#include <string.h>
#include <errno.h>
#include <sys/wait.h>
-#include <ucontext.h>
#include "hashtable.h"
#include "snapshot.h"
#include "mymemory.h"
#include "common.h"
-
-#define FAILURE(mesg) { model_print("failed in the API: %s with errno relative message: %s\n", mesg, strerror(errno)); exit(EXIT_FAILURE); }
+#include "context.h"
/** PageAlignedAdressUpdate return a page aligned address for the
* address being added as a side effect the numBytes are also changed.
/* Primary struct for snapshotting system */
struct mprot_snapshotter {
mprot_snapshotter(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions);
+ ~mprot_snapshotter();
struct MemoryRegion *regionsToSnapShot; //This pointer references an array of memory regions to snapshot
snapshot_page_t *backingStore; //This pointer references an array of snapshotpage's that form the backing store
snapShots = (struct SnapShotRecord *)model_malloc(sizeof(struct SnapShotRecord) * snapshots);
}
-/** HandlePF is the page fault handler for mprotect based snapshotting
+mprot_snapshotter::~mprot_snapshotter()
+{
+ model_free(regionsToSnapShot);
+ model_free(backingStoreBasePtr);
+ model_free(backingRecords);
+ model_free(snapShots);
+}
+
+/** mprot_handle_pf is the page fault handler for mprotect based snapshotting
* algorithm.
*/
-static void HandlePF(int sig, siginfo_t *si, void *unused)
+static void mprot_handle_pf(int sig, siginfo_t *si, void *unused)
{
if (si->si_code == SEGV_MAPERR) {
model_print("Real Fault at %p\n", si->si_addr);
struct sigaction sa;
sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
sigemptyset(&sa.sa_mask);
- sa.sa_sigaction = HandlePF;
+ sa.sa_sigaction = mprot_handle_pf;
#ifdef MAC
if (sigaction(SIGBUS, &sa, NULL) == -1) {
model_print("SIGACTION CANNOT BE INSTALLED\n");
mprot_snap = new mprot_snapshotter(numbackingpages, numsnapshots, nummemoryregions);
- // EVIL HACK: We need to make sure that calls into the HandlePF method don't cause dynamic links
+ // EVIL HACK: We need to make sure that calls into the mprot_handle_pf method don't cause dynamic links
// The problem is that we end up protecting state in the dynamic linker...
// Solution is to call our signal handler before we start protecting stuff...
siginfo_t si;
memset(&si, 0, sizeof(si));
si.si_addr = ss.ss_sp;
- HandlePF(SIGSEGV, &si, NULL);
+ mprot_handle_pf(SIGSEGV, &si, NULL);
mprot_snap->lastBackingPage--; //remove the fake page we copied
void *basemySpace = model_malloc((numheappages + 1) * PAGESIZE);
void *pagealignedbase = PageAlignAddressUpward(basemySpace);
user_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
- addMemoryRegionToSnapShot(pagealignedbase, numheappages);
+ snapshot_add_memory_region(pagealignedbase, numheappages);
void *base_model_snapshot_space = model_malloc((numheappages + 1) * PAGESIZE);
pagealignedbase = PageAlignAddressUpward(base_model_snapshot_space);
model_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
- addMemoryRegionToSnapShot(pagealignedbase, numheappages);
+ snapshot_add_memory_region(pagealignedbase, numheappages);
entryPoint();
}
#else /* !USE_MPROTECT_SNAPSHOT */
-#include <ucontext.h>
-
#define SHARED_MEMORY_DEFAULT (100 * ((size_t)1 << 20)) // 100mb for the shared memory
#define STACK_SIZE_DEFAULT (((size_t)1 << 20) * 20) // 20 mb out of the above 100 mb for my stack
{
//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);
- if (MAP_FAILED == memMapBase)
- FAILURE("mmap");
+ if (memMapBase == MAP_FAILED) {
+ perror("mmap");
+ exit(EXIT_FAILURE);
+ }
//Setup snapshot record at top of free region
fork_snap = (struct fork_snapshotter *)memMapBase;
newContext.uc_stack.ss_size = STACK_SIZE_DEFAULT;
makecontext(&newContext, entryPoint, 0);
/* switch to a new entryPoint context, on a new stack */
- swapcontext(&savedSnapshotContext, &newContext);
+ model_swapcontext(&savedSnapshotContext, &newContext);
/* switch back here when takesnapshot is called */
pid_t forkedID = 0;
setcontext(&savedUserSnapshotContext);
}
} else {
- int status;
- int retVal;
-
- DEBUG("The process id of child is %d and the process id of this process is %d and snapshot id is %d\n",
- forkedID, getpid(), snapshotid);
-
- do {
- retVal = waitpid(forkedID, &status, 0);
- } while (-1 == retVal && errno == EINTR);
+ DEBUG("parent PID: %d, child PID: %d, snapshot ID: %d\n",
+ getpid(), forkedID, snapshotid);
+
+ while (waitpid(forkedID, NULL, 0) < 0) {
+ /* waitpid() may be interrupted */
+ if (errno != EINTR) {
+ perror("waitpid");
+ exit(EXIT_FAILURE);
+ }
+ }
- if (fork_snap->mIDToRollback != snapshotid) {
+ if (fork_snap->mIDToRollback != snapshotid)
exit(EXIT_SUCCESS);
- }
rollback = true;
}
}
static snapshot_id fork_take_snapshot()
{
- swapcontext(&savedUserSnapshotContext, &savedSnapshotContext);
+ model_swapcontext(&savedUserSnapshotContext, &savedSnapshotContext);
DEBUG("TAKESNAPSHOT RETURN\n");
return snapshotid;
}
#endif /* !USE_MPROTECT_SNAPSHOT */
-/** The initSnapshotLibrary function initializes the snapshot library.
- * @param entryPoint the function that should run the program.
+/**
+ * @brief Initializes the snapshot system
+ * @param entryPoint the function that should run the program.
*/
-void initSnapshotLibrary(unsigned int numbackingpages,
+void snapshot_system_init(unsigned int numbackingpages,
unsigned int numsnapshots, unsigned int nummemoryregions,
unsigned int numheappages, VoidFuncPtr entryPoint)
{
#endif
}
-/** The addMemoryRegionToSnapShot function assumes that addr is page aligned. */
-void addMemoryRegionToSnapShot(void *addr, unsigned int numPages)
+/** Assumes that addr is page aligned. */
+void snapshot_add_memory_region(void *addr, unsigned int numPages)
{
#if USE_MPROTECT_SNAPSHOT
mprot_add_to_snapshot(addr, numPages);
#endif
}
-/** The takeSnapshot function takes a snapshot.
+/** Takes a snapshot of memory.
* @return The snapshot identifier.
*/
-snapshot_id takeSnapshot()
+snapshot_id take_snapshot()
{
#if USE_MPROTECT_SNAPSHOT
return mprot_take_snapshot();
#endif
}
-/** The rollBack function rollback to the given snapshot identifier.
+/** Rolls the memory state back to the given snapshot identifier.
* @param theID is the snapshot identifier to rollback to.
*/
-void rollBack(snapshot_id theID)
+void snapshot_roll_back(snapshot_id theID)
{
#if USE_MPROTECT_SNAPSHOT
mprot_roll_back(theID);
projects / c11tester.git / blobdiff