Clean up jtag command queue handling:

- Rename last_command_pointer as next_command_pointer, because this variable
  stores the address where jtag_queue_command() will store a command pointer.
- Make that variable static, since it is only used internally in jtag.c.
- Remove superfluous accessor for that now-static variable.
- Deobfuscate use of variables in jtag_command_queue.
- Add jtag_command_queue_reset helper function.
- Use it in interface_jtag_execute_queue.

git-svn-id: svn://svn.berlios.de/openocd/trunk@1992 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 64a168cbbc70c4bf8ccc5245fd33960c3825b3b8..d55888ca8dc2f7561b7028bc264d7b52baad80d5 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -91,7 +91,7 @@ static struct jtag_callback_entry *jtag_callback_queue_tail = NULL;
 
 
 jtag_command_t *jtag_command_queue = NULL;
-jtag_command_t **last_command_pointer = &jtag_command_queue;
+static jtag_command_t **next_command_pointer = &jtag_command_queue;
 static jtag_tap_t *jtag_all_taps = NULL;
 
 enum reset_types jtag_reset_config = RESET_NONE;
@@ -423,40 +423,20 @@ int jtag_call_event_callbacks(enum jtag_event event)
        return ERROR_OK;
 }
 
-/* returns a pointer to the pointer of the last command in queue
- * this may be a pointer to the root pointer (jtag_command_queue)
- * or to the next member of the last but one command
- */
-jtag_command_t** jtag_get_last_command_p(void)
-{
-/*     jtag_command_t *cmd = jtag_command_queue;
-
-       if (cmd)
-               while (cmd->next)
-                       cmd = cmd->next;
-       else
-               return &jtag_command_queue;
-
-       return &cmd->next;*/
-
-       return last_command_pointer;
-}
-
-
 void jtag_queue_command(jtag_command_t * cmd)
 {
-       jtag_command_t **last_cmd;
-
-       last_cmd = jtag_get_last_command_p();
+       // this command goes on the end, so ensure the queue terminates
+       cmd->next = NULL;
 
+       jtag_command_t **last_cmd = next_command_pointer;
+       assert(NULL != last_cmd);
+       assert(NULL == *last_cmd);
        *last_cmd = cmd;
 
-       (*last_cmd)->next = NULL;
-
-       last_command_pointer = &((*last_cmd)->next);
+       // store location where the next command pointer will be stored
+       next_command_pointer = &cmd->next;
 }
 
-
 void* cmd_queue_alloc(size_t size)
 {
        cmd_queue_page_t **p_page = &cmd_queue_pages;
@@ -533,6 +513,14 @@ void cmd_queue_free(void)
        cmd_queue_pages = NULL;
 }
 
+void jtag_command_queue_reset(void)
+{
+       cmd_queue_free();
+
+       jtag_command_queue = NULL;
+       next_command_pointer = &jtag_command_queue;
+}
+
 /**
  * Copy a scan_field_t for insertion into the queue.
  *
@@ -1595,13 +1583,10 @@ int interface_jtag_execute_queue(void)
                }
        }
 
-       cmd_queue_free();
-
        jtag_callback_queue_head = NULL;
        jtag_callback_queue_tail = NULL;
 
-       jtag_command_queue = NULL;
-       last_command_pointer = &jtag_command_queue;
+       jtag_command_queue_reset();
 
        return retval;
 }