STACKS

a pool of stacks for a threading package. More...

Classes
struct	tagSTACKS
struct	tagSTACK_ENTRY
Typedefs
typedef struct tagSTACKS	STACKS
typedef struct tagSTACK_ENTRY	STACK_ENTRY
Functions
int	STACKS_init (STACKS *stack, int num_stacks, int pages_per_stack)
int	STACKS_destroy (STACKS *stack)
void *	STACKS_get (STACKS *stack, STACK_ENTRY **rentry)
int	STACKS_release (STACK_ENTRY *entry)
M_INLINE size_t	STACKS_get_stack_size (STACKS *stack)
Variables
size_t	tagSTACKS::mapping_length
int	tagSTACKS::num_stacks
size_t	tagSTACKS::one_stack_size
DLIST	tagSTACKS::root
void *	tagSTACK_ENTRY::stack_start
STACKS *	tagSTACK_ENTRY::stacks

---

Detailed Description

a pool of stacks for a threading package.

---

Typedef Documentation

typedef struct tagSTACK_ENTRY STACK_ENTRY

typedef struct tagSTACKS STACKS

---

Function Documentation

int STACKS_destroy

(

STACKS *

stack

)

Definition at line 83 of file stacks.c.

{
  if ( DLIST_size( &stack->root) != (size_t) stack->num_stacks ) {
    return -1;
  }
  
  if (munmap( stack->mapping, stack->mapping_length)) {
    return -1;
  }
  return 0;
}

void* STACKS_get	(	STACKS *	stack,
		STACK_ENTRY **	rentry
	)

Definition at line 96 of file stacks.c.

{
  STACK_ENTRY *entry;
  if (DLIST_isempty( &stack->root ) ) {
    return 0;
  }
  entry = (STACK_ENTRY *) DLIST_pop_front( &stack->root );
  *rentry = entry;
  return entry->stack_start;
}

M_INLINE size_t STACKS_get_stack_size

(

STACKS *

stack

)

Definition at line 38 of file stacks.h.

                                                     {
  return stack->one_stack_size;
}

int STACKS_init	(	STACKS *	stack,
		int	num_stacks,
		int	pages_per_stack
	)

Definition at line 22 of file stacks.c.

{
  int page_size;
  size_t len, one_stack_size;
  STACK_DIR dir;
  STACK_ENTRY *entry;
  uint8_t *mapping, *stack_start;
  uint8_t *guard_page;
  int i;
  
  page_size = sysconf( _SC_PAGE_SIZE );
  one_stack_size = page_size *  pages_per_stack; 
  len = num_stacks * one_stack_size;
  dir = stack_direction();

  mapping = (uint8_t *) mmap( 0 , len, PROT_READ|PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS 

#if 0
#ifdef MAP_STACK
                        | MAP_STACK
#endif
#endif
                      , -1, 0 );
  if (!mapping) {
    return -1;
  }

  //fprintf( stderr, "all stacks %p - %p\n", mapping, mapping + len );
  
  stack->mapping = mapping;
  stack->mapping_length = len;
  stack->num_stacks = num_stacks;
  stack->one_stack_size = one_stack_size - page_size;
 
  DLIST_init( &stack->root );

  for( i = 0; i < num_stacks; i ++ ) {
    stack_start = mapping + ( i * one_stack_size);
    
    if (dir == STACK_DIR_GROWING_DOWN) {
    //stack_start = mapping + ( (i + 1) * one_stack_size) - 1;
      guard_page =  mapping + (i * one_stack_size);
    } else {
      guard_page = mapping + ( i + 1 ) * one_stack_size - page_size;
    }
  
    if (mprotect( guard_page , page_size, PROT_NONE )) {
      return -1;
    }
    
    entry = (STACK_ENTRY *) malloc( sizeof( STACK_ENTRY ) );
    if (!entry) {
      return -1;
    }
    entry->stack_start = stack_start;
    entry->stacks = stack;
    DLIST_push_back( &stack->root, &entry->entry );
  }
  return 0;
}

int STACKS_release

(

STACK_ENTRY *

entry

)

Definition at line 107 of file stacks.c.

{
  STACKS *stack = entry->stacks;
  DLIST_push_front( &stack->root, &entry->entry );
  return 0;
}

---

Variable Documentation

size_t tagSTACKS::mapping_length

Definition at line 20 of file stacks.h.

int tagSTACKS::num_stacks

Definition at line 21 of file stacks.h.

size_t tagSTACKS::one_stack_size

Definition at line 22 of file stacks.h.

DLIST tagSTACKS::root

Definition at line 23 of file stacks.h.

void* tagSTACK_ENTRY::stack_start

Definition at line 28 of file stacks.h.

STACKS* tagSTACK_ENTRY::stacks

Definition at line 29 of file stacks.h.