No more warnings for the threaded case compilation. Some of the fields have to be declared

as volatile to make sure the compiler don't try to optimize them out. 

This commit was SVN r7302.

ompi/mca/pml/ob1/pml_ob1_comm.h

@@ -31,7 +31,7 @@ extern "C" {
 struct mca_pml_ob1_comm_proc_t {
     opal_object_t super;
     uint16_t expected_sequence;    /**< send message sequence number - receiver side */
-    volatile uint32_t send_sequence; /**< send side sequence number */
+    volatile int32_t send_sequence; /**< send side sequence number */
     opal_list_t frags_cant_match;  /**< out-of-order fragment queues */
     opal_list_t specific_receives; /**< queues of unmatched specific receives */
     opal_list_t unexpected_frags;  /**< unexpected fragment queues */

ompi/mca/pml/ob1/pml_ob1_recvreq.h

@@ -35,7 +35,7 @@ struct  mca_pml_ob1_recv_request_t {
     struct mca_mpool_base_chunk_t* req_chunk;
     struct mca_mpool_base_reg_mpool_t* req_mpool;
     ompi_ptr_t req_send;
-    int32_t req_lock;
+    volatile int32_t req_lock;
     size_t  req_pipeline_depth;
     size_t  req_bytes_received;
     size_t  req_bytes_delivered;

ompi/mca/pml/ob1/pml_ob1_sendreq.h

@@ -40,7 +40,7 @@ struct mca_pml_ob1_send_request_t {
     volatile int32_t req_state;
     struct mca_mpool_base_chunk_t* req_chunk;
     ompi_ptr_t req_recv;
-    int32_t req_lock;
+    volatile int32_t req_lock;
     size_t req_pipeline_depth;
     size_t req_bytes_delivered;
     size_t req_send_offset;