 
 #define CK_COHORT_PROTOTYPE(N, GL, GU, LL, LU)					\
 	CK_COHORT_INSTANCE(N) {							\
@@ -112,6 +113,33 @@ enum ck_cohort_state {
 		return;								\
 	}
 
+#define CK_COHORT_TRYLOCK_PROTOTYPE(N, GL, GU, GTL, LL, LU, LTL)		\
+	CK_COHORT_PROTOTYPE(N, GL, GU, LL, LU)					\
+	CK_CC_INLINE static bool						\
+	ck_cohort_##N##_trylock(CK_COHORT_INSTANCE(N) *cohort,			\
+	    void *global_context, void *local_context,				\
+	    void *local_unlock_context)						\
+	{									\
+										\
+		bool trylock_result;						\
+										\
+		ck_pr_inc_uint(&cohort->waiting_threads);			\
+		trylock_result = LTL(cohort->local_lock, local_context);	\
+		ck_pr_dec_uint(&cohort->waiting_threads);			\
+		if (trylock_result == false) {					\
+			return false;						\
+		}								\
+										\
+		if (cohort->release_state == CK_COHORT_STATE_GLOBAL &&		\
+		    GTL(cohort->global_lock, global_context) == false) {	\
+		    	LU(cohort->local_lock, local_unlock_context);			\
+			return false;						\
+		}								\
+										\
+		++cohort->acquire_count;					\
+		return true;							\
+	}
+
 #define CK_COHORT_INITIALIZER {							\
 	.global_lock = NULL,							\
 	.local_lock = NULL,							\

regressions/ck_cohort/validate/validate.c

@@ -59,9 +59,16 @@ ck_spinlock_fas_unlock_with_context(ck_spinlock_fas_t *lock, void *context)
 	ck_spinlock_fas_unlock(lock);
 }
 
-CK_COHORT_PROTOTYPE(fas_fas,
-	ck_spinlock_fas_lock_with_context, ck_spinlock_fas_unlock_with_context,
-	ck_spinlock_fas_lock_with_context, ck_spinlock_fas_unlock_with_context)
+static bool
+ck_spinlock_fas_trylock_with_context(ck_spinlock_fas_t *lock, void *context)
+{
+	(void)context;
+	return ck_spinlock_fas_trylock(lock);
+}
+
+CK_COHORT_TRYLOCK_PROTOTYPE(fas_fas,
+	ck_spinlock_fas_lock_with_context, ck_spinlock_fas_unlock_with_context, ck_spinlock_fas_trylock_with_context,
+	ck_spinlock_fas_lock_with_context, ck_spinlock_fas_unlock_with_context, ck_spinlock_fas_trylock_with_context)
 static CK_COHORT_INSTANCE(fas_fas) *cohorts;
 static int n_cohorts;
 
@@ -81,7 +88,15 @@ thread(void *null CK_CC_UNUSED)
 	cohort = cohorts + (core / (int)(a.delta)) % n_cohorts;
 
 	while (i--) {
-		CK_COHORT_LOCK(fas_fas, cohort, NULL, NULL);
+
+		if (i & 1) {
+			CK_COHORT_LOCK(fas_fas, cohort, NULL, NULL);
+		} else {
+			while (CK_COHORT_TRYLOCK(fas_fas, cohort, NULL, NULL, NULL) == false) {
+				ck_pr_stall();
+			}
+		}
+
 		{
 			l = ck_pr_load_uint(&locked);
 			if (l != 0) {