X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mymemory.cc;h=e8518182c55a71800637c981f1d3ad0db0cc3b2d;hb=84e24d516d4e9dbd30f1fff7e9a185d1540d20eb;hp=2b9c44d516282e1041487c6d0d1a5f1a78a1f472;hpb=7bec9f8bcc8c63a0be2b31f8aa01a61a50afe4f9;p=model-checker.git

diff --git a/mymemory.cc b/mymemory.cc
index 2b9c44d..e851818 100644
--- a/mymemory.cc
+++ b/mymemory.cc
@@ -3,18 +3,23 @@
 #include "snapshotimp.h"
 #include <stdio.h>
 #include <dlfcn.h>
+#include <unistd.h>
+#include <cstring>
+#define REQUESTS_BEFORE_ALLOC 1024
+size_t allocatedReqs[ REQUESTS_BEFORE_ALLOC ] = { 0 };
+int nextRequest = 0;
+int howManyFreed = 0;
 #if !USE_MPROTECT_SNAPSHOT
 static mspace sStaticSpace = NULL;
 #endif
 
 /** Non-snapshotting malloc for our use. */
-
 void *MYMALLOC(size_t size) {
 #if USE_MPROTECT_SNAPSHOT
 	static void *(*mallocp)(size_t size);
 	char *error;
 	void *ptr;
-  
+
 	/* get address of libc malloc */
 	if (!mallocp) {
 		mallocp = ( void * ( * )( size_t ) )dlsym(RTLD_NEXT, "malloc");
@@ -23,14 +28,14 @@ void *MYMALLOC(size_t size) {
 			exit(EXIT_FAILURE);
 		}
 	}
-	ptr = mallocp(size);     
+	ptr = mallocp(size);
 	return ptr;
 #else
-	if( !sTheRecord ){
-		createSharedLibrary();
+	if( !snapshotrecord) {
+		createSharedMemory();
 	}
 	if( NULL == sStaticSpace )
-		sStaticSpace = create_mspace_with_base( ( void * )( sTheRecord->mSharedMemoryBase ), SHARED_MEMORY_DEFAULT -sizeof( struct Snapshot_t ), 1 );
+		sStaticSpace = create_mspace_with_base( ( void * )( snapshotrecord->mSharedMemoryBase ), SHARED_MEMORY_DEFAULT -sizeof( struct SnapShot ), 1 );
 	return mspace_malloc( sStaticSpace, size );
 #endif
 }
@@ -94,46 +99,77 @@ mspace mySpace = NULL;
 /** This global references the unaligned memory address that was malloced for the snapshotting heap */
 void * basemySpace = NULL;
 
-//Subramanian --- please make these work for the fork based approach
+/** Adding the fix for not able to allocate through a reimplemented calloc at the beginning before instantiating our allocator
+A bit circumspect about adding an sbrk. linux docs say to avoid using it... */
+void * HandleEarlyAllocationRequest( size_t sz ){
+	if( 0 == mySpace ){
+		void * returnAddress = sbrk( sz );
+		if( nextRequest >= REQUESTS_BEFORE_ALLOC ){
+			exit( EXIT_FAILURE );
+		}
+		allocatedReqs[ nextRequest++ ] = ( size_t )returnAddress;
+		return returnAddress;
+	}
+	return NULL;
+}
 
-/** Snapshotting malloc implementation for user programs. */
+/** The fact that I am not expecting more than a handful requests is implicit in my not using a binary search here*/
+bool DontFree( void * ptr ){
+	if( howManyFreed == nextRequest ) return false; //a minor optimization to reduce the number of instructions executed on each free call....
+	if( NULL == ptr ) return true;
+	for( int i =  nextRequest - 1; i >= 0; --i ){
+		if( allocatedReqs[ i ] ==  ( size_t )ptr ) {
+			++howManyFreed;
+			return true;
+		}
+	}
+	return false;
+}
 
+/** Snapshotting malloc implementation for user programs. */
 void *malloc( size_t size ) {
+	void * earlyReq = HandleEarlyAllocationRequest( size );
+	if( earlyReq ) return earlyReq;
 	return mspace_malloc( mySpace, size );
 }
 
 /** Snapshotting free implementation for user programs. */
-
 void free( void * ptr ){
+	if( DontFree( ptr ) ) return;
 	mspace_free( mySpace, ptr );
 }
 
 /** Snapshotting realloc implementation for user programs. */
-
 void *realloc( void *ptr, size_t size ){
 	return mspace_realloc( mySpace, ptr, size );
 }
 
-/** Snapshotting new operator for user programs. */
+/** Snapshotting calloc implementation for user programs. */
+void * calloc( size_t num, size_t size ){
+	void * earlyReq = HandleEarlyAllocationRequest( size * num );
+	if( earlyReq ) {
+		std::memset( earlyReq, 0, size * num );
+		return earlyReq;
+	}
+	return mspace_calloc( mySpace, num, size );
+}
 
+/** Snapshotting new operator for user programs. */
 void * operator new(size_t size) throw(std::bad_alloc) {
 	return malloc(size);
 }
 
 /** Snapshotting delete operator for user programs. */
-
 void operator delete(void *p) throw() {
 	free(p);
 }
 
 /** Snapshotting new[] operator for user programs. */
-
 void * operator new[](size_t size) throw(std::bad_alloc) {
 	return malloc(size);
 }
 
 /** Snapshotting delete[] operator for user programs. */
-
 void operator delete[](void *p, size_t size) {
 	free(p);
 }