Cancellation fixes

ChangeLog

@@ -1,5 +1,13 @@
 2015-09-09  Niibe Yutaka  <gniibe@fsij.org>
 
+	* example-cdc/usb-cdc.c (usb_cb_ctrl_write_finish): Distinguish
+	DTR signal.
+	(usb_cb_device_reset): Fix USB reset handling.
+
+	* chopstx.c (chopstx_usec_wait_var, chopstx_cond_wait)
+	(chopstx_intr_wait): Call chopstx_testcancel.
+	(chopstx_setcancelstate): New.
+
 	* chopstx.c (chx_systick_reset, chx_systick_reload)
 	(chx_systick_get): Factor out systick functions.
 	(chx_prio_init): Factor out.

NEWS

@@ -1,6 +1,17 @@
 NEWS - Noteworthy changes
 
 
+* Major changes in Chopstx 0.09
+
+  Released 2015-09-??
+
+** New board support: Nitrokey-Start
+It is contributed by Mateusz Zalega.
+
+** Thread cancellation
+Add new API: chopstx_setcancelstate.
+
+
 * Major changes in Chopstx 0.08
 
   Released 2015-07-31

chopstx.c

@@ -290,7 +290,8 @@ struct chx_thread {
   uint32_t flag_got_cancel  : 1;
   uint32_t flag_join_req    : 1;
   uint32_t flag_sched_rr    : 1;
-  uint32_t                  : 8;
+  uint32_t flag_cancelable  : 1;
+  uint32_t                  : 7;
   uint32_t prio_orig        : 8;
   uint32_t prio             : 8;
   uint32_t v;
@@ -636,7 +637,7 @@ chx_init (struct chx_thread *tp)
   tp->mutex_list = NULL;
   tp->clp = NULL;
   tp->state = THREAD_RUNNING;
-  tp->flag_got_cancel = tp->flag_join_req = 0;
+  tp->flag_got_cancel = tp->flag_join_req = tp->flag_cancelable = 0;
   tp->flag_sched_rr = (CHX_FLAGS_MAIN & CHOPSTX_SCHED_RR)? 1 : 0;
   tp->flag_detached = (CHX_FLAGS_MAIN & CHOPSTX_DETACHED)? 1 : 0;
   tp->prio_orig = CHX_PRIO_MAIN_INIT;
@@ -782,7 +783,7 @@ extern void cause_link_time_error_unexpected_size_of_struct_chx_thread (void);
  * @thread_entry: Entry function of new thread
  * @arg: Argument to the thread entry function
  *
- * Create a thread.
+ * Create a thread.  Returns thread ID.
  */
 chopstx_t
 chopstx_create (uint32_t flags_and_prio,
@@ -816,7 +817,7 @@ chopstx_create (uint32_t flags_and_prio,
   tp->mutex_list = NULL;
   tp->clp = NULL;
   tp->state = THREAD_EXITED;
-  tp->flag_got_cancel = tp->flag_join_req = 0;
+  tp->flag_got_cancel = tp->flag_join_req = tp->flag_cancelable = 0;
   tp->flag_sched_rr = (flags_and_prio & CHOPSTX_SCHED_RR)? 1 : 0;
   tp->flag_detached = (flags_and_prio & CHOPSTX_DETACHED)? 1 : 0;
   tp->prio_orig = tp->prio = prio;
@@ -851,6 +852,7 @@ chopstx_usec_wait_var (uint32_t *var)
   asm volatile ("mov	%0, %1" : "=r" (r8) : "r" (usec_p));
   while (1)
     {
+      chopstx_testcancel ();
       chx_cpu_sched_lock ();
       if (!r8)		/* awakened */
 	break;
@@ -1019,6 +1021,7 @@ chopstx_cond_wait (chopstx_cond_t *cond, chopstx_mutex_t *mutex)
 {
   struct chx_thread *tp = running;
 
+  chopstx_testcancel ();
   chx_cpu_sched_lock ();
 
   if (mutex)
@@ -1185,6 +1188,7 @@ chopstx_release_irq_thread (struct chx_thread *tp)
 void
 chopstx_intr_wait (chopstx_intr_t *intr)
 {
+  chopstx_testcancel ();
   chx_cpu_sched_lock ();
   if (intr->ready == 0)
     {
@@ -1369,6 +1373,12 @@ chopstx_cancel (chopstx_t thd)
   /* Assume it's UP, it's *never*: tp->state==RUNNING on SMP??? */
   chx_cpu_sched_lock ();
   tp->flag_got_cancel = 1;
+  if (!tp->flag_cancelable)
+    {
+      chx_cpu_sched_unlock ();
+      return;
+    }
+
   /* Cancellation points: cond_wait, intr_wait, and usec_wait.  */
   if (tp->state == THREAD_WAIT_CND || tp->state == THREAD_WAIT_INT
       || tp->state == THREAD_WAIT_TIME)
@@ -1405,9 +1415,28 @@ chopstx_cancel (chopstx_t thd)
 void
 chopstx_testcancel (void)
 {
-  if (running->flag_got_cancel)
+  if (running->flag_cancelable && running->flag_got_cancel)
     chopstx_exit ((void *)CHOPSTX_EXIT_CANCELED_IN_SYNC);
 }
+
+
+/**
+ * chopstx_setcancelstate - set cancelability state
+ * @cancel_disable: 0 to enable cancelation, otherwise disabled.
+ * 
+ * Calling chopstx_setcancelstate sets cancelability state.
+ *
+ * Returns old state which is 0 when it was enabled.
+ */
+int
+chopstx_setcancelstate (int cancel_disable)
+{
+  int old_state = !running->flag_cancelable;
+
+  running->flag_cancelable = (cancel_disable == 0);
+  chopstx_testcancel ();
+  return old_state;
+}
 
 /*
  * Lower layer architecture specific exception handling entries.

chopstx.h

@@ -118,6 +118,7 @@ enum {
 
 void chopstx_cancel (chopstx_t thd);
 void chopstx_testcancel (void);
+int chopstx_setcancelstate (int);
 
 struct chx_cleanup {
   struct chx_cleanup *next;

example-cdc/usb-cdc.c

@@ -173,9 +173,17 @@ usb_cb_device_reset (void)
 
   /* Initialize Endpoint 0 */
   usb_lld_setup_endpoint (ENDP0, EP_CONTROL, 0, ENDP0_RXADDR, ENDP0_TXADDR, 64);
+
+  chopstx_mutex_lock (&usb_mtx);
+  connected = 0;
+  bDeviceState = ATTACHED;
+  chopstx_cond_signal (&cnd_usb);
+  chopstx_mutex_unlock (&usb_mtx);
 }
 
 
+#define CDC_CTRL_DTR            0x0001
+
 void
 usb_cb_ctrl_write_finish (uint8_t req, uint8_t req_no, uint16_t value)
 {
@@ -186,7 +194,7 @@ usb_cb_ctrl_write_finish (uint8_t req, uint8_t req_no, uint16_t value)
     {
       /* Open/close the connection.  */
       chopstx_mutex_lock (&usb_mtx);
-      connected = (value != 0)? 1 : 0;
+      connected = ((value & CDC_CTRL_DTR) != 0)? 1 : 0;
       chopstx_cond_signal (&cnd_usb);
       chopstx_mutex_unlock (&usb_mtx);
     }