uhd: replace managed buffer shared pointer w/ intrusive pointer to reduce overhead

6 files changed, 39 insertions, 51 deletions

diff --git a/host/include/uhd/transport/zero_copy.hpp b/host/include/uhd/transport/zero_copy.hpp
index 092028d09..f80c738aa 100644
--- a/host/include/uhd/transport/zero_copy.hpp
+++ b/host/include/uhd/transport/zero_copy.hpp
@@ -21,9 +21,16 @@
 #include <uhd/config.hpp>
 #include <boost/utility.hpp>
 #include <boost/shared_ptr.hpp>
+#include <boost/intrusive_ptr.hpp>
 
 namespace uhd{ namespace transport{
 
+    //! Create smart pointer to a reusable managed buffer
+    template <typename T> UHD_INLINE boost::intrusive_ptr<T> make_managed_buffer(T *p){
+        p->_ref_count = 1; //reset the count to 1 reference
+        return boost::intrusive_ptr<T>(p, false);
+    }
+
     /*!
      * A managed receive buffer:
      * Contains a reference to transport-managed memory,
@@ -31,7 +38,7 @@ namespace uhd{ namespace transport{
      */
     class UHD_API managed_recv_buffer{
     public:
-        typedef boost::shared_ptr<managed_recv_buffer> sptr;
+        typedef boost::intrusive_ptr<managed_recv_buffer> sptr;
 
         /*!
          * Signal to the transport that we are done with the buffer.
@@ -59,8 +66,18 @@ namespace uhd{ namespace transport{
     private:
         virtual const void *get_buff(void) const = 0;
         virtual size_t get_size(void) const = 0;
+
+    public: int _ref_count;
     };
 
+    UHD_INLINE void intrusive_ptr_add_ref(managed_recv_buffer *p){
+        ++(p->_ref_count);
+    }
+
+    UHD_INLINE void intrusive_ptr_release(managed_recv_buffer *p){
+        if (--(p->_ref_count) == 0) p->release();
+    }
+
     /*!
      * A managed send buffer:
      * Contains a reference to transport-managed memory,
@@ -68,7 +85,7 @@ namespace uhd{ namespace transport{
      */
     class UHD_API managed_send_buffer{
     public:
-        typedef boost::shared_ptr<managed_send_buffer> sptr;
+        typedef boost::intrusive_ptr<managed_send_buffer> sptr;
 
         /*!
          * Signal to the transport that we are done with the buffer.
@@ -97,8 +114,18 @@ namespace uhd{ namespace transport{
     private:
         virtual void *get_buff(void) const = 0;
         virtual size_t get_size(void) const = 0;
+
+    public: int _ref_count;
     };
 
+    UHD_INLINE void intrusive_ptr_add_ref(managed_send_buffer *p){
+        ++(p->_ref_count);
+    }
+
+    UHD_INLINE void intrusive_ptr_release(managed_send_buffer *p){
+        if (--(p->_ref_count) == 0) p->commit(0);
+    }
+
     /*!
      * A zero-copy interface for transport objects.
      * Provides a way to get send and receive buffers
diff --git a/host/lib/CMakeLists.txt b/host/lib/CMakeLists.txt
index fca4730d8..ebb211566 100644
--- a/host/lib/CMakeLists.txt
+++ b/host/lib/CMakeLists.txt
@@ -15,10 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-#Creating a shared pointer itself has allocation overhead.
-#Define the quick allocator to reduce fast-path overhead.
-ADD_DEFINITIONS(-DBOOST_SP_USE_QUICK_ALLOCATOR)
-
 ########################################################################
 # Helpful Macros
 ########################################################################
diff --git a/host/lib/transport/libusb1_zero_copy.cpp b/host/lib/transport/libusb1_zero_copy.cpp
index d4cfab422..28bea978b 100644
--- a/host/lib/transport/libusb1_zero_copy.cpp
+++ b/host/lib/transport/libusb1_zero_copy.cpp
@@ -73,14 +73,10 @@ public:
 
     sptr get_new(void){
         _expired = false;
-        return sptr(this, &libusb_zero_copy_mrb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<libusb_zero_copy_mrb *>(obj)->release();
-    }
-
     const void *get_buff(void) const{return _lut->buffer;}
     size_t get_size(void) const{return _lut->actual_length;}
 
@@ -108,14 +104,10 @@ public:
 
     sptr get_new(void){
         _expired = false;
-        return sptr(this, &libusb_zero_copy_msb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<libusb_zero_copy_msb *>(obj)->commit(0);
-    }
-
     void *get_buff(void) const{return _lut->buffer;}
     size_t get_size(void) const{return _lut->length;}
 
diff --git a/host/lib/transport/udp_zero_copy.cpp b/host/lib/transport/udp_zero_copy.cpp
index c3ba085bf..8c97e1e99 100644
--- a/host/lib/transport/udp_zero_copy.cpp
+++ b/host/lib/transport/udp_zero_copy.cpp
@@ -52,16 +52,12 @@ public:
 
     sptr get_new(size_t len){
         _len = len;
-        return sptr(this, &udp_zero_copy_asio_mrb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
     template <class T> T cast(void) const{return static_cast<T>(_mem);}
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<udp_zero_copy_asio_mrb *>(obj)->release();
-    }
-
     const void *get_buff(void) const{return _mem;}
     size_t get_size(void) const{return _len;}
 
@@ -90,14 +86,10 @@ public:
 
     sptr get_new(size_t len){
         _len = len;
-        return sptr(this, &udp_zero_copy_asio_msb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<udp_zero_copy_asio_msb *>(obj)->commit(0);
-    }
-
     void *get_buff(void) const{return _mem;}
     size_t get_size(void) const{return _len;}
 
diff --git a/host/lib/usrp/usrp1/io_impl.cpp b/host/lib/usrp/usrp1/io_impl.cpp
index 7252ac587..8ac2696eb 100644
--- a/host/lib/usrp/usrp1/io_impl.cpp
+++ b/host/lib/usrp/usrp1/io_impl.cpp
@@ -61,39 +61,28 @@ class offset_managed_send_buffer : public managed_send_buffer{
 public:
     typedef boost::function<void(offset_send_buffer&, offset_send_buffer&, size_t)> commit_cb_type;
     offset_managed_send_buffer(const commit_cb_type &commit_cb):
-        _expired(true), _commit_cb(commit_cb)
+        _commit_cb(commit_cb)
     {
         /* NOP */
     }
 
-    bool expired(void){return _expired;}
-
     void commit(size_t size){
-        if (_expired) return;
-        this->_commit_cb(_curr_buff, _next_buff, size);
-        _expired = true;
+        if (size != 0) this->_commit_cb(_curr_buff, _next_buff, size);
     }
 
     sptr get_new(
         offset_send_buffer &curr_buff,
         offset_send_buffer &next_buff
     ){
-        _expired = false;
         _curr_buff = curr_buff;
         _next_buff = next_buff;
-        return sptr(this, &offset_managed_send_buffer::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *){
-        //dont do anything and assume the bastard committed it
-        //static_cast<offset_managed_send_buffer *>(obj)->commit(0);
-    }
-
     void  *get_buff(void) const{return _curr_buff.buff->cast<char *>() + _curr_buff.offset;}
     size_t get_size(void) const{return _curr_buff.buff->size()         - _curr_buff.offset;}
 
-    bool _expired;
     offset_send_buffer _curr_buff, _next_buff;
     commit_cb_type _commit_cb;
 };
@@ -210,7 +199,7 @@ void usrp1_impl::io_impl::flush_send_buff(void){
 bool usrp1_impl::io_impl::get_send_buffs(
     vrt_packet_handler::managed_send_buffs_t &buffs
 ){
-    UHD_ASSERT_THROW(omsb.expired() and buffs.size() == 1);
+    UHD_ASSERT_THROW(buffs.size() == 1);
 
     //try to get a new managed buffer with timeout
     offset_send_buffer next_buff(data_transport->get_send_buff(send_timeout));
diff --git a/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp b/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
index 26774aeda..bb421507a 100644
--- a/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
+++ b/host/lib/usrp/usrp_e100/usrp_e100_mmap_zero_copy.cpp
@@ -51,14 +51,10 @@ public:
     sptr get_new(void){
         if (fp_verbose) UHD_LOGV(always) << "  make_recv_buff: " << get_size() << std::endl;
         _info->flags = RB_USER_PROCESS; //claim the frame
-        return sptr(this, &usrp_e100_mmap_zero_copy_mrb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<usrp_e100_mmap_zero_copy_mrb *>(obj)->release();
-    }
-
     const void *get_buff(void) const{return _mem;}
     size_t get_size(void) const{return _info->len;}
 
@@ -90,14 +86,10 @@ public:
     sptr get_new(void){
         if (fp_verbose) UHD_LOGV(always) << "  make_send_buff: " << get_size() << std::endl;
         _info->flags = RB_USER_PROCESS; //claim the frame
-        return sptr(this, &usrp_e100_mmap_zero_copy_msb::fake_deleter);
+        return make_managed_buffer(this);
     }
 
 private:
-    static void fake_deleter(void *obj){
-        static_cast<usrp_e100_mmap_zero_copy_msb *>(obj)->commit(0);
-    }
-
     void *get_buff(void) const{return _mem;}
     size_t get_size(void) const{return _len;}