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-rw-r--r--src/kservice.c48
-rw-r--r--src/scheduler.c80
2 files changed, 58 insertions, 70 deletions
diff --git a/src/kservice.c b/src/kservice.c
index 4276fc28ec..67262ff084 100644
--- a/src/kservice.c
+++ b/src/kservice.c
@@ -1190,6 +1190,54 @@ void rt_free_align(void *ptr)
RTM_EXPORT(rt_free_align);
#endif
+#ifndef RT_USING_CPU_FFS
+const rt_uint8_t __lowest_bit_bitmap[] =
+{
+ /* 00 */ 0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 10 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 20 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 30 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 40 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 50 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 60 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 70 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 80 */ 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* 90 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* A0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* B0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* C0 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* D0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* E0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+ /* F0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
+};
+
+/**
+ * This function finds the first bit set (beginning with the least significant bit)
+ * in value and return the index of that bit.
+ *
+ * Bits are numbered starting at 1 (the least significant bit). A return value of
+ * zero from any of these functions means that the argument was zero.
+ *
+ * @return return the index of the first bit set. If value is 0, then this function
+ * shall return 0.
+ */
+int __rt_ffs(int value)
+{
+ if (value == 0) return 0;
+
+ if (value & 0xff)
+ return __lowest_bit_bitmap[value & 0xff] + 1;
+
+ if (value & 0xff00)
+ return __lowest_bit_bitmap[(value & 0xff00) >> 8] + 9;
+
+ if (value & 0xff0000)
+ return __lowest_bit_bitmap[(value & 0xff0000) >> 16] + 17;
+
+ return __lowest_bit_bitmap[(value & 0xff000000) >> 24] + 25;
+}
+#endif
+
#if !defined (RT_USING_NEWLIB) && defined (RT_USING_MINILIBC) && defined (__GNUC__)
#include <sys/types.h>
void *memcpy(void *dest, const void *src, size_t n) __attribute__((weak, alias("rt_memcpy")));
diff --git a/src/scheduler.c b/src/scheduler.c
index 03423c9f5d..ad618d1a61 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -31,6 +31,7 @@
static rt_int16_t rt_scheduler_lock_nest;
extern volatile rt_uint8_t rt_interrupt_nest;
+extern int __rt_ffs(int value);
rt_list_t rt_thread_priority_table[RT_THREAD_PRIORITY_MAX];
struct rt_thread *rt_current_thread;
@@ -48,26 +49,6 @@ rt_uint32_t rt_thread_ready_priority_group;
rt_list_t rt_thread_defunct;
-const rt_uint8_t rt_lowest_bitmap[] =
-{
- /* 00 */ 0, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 10 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 20 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 30 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 40 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 50 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 60 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 70 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 80 */ 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* 90 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* A0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* B0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* C0 */ 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* D0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* E0 */ 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
- /* F0 */ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
-};
-
#ifdef RT_USING_HOOK
static void (*rt_scheduler_hook)(struct rt_thread *from, struct rt_thread *to);
@@ -164,34 +145,13 @@ void rt_system_scheduler_start(void)
register struct rt_thread *to_thread;
register rt_ubase_t highest_ready_priority;
-#if RT_THREAD_PRIORITY_MAX == 8
- highest_ready_priority = rt_lowest_bitmap[rt_thread_ready_priority_group];
-#else
+#if RT_THREAD_PRIORITY_MAX > 32
register rt_ubase_t number;
- /* find out the highest priority task */
- if (rt_thread_ready_priority_group & 0xff)
- {
- number = rt_lowest_bitmap[rt_thread_ready_priority_group & 0xff];
- }
- else if (rt_thread_ready_priority_group & 0xff00)
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 8) & 0xff] + 8;
- }
- else if (rt_thread_ready_priority_group & 0xff0000)
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 16) & 0xff] + 16;
- }
- else
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 24) & 0xff] + 24;
- }
-#if RT_THREAD_PRIORITY_MAX > 32
- highest_ready_priority = (number << 3) +
- rt_lowest_bitmap[rt_thread_ready_table[number]];
+ number = __rt_ffs(rt_thread_ready_priority_group) - 1;
+ highest_ready_priority = (number << 3) + __rt_ffs(rt_thread_ready_table[number]) - 1;
#else
- highest_ready_priority = number;
-#endif
+ highest_ready_priority = __rt_ffs(rt_thread_ready_priority_group) - 1;
#endif
/* get switch to thread */
@@ -231,35 +191,15 @@ void rt_schedule(void)
{
register rt_ubase_t highest_ready_priority;
-#if RT_THREAD_PRIORITY_MAX == 8
- highest_ready_priority = rt_lowest_bitmap[rt_thread_ready_priority_group];
+#if RT_THREAD_PRIORITY_MAX <= 32
+ highest_ready_priority = __rt_ffs(rt_thread_ready_priority_group) - 1;
#else
register rt_ubase_t number;
- /* find out the highest priority task */
- if (rt_thread_ready_priority_group & 0xff)
- {
- number = rt_lowest_bitmap[rt_thread_ready_priority_group & 0xff];
- }
- else if (rt_thread_ready_priority_group & 0xff00)
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 8) & 0xff] + 8;
- }
- else if (rt_thread_ready_priority_group & 0xff0000)
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 16) & 0xff] + 16;
- }
- else
- {
- number = rt_lowest_bitmap[(rt_thread_ready_priority_group >> 24) & 0xff] + 24;
- }
-#if RT_THREAD_PRIORITY_MAX > 32
- highest_ready_priority = (number << 3) +
- rt_lowest_bitmap[rt_thread_ready_table[number]];
-#else
- highest_ready_priority = number;
-#endif
+ number = __rt_ffs(rt_thread_ready_priority_group) - 1;
+ highest_ready_priority = (number << 3) + __rt_ffs(rt_thread_ready_table[number]) - 1;
#endif
+
/* get switch to thread */
to_thread = rt_list_entry(rt_thread_priority_table[highest_ready_priority].next,
struct rt_thread,
generated by cgit v1.3.1 (git 2.54.0) at 2026-10-30 10:00:05 +0000