[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/build/uClibc/libc/stdlib/malloc/free.c b/ap/build/uClibc/libc/stdlib/malloc/free.c
new file mode 100644
index 0000000..e7b6a29
--- /dev/null
+++ b/ap/build/uClibc/libc/stdlib/malloc/free.c
@@ -0,0 +1,272 @@
+/*
+ * libc/stdlib/malloc/free.c -- free function
+ *
+ *  Copyright (C) 2002,03  NEC Electronics Corporation
+ *  Copyright (C) 2002,03  Miles Bader <miles@gnu.org>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License.  See the file COPYING.LIB in the main
+ * directory of this archive for more details.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+
+#include "malloc.h"
+#include "heap.h"
+
+#ifdef HEAP_USE_LOCKING
+#define free_to_heap(mem, heap, lck) __free_to_heap(mem, heap, lck)
+#else
+#define free_to_heap(mem, heap, lck) __free_to_heap(mem, heap)
+#endif
+
+static void
+__free_to_heap (void *mem, struct heap_free_area **heap
+#ifdef HEAP_USE_LOCKING
+		, malloc_mutex_t *heap_lock
+#endif
+	       )
+{
+  size_t size;
+  struct heap_free_area *fa;
+
+  /* Check for special cases.  */
+  if (unlikely (! mem))
+    return;
+
+  /* Normal free.  */
+
+  MALLOC_DEBUG (1, "free: 0x%lx (base = 0x%lx, total_size = %d)",
+		(long)mem, (long)MALLOC_BASE (mem), MALLOC_SIZE (mem));
+
+  size = MALLOC_SIZE (mem);
+  mem = MALLOC_BASE (mem);
+
+  __heap_lock (heap_lock);
+
+  /* Put MEM back in the heap, and get the free-area it was placed in.  */
+  fa = __heap_free (heap, mem, size);
+
+  /* See if the free-area FA has grown big enough that it should be
+     unmapped.  */
+  if (HEAP_FREE_AREA_SIZE (fa) < MALLOC_UNMAP_THRESHOLD)
+    /* Nope, nothing left to do, just release the lock.  */
+    __heap_unlock (heap_lock);
+  else
+    /* Yup, try to unmap FA.  */
+    {
+      unsigned long start = (unsigned long)HEAP_FREE_AREA_START (fa);
+      unsigned long end = (unsigned long)HEAP_FREE_AREA_END (fa);
+#ifndef MALLOC_USE_SBRK
+# ifdef __UCLIBC_UCLINUX_BROKEN_MUNMAP__
+      struct malloc_mmb *mmb, *prev_mmb;
+      unsigned long mmb_start, mmb_end;
+# else /* !__UCLIBC_UCLINUX_BROKEN_MUNMAP__ */
+      unsigned long unmap_start, unmap_end;
+# endif /* __UCLIBC_UCLINUX_BROKEN_MUNMAP__ */
+#endif /* !MALLOC_USE_SBRK */
+
+#ifdef MALLOC_USE_SBRK
+      /* Get the sbrk lock so that the two possible calls to sbrk below
+	 are guaranteed to be contiguous.  */
+      __malloc_lock_sbrk ();
+      /* When using sbrk, we only shrink the heap from the end.  It would
+	 be possible to allow _both_ -- shrinking via sbrk when possible,
+	 and otherwise shrinking via munmap, but this results in holes in
+	 memory that prevent the brk from every growing back down; since
+	 we only ever grow the heap via sbrk, this tends to produce a
+	 continuously growing brk (though the actual memory is unmapped),
+	 which could eventually run out of address space.  Note that
+	 `sbrk(0)' shouldn't normally do a system call, so this test is
+	 reasonably cheap.  */
+      if ((void *)end != sbrk (0))
+	{
+	  MALLOC_DEBUG (-1, "not unmapping: 0x%lx - 0x%lx (%ld bytes)",
+			start, end, end - start);
+	  __malloc_unlock_sbrk ();
+	  __heap_unlock (heap_lock);
+	  return;
+	}
+#endif
+
+      MALLOC_DEBUG (0, "unmapping: 0x%lx - 0x%lx (%ld bytes)",
+		    start, end, end - start);
+
+      /* Remove FA from the heap.  */
+      __heap_delete (heap, fa);
+
+      if (__heap_is_empty (heap))
+	/* We want to avoid the heap from losing all memory, so reserve
+	   a bit.  This test is only a heuristic -- the existance of
+	   another free area, even if it's smaller than
+	   MALLOC_MIN_SIZE, will cause us not to reserve anything.  */
+	{
+	  /* Put the reserved memory back in the heap; we assume that
+	     MALLOC_UNMAP_THRESHOLD is greater than MALLOC_MIN_SIZE, so
+	     we use the latter unconditionally here.  */
+	  __heap_free (heap, (void *)start, MALLOC_MIN_SIZE);
+	  start += MALLOC_MIN_SIZE;
+	}
+
+#ifdef MALLOC_USE_SBRK
+
+      /* Release the heap lock; we're still holding the sbrk lock.  */
+      __heap_unlock (heap_lock);
+      /* Lower the brk.  */
+      sbrk (start - end);
+      /* Release the sbrk lock too; now we hold no locks.  */
+      __malloc_unlock_sbrk ();
+
+#else /* !MALLOC_USE_SBRK */
+
+# ifdef __UCLIBC_UCLINUX_BROKEN_MUNMAP__
+      /* Using the uClinux broken munmap, we have to only munmap blocks
+	 exactly as we got them from mmap, so scan through our list of
+	 mmapped blocks, and return them in order.  */
+
+      MALLOC_MMB_DEBUG (1, "walking mmb list for region 0x%x[%d]...",
+			start, end - start);
+
+      prev_mmb = 0;
+      mmb = __malloc_mmapped_blocks;
+      while (mmb
+	     && ((mmb_end = (mmb_start = (unsigned long)mmb->mem) + mmb->size)
+		 <= end))
+	{
+	  MALLOC_MMB_DEBUG (1, "considering mmb at 0x%x: 0x%x[%d]",
+			    (unsigned)mmb, mmb_start, mmb_end - mmb_start);
+
+	  if (mmb_start >= start
+	      /* If the space between START and MMB_START is non-zero, but
+		 too small to return to the heap, we can't unmap MMB.  */
+	      && (start == mmb_start
+		  || mmb_start - start > HEAP_MIN_FREE_AREA_SIZE))
+	    {
+	      struct malloc_mmb *next_mmb = mmb->next;
+
+	      if (mmb_end != end && mmb_end + HEAP_MIN_FREE_AREA_SIZE > end)
+		/* There's too little space left at the end to deallocate
+		   this block, so give up.  */
+		break;
+
+	      MALLOC_MMB_DEBUG (1, "unmapping mmb at 0x%x: 0x%x[%d]",
+				(unsigned)mmb, mmb_start, mmb_end - mmb_start);
+
+	      if (mmb_start != start)
+		/* We're going to unmap a part of the heap that begins after
+		   start, so put the intervening region back into the heap.  */
+		{
+		  MALLOC_MMB_DEBUG (0, "putting intervening region back into heap: 0x%x[%d]",
+				    start, mmb_start - start);
+		  __heap_free (heap, (void *)start, mmb_start - start);
+		}
+
+	      MALLOC_MMB_DEBUG_INDENT (-1);
+
+	      /* Unlink MMB from the list.  */
+	      if (prev_mmb)
+		prev_mmb->next = next_mmb;
+	      else
+		__malloc_mmapped_blocks = next_mmb;
+
+	      /* Start searching again from the end of this block.  */
+	      start = mmb_end;
+
+	      /* Release the descriptor block we used.  */
+	      free_to_heap (mmb, &__malloc_mmb_heap, &__malloc_mmb_heap_lock);
+
+	      /* We have to unlock the heap before we recurse to free the mmb
+		 descriptor, because we might be unmapping from the mmb
+		 heap.  */
+              __heap_unlock (heap_lock);
+
+	      /* Do the actual munmap.  */
+	      munmap ((void *)mmb_start, mmb_end - mmb_start);
+
+	      __heap_lock (heap_lock);
+
+#  ifdef __UCLIBC_HAS_THREADS__
+	      /* In a multi-threaded program, it's possible that PREV_MMB has
+		 been invalidated by another thread when we released the
+		 heap lock to do the munmap system call, so just start over
+		 from the beginning of the list.  It sucks, but oh well;
+		 it's probably not worth the bother to do better.  */
+	      prev_mmb = 0;
+	      mmb = __malloc_mmapped_blocks;
+#  else
+	      mmb = next_mmb;
+#  endif
+	    }
+	  else
+	    {
+	      prev_mmb = mmb;
+	      mmb = mmb->next;
+	    }
+
+	  MALLOC_MMB_DEBUG_INDENT (-1);
+	}
+
+      if (start != end)
+	/* Hmm, well there's something we couldn't unmap, so put it back
+	   into the heap.  */
+	{
+	  MALLOC_MMB_DEBUG (0, "putting tail region back into heap: 0x%x[%d]",
+			    start, end - start);
+	  __heap_free (heap, (void *)start, end - start);
+	}
+
+      /* Finally release the lock for good.  */
+      __heap_unlock (heap_lock);
+
+      MALLOC_MMB_DEBUG_INDENT (-1);
+
+# else /* !__UCLIBC_UCLINUX_BROKEN_MUNMAP__ */
+
+      /* MEM/LEN may not be page-aligned, so we have to page-align them,
+	 and return any left-over bits on the end to the heap.  */
+      unmap_start = MALLOC_ROUND_UP_TO_PAGE_SIZE (start);
+      unmap_end = MALLOC_ROUND_DOWN_TO_PAGE_SIZE (end);
+
+      /* We have to be careful that any left-over bits are large enough to
+	 return.  Note that we _don't check_ to make sure there's room to
+	 grow/shrink the start/end by another page, we just assume that
+	 the unmap threshold is high enough so that this is always safe
+	 (i.e., it should probably be at least 3 pages).  */
+      if (unmap_start > start)
+	{
+	  if (unmap_start - start < HEAP_MIN_FREE_AREA_SIZE)
+	    unmap_start += MALLOC_PAGE_SIZE;
+	  __heap_free (heap, (void *)start, unmap_start - start);
+	}
+      if (end > unmap_end)
+	{
+	  if (end - unmap_end < HEAP_MIN_FREE_AREA_SIZE)
+	    unmap_end -= MALLOC_PAGE_SIZE;
+	  __heap_free (heap, (void *)unmap_end, end - unmap_end);
+	}
+
+      /* Release the heap lock before we do the system call.  */
+      __heap_unlock (heap_lock);
+
+      if (unmap_end > unmap_start)
+	/* Finally, actually unmap the memory.  */
+	munmap ((void *)unmap_start, unmap_end - unmap_start);
+
+# endif /* __UCLIBC_UCLINUX_BROKEN_MUNMAP__ */
+
+#endif /* MALLOC_USE_SBRK */
+    }
+
+  MALLOC_DEBUG_INDENT (-1);
+}
+
+void
+free (void *mem)
+{
+  free_to_heap (mem, &__malloc_heap, &__malloc_heap_lock);
+}