subramanian lied when he said he fixed these...

[model-checker.git] / mymemory.cc

diff --git a/mymemory.cc b/mymemory.cc
index a825bb940f66f4331e723eadd8983f9bd8d05e70..2c5adc0a84324e045d66e33332472bd8f7fd56e2 100644 (file)
--- a/mymemory.cc
+++ b/mymemory.cc
@@ -3,12 +3,23 @@
 #include "snapshotimp.h"
 #include <stdio.h>
 #include <dlfcn.h>
-#if !USE_CHECKPOINTING
+#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
 
+//SUBRAMANIAN!!! PLEASE FIX THE MALLOC/FREE/CALLOC/ETC FOR FORK-BASED APPROACH
+//YOU HAVE NOT DONE THIS!!!!!!!!!!!
+
+/** Non-snapshotting malloc for our use. */
+
 void *MYMALLOC(size_t size) {
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        static void *(*mallocp)(size_t size);
        char *error;
        void *ptr;
@@ -18,7 +29,7 @@ void *MYMALLOC(size_t size) {
                mallocp = ( void * ( * )( size_t ) )dlsym(RTLD_NEXT, "malloc");
                if ((error = dlerror()) != NULL) {
                        fputs(error, stderr);
-                       exit(1);
+                       exit(EXIT_FAILURE);
                }
        }
        ptr = mallocp(size);     
@@ -28,13 +39,46 @@ void *MYMALLOC(size_t size) {
                createSharedLibrary();
        }
        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 * )( sTheRecord->mSharedMemoryBase ), SHARED_MEMORY_DEFAULT -sizeof( struct Snapshot ), 1 );
        return mspace_malloc( sStaticSpace, size );
 #endif
 }
 
+void *system_malloc( size_t size ){
+       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");
+               if ((error = dlerror()) != NULL) {
+                       fputs(error, stderr);
+                       exit(EXIT_FAILURE);
+               }
+       }
+       ptr = mallocp(size);
+       return ptr;
+}
+
+void system_free( void * ptr ){
+       static void (*freep)(void *);
+       char *error;
+
+       /* get address of libc free */
+       if (!freep) {
+               freep = ( void  ( * )( void * ) )dlsym(RTLD_NEXT, "free");
+               if ((error = dlerror()) != NULL) {
+                       fputs(error, stderr);
+                       exit(EXIT_FAILURE);
+               }
+       }
+       freep(ptr);
+}
+
+/** Non-snapshotting free for our use. */
 void MYFREE(void *ptr) {
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        static void (*freep)(void *);
        char *error;
 
@@ -43,7 +87,7 @@ void MYFREE(void *ptr) {
                freep = ( void  ( * )( void * ) )dlsym(RTLD_NEXT, "free");
                if ((error = dlerror()) != NULL) {
                        fputs(error, stderr);
-                       exit(1);
+                       exit(EXIT_FAILURE);
                }
        }
        freep(ptr);
@@ -51,21 +95,95 @@ void MYFREE(void *ptr) {
        mspace_free( sStaticSpace, ptr );
 #endif
 }
+
+
+/** This global references the mspace for the snapshotting heap */
 mspace mySpace = NULL;
+
+/** This global references the unaligned memory address that was malloced for the snapshotting heap */
 void * basemySpace = NULL;
 
+/** 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;
+}
+
+/** 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 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 MYMALLOC(size);
+       return malloc(size);
 }
 
+/** Snapshotting delete operator for user programs. */
+
 void operator delete(void *p) throw() {
-       MYFREE(p);
+       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);
 }