mymemory/snapshot: rearrange snapshot implementation

[model-checker.git] / snapshot.cc

diff --git a/snapshot.cc b/snapshot.cc
index 5ac9b46c92a43b402938167dc7eb8670322259c7..e6b38b58ff2fbd148f30695aff830a27a5810112 100644 (file)
--- a/snapshot.cc
+++ b/snapshot.cc
@@ -66,9 +66,9 @@ static void initSnapShotRecord(unsigned int numbackingpages, unsigned int numsna
 {
        snapshotrecord = (struct SnapShot *)model_malloc(sizeof(struct SnapShot));
        snapshotrecord->regionsToSnapShot = (struct MemoryRegion *)model_malloc(sizeof(struct MemoryRegion) * nummemoryregions);
-       snapshotrecord->backingStoreBasePtr = (struct SnapShotPage *)model_malloc(sizeof(struct SnapShotPage) * (numbackingpages + 1));
+       snapshotrecord->backingStoreBasePtr = (void *)model_malloc(sizeof(snapshot_page_t) * (numbackingpages + 1));
        //Page align the backingstorepages
-       snapshotrecord->backingStore = (struct SnapShotPage *)PageAlignAddressUpward(snapshotrecord->backingStoreBasePtr);
+       snapshotrecord->backingStore = (snapshot_page_t *)PageAlignAddressUpward(snapshotrecord->backingStoreBasePtr);
        snapshotrecord->backingRecords = (struct BackingPageRecord *)model_malloc(sizeof(struct BackingPageRecord) * numbackingpages);
        snapshotrecord->snapShots = (struct SnapShotRecord *)model_malloc(sizeof(struct SnapShotRecord) * numsnapshots);
        snapshotrecord->lastSnapShot = 0;
@@ -100,11 +100,11 @@ static void HandlePF(int sig, siginfo_t *si, void *unused)
        }
 
        //copy page
-       memcpy(&(snapshotrecord->backingStore[backingpage]), addr, sizeof(struct SnapShotPage));
+       memcpy(&(snapshotrecord->backingStore[backingpage]), addr, sizeof(snapshot_page_t));
        //remember where to copy page back to
        snapshotrecord->backingRecords[backingpage].basePtrOfPage = addr;
        //set protection to read/write
-       if (mprotect(addr, sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE)) {
+       if (mprotect(addr, sizeof(snapshot_page_t), PROT_READ | PROT_WRITE)) {
                perror("mprotect");
                // Handle error by quitting?
        }
@@ -112,7 +112,7 @@ static void HandlePF(int sig, siginfo_t *si, void *unused)
 #endif /* USE_MPROTECT_SNAPSHOT */
 
 #if !USE_MPROTECT_SNAPSHOT
-void createSharedMemory()
+static void createSharedMemory()
 {
        //step 1. create shared memory.
        void *memMapBase = mmap(0, SHARED_MEMORY_DEFAULT + STACK_SIZE_DEFAULT, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
@@ -127,6 +127,19 @@ void createSharedMemory()
        snapshotrecord->mIDToRollback = -1;
        snapshotrecord->currSnapShotID = 0;
 }
+
+/**
+ * Create a new mspace pointer for the non-snapshotting (i.e., inter-process
+ * shared) memory region. Only for fork-based snapshotting.
+ *
+ * @return The shared memory mspace
+ */
+mspace create_shared_mspace()
+{
+       if (!snapshotrecord)
+               createSharedMemory();
+       return create_mspace_with_base((void *)(snapshotrecord->mSharedMemoryBase), SHARED_MEMORY_DEFAULT - sizeof(struct SnapShot), 1);
+}
 #endif
 
 
@@ -270,7 +283,7 @@ snapshot_id takeSnapshot()
 {
 #if USE_MPROTECT_SNAPSHOT
        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) {
+               if (mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages * sizeof(snapshot_page_t), PROT_READ) == -1) {
                        perror("mprotect");
                        model_print("Failed to mprotect inside of takeSnapShot\n");
                        exit(EXIT_FAILURE);
@@ -299,7 +312,7 @@ void rollBack(snapshot_id theID)
 #if USE_MPROTECT_SNAPSHOT == 2
        if (snapshotrecord->lastSnapShot == (theID + 1)) {
                for (unsigned int page = snapshotrecord->snapShots[theID].firstBackingPage; page < snapshotrecord->lastBackingPage; page++) {
-                       memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(struct SnapShotPage));
+                       memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(snapshot_page_t));
                }
                return;
        }
@@ -308,7 +321,7 @@ void rollBack(snapshot_id theID)
 #if USE_MPROTECT_SNAPSHOT
        HashTable< void *, bool, uintptr_t, 4, model_malloc, model_calloc, model_free> 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) {
+               if (mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages * sizeof(snapshot_page_t), PROT_READ | PROT_WRITE) == -1) {
                        perror("mprotect");
                        model_print("Failed to mprotect inside of takeSnapShot\n");
                        exit(EXIT_FAILURE);
@@ -317,7 +330,7 @@ void rollBack(snapshot_id theID)
        for (unsigned int page = snapshotrecord->snapShots[theID].firstBackingPage; page < snapshotrecord->lastBackingPage; page++) {
                if (!duplicateMap.contains(snapshotrecord->backingRecords[page].basePtrOfPage)) {
                        duplicateMap.put(snapshotrecord->backingRecords[page].basePtrOfPage, true);
-                       memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(struct SnapShotPage));
+                       memcpy(snapshotrecord->backingRecords[page].basePtrOfPage, &snapshotrecord->backingStore[page], sizeof(snapshot_page_t));
                }
        }
        snapshotrecord->lastSnapShot = theID;