git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1148 35acf78f-673a-0410-8e92-d51de3d6d3f4

6 files changed, 131 insertions, 35 deletions

diff --git a/os/kernel/include/scheduler.h b/os/kernel/include/scheduler.h
index 235761216..00294e190 100644
--- a/os/kernel/include/scheduler.h
+++ b/os/kernel/include/scheduler.h
@@ -78,6 +78,12 @@ typedef struct {
 
 extern ReadyList rlist;
 
+#ifdef CH_CURRP_REGISTER_CACHE
+register Thread *currp asm(CH_CURRP_REGISTER_CACHE);
+#else
+#define currp rlist.r_current
+#endif
+
 /*
  * Scheduler APIs.
  */
@@ -96,11 +102,19 @@ extern "C" {
 }
 #endif
 
-#ifdef CH_CURRP_REGISTER_CACHE
-register Thread *currp asm(CH_CURRP_REGISTER_CACHE);
-#else
-#define currp rlist.r_current
-#endif
+/**
+ * @brief Determines if yielding is possible.
+ * @details This function returns @p TRUE if there is a ready thread with
+ *          equal or higher priority.
+ */
+#define chSchCanYieldS() (firstprio(&rlist.r_queue) >= currp->p_prio)
+
+/**
+ * @brief Determines if the current thread must reschedule.
+ * @details This function returns @p TRUE if there is a ready thread with
+ *          higher priority.
+ */
+#define chSchMustRescheduleS() (firstprio(&rlist.r_queue) >= currp->p_prio)
 
 #endif /* _SCHEDULER_H_ */
 
diff --git a/os/kernel/include/threads.h b/os/kernel/include/threads.h
index 7155e9b32..da7dfc152 100644
--- a/os/kernel/include/threads.h
+++ b/os/kernel/include/threads.h
@@ -183,6 +183,9 @@ extern "C" {
 #if CH_USE_WAITEXIT
   msg_t chThdWait(Thread *tp);
 #endif
+#if CH_USE_ROUNDROBIN
+  void chThdYield(void);
+#endif
 #ifdef __cplusplus
 }
 #endif
diff --git a/os/kernel/src/chschd.c b/os/kernel/src/chschd.c
index af24f5cf4..6183180bc 100644
--- a/os/kernel/src/chschd.c
+++ b/os/kernel/src/chschd.c
@@ -211,7 +211,7 @@ void chSchDoRescheduleI(void) {
 void chSchRescheduleS(void) {
   /* first thread in the runnable queue has higher priority than the running
    * thread? */
-  if (firstprio(&rlist.r_queue) > currp->p_prio)
+  if (chSchMustRescheduleS())
     chSchDoRescheduleI();
 }
 
diff --git a/os/kernel/src/chthreads.c b/os/kernel/src/chthreads.c
index 583bc7c04..c18a4f8cd 100644
--- a/os/kernel/src/chthreads.c
+++ b/os/kernel/src/chthreads.c
@@ -290,6 +290,21 @@ void chThdSleepUntil(systime_t time) {
   chSysUnlock();
 }
 
+#if CH_USE_ROUNDROBIN
+/**
+ * @brief Yields the time slot.
+ * @details Yields the CPU control to the next thread in the ready list with
+ *          equal priority, if any.
+ */
+void chThdYield(void) {
+
+  chSysLock();
+  if (chSchCanYieldS())
+    chSchDoRescheduleI();
+  chSysUnlock();
+}
+#endif /* CH_USE_ROUNDROBIN */
+
 /**
  * @brief Terminates the current thread by specifying an exit status code.
  *
diff --git a/readme.txt b/readme.txt
index 8b0608363..8a90b6f15 100644
--- a/readme.txt
+++ b/readme.txt
@@ -12,6 +12,8 @@
 - FIX: Fixed GCC 4.4.x related problems in CM3 port (bug 2846162).(backported

   in stable branch)

 - FIX: Fixed LPC214x UART problem (bug 2841088)(backported in stable branch).

+- NEW: Added new API chThdYield().

+- MEW: Added new benchmark about round robin rescheduling.

 - NEW: Reorganized and rationalized the distribution tree and the

   documentation.

 - NEW: Enhanced serial driver. The driver now supports speed change at runtime

diff --git a/test/testbmk.c b/test/testbmk.c
index 7a99c37af..f44ae0b8b 100644
--- a/test/testbmk.c
+++ b/test/testbmk.c
@@ -418,7 +418,66 @@ const struct testcase testbmk7 = {
 };

 

 /**

- * @page test_benchmarks_008 I/O Queues throughput

+ * @page test_benchmarks_009 I/O Round-Robin voluntary rescedulation.

+ *

+ * <h2>Description</h2>

+ * Five threads are created at equal priority, each thread just increases a

+ * variable and yields.<br>

+ * The performance is calculated by measuring the number of iterations after

+ * a second of continuous operations.

+ */

+

+#if CH_USE_ROUNDROBIN

+static msg_t thread8(void *p) {

+

+  do {

+    chThdYield();

+    chThdYield();

+    chThdYield();

+    chThdYield();

+    (*(uint32_t *)p) += 4;

+  } while(!chThdShouldTerminate());

+  return 0;

+}

+

+static char *bmk8_gettest(void) {

+

+  return "Benchmark, round robin context switching";

+}

+

+static void bmk8_execute(void) {

+  uint32_t n;

+

+  n = 0;

+  test_wait_tick();

+

+  threads[0] = chThdCreateStatic(wa[0], WA_SIZE, chThdGetPriority()-1, thread8, (void *)&n);

+  threads[1] = chThdCreateStatic(wa[1], WA_SIZE, chThdGetPriority()-1, thread8, (void *)&n);

+  threads[2] = chThdCreateStatic(wa[2], WA_SIZE, chThdGetPriority()-1, thread8, (void *)&n);

+  threads[3] = chThdCreateStatic(wa[3], WA_SIZE, chThdGetPriority()-1, thread8, (void *)&n);

+  threads[4] = chThdCreateStatic(wa[4], WA_SIZE, chThdGetPriority()-1, thread8, (void *)&n);

+

+  chThdSleepSeconds(1);

+  test_terminate_threads();

+  test_wait_threads();

+

+  test_print("--- Score : ");

+  test_printn(n);

+  test_print(" reschedulations/S, ");

+  test_printn(n);

+  test_println(" ctxswc/S");

+}

+

+const struct testcase testbmk8 = {

+  bmk8_gettest,

+  NULL,

+  NULL,

+  bmk8_execute

+};

+#endif

+

+/**

+ * @page test_benchmarks_009 I/O Queues throughput

  *

  * <h2>Description</h2>

  * Four bytes are written and then read from an @p InputQueue into a continuous

@@ -427,12 +486,12 @@ const struct testcase testbmk7 = {
  * a second of continuous operations.

  */

 

-static char *bmk8_gettest(void) {

+static char *bmk9_gettest(void) {

 

   return "Benchmark, I/O Queues throughput";

 }

 

-static void bmk8_execute(void) {

+static void bmk9_execute(void) {

   static uint8_t ib[16];

   static InputQueue iq;

 

@@ -459,15 +518,15 @@ static void bmk8_execute(void) {
   test_println(" bytes/S");

 }

 

-const struct testcase testbmk8 = {

-  bmk8_gettest,

+const struct testcase testbmk9 = {

+  bmk9_gettest,

   NULL,

   NULL,

-  bmk8_execute

+  bmk9_execute

 };

 

 /**

- * @page test_benchmarks_009 Virtual Timers set/reset performance

+ * @page test_benchmarks_010 Virtual Timers set/reset performance

  *

  * <h2>Description</h2>

  * A virtual timer is set and immediately reset into a continuous loop.<br>

@@ -475,14 +534,14 @@ const struct testcase testbmk8 = {
  * a second of continuous operations.

  */

 

-static char *bmk9_gettest(void) {

+static char *bmk10_gettest(void) {

 

   return "Benchmark, virtual timers set/reset";

 }

 

 static void tmo(void *param) {}

 

-static void bmk9_execute(void) {

+static void bmk10_execute(void) {

   static VirtualTimer vt1, vt2;

   uint32_t n = 0;

 

@@ -505,15 +564,15 @@ static void bmk9_execute(void) {
   test_println(" timers/S");

 }

 

-const struct testcase testbmk9 = {

-  bmk9_gettest,

+const struct testcase testbmk10 = {

+  bmk10_gettest,

   NULL,

   NULL,

-  bmk9_execute

+  bmk10_execute

 };

 

 /**

- * @page test_benchmarks_010 Semaphores wait/signal performance

+ * @page test_benchmarks_011 Semaphores wait/signal performance

  *

  * <h2>Description</h2>

  * A counting semaphore is taken/released into a continuous loop, no Context

@@ -522,17 +581,17 @@ const struct testcase testbmk9 = {
  * a second of continuous operations.

  */

 

-static char *bmk10_gettest(void) {

+static char *bmk11_gettest(void) {

 

   return "Benchmark, semaphores wait/signal";

 }

 

-static void bmk10_setup(void) {

+static void bmk11_setup(void) {

 

   chSemInit(&sem1, 1);

 }

 

-static void bmk10_execute(void) {

+static void bmk11_execute(void) {

   uint32_t n = 0;

 

   test_wait_tick();

@@ -556,16 +615,16 @@ static void bmk10_execute(void) {
   test_println(" wait+signal/S");

 }

 

-const struct testcase testbmk10 = {

-  bmk10_gettest,

-  bmk10_setup,

+const struct testcase testbmk11 = {

+  bmk11_gettest,

+  bmk11_setup,

   NULL,

-  bmk10_execute

+  bmk11_execute

 };

 

 #if CH_USE_MUTEXES

 /**

- * @page test_benchmarks_011 Mutexes lock/unlock performance

+ * @page test_benchmarks_012 Mutexes lock/unlock performance

  *

  * <h2>Description</h2>

  * A mutex is locked/unlocked into a continuous loop, no Context Switch happens

@@ -574,17 +633,17 @@ const struct testcase testbmk10 = {
  * a second of continuous operations.

  */

 

-static char *bmk11_gettest(void) {

+static char *bmk12_gettest(void) {

 

   return "Benchmark, mutexes lock/unlock";

 }

 

-static void bmk11_setup(void) {

+static void bmk12_setup(void) {

 

   chMtxInit(&mtx1);

 }

 

-static void bmk11_execute(void) {

+static void bmk12_execute(void) {

   uint32_t n = 0;

 

   test_wait_tick();

@@ -608,11 +667,11 @@ static void bmk11_execute(void) {
   test_println(" lock+unlock/S");

 }

 

-const struct testcase testbmk11 = {

-  bmk11_gettest,

-  bmk11_setup,

+const struct testcase testbmk12 = {

+  bmk12_gettest,

+  bmk12_setup,

   NULL,

-  bmk11_execute

+  bmk12_execute

 };

 #endif

 

@@ -628,11 +687,14 @@ const struct testcase * const patternbmk[] = {
   &testbmk5,

   &testbmk6,

   &testbmk7,

+#if CH_USE_ROUNDROBIN

   &testbmk8,

+#endif

   &testbmk9,

   &testbmk10,

-#if CH_USE_MUTEXES

   &testbmk11,

+#if CH_USE_MUTEXES

+  &testbmk12,

 #endif

 #endif

   NULL