Fix select handler

lib_xcore_c/src/xcore_c_select.S

@@ -7,6 +7,29 @@
 # define _SELECT_CALLBACK_STACK_SIZE  1
 #endif
 
+// Callback functions may be triggered during select setup phase.
+// If this happens, we need to re-run the setup.
+// It is always safe to re-run the setup.
+// We need a rerun-address, and arguments r0 & r1
+// The data is layed out to make access most efficient.
+.section  .dp.bss,"awd",@nobits
+.cc_top _xcore_c_select_rerun.data,_xcore_c_select_rerun
+#ifdef __XS2A__
+.align  8
+#else
+.align  4
+#endif
+.type _xcore_c_select_rerun,@object
+_xcore_c_select_rerun:
+#ifdef __XS2A__
+  .size _xcore_c_select_rerun, (4*2*8)*2
+  .space  (4*2*8)*2    // {recall,r0}[number of threads], {r1,padding}[number of threads]
+#else
+  .size _xcore_c_select_rerun, 4*8*3
+  .space  4*8*3    // recall[number of threads], r0[number of threads], r1[number of threads]
+#endif
+.cc_bottom _xcore_c_select_rerun.data
+
 .text
 
 .globl _xcore_c_select_callback_common
@@ -26,7 +49,24 @@ _xcore_c_select_callback_common:
   bla r1              // The select_callback_t function.
   ldw lr, sp[_SELECT_CALLBACK_STACK_SIZE]
   ldaw sp, sp[_SELECT_CALLBACK_STACK_SIZE]
-  waiteu              // setsr 0x1
+  // Do we need to re-run the select setup or can we do a waite?
+  ldaw r3, dp[_xcore_c_select_rerun]
+  get r11, id
+#ifdef __XS2A__
+  ldd  r2, r0, r3[r11]
+  waitef r2   // setsr 0x1
+  add r11, r11, 8
+  ldd r1, r3, r3[r11]
+  bau r2;     // re-run the select setup.
+#else
+  ldw  r2, r3[r11]
+  waitef r2   // setsr 0x1  // no rerun needed
+  add r11, r11, 8
+  ldw  r0, r3[r11]
+  add r11, r11, 8
+  ldw  r1, r3[r11]
+  bau r2;     // re-run the select setup.
+#endif
 .cc_bottom _xcore_c_select_callback_common.function
 .set   _xcore_c_select_callback_common.nstackwords, 0
 .globl _xcore_c_select_callback_common.nstackwords
@@ -72,18 +112,27 @@ _select_non_callback:
 
 .globl select_wait
 #ifdef __XS2A__
-.issue_mode dual
+.issue_mode single
 .align 4
 #else
 .align 2
 #endif
 .type  select_wait,@function
 .cc_top select_wait.function,select_wait
-select_wait:
-  waiteu              // setsr 0x1
+select_wait: // no args.
 #ifdef __XS2A__
-  nop // handle dual issue.
+  ENTSP_lu6 0
+#endif
+  // clear the recall state
+  ldc r2, 0
+  ldaw r3, dp[_xcore_c_select_rerun]
+  get r11, id
+#ifdef __XS2A__
+  std  r2, r0, r3[r11]
+#else
+  stw r2, r3[r11]
 #endif
+  waiteu              // setsr 0x1
   // function returns via _select_non_callback
 .cc_bottom select_wait.function
 .set   select_wait.nstackwords, 0 + _select_non_callback.nstackwords
@@ -106,10 +155,23 @@ select_wait:
 #endif
 .type  select_no_wait,@function
 .cc_top select_no_wait.function,select_no_wait
-select_no_wait:
+select_no_wait: // r0 = 'nowait' return
 #ifdef __XS2A__
   ENTSP_lu6 0
 #endif
+  // set up the recall state
+  ldap r11, _select_no_wait_rerun
+  add r2, r11, 0
+  ldaw r3, dp[_xcore_c_select_rerun]
+  get r11, id
+#ifdef __XS2A__
+  std  r2, r0, r3[r11]
+#else
+  stw r2, r3[r11]
+  add r11, r11, 8
+  stw r0, r3[r11]
+#endif
+_select_no_wait_rerun:
   setsr 0x1           // Enable events
 #if defined(__XS2A__)
   nop                 // Allow channel events to fire
@@ -139,10 +201,23 @@ select_no_wait:
 #endif
 .type  select_wait_ordered,@function
 .cc_top select_wait_ordered.function,select_wait_ordered
-select_wait_ordered:
+select_wait_ordered: // r0 = resoure_order[]
 #ifdef __XS2A__
   ENTSP_lu6 0
 #endif
+  // set up the recall state
+  ldap r11, _select_wait_ordered_rerun
+  add r2, r11, 0
+  ldaw r3, dp[_xcore_c_select_rerun]
+  get r11, id
+#ifdef __XS2A__
+  std  r2, r0, r3[r11]
+#else
+  stw r2, r3[r11]
+  add r11, r11, 8
+  stw r0, r3[r11]
+#endif
+_select_wait_ordered_rerun:
   clre                // disable all 'select event' resources
   setsr 0x1           // Enable events on core
   ldc r2, 0           // Resource list index
@@ -177,10 +252,27 @@ select_wait_ordered_done:
 #endif
 .type  select_no_wait_ordered,@function
 .cc_top select_no_wait_ordered.function,select_no_wait_ordered
-select_no_wait_ordered:
+select_no_wait_ordered: // r0 = 'nowait' return, r1 = resoure_order[]
 #ifdef __XS2A__
   ENTSP_lu6 0
 #endif
+  // set up the recall state
+  ldap r11, _select_no_wait_ordered_rerun
+  add r2, r11, 0
+  ldaw r3, dp[_xcore_c_select_rerun]
+  get r11, id
+#ifdef __XS2A__
+  std r2, r0, r3[r11]
+  add r11, r11, 8
+  std r1, r1, r3[r11]
+#else
+  stw r2, r3[r11]
+  add r11, r11, 8
+  stw r0, r3[r11]
+  add r11, r11, 8
+  stw r1, r3[r11]
+#endif
+_select_no_wait_ordered_rerun:
   clre                // disable all 'select event' resources
   setsr 0x1           // Enable events on core
   ldc r2, 0           // Resource list index

tests/select_handler_functions.expect

@@ -1,38 +1,47 @@
-Received 0 on channel c
-Received 1 on channel c
+Timer event data 0xFEEDBEEF
 Received 0 on channel d
+Received 0 on channel c
 Received 1 on channel d
-Received 2 on channel c
+Received 1 on channel c
+Timer event data 0xFEEDBEEF
 Received 2 on channel d
+Received 2 on channel c
+Timer event data 0xFEEDBEEF
 Timer event data 0xFEEDBEEF
-Received 3 on channel c
 Received 3 on channel d
+Received 3 on channel c
 Timer event data 0xFEEDBEEF
 Timer event data 0xFEEDBEEF
-Received 4 on channel c
 Received 4 on channel d
-Received 555 on channel c
-Received 556 on channel c
 Received 333 on channel d
+Received 4 on channel c
+Received 555 on channel c
 Received 334 on channel d
-Received 557 on channel c
+Received 556 on channel c
+Timer event data 0xFEEDBEEF
 Received 335 on channel d
-Received 558 on channel c
+Received 557 on channel c
+Timer event data 0xFEEDBEEF
+Timer event data 0xFEEDBEEF
 Received 336 on channel d
-Received 559 on channel c
-Received 337 on channel d
+Received 558 on channel c
+Timer event data 0xFEEDBEEF
 Timer event data 0xFEEDBEEF
+Received 337 on channel d
+Received 666 on channel d
+Received 667 on channel d
+Received 559 on channel c
 Received 1110 on channel c
 Received 1111 on channel c
-Received 666 on channel d
 Timer event data 0xFEEDBEEF
-Received 667 on channel d
-Received 1112 on channel c
 Received 668 on channel d
+Received 1112 on channel c
 Timer event data 0xFEEDBEEF
-Received 1113 on channel c
 Received 669 on channel d
 Timer event data 0xFEEDBEEF
-Received 1114 on channel c
+Received 1113 on channel c
 Timer event data 0xFEEDBEEF
 Received 670 on channel d
+Timer event data 0xFEEDBEEF
+Received 1114 on channel c
+

tests/select_handler_functions/src/main.xc

@@ -20,16 +20,16 @@ int main()
     // Provide test data
     for (int test = 0; test < num_tests; ++test) {
       for (int i = 0; i < 5; i++) {
-        c <: 555*test + i;
         delay_ticks(5000 * i);
+        c <: 555*test + i;
       }
     }
 
     // Provide test data
     for (int test = 0; test < num_tests; ++test) {
       for (int i = 0; i < 5; i++) {
-        d <: 333*test + i;
         delay_ticks(5000 * i);
+        d <: 333*test + i;
       }
     }
   }

tests/select_handler_functions/src/test.c

@@ -10,19 +10,22 @@ static const int period = 10000;
 // For XS1 support all values passed to the event_setup function must have bit 16 set
 typedef enum {
   EVENT_CHAN_C = ENUM_ID_BASE,
-  EVENT_CHAN_D
+  EVENT_CHAN_D,
+  EVENT_NONE,
 } event_choice_t;
 
-void test_select_function(chanend c, chanend d)
+void test_select_function(chanend c, chanend d, hwtimer_t t)
 {
   // Setup the channels to generate events
   chanend_setup_select(c, EVENT_CHAN_C);
   chanend_setup_select(d, EVENT_CHAN_D);
   chanend_enable_trigger(c);
   chanend_enable_trigger(d);
 
+  resource_t ids[4] = {t, d, c, 0};
+
   for (int count = 0; count < 10; count++) {
-    event_choice_t choice = select_wait();
+    event_choice_t choice = select_no_wait_ordered(EVENT_NONE,ids);
     switch (choice) {
       case EVENT_CHAN_C: {
         // Read value and clear event
@@ -38,6 +41,8 @@ void test_select_function(chanend c, chanend d)
         debug_printf("Received %d on channel d\n", x);
         break;
       }
+      case EVENT_NONE:
+        count--;
     }
   }
   chanend_disable_trigger(c);
@@ -76,19 +81,19 @@ void test(chanend c, chanend d)
   // Test 1: Run the test function with the timer enabled
   uint32_t time;
   hwtimer_get_time(t, &time);
-  hwtimer_setup_select_callback(t, time + period, (void*)&data, SELECT_CALLBACK(handle_timer));
+  hwtimer_setup_select_callback(t, time-10, (void*)&data, SELECT_CALLBACK(handle_timer));
   hwtimer_enable_trigger(t);
-  test_select_function(c, d);
+  test_select_function(c, d, t);
   hwtimer_disable_trigger(t);
 
   // Test 2: Run the test function again with the timer disabled
-  test_select_function(c, d);
+  test_select_function(c, d, t);
 
   // Test 3: Run the test function again with the timer enabled
   hwtimer_get_time(t, &time);
   hwtimer_change_trigger_time(t, time + period);
   hwtimer_enable_trigger(t);
-  test_select_function(c, d);
+  test_select_function(c, d, t);
   hwtimer_disable_trigger(t);
 
   hwtimer_free(&t);