diff options
Diffstat (limited to 'doc/guides/prog_guide/ring_lib.rst')
| -rw-r--r-- | doc/guides/prog_guide/ring_lib.rst | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/doc/guides/prog_guide/ring_lib.rst b/doc/guides/prog_guide/ring_lib.rst index 3b92a8f0..9f697538 100644 --- a/doc/guides/prog_guide/ring_lib.rst +++ b/doc/guides/prog_guide/ring_lib.rst @@ -252,8 +252,8 @@ In this example, only the producer head and tail (prod_head and prod_tail) are m The initial state is to have a prod_head and prod_tail pointing at the same location. -Multiple Consumer Enqueue First Step -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple Producers Enqueue First Step +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ On both cores, *ring->prod_head* and ring->cons_tail are copied in local variables. The prod_next local variable points to the next element of the table, @@ -266,11 +266,11 @@ If there is not enough room in the ring (this is detected by checking cons_tail) .. figure:: img/ring-mp-enqueue1.* - Multiple consumer enqueue first step + Multiple producer enqueue first step -Multiple Consumer Enqueue Second Step -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple Producers Enqueue Second Step +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The second step is to modify ring->prod_head in the ring structure to point to the same location as prod_next. This operation is done using a Compare And Swap (CAS) instruction, which does the following operations atomically: @@ -288,11 +288,11 @@ In the figure, the operation succeeded on core 1, and step one restarted on core .. figure:: img/ring-mp-enqueue2.* - Multiple consumer enqueue second step + Multiple producer enqueue second step -Multiple Consumer Enqueue Third Step -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple Producers Enqueue Third Step +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The CAS operation is retried on core 2 with success. @@ -303,11 +303,11 @@ The core 1 updates one element of the ring(obj4), and the core 2 updates another .. figure:: img/ring-mp-enqueue3.* - Multiple consumer enqueue third step + Multiple producer enqueue third step -Multiple Consumer Enqueue Fourth Step -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple Producers Enqueue Fourth Step +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Each core now wants to update ring->prod_tail. A core can only update it if ring->prod_tail is equal to the prod_head local variable. @@ -318,11 +318,11 @@ This is only true on core 1. The operation is finished on core 1. .. figure:: img/ring-mp-enqueue4.* - Multiple consumer enqueue fourth step + Multiple producer enqueue fourth step -Multiple Consumer Enqueue Last Step -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Multiple Producers Enqueue Last Step +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Once ring->prod_tail is updated by core 1, core 2 is allowed to update it too. The operation is also finished on core 2. @@ -332,7 +332,7 @@ The operation is also finished on core 2. .. figure:: img/ring-mp-enqueue5.* - Multiple consumer enqueue last step + Multiple producer enqueue last step Modulo 32-bit Indexes |