From be44179b005ee33d936ff55ef743bca5e84ee1b3 Mon Sep 17 00:00:00 2001
From: Bryan Ward <bcw@cs.unc.edu>
Date: Tue, 14 May 2013 12:38:08 -0400
Subject: latest changes on pound.

---
 src/spinlocks.c | 41 ++++++++++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 15 deletions(-)

(limited to 'src')

diff --git a/src/spinlocks.c b/src/spinlocks.c
index 9b04702..520e12a 100644
--- a/src/spinlocks.c
+++ b/src/spinlocks.c
@@ -60,12 +60,13 @@ void rwrnlp_init(rwrnlp *lock)
     for(i = 0; i < NR_CPUS; i++){
         lock->enter[i] = 0;
         lock->leave[i] = 0;
+        lock->curr[i]  = 0;
     }
     spin_init(lock->enqueue);
     spin_init(lock->state);
 }
 
-void rwrnlp_read_lock(rwrnlp *lock, resource_mask_t resources, int processor)
+long rwrnlp_read_lock(rwrnlp *lock, resource_mask_t resources, int processor)
 {
     request *req;
 #if MEASURE==TRUE
@@ -76,7 +77,7 @@ void rwrnlp_read_lock(rwrnlp *lock, resource_mask_t resources, int processor)
     
     enter_np();
 
-    req = &lock->requests[processor];
+    req = &lock->requests[processor][lock->curr[processor]];
     req->resources = resources;
     req->type      = read_req;
     req->status    = waiting;
@@ -116,13 +117,15 @@ void rwrnlp_read_lock(rwrnlp *lock, resource_mask_t resources, int processor)
         clock_gettime(CLOCK_MONOTONIC, &now);
         overhead += diff_ns(&last, &now);
     }
-    printf("read lock overhead: %ld\n", overhead);
+    return overhead;
+#else
+    return 0;
 #endif
     
 //    printf("%d:%d reader satisfied\n", __sync_fetch_and_add(&events,1), gettid());
 }
 
-void rwrnlp_write_lock(rwrnlp *lock, resource_mask_t resources, int processor)
+long rwrnlp_write_lock(rwrnlp *lock, resource_mask_t resources, int processor)
 {
     int r,i,start,end;
     request *req, *contender;
@@ -137,7 +140,7 @@ void rwrnlp_write_lock(rwrnlp *lock, resource_mask_t resources, int processor)
 
 //    printf("%d:%d rwrnlp_write_lock\n", __sync_fetch_and_add(&events,1), gettid());
 
-    req = &lock->requests[processor];
+    req = &lock->requests[processor][lock->curr[processor]];
 
     req->resources = resources;
     req->type = write_req;
@@ -179,9 +182,9 @@ void rwrnlp_write_lock(rwrnlp *lock, resource_mask_t resources, int processor)
     
     for(i = 0; i < NR_CPUS; i++){
         if(i != processor){
-            start = lock->enter[i];
-            contender = &lock->requests[i];
             end = lock->leave[i];
+            contender = &lock->requests[i][lock->curr[processor]];
+            start = lock->enter[i];
             if(start <= end ||
                contender->type == write_req ||
                contender->status == waiting ||
@@ -210,27 +213,32 @@ void rwrnlp_write_lock(rwrnlp *lock, resource_mask_t resources, int processor)
 #if MEASURE==TRUE
     clock_gettime(CLOCK_MONOTONIC, &now);
     overhead += diff_ns(&last, &now);
-    printf("write lock overhead: %ld\n", overhead);
+    return overhead;
+#else
+    return 0;
 #endif
 }
 
-void rwrnlp_read_unlock(rwrnlp *lock, int processor)
+long rwrnlp_read_unlock(rwrnlp *lock, int processor)
 {
 #if MEASURE==TRUE
     struct timespec now, last;
     clock_gettime(CLOCK_MONOTONIC, &last);
 #endif
     lock->leave[processor] += 1;
+    lock->curr[processor] = (lock->curr[processor] + 1) % 2;
 //    printf("%d:%d rwrnlp_read_unlock\n", __sync_fetch_and_add(&events,1), gettid());
     exit_np();
 
 #if MEASURE==TRUE
     clock_gettime(CLOCK_MONOTONIC, &now);
-    printf("read unlock overhead: %ld\n", diff_ns(&last, &now));
+    return diff_ns(&last, &now);
+#else
+    return 0;
 #endif
 }
 
-void rwrnlp_write_unlock(rwrnlp *lock, int processor)
+long rwrnlp_write_unlock(rwrnlp *lock, int processor)
 {
     int r;
     request *req;
@@ -239,13 +247,11 @@ void rwrnlp_write_unlock(rwrnlp *lock, int processor)
     struct timespec now, last;
     clock_gettime(CLOCK_MONOTONIC, &last);
 #endif
-    req= &lock->requests[processor];
+    req= &lock->requests[processor][lock->curr[processor]];
     tmp = req->resources;
 
 //    printf("%d:%d rwrnlp_write_unlock\n", __sync_fetch_and_add(&events,1), gettid());
 
-    lock->leave[processor] += 1;
-
     spin_lock(lock->state);
     r = ffsl(tmp);
     while(r != 0){
@@ -257,12 +263,17 @@ void rwrnlp_write_unlock(rwrnlp *lock, int processor)
     lock->wlocked &= ~(req->resources);
     lock->unavailable &= ~(req->resources);
     spin_unlock(lock->state);
+
+    lock->leave[processor] += 1;
+    lock->curr[processor] = (lock->curr[processor] + 1) % 2;
     
 //    printf("%d:%d write unlocked %lu\n", __sync_fetch_and_add(&events,1), gettid(), req->resources);
 //    printf("unavailable %lu\nwentitled %lu\nwlocked %lu\n", lock->unavailable, lock->wentitled, lock->wlocked);
     exit_np();
 #if MEASURE==TRUE
     clock_gettime(CLOCK_MONOTONIC, &now);
-    printf("write unlock overhead: %ld\n", diff_ns(&last, &now));
+    return diff_ns(&last, &now);
+#else
+    return 0;
 #endif
 }
-- 
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