research st: refine sched.

winlin
Commit 22710db9117a0406d7ac9767af6296d7febff975 22710db9 1 parent f5f8e894
trunk/research/st/sched.c
--- a/trunk/research/st/sched.c
查看文件 @22710db
+++ b/trunk/research/st/sched.c
查看文件 @22710db
@@ -47,7 +47,6 @@
 #include <errno.h>
 #include "common.h"
-
 /* Global data */
 _st_vp_t _st_this_vp;           /* This VP */
 _st_thread_t *_st_this_thread;  /* Current thread */
@@ -56,7 +55,6 @@ int _st_active_count = 0;       /* Active thread count */
 time_t _st_curr_time = 0;       /* Current time as returned by time(2) */
 st_utime_t _st_last_tset;       /* Last time it was fetched */
-
 int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
 {
     struct pollfd *pd;
@@ -71,16 +69,18 @@ int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
         return -1;
     }
-  if ((*_st_eventsys->pollset_add)(pds, npds) < 0)
+    if ((*_st_eventsys->pollset_add)(pds, npds) < 0) {
         return -1;
+    }
     pq.pds = pds;
     pq.npds = npds;
     pq.thread = me;
     pq.on_ioq = 1;
     _ST_ADD_IOQ(pq);
-  if (timeout != ST_UTIME_NO_TIMEOUT)
+    if (timeout != ST_UTIME_NO_TIMEOUT) {
         _ST_ADD_SLEEPQ(me, timeout);
+    }
     me->state = _ST_ST_IO_WAIT;
     _ST_SWITCH_CONTEXT(me);
@@ -93,10 +93,11 @@ int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
     } else {
         /* Count the number of ready descriptors */
         for (pd = pds; pd < epd; pd++) {
-      if (pd->revents)
+            if (pd->revents) {
                 n++;
             }
         }
+    }
     if (me->flags & _ST_FL_INTERRUPT) {
         me->flags &= ~_ST_FL_INTERRUPT;
@@ -107,7 +108,6 @@ int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
     return n;
 }
-
 void _st_vp_schedule(void)
 {
     _st_thread_t *thread;
@@ -127,7 +127,6 @@ void _st_vp_schedule(void)
     _ST_RESTORE_CONTEXT(thread);
 }
-
 /*
  * Initialize this Virtual Processor
  */
@@ -143,8 +142,9 @@ int st_init(void)
     /* We can ignore return value here */
     st_set_eventsys(ST_EVENTSYS_DEFAULT);
-  if (_st_io_init() < 0)
+    if (_st_io_init() < 0) {
         return -1;
+    }
     memset(&_st_this_vp, 0, sizeof(_st_vp_t));
@@ -155,8 +155,9 @@ int st_init(void)
     ST_INIT_CLIST(&_ST_THREADQ);
 #endif
-  if ((*_st_eventsys->init)() < 0)
+    if ((*_st_eventsys->init)() < 0) {
         return -1;
+    }
     _st_this_vp.pagesize = getpagesize();
     _st_this_vp.last_clock = st_utime();
@@ -164,10 +165,10 @@ int st_init(void)
     /*
     * Create idle thread
     */
-  _st_this_vp.idle_thread = st_thread_create(_st_idle_thread_start,
-                         NULL, 0, 0);
-  if (!_st_this_vp.idle_thread)
+    _st_this_vp.idle_thread = st_thread_create(_st_idle_thread_start, NULL, 0, 0);
+    if (!_st_this_vp.idle_thread) {
         return -1;
+    }
     _st_this_vp.idle_thread->flags = _ST_FL_IDLE_THREAD;
     _st_active_count--;
     _ST_DEL_RUNQ(_st_this_vp.idle_thread);
@@ -177,8 +178,9 @@ int st_init(void)
     */
     thread = (_st_thread_t *) calloc(1, sizeof(_st_thread_t) +
     (ST_KEYS_MAX * sizeof(void *)));
-  if (!thread)
+    if (!thread) {
         return -1;
+    }
     thread->private_data = (void **) (thread + 1);
     thread->state = _ST_ST_RUNNING;
     thread->flags = _ST_FL_PRIMORDIAL;
@@ -191,7 +193,6 @@ int st_init(void)
     return 0;
 }
-
 #ifdef ST_SWITCH_CB
 st_switch_cb_t st_set_switch_in_cb(st_switch_cb_t cb)
 {
@@ -208,7 +209,6 @@ st_switch_cb_t st_set_switch_out_cb(st_switch_cb_t cb)
 }
 #endif
-
 /*
  * Start function for the idle thread
  */
@@ -235,7 +235,6 @@ void *_st_idle_thread_start(void *arg)
     return NULL;
 }
-
 void st_thread_exit(void *retval)
 {
     _st_thread_t *thread = _ST_CURRENT_THREAD();
@@ -263,15 +262,15 @@ void st_thread_exit(void *retval)
     _ST_DEL_THREADQ(thread);
 #endif
-  if (!(thread->flags & _ST_FL_PRIMORDIAL))
+    if (!(thread->flags & _ST_FL_PRIMORDIAL)) {
         _st_stack_free(thread->stack);
+    }
     /* Find another thread to run */
     _ST_SWITCH_CONTEXT(thread);
     /* Not going to land here */
 }
-
 int st_thread_join(_st_thread_t *thread, void **retvalp)
 {
     _st_cond_t *term = thread->term;
@@ -293,12 +292,14 @@ int st_thread_join(_st_thread_t *thread, void **retvalp)
     }
     while (thread->state != _ST_ST_ZOMBIE) {
-    if (st_cond_timedwait(term, ST_UTIME_NO_TIMEOUT) != 0)
+        if (st_cond_timedwait(term, ST_UTIME_NO_TIMEOUT) != 0) {
             return -1;
         }
+    }
-  if (retvalp)
+    if (retvalp) {
         *retvalp = thread->retval;
+    }
     /*
     * Remove target thread from the zombie queue and make it runnable.
@@ -311,7 +312,6 @@ int st_thread_join(_st_thread_t *thread, void **retvalp)
     return 0;
 }
-
 void _st_thread_main(void)
 {
     _st_thread_t *thread = _ST_CURRENT_THREAD();
@@ -330,13 +330,13 @@ void _st_thread_main(void)
     st_thread_exit(thread->retval);
 }
-
 /*
  * Insert "thread" into the timeout heap, in the position
  * specified by thread->heap_index.  See docs/timeout_heap.txt
  * for details about the timeout heap.
  */
-static _st_thread_t **heap_insert(_st_thread_t *thread) {
+static _st_thread_t **heap_insert(_st_thread_t *thread)
+{
     int target = thread->heap_index;
     int s = target;
     _st_thread_t **p = &_ST_SLEEPQ;
@@ -348,6 +348,7 @@ static _st_thread_t **heap_insert(_st_thread_t *thread) {
         s >>= 1;
         bits++;
     }
+    
     for (bit = bits - 2; bit >= 0; bit--) {
         if (thread->due < (*p)->due) {
             _st_thread_t *t = *p;
@@ -365,17 +366,19 @@ static _st_thread_t **heap_insert(_st_thread_t *thread) {
             p = &((*p)->left);
         }
     }
+    
     thread->heap_index = index;
     *p = thread;
     thread->left = thread->right = NULL;
+    
     return p;
 }
-
 /*
  * Delete "thread" from the timeout heap.
  */
-static void heap_delete(_st_thread_t *thread) {
+static void heap_delete(_st_thread_t *thread) 
+{
     _st_thread_t *t, **p;
     int bits = 0;
     int s, bit;
@@ -387,6 +390,7 @@ static void heap_delete(_st_thread_t *thread) {
         s >>= 1;
         bits++;
     }
+    
     for (bit = bits - 2; bit >= 0; bit--) {
         if (_ST_SLEEPQ_SIZE & (1 << bit)) {
             p = &((*p)->right);
@@ -394,6 +398,7 @@ static void heap_delete(_st_thread_t *thread) {
             p = &((*p)->left);
         }
     }
+    
     t = *p;
     *p = NULL;
     --_ST_SLEEPQ_SIZE;
@@ -413,14 +418,17 @@ static void heap_delete(_st_thread_t *thread) {
         for (;;) {
             _st_thread_t *y; /* The younger child */
             int index_tmp;
-      if (t->left == NULL)
+            
+            if (t->left == NULL) {
                 break;
-      else if (t->right == NULL)
+            } else if (t->right == NULL) {
                 y = t->left;
-      else if (t->left->due < t->right->due)
+            } else if (t->left->due < t->right->due) {
                 y = t->left;
-      else
+            } else {
                 y = t->right;
+            }
+            
             if (t->due > y->due) {
                 _st_thread_t *tl = y->left;
                 _st_thread_t *tr = y->right;
@@ -444,10 +452,10 @@ static void heap_delete(_st_thread_t *thread) {
             }
         }
     }
+    
     thread->left = thread->right = NULL;
 }
-
 void _st_add_sleep_q(_st_thread_t *thread, st_utime_t timeout)
 {
     thread->due = _ST_LAST_CLOCK + timeout;
@@ -456,14 +464,12 @@ void _st_add_sleep_q(_st_thread_t *thread, st_utime_t timeout)
     heap_insert(thread);
 }
-
 void _st_del_sleep_q(_st_thread_t *thread)
 {
     heap_delete(thread);
     thread->flags &= ~_ST_FL_ON_SLEEPQ;
 }
-
 void _st_vp_check_clock(void)
 {
     _st_thread_t *thread;
@@ -481,13 +487,15 @@ void _st_vp_check_clock(void)
     while (_ST_SLEEPQ != NULL) {
         thread = _ST_SLEEPQ;
         ST_ASSERT(thread->flags & _ST_FL_ON_SLEEPQ);
-    if (thread->due > now)
+        if (thread->due > now) {
             break;
+        }
         _ST_DEL_SLEEPQ(thread);
         /* If thread is waiting on condition variable, set the time out flag */
-    if (thread->state == _ST_ST_COND_WAIT)
+        if (thread->state == _ST_ST_COND_WAIT) {
             thread->flags |= _ST_FL_TIMEDOUT;
+        }
         /* Make thread runnable */
         ST_ASSERT(!(thread->flags & _ST_FL_IDLE_THREAD));
@@ -496,29 +504,29 @@ void _st_vp_check_clock(void)
     }
 }
-
 void st_thread_interrupt(_st_thread_t *thread)
 {
     /* If thread is already dead */
-  if (thread->state == _ST_ST_ZOMBIE)
+    if (thread->state == _ST_ST_ZOMBIE) {
         return;
+    }
     thread->flags |= _ST_FL_INTERRUPT;
-  if (thread->state == _ST_ST_RUNNING || thread->state == _ST_ST_RUNNABLE)
+    if (thread->state == _ST_ST_RUNNING || thread->state == _ST_ST_RUNNABLE) {
         return;
+    }
-  if (thread->flags & _ST_FL_ON_SLEEPQ)
+    if (thread->flags & _ST_FL_ON_SLEEPQ) {
         _ST_DEL_SLEEPQ(thread);
+    }
     /* Make thread runnable */
     thread->state = _ST_ST_RUNNABLE;
     _ST_ADD_RUNQ(thread);
 }
-
-_st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg,
-                   int joinable, int stk_size)
+_st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinable, int stk_size)
 {
     _st_thread_t *thread;
     _st_stack_t *stack;
@@ -529,17 +537,19 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg,
 #endif
     /* Adjust stack size */
-  if (stk_size == 0)
+    if (stk_size == 0) {
         stk_size = ST_DEFAULT_STACK_SIZE;
+    }
     stk_size = ((stk_size + _ST_PAGE_SIZE - 1) / _ST_PAGE_SIZE) * _ST_PAGE_SIZE;
     stack = _st_stack_new(stk_size);
-  if (!stack)
+    if (!stack) {
         return NULL;
+    }
     /* Allocate thread object and per-thread data off the stack */
 #if defined (MD_STACK_GROWS_DOWN)
     sp = stack->stk_top;
-#ifdef __ia64__
+    #ifdef __ia64__
     /*
     * The stack segment is split in the middle. The upper half is used
     * as backing store for the register stack which grows upward.
@@ -550,18 +560,20 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg,
     sp -= (stk_size >> 1);
     bsp = sp;
     /* Make register stack 64-byte aligned */
-  if ((unsigned long)bsp & 0x3f)
+    if ((unsigned long)bsp & 0x3f) {
         bsp = bsp + (0x40 - ((unsigned long)bsp & 0x3f));
+    }
     stack->bsp = bsp + _ST_STACK_PAD_SIZE;
-#endif
+    #endif
     sp = sp - (ST_KEYS_MAX * sizeof(void *));
     ptds = (void **) sp;
     sp = sp - sizeof(_st_thread_t);
     thread = (_st_thread_t *) sp;
     /* Make stack 64-byte aligned */
-  if ((unsigned long)sp & 0x3f)
+    if ((unsigned long)sp & 0x3f) {
         sp = sp - ((unsigned long)sp & 0x3f);
+    }
     stack->sp = sp - _ST_STACK_PAD_SIZE;
 #elif defined (MD_STACK_GROWS_UP)
     sp = stack->stk_bottom;
@@ -571,11 +583,12 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg,
     sp = sp + (ST_KEYS_MAX * sizeof(void *));
     /* Make stack 64-byte aligned */
-  if ((unsigned long)sp & 0x3f)
+    if ((unsigned long)sp & 0x3f) {
         sp = sp + (0x40 - ((unsigned long)sp & 0x3f));
+    }
     stack->sp = sp + _ST_STACK_PAD_SIZE;
 #else
-#error Unknown OS
+    #error Unknown OS
 #endif
     memset(thread, 0, sizeof(_st_thread_t));
@@ -613,18 +626,15 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg,
     return thread;
 }
-
 _st_thread_t *st_thread_self(void)
 {
     return _ST_CURRENT_THREAD();
 }
-
 #ifdef DEBUG
 /* ARGSUSED */
 void _st_show_thread_stack(_st_thread_t *thread, const char *messg)
 {
-
 }
 /* To be set from debugger */
@@ -659,12 +669,14 @@ void _st_iterate_threads(void)
     }
     q = thread->tlink.next;
-  if (q == &_ST_THREADQ)
+    if (q == &_ST_THREADQ) {
         q = q->next;
+    }
     ST_ASSERT(q != &_ST_THREADQ);
     thread = _ST_THREAD_THREADQ_PTR(q);
-  if (thread == _ST_CURRENT_THREAD())
+    if (thread == _ST_CURRENT_THREAD()) {
         MD_LONGJMP(orig_jb, 1);
+    }
     memcpy(save_jb, thread->context, sizeof(jmp_buf));
     MD_LONGJMP(thread->context, 1);
 }