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authorHoward Hinnant <hhinnant@apple.com>2012-01-24 21:02:21 +0000
committerHoward Hinnant <hhinnant@apple.com>2012-01-24 21:02:21 +0000
commitc2dfdeb45185892867d765a75668760285dbfbf0 (patch)
tree6578a169dffe888737325d9a7ff6a069a6417831 /src/fallback_malloc.cpp
parent73fd45bc7dbe3f3874a69783cc8d5419201c4f1f (diff)
Got fooled by fallback_malloc.cpp source file: it is really a private header. I've manually included it into the only place it is used: cxa_exception.cpp.
git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@148854 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'src/fallback_malloc.cpp')
-rw-r--r--src/fallback_malloc.cpp177
1 files changed, 0 insertions, 177 deletions
diff --git a/src/fallback_malloc.cpp b/src/fallback_malloc.cpp
deleted file mode 100644
index b83cb8f..0000000
--- a/src/fallback_malloc.cpp
+++ /dev/null
@@ -1,177 +0,0 @@
-//===------------------------ fallback_malloc.cpp -------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//
-// This file implements the a small heap for allocation of exception
-// in the situation where malloc fails.
-// http://www.codesourcery.com/public/cxx-abi/abi-eh.html (section 2.4.2)
-//
-//===----------------------------------------------------------------------===//
-
-// A small, simple heap manager based (loosely) on
-// the startup heap manager from FreeBSD, optimized for space.
-//
-// Manages a fixed-size memory pool, supports malloc and free only.
-// No support for realloc.
-//
-// Allocates chunks in multiples of four bytes, with a four byte header
-// for each chunk. The overhead of each chunk is kept low by keeping pointers
-// as two byte offsets within the heap, rather than (4 or 8 byte) pointers.
-
-#include <pthread.h>
-
-namespace {
-
-static pthread_mutex_t heap_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-class mutexor {
-public:
- mutexor ( pthread_mutex_t *m ) : mtx_(m) { pthread_mutex_lock ( mtx_ ); }
- ~mutexor () { pthread_mutex_unlock ( mtx_ ); }
-private:
- mutexor ( const mutexor &rhs );
- mutexor & operator = ( const mutexor &rhs );
- pthread_mutex_t *mtx_;
- };
-
-
-#define HEAP_SIZE 512
-char heap [ HEAP_SIZE ];
-
-typedef unsigned short heap_offset;
-typedef unsigned short heap_size;
-
-struct heap_node {
- heap_offset next_node; // offset into heap
- heap_size len; // size in units of "sizeof(heap_node)"
-};
-
-static const heap_node *list_end = (heap_node *) ( &heap [ HEAP_SIZE ] ); // one past the end of the heap
-static heap_node *freelist = NULL;
-
-heap_node *node_from_offset ( const heap_offset offset ) throw()
- { return (heap_node *) ( heap + ( offset * sizeof (heap_node))); }
-
-heap_offset offset_from_node ( const heap_node *ptr ) throw()
- { return (((char *) ptr ) - heap) / sizeof (heap_node); }
-
-void init_heap () throw() {
- freelist = (heap_node *) heap;
- freelist->next_node = offset_from_node ( list_end );
- freelist->len = HEAP_SIZE / sizeof (heap_node);
- }
-
-// How big a chunk we allocate
-size_t alloc_size (size_t len) throw()
- { return (len + sizeof(heap_node) - 1) / sizeof(heap_node) + 1; }
-
-bool is_fallback_ptr ( void *ptr ) throw()
- { return ptr >= heap && ptr < ( heap + HEAP_SIZE ); }
-
-void *fallback_malloc(size_t len) throw() {
- heap_node *p, *prev;
- const size_t nelems = alloc_size ( len );
- mutexor mtx ( &heap_mutex );
-
- if ( NULL == freelist )
- init_heap ();
-
-// Walk the free list, looking for a "big enough" chunk
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset ( p->next_node)) {
-
- if (p->len > nelems) { // chunk is larger, shorten, and return the tail
- heap_node *q;
-
- p->len -= nelems;
- q = p + p->len;
- q->next_node = 0;
- q->len = nelems;
- return (void *) (q + 1);
- }
-
- if (p->len == nelems) { // exact size match
- if (prev == 0)
- freelist = node_from_offset(p->next_node);
- else
- prev->next_node = p->next_node;
- p->next_node = 0;
- return (void *) (p + 1);
- }
- }
- return NULL; // couldn't find a spot big enough
-}
-
-// Return the start of the next block
-heap_node *after ( struct heap_node *p ) throw() { return p + p->len; }
-
-void fallback_free (void *ptr) throw() {
- struct heap_node *cp = ((struct heap_node *) ptr) - 1; // retrieve the chunk
- struct heap_node *p, *prev;
-
- mutexor mtx ( &heap_mutex );
-
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << "Freeing item at " << offset_from_node ( cp ) << " of size " << cp->len << std::endl;
-#endif
-
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset (p->next_node)) {
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " p, cp, after (p), after(cp) "
- << offset_from_node ( p ) << ' '
- << offset_from_node ( cp ) << ' '
- << offset_from_node ( after ( p )) << ' '
- << offset_from_node ( after ( cp )) << std::endl;
-#endif
- if ( after ( p ) == cp ) {
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Appending onto chunk at " << offset_from_node ( p ) << std::endl;
-#endif
- p->len += cp->len; // make the free heap_node larger
- return;
- }
- else if ( after ( cp ) == p ) { // there's a free heap_node right after
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Appending free chunk at " << offset_from_node ( p ) << std::endl;
-#endif
- cp->len += p->len;
- if ( prev == 0 ) {
- freelist = cp;
- cp->next_node = p->next_node;
- }
- else
- prev->next_node = offset_from_node(cp);
- return;
- }
- }
-// Nothing to merge with, add it to the start of the free list
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Making new free list entry " << offset_from_node ( cp ) << std::endl;
-#endif
- cp->next_node = offset_from_node ( freelist );
- freelist = cp;
-}
-
-#ifdef INSTRUMENT_FALLBACK_MALLOC
-size_t print_free_list () {
- struct heap_node *p, *prev;
- heap_size total_free = 0;
- if ( NULL == freelist )
- init_heap ();
-
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset (p->next_node)) {
- std::cout << ( prev == 0 ? "" : " ") << "Offset: " << offset_from_node ( p )
- << "\tsize: " << p->len << " Next: " << p->next_node << std::endl;
- total_free += p->len;
- }
- std::cout << "Total Free space: " << total_free << std::endl;
- return total_free;
- }
-#endif
-}