snapshotrecord->regionsToSnapShot=( struct MemoryRegion * )MYMALLOC(sizeof(struct MemoryRegion)*nummemoryregions);
snapshotrecord->backingStoreBasePtr= ( struct SnapShotPage * )MYMALLOC( sizeof( struct SnapShotPage ) * (numbackingpages + 1) );
//Page align the backingstorepages
- snapshotrecord->backingStore=( struct SnapShotPage * )ReturnPageAlignedAddress((void*) ((uintptr_t)(snapshotrecord->backingStoreBasePtr)+sizeof(struct SnapShotPage)-1));
+ snapshotrecord->backingStore=( struct SnapShotPage * )PageAlignAddressUpward(snapshotrecord->backingStoreBasePtr);
snapshotrecord->backingRecords=( struct BackingPageRecord * )MYMALLOC(sizeof(struct BackingPageRecord)*numbackingpages);
snapshotrecord->snapShots= ( struct SnapShotRecord * )MYMALLOC(sizeof(struct SnapShotRecord)*numsnapshots);
snapshotrecord->lastSnapShot=0;
//remember where to copy page back to
snapshotrecord->backingRecords[backingpage].basePtrOfPage=addr;
//set protection to read/write
- mprotect( addr, sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE );
+ if (mprotect( addr, sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE )) {
+ perror("mprotect");
+ // Handle error by quitting?
+ }
#endif //nothing to handle for non snapshotting case.
}
void * ReturnPageAlignedAddress(void * addr) {
return (void *)(((uintptr_t)addr)&~(PAGESIZE-1));
}
+
+//Return a page aligned address for the address being added
+//as a side effect the numBytes are also changed.
+void * PageAlignAddressUpward(void * addr) {
+ return (void *)((((uintptr_t)addr)+PAGESIZE-1)&~(PAGESIZE-1));
+}
#ifdef __cplusplus
extern "C" {
#endif
#endif
void initSnapShotLibrary(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions, unsigned int numheappages, MyFuncPtr entryPoint){
#if USE_CHECKPOINTING
+ /* Setup a stack for our signal handler.... */
+ stack_t ss;
+ ss.ss_sp = MYMALLOC(SIGSTACKSIZE);
+ ss.ss_size = SIGSTACKSIZE;
+ ss.ss_flags = 0;
+ sigaltstack(&ss, NULL);
+
struct sigaction sa;
- sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART;
+ sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
sigemptyset( &sa.sa_mask );
sa.sa_sigaction = HandlePF;
if( sigaction( SIGSEGV, &sa, NULL ) == -1 ){
exit(-1);
}
initSnapShotRecord(numbackingpages, numsnapshots, nummemoryregions);
- mySpace = create_mspace( numheappages*PAGESIZE, 1 );
- addMemoryRegionToSnapShot(mySpace, numheappages);
+
+ basemySpace=MYMALLOC((numheappages+1)*PAGESIZE);
+ void * pagealignedbase=PageAlignAddressUpward(basemySpace);
+ mySpace = create_mspace_with_base(pagealignedbase, numheappages*PAGESIZE, 1 );
+ addMemoryRegionToSnapShot(pagealignedbase, numheappages);
entryPoint();
#else
//add a signal to indicate that the process is going to terminate.
#if USE_CHECKPOINTING
for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ ) == -1 ){
+ perror("mprotect");
printf("Failed to mprotect inside of takeSnapShot\n");
exit(-1);
}
std::map< void *, bool, std::less< void * >, MyAlloc< std::pair< const void *, bool > > > duplicateMap;
for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE ) == -1 ){
+ perror("mprotect");
printf("Failed to mprotect inside of takeSnapShot\n");
exit(-1);
}