[Commit-gnuradio] r8855 - usrp2/branches/features/host-ng/host-ng/lib

[jcorgan]

Author: jcorgan
Date: 2008-07-09 21:29:08 -0600 (Wed, 09 Jul 2008)
New Revision: 8855

Modified:
   usrp2/branches/features/host-ng/host-ng/lib/ring.cc
   usrp2/branches/features/host-ng/host-ng/lib/ring.h
   usrp2/branches/features/host-ng/host-ng/lib/usrp2_impl.cc
Log:
Reimplement ring semantics.  Appears to fix deadlock.

Modified: usrp2/branches/features/host-ng/host-ng/lib/ring.cc
===================================================================
--- usrp2/branches/features/host-ng/host-ng/lib/ring.cc 2008-07-10 02:14:07 UTC 
(rev 8854)
+++ usrp2/branches/features/host-ng/host-ng/lib/ring.cc 2008-07-10 03:29:08 UTC 
(rev 8855)
@@ -28,8 +28,8 @@
 namespace usrp2 {
 
   ring::ring(unsigned int entries)
-    : d_max(entries), d_head(0), d_next(0), d_ring(entries),
-      d_mutex(), d_cond(&d_mutex)
+    : d_max(entries), d_read_ind(0), d_write_ind(0), d_ring(entries),
+      d_mutex(), d_not_empty(&d_mutex)
   {
     for (unsigned int i = 0; i < entries; i++) {
       d_ring[i].d_base = 0;
@@ -37,32 +37,40 @@
     }
   }
 
-  bool ring::enqueue(void *p, size_t len)
+  void 
+  ring::wait_for_not_empty() 
+  { 
+    omni_mutex_lock l(d_mutex);
+    while (empty()) 
+      d_not_empty.wait();
+  }
+
+  bool
+  ring::enqueue(void *p, size_t len)
   {
-    if (d_ring[d_next].d_base != 0)
+    if (full())
       return false;
       
-    d_ring[d_next].d_len = len;
-    d_ring[d_next].d_base = p;
-    inc_next();
-    d_cond.signal();
+    d_ring[d_write_ind].d_len = len;
+    d_ring[d_write_ind].d_base = p;
+    d_not_empty.signal();
 
+    inc_write_ind();
     return true;
   }
 
-  bool ring::dequeue(void **p, size_t *len)
+  bool
+  ring::dequeue(void **p, size_t *len)
   {
-    void *base = d_ring[d_head].d_base;
-    if (!base)
+    if (empty())
       return false;
+      
+    *p   = d_ring[d_read_ind].d_base;
+    *len = d_ring[d_read_ind].d_len;
 
-    *p = base;
-    *len = d_ring[d_head].d_len;
-    d_ring[d_head].d_base = 0;
-    inc_head();
-
+    inc_read_ind();
     return true;
-  };
+  }
   
 } // namespace usrp2
 

Modified: usrp2/branches/features/host-ng/host-ng/lib/ring.h
===================================================================
--- usrp2/branches/features/host-ng/host-ng/lib/ring.h  2008-07-10 02:14:07 UTC 
(rev 8854)
+++ usrp2/branches/features/host-ng/host-ng/lib/ring.h  2008-07-10 03:29:08 UTC 
(rev 8855)
@@ -32,8 +32,8 @@
   private:
  
     size_t d_max;
-    size_t d_head;
-    size_t d_next;
+    size_t d_read_ind;
+    size_t d_write_ind;
 
     struct ring_desc
     {
@@ -43,34 +43,33 @@
     std::vector<ring_desc> d_ring;
 
     omni_mutex d_mutex;
-    omni_condition d_cond;
+    omni_condition d_not_empty;
 
-    void inc_head()
+    void inc_read_ind()
     {
-      if (d_head + 1 >= d_max)
-       d_head = 0;
+      if (d_read_ind + 1 >= d_max)
+       d_read_ind = 0;
       else
-       d_head = d_head + 1;
+       d_read_ind = d_read_ind + 1;
     }
 
-    void inc_next()
+    void inc_write_ind()
     {
-      if (d_next + 1 >= d_max)
-       d_next = 0;
+      if (d_write_ind + 1 >= d_max)
+       d_write_ind = 0;
       else
-       d_next = d_next + 1;
+       d_write_ind = d_write_ind + 1;
     }
         
   public:
     
     ring(unsigned int entries);
 
-    bool not_empty() const { return d_ring[d_head].d_base != 0; }
-    void wait() { 
-      omni_mutex_lock l(d_mutex);
-      d_cond.wait(); 
-    }
+    bool empty() const { return d_read_ind == d_write_ind; }
+    bool full() const { return (d_write_ind+1)%d_max == d_read_ind; }
 
+    void wait_for_not_empty();
+
     bool enqueue(void *p, size_t len);
     bool dequeue(void **p, size_t *len);
   };

Modified: usrp2/branches/features/host-ng/host-ng/lib/usrp2_impl.cc
===================================================================
--- usrp2/branches/features/host-ng/host-ng/lib/usrp2_impl.cc   2008-07-10 
02:14:07 UTC (rev 8854)
+++ usrp2/branches/features/host-ng/host-ng/lib/usrp2_impl.cc   2008-07-10 
03:29:08 UTC (rev 8855)
@@ -526,16 +526,14 @@
     ring *rp = d_channel_rings[channel];
     if (rp == 0) {
       std::cerr << "usrp2: channel " << channel
-                << " not streaming" << std::endl;
+                << " not receiving" << std::endl;
       return false;
     }
     
     // Wait for frames available in channel ring
-    while (!rp->not_empty()) {
-      DEBUG_LOG("W");
-      rp->wait();
-      DEBUG_LOG("s");
-    }
+    DEBUG_LOG("W");
+    rp->wait_for_not_empty();
+    DEBUG_LOG("s");
     
     // Iterate through frames and present to user
     void *p;