[cfe-commits] [libcxxabi] r148863 - in /libcxxabi/trunk: src/cxa_exception.cpp src/fallback_malloc.ipp test/test_fallback_malloc.cpp
Howard Hinnant
hhinnant at apple.com
Tue Jan 24 13:41:28 PST 2012
Author: hhinnant
Date: Tue Jan 24 15:41:27 2012
New Revision: 148863
URL: http://llvm.org/viewvc/llvm-project?rev=148863&view=rev
Log:
Marshall Clow reminded me that fallback_malloc.cpp was broken out for testing purposes. We've agreed to simply rename fallback_malloc.cpp to fallback_malloc.ipp. Thanks Marshall.
Added:
libcxxabi/trunk/src/fallback_malloc.ipp
Modified:
libcxxabi/trunk/src/cxa_exception.cpp
libcxxabi/trunk/test/test_fallback_malloc.cpp
Modified: libcxxabi/trunk/src/cxa_exception.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_exception.cpp?rev=148863&r1=148862&r2=148863&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_exception.cpp (original)
+++ libcxxabi/trunk/src/cxa_exception.cpp Tue Jan 24 15:41:27 2012
@@ -101,167 +101,7 @@
return --exception->handlerCount;
}
-// 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.
-
-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
-} // end unnamed namespace
+#include "fallback_malloc.ipp"
// Allocate some memory from _somewhere_
static void *do_malloc(size_t size) throw() {
Added: libcxxabi/trunk/src/fallback_malloc.ipp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/fallback_malloc.ipp?rev=148863&view=auto
==============================================================================
--- libcxxabi/trunk/src/fallback_malloc.ipp (added)
+++ libcxxabi/trunk/src/fallback_malloc.ipp Tue Jan 24 15:41:27 2012
@@ -0,0 +1,174 @@
+//===------------------------ fallback_malloc.ipp -------------------------===//
+//
+// 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 "Exception Handling APIs"
+// http://www.codesourcery.com/public/cxx-abi/abi-eh.html
+//
+//===----------------------------------------------------------------------===//
+
+// 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.
+
+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
+} // end unnamed namespace
Modified: libcxxabi/trunk/test/test_fallback_malloc.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/test/test_fallback_malloc.cpp?rev=148863&r1=148862&r2=148863&view=diff
==============================================================================
--- libcxxabi/trunk/test/test_fallback_malloc.cpp (original)
+++ libcxxabi/trunk/test/test_fallback_malloc.cpp Tue Jan 24 15:41:27 2012
@@ -16,7 +16,7 @@
// #define DEBUG_FALLBACK_MALLOC
#define INSTRUMENT_FALLBACK_MALLOC
-#include "../src/fallback_malloc.cpp"
+#include "../src/fallback_malloc.ipp"
container alloc_series ( size_t sz ) {
container ptrs;
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