X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=snapshot.cc;h=24e8d073ca1330eb778b897955e500dab30f9c5e;hp=ca54c785385bb85b0fa68ada3267c933dd9ca8f0;hb=a7b4dab68db8b1fc466a7ca4098d5a6fb006e353;hpb=63b2c687570085f2a87b6a659d26608228af1ee0

diff --git a/snapshot.cc b/snapshot.cc
index ca54c785..24e8d073 100644
--- a/snapshot.cc
+++ b/snapshot.cc
@@ -12,6 +12,10 @@
 #include "mymemory.h"
 #include "common.h"
 #include "context.h"
+#include "model.h"
+
+
+#if USE_MPROTECT_SNAPSHOT
 
 /** PageAlignedAdressUpdate return a page aligned address for the
  * address being added as a side effect the numBytes are also changed.
@@ -21,8 +25,6 @@ static void * PageAlignAddressUpward(void *addr)
 	return (void *)((((uintptr_t)addr) + PAGESIZE - 1) & ~(PAGESIZE - 1));
 }
 
-#if USE_MPROTECT_SNAPSHOT
-
 /* Each SnapShotRecord lists the firstbackingpage that must be written to
  * revert to that snapshot */
 struct SnapShotRecord {
@@ -133,7 +135,7 @@ static void mprot_handle_pf(int sig, siginfo_t *si, void *unused)
 
 static void mprot_snapshot_init(unsigned int numbackingpages,
 																unsigned int numsnapshots, unsigned int nummemoryregions,
-																unsigned int numheappages, VoidFuncPtr entryPoint)
+																unsigned int numheappages)
 {
 	/* Setup a stack for our signal handler....  */
 	stack_t ss;
@@ -178,8 +180,11 @@ static void mprot_snapshot_init(unsigned int numbackingpages,
 	pagealignedbase = PageAlignAddressUpward(base_model_snapshot_space);
 	model_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
 	snapshot_add_memory_region(pagealignedbase, numheappages);
+}
 
-	entryPoint();
+static void mprot_startExecution(ucontext_t * context, VoidFuncPtr entryPoint) {
+	/* setup the shared-stack context */
+	create_context(context, fork_snap->mStackBase, model_calloc(STACK_SIZE_DEFAULT, 1), STACK_SIZE_DEFAULT, entryPoint);
 }
 
 static void mprot_add_to_snapshot(void *addr, unsigned int numPages)
@@ -248,7 +253,7 @@ static void mprot_roll_back(snapshot_id theID)
 
 #else	/* !USE_MPROTECT_SNAPSHOT */
 
-#define SHARED_MEMORY_DEFAULT  (100 * ((size_t)1 << 20))	// 100mb for the shared memory
+#define SHARED_MEMORY_DEFAULT  (200 * ((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
 
 struct fork_snapshotter {
@@ -273,20 +278,14 @@ struct fork_snapshotter {
 	 */
 	volatile snapshot_id mIDToRollback;
 
-	/**
-	 * @brief The context for the shared (non-snapshot) stack
-	 *
-	 * This context is passed between the various processes which represent
-	 * various snapshot states. It should be used primarily for the
-	 * "client-side" code, not the main snapshot loop.
-	 */
-	ucontext_t shared_ctxt;
+
 
 	/** @brief Inter-process tracking of the next snapshot ID */
 	snapshot_id currSnapShotID;
 };
 
 static struct fork_snapshotter *fork_snap = NULL;
+ucontext_t shared_ctxt;
 
 /** @statics
  *   These variables are necessary because the stack is shared region and
@@ -319,6 +318,7 @@ static void create_context(ucontext_t *ctxt, void *stack, size_t stacksize,
 	getcontext(ctxt);
 	ctxt->uc_stack.ss_sp = stack;
 	ctxt->uc_stack.ss_size = stacksize;
+	ctxt->uc_link = NULL;
 	makecontext(ctxt, func, 0);
 }
 
@@ -326,7 +326,7 @@ static void create_context(ucontext_t *ctxt, void *stack, size_t stacksize,
  *  process */
 static void fork_exit()
 {
-	/* Intentionally empty */
+	_Exit(EXIT_SUCCESS);
 }
 
 static void createSharedMemory()
@@ -362,35 +362,34 @@ mspace create_shared_mspace()
 
 static void fork_snapshot_init(unsigned int numbackingpages,
 															 unsigned int numsnapshots, unsigned int nummemoryregions,
-															 unsigned int numheappages, VoidFuncPtr entryPoint)
+															 unsigned int numheappages)
 {
 	if (!fork_snap)
 		createSharedMemory();
 
-	void *base_model_snapshot_space = malloc((numheappages + 1) * PAGESIZE);
-	void *pagealignedbase = PageAlignAddressUpward(base_model_snapshot_space);
-	model_snapshot_space = create_mspace_with_base(pagealignedbase, numheappages * PAGESIZE, 1);
+	model_snapshot_space = create_mspace(numheappages * PAGESIZE, 1);
+}
 
-	/* setup an "exiting" context */
-	char stack[128];
-	create_context(&exit_ctxt, stack, sizeof(stack), fork_exit);
-
-	/* setup the shared-stack context */
-	create_context(&fork_snap->shared_ctxt, fork_snap->mStackBase,
-								 STACK_SIZE_DEFAULT, entryPoint);
-	/* switch to a new entryPoint context, on a new stack */
-	model_swapcontext(&private_ctxt, &fork_snap->shared_ctxt);
+volatile int modellock = 0;
 
+static void fork_loop() {
 	/* switch back here when takesnapshot is called */
 	snapshotid = fork_snap->currSnapShotID;
+	if (model->params.nofork) {
+		setcontext(&shared_ctxt);
+		_Exit(EXIT_SUCCESS);
+	}
 
 	while (true) {
 		pid_t forkedID;
 		fork_snap->currSnapShotID = snapshotid + 1;
+
+		modellock = 1;
 		forkedID = fork();
+		modellock = 0;
 
 		if (0 == forkedID) {
-			setcontext(&fork_snap->shared_ctxt);
+			setcontext(&shared_ctxt);
 		} else {
 			DEBUG("parent PID: %d, child PID: %d, snapshot ID: %d\n",
 						getpid(), forkedID, snapshotid);
@@ -404,14 +403,24 @@ static void fork_snapshot_init(unsigned int numbackingpages,
 			}
 
 			if (fork_snap->mIDToRollback != snapshotid)
-				exit(EXIT_SUCCESS);
+				_Exit(EXIT_SUCCESS);
 		}
 	}
 }
 
-static snapshot_id fork_take_snapshot()
-{
-	model_swapcontext(&fork_snap->shared_ctxt, &private_ctxt);
+static void fork_startExecution(ucontext_t *context, VoidFuncPtr entryPoint) {
+	/* setup an "exiting" context */
+	int exit_stack_size = 256;
+	create_context(&exit_ctxt, snapshot_calloc(exit_stack_size, 1), exit_stack_size, fork_exit);
+
+	/* setup the system context */
+	create_context(context, fork_snap->mStackBase, STACK_SIZE_DEFAULT, entryPoint);
+	/* switch to a new entryPoint context, on a new stack */
+	create_context(&private_ctxt, snapshot_calloc(STACK_SIZE_DEFAULT, 1), STACK_SIZE_DEFAULT, fork_loop);
+}
+
+static snapshot_id fork_take_snapshot() {
+	model_swapcontext(&shared_ctxt, &private_ctxt);
 	DEBUG("TAKESNAPSHOT RETURN\n");
 	return snapshotid;
 }
@@ -420,7 +429,7 @@ static void fork_roll_back(snapshot_id theID)
 {
 	DEBUG("Rollback\n");
 	fork_snap->mIDToRollback = theID;
-	model_swapcontext(&fork_snap->shared_ctxt, &exit_ctxt);
+	model_swapcontext(model->get_system_context(), &exit_ctxt);
 	fork_snap->mIDToRollback = -1;
 }
 
@@ -432,12 +441,21 @@ static void fork_roll_back(snapshot_id theID)
  */
 void snapshot_system_init(unsigned int numbackingpages,
 													unsigned int numsnapshots, unsigned int nummemoryregions,
-													unsigned int numheappages, VoidFuncPtr entryPoint)
+													unsigned int numheappages)
+{
+#if USE_MPROTECT_SNAPSHOT
+	mprot_snapshot_init(numbackingpages, numsnapshots, nummemoryregions, numheappages);
+#else
+	fork_snapshot_init(numbackingpages, numsnapshots, nummemoryregions, numheappages);
+#endif
+}
+
+void startExecution(ucontext_t *context, VoidFuncPtr entryPoint)
 {
 #if USE_MPROTECT_SNAPSHOT
-	mprot_snapshot_init(numbackingpages, numsnapshots, nummemoryregions, numheappages, entryPoint);
+	mprot_startExecution(context, entryPoint);
 #else
-	fork_snapshot_init(numbackingpages, numsnapshots, nummemoryregions, numheappages, entryPoint);
+	fork_startExecution(context, entryPoint);
 #endif
 }