Changeset db24058 in mainline for uspace/lib/libc/generic/as.c

Timestamp:

2009-06-30T15:53:15Z (15 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2d11a7d8

Parents:

6db6fd1

Message:

small fixes and coding style changes related to the new memory allocator

File:

• uspace/lib/libc/generic/as.c (modified) (5 diffs)

uspace/lib/libc/generic/as.c

@@ -39 +39 @@
 #include <sys/types.h>
 #include <bitops.h>
+#include <malloc.h>
 
-/**
- * Either 4*256M on 32-bit architecures or 16*256M on 64-bit architectures.
- */
-#define MAX_HEAP_SIZE   (sizeof(uintptr_t)<<28)
+/** Last position allocated by as_get_mappable_page */
+static uintptr_t last_allocated = 0;
 
 /** Create address space area.
  *
  * @param address Virtual address where to place new address space area.
- * @param size Size of the area.
- * @param flags Flags describing type of the area.
+ * @param size    Size of the area.
+ * @param flags   Flags describing type of the area.
  *
  * @return address on success, (void *) -1 otherwise.
+ *
  */
 void *as_area_create(void *address, size_t size, int flags)
 {
-        return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address,
+        return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t) address,
             (sysarg_t) size, (sysarg_t) flags);
 }
@@ -62 +62 @@
  *
  * @param address Virtual address pointing into already existing address space
- *      area.
- * @param size New requested size of the area.
- * @param flags Currently unused.
+ *                area.
+ * @param size    New requested size of the area.
+ * @param flags   Currently unused.
  *
- * @return Zero on success or a code from @ref errno.h on failure.
+ * @return zero on success or a code from @ref errno.h on failure.
+ *
  */
 int as_area_resize(void *address, size_t size, int flags)
 {
-        return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address,
+        return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t) address,
             (sysarg_t) size, (sysarg_t) flags);
 }
@@ -77 +78 @@
  *
  * @param address Virtual address pointing into the address space area being
- *      destroyed.
+ *                destroyed.
  *
- * @return Zero on success or a code from @ref errno.h on failure.
+ * @return zero on success or a code from @ref errno.h on failure.
+ *
  */
 int as_area_destroy(void *address)
 {
-        return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t ) address);
+        return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t) address);
 }
 
@@ -89 +91 @@
  *
  * @param address Virtual address pointing into the address space area being
- *      modified.
- * @param flags New flags describing type of the area.
+ *                modified.
+ * @param flags   New flags describing type of the area.
  *
- * @return Zero on success or a code from @ref errno.h on failure.
+ * @return zero on success or a code from @ref errno.h on failure.
+ *
  */
 int as_area_change_flags(void *address, int flags)
@@ -100 +103 @@
 }
 
-static size_t heapsize = 0;
-static size_t maxheapsize = (size_t) (-1);
-
-static void *last_allocated = 0;
-
-/* Start of heap linker symbol */
-extern char _heap;
-
-/** Sbrk emulation 
+/** Return pointer to some unmapped area, where fits new as_area
  *
- * @param incr New area that should be allocated or negative, 
-               if it should be shrinked
- * @return Pointer to newly allocated area
+ * @param size Requested size of the allocation.
+ *
+ * @return pointer to the beginning
+ *
  */
-void *sbrk(ssize_t incr)
+void *as_get_mappable_page(size_t size)
 {
-        int rc;
-        void *res;
-        
-        /* Check for invalid values */
-        if ((incr < 0) && (((size_t) -incr) > heapsize))
+        if (size == 0)
                 return NULL;
         
-        /* Check for too large value */
-        if ((incr > 0) && (incr + heapsize < heapsize))
-                return NULL;
-        
-        /* Check for too small values */
-        if ((incr < 0) && (incr + heapsize > heapsize))
-                return NULL;
-        
-        /* Check for user limit */
-        if ((maxheapsize != (size_t) (-1)) && (heapsize + incr) > maxheapsize)
-                return NULL;
-        
-        rc = as_area_resize(&_heap, heapsize + incr, 0);
-        if (rc != 0)
-                return NULL;
-        
-        /* Compute start of new area */
-        res = (void *) &_heap + heapsize;
-
-        heapsize += incr;
-
-        return res;
-}
-
-/** Set maximum heap size and return pointer just after the heap */
-void *set_maxheapsize(size_t mhs)
-{
-        maxheapsize = mhs;
-        /* Return pointer to area not managed by sbrk */
-        return ((void *) &_heap + maxheapsize);
-}
-
-/** Return pointer to some unmapped area, where fits new as_area
- *
- * @param sz Requested size of the allocation.
- *
- * @return Pointer to the beginning 
- *
- * TODO: make some first_fit/... algorithm, we are now just incrementing
- *       the pointer to last area
- */
-void *as_get_mappable_page(size_t sz)
-{
-        void *res;
-        uint64_t asz;
-        int i;
-        
-        if (!sz)
-                return NULL;    
-
-        asz = 1 << (fnzb64(sz - 1) + 1);
-
-        /* Set heapsize to some meaningful value */
-        if (maxheapsize == (size_t) -1)
-                set_maxheapsize(MAX_HEAP_SIZE);
+        size_t sz = 1 << (fnzb(size - 1) + 1);
+        if (last_allocated == 0)
+                last_allocated = get_max_heap_addr();
         
         /*
          * Make sure we allocate from naturally aligned address.
          */
-        i = 0;
-        if (!last_allocated) {
-                last_allocated = (void *) ALIGN_UP((void *) &_heap +
-                    maxheapsize, asz);
-        } else {
-                last_allocated = (void *) ALIGN_UP(((uintptr_t)
-                    last_allocated) + (int) (i > 0), asz);
-        }
-
-        res = last_allocated;
-        last_allocated += ALIGN_UP(sz, PAGE_SIZE);
-
-        return res;
+        uintptr_t res = ALIGN_UP(last_allocated, sz);
+        last_allocated = res + ALIGN_UP(size, PAGE_SIZE);
+        
+        return ((void *) res);
 }