WebSVN – HelenOS – Diff – /branches/dynload/uspace/lib/libc/generic/as.c

 /** @addtogroup libc
  * @{
  */
 /** @file
  */
 #include <as.h>
 #include <libc.h>
 #include <unistd.h>
 #include <align.h>
 #include <sys/types.h>
 #include <bitops.h>
+#include <malloc.h>
-/**
- * Either 4*256M on 32-bit architecures or 16*256M on 64-bit architectures.
+/** Last position allocated by as_get_mappable_page */
- */
-#define MAX_HEAP_SIZE   (sizeof(uintptr_t)<<28)
+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 size    Size of the area.
- * @param flags Flags describing type 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);
+}
 /** Resize address space area.
+ *
  * @param address Virtual address pointing into already existing address space
- *  area.
+ *                area.
- * @param size New requested size of the area.
+ * @param size    New requested size of the area.
- * @param flags Currently unused.
+ * @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);
+}
 /** Destroy address space area.
+ *
  * @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);
+}
 /** Change address-space area flags.
+ *
  * @param address Virtual address pointing into the address space area being
- *  modified.
+ *                modified.
- * @param flags New flags describing type of the area.
+ * @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)
+{
     return __SYSCALL2(SYS_AS_AREA_CHANGE_FLAGS, (sysarg_t) address,
         (sysarg_t) flags);
+}
-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
- *
- * @param incr New area that should be allocated or negative,
-               if it should be shrinked
- * @return Pointer to newly allocated area
- */
-void *sbrk(ssize_t incr)
-{
-    int rc;
-    void *res;
-    /* Check for invalid values */
-    if (incr < 0 && -incr > heapsize)
-        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.
+ * @param size Requested size of the allocation.
+ *
- * @return Pointer to the beginning
+ * @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 *as_get_mappable_page(size_t size)
+{
-    void *res;
+    if (size == 0)
-    uint64_t asz;
+        return NULL;
-    int i;
-    if (!sz)
-        return NULL;
-    asz = 1 << (fnzb64(sz - 1) + 1);
+    size_t sz = 1 << (fnzb(size - 1) + 1);
-    /* Set heapsize to some meaningful value */
-    if (maxheapsize == -1)
+    if (last_allocated == 0)
-        set_maxheapsize(MAX_HEAP_SIZE);
+        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;
+    uintptr_t res = ALIGN_UP(last_allocated, sz);
-    last_allocated += ALIGN_UP(sz, PAGE_SIZE);
+    last_allocated = res + ALIGN_UP(size, PAGE_SIZE);
-    return res;
+    return ((void *) res);
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/branches/dynload/uspace/lib/libc/generic/as.c – Rev 2985 → 4691