research st: refine skt.

@@ -46,7 +46,6 @@
 #include <sys/mman.h>
 #include "common.h"
 
-
 /* How much space to leave between the stacks, at each end */
 #define REDZONE    _ST_PAGE_SIZE
 
@@ -58,116 +57,118 @@ static char *_st_new_stk_segment(int size);
 
 _st_stack_t *_st_stack_new(int stack_size)
 {
-  _st_clist_t *qp;
-  _st_stack_t *ts;
-  int extra;
-
-  for (qp = _st_free_stacks.next; qp != &_st_free_stacks; qp = qp->next) {
-    ts = _ST_THREAD_STACK_PTR(qp);
-    if (ts->stk_size >= stack_size) {
-      /* Found a stack that is big enough */
-      ST_REMOVE_LINK(&ts->links);
-      _st_num_free_stacks--;
-      ts->links.next = NULL;
-      ts->links.prev = NULL;
-      return ts;
+    _st_clist_t *qp;
+    _st_stack_t *ts;
+    int extra;
+    
+    for (qp = _st_free_stacks.next; qp != &_st_free_stacks; qp = qp->next) {
+        ts = _ST_THREAD_STACK_PTR(qp);
+        if (ts->stk_size >= stack_size) {
+            /* Found a stack that is big enough */
+            ST_REMOVE_LINK(&ts->links);
+            _st_num_free_stacks--;
+            ts->links.next = NULL;
+            ts->links.prev = NULL;
+            return ts;
+        }
     }
-  }
-
-  /* Make a new thread stack object. */
-  if ((ts = (_st_stack_t *)calloc(1, sizeof(_st_stack_t))) == NULL)
-    return NULL;
-  extra = _st_randomize_stacks ? _ST_PAGE_SIZE : 0;
-  ts->vaddr_size = stack_size + 2*REDZONE + extra;
-  ts->vaddr = _st_new_stk_segment(ts->vaddr_size);
-  if (!ts->vaddr) {
-    free(ts);
-    return NULL;
-  }
-  ts->stk_size = stack_size;
-  ts->stk_bottom = ts->vaddr + REDZONE;
-  ts->stk_top = ts->stk_bottom + stack_size;
-
+    
+    /* Make a new thread stack object. */
+    if ((ts = (_st_stack_t *)calloc(1, sizeof(_st_stack_t))) == NULL) {
+        return NULL;
+    }
+    extra = _st_randomize_stacks ? _ST_PAGE_SIZE : 0;
+    ts->vaddr_size = stack_size + 2*REDZONE + extra;
+    ts->vaddr = _st_new_stk_segment(ts->vaddr_size);
+    if (!ts->vaddr) {
+        free(ts);
+        return NULL;
+    }
+    ts->stk_size = stack_size;
+    ts->stk_bottom = ts->vaddr + REDZONE;
+    ts->stk_top = ts->stk_bottom + stack_size;
+    
 #ifdef DEBUG
-  mprotect(ts->vaddr, REDZONE, PROT_NONE);
-  mprotect(ts->stk_top + extra, REDZONE, PROT_NONE);
+    mprotect(ts->vaddr, REDZONE, PROT_NONE);
+    mprotect(ts->stk_top + extra, REDZONE, PROT_NONE);
 #endif
-
-  if (extra) {
-    long offset = (random() % extra) & ~0xf;
-
-    ts->stk_bottom += offset;
-    ts->stk_top += offset;
-  }
-
-  return ts;
+    
+    if (extra) {
+        long offset = (random() % extra) & ~0xf;
+        
+        ts->stk_bottom += offset;
+        ts->stk_top += offset;
+    }
+    
+    return ts;
 }
 
-
 /*
  * Free the stack for the current thread
  */
 void _st_stack_free(_st_stack_t *ts)
 {
-  if (!ts)
-    return;
-
-  /* Put the stack on the free list */
-  ST_APPEND_LINK(&ts->links, _st_free_stacks.prev);
-  _st_num_free_stacks++;
+    if (!ts) {
+        return;
+    }
+    
+    /* Put the stack on the free list */
+    ST_APPEND_LINK(&ts->links, _st_free_stacks.prev);
+    _st_num_free_stacks++;
 }
 
-
 static char *_st_new_stk_segment(int size)
 {
 #ifdef MALLOC_STACK
-  void *vaddr = malloc(size);
-#else
-  static int zero_fd = -1;
-  int mmap_flags = MAP_PRIVATE;
-  void *vaddr;
-
-#if defined (MD_USE_SYSV_ANON_MMAP)
-  if (zero_fd < 0) {
-    if ((zero_fd = open("/dev/zero", O_RDWR, 0)) < 0)
-      return NULL;
-    fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
-  }
-#elif defined (MD_USE_BSD_ANON_MMAP)
-  mmap_flags |= MAP_ANON;
+    void *vaddr = malloc(size);
 #else
-#error Unknown OS
+    static int zero_fd = -1;
+    int mmap_flags = MAP_PRIVATE;
+    void *vaddr;
+    
+    #if defined (MD_USE_SYSV_ANON_MMAP)
+    if (zero_fd < 0) {
+        if ((zero_fd = open("/dev/zero", O_RDWR, 0)) < 0) {
+            return NULL;
+        }
+        fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
+    }
+    #elif defined (MD_USE_BSD_ANON_MMAP)
+    mmap_flags |= MAP_ANON;
+    #else
+        #error Unknown OS
+    #endif
+    
+    vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, mmap_flags, zero_fd, 0);
+    if (vaddr == (void *)MAP_FAILED) {
+        return NULL;
+    }
+    
 #endif
-
-  vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, mmap_flags, zero_fd, 0);
-  if (vaddr == (void *)MAP_FAILED)
-    return NULL;
-
-#endif /* MALLOC_STACK */
-
-  return (char *)vaddr;
+    
+    return (char *)vaddr;
 }
 
-
 /* Not used */
 #if 0
 void _st_delete_stk_segment(char *vaddr, int size)
 {
 #ifdef MALLOC_STACK
-  free(vaddr);
+    free(vaddr);
 #else
-  (void) munmap(vaddr, size);
+    (void) munmap(vaddr, size);
 #endif
 }
 #endif
 
 int st_randomize_stacks(int on)
 {
-  int wason = _st_randomize_stacks;
-
-  _st_randomize_stacks = on;
-  if (on)
-    srandom((unsigned int) st_utime());
-
-  return wason;
+    int wason = _st_randomize_stacks;
+    
+    _st_randomize_stacks = on;
+    if (on) {
+        srandom((unsigned int) st_utime());
+    }
+    
+    return wason;
 }