Improved comments only

git-svn-id: file:///svn/toku/tokudb@11700 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/cachetable.c

@@ -164,7 +164,10 @@ static inline void cachetable_unlock(CACHETABLE ct __attribute__((unused))) {
 }
 
 // Wait for cache table space to become available 
+// size_current is number of bytes currently occupied by data (referred to by pairs)
+// size_writing is number of bytes queued up to be written out (sum of sizes of pairs in CTPAIR_WRITING state)
 static inline void cachetable_wait_write(CACHETABLE ct) {
+    // if we're writing more than half the data in the cachetable
     while (2*ct->size_writing > ct->size_current) {
         workqueue_wait_write(&ct->wq, 0);
     }

newbrt/workqueue.h

@@ -169,7 +169,7 @@ static int workqueue_deq(WORKQUEUE wq, WORKITEM *wiptr, int dolock) {
     return 0;
 }
 
-// Suspend a work queue writer thread
+// Suspend the caller (thread that is currently attempting to put more work items into the work queue)
 __attribute__((unused))
 static void workqueue_wait_write(WORKQUEUE wq, int dolock) {
     if (dolock) workqueue_lock(wq);
@@ -179,7 +179,7 @@ static void workqueue_wait_write(WORKQUEUE wq, int dolock) {
     if (dolock) workqueue_unlock(wq);
 }
 
-// Wakeup the waiting work queue writer threads
+// Wakeup all threads that are currently attempting to put more work items into the work queue
 __attribute__((unused))
 static void workqueue_wakeup_write(WORKQUEUE wq, int dolock) {
     if (wq->want_write) {