Makefile: fix config.h dependencies

[model-checker.git] / datarace.cc

diff --git a/datarace.cc b/datarace.cc
index 1040a3b0df2d4871f21515e62d2d94e5a6651313..f0d3dc619489d780ea7e9be237b2007d428a4b33 100644 (file)
--- a/datarace.cc
+++ b/datarace.cc
@@ -5,14 +5,17 @@
 
 struct ShadowTable *root;
 
+/** This function initialized the data race detector. */
 void initRaceDetector() {
        root=(struct ShadowTable *) calloc(sizeof(struct ShadowTable),1);
 }
 
+/** This function looks up the entry in the shadow table corresponding to a
+ * given address.*/
 static uint64_t * lookupAddressEntry(void * address) {
        struct ShadowTable *currtable=root;
-#ifdef BIT48
-       currtable=(struct ShadowTable *) currtable->array[(((uintptr_t)address)>>32)&0xffff];
+#if BIT48
+       currtable=(struct ShadowTable *) currtable->array[(((uintptr_t)address)>>32)&MASK16BIT];
        if (currtable==NULL) {
                currtable=(struct ShadowTable *) (root->array[(((uintptr_t)address)>>32)&MASK16BIT]=calloc(sizeof(struct ShadowTable),1));
        }
@@ -40,6 +43,10 @@ static bool clock_may_race(ClockVector *clock1, thread_id_t tid1,
        return tid1 != tid2 && clock2 != 0 && clock1->getClock(tid2) <= clock2;
 }
 
+/**
+ * Expands a record from the compact form to the full form.  This is
+ * necessary for multiple readers or for very large thread ids or time
+ * stamps. */
 static void expandRecord(uint64_t * shadow) {
        uint64_t shadowval=*shadow;
 
@@ -63,10 +70,12 @@ static void expandRecord(uint64_t * shadow) {
        *shadow=(uint64_t) record;
 }
 
+/** This function is called when we detect a data race.*/
 static void reportDataRace() {
        printf("The reportDataRace method should report useful things about this datarace!\n");
 }
 
+/** This function does race detection for a write on an expanded record. */
 void fullRaceCheckWrite(thread_id_t thread, uint64_t * shadow, ClockVector *currClock) {
        struct RaceRecord * record=(struct RaceRecord *) (*shadow);
 
@@ -76,6 +85,9 @@ void fullRaceCheckWrite(thread_id_t thread, uint64_t * shadow, ClockVector *curr
                modelclock_t readClock = record->readClock[i];
                thread_id_t readThread = record->thread[i];
 
+               /* Note that readClock can't actuall be zero here, so it could be
+                        optimized. */
+
                if (clock_may_race(currClock, thread, readClock, readThread)) {
                        /* We have a datarace */
                        reportDataRace();
@@ -98,6 +110,7 @@ void fullRaceCheckWrite(thread_id_t thread, uint64_t * shadow, ClockVector *curr
        record->writeClock=ourClock;
 }
 
+/** This function does race detection on a write. */
 void raceCheckWrite(thread_id_t thread, void *location, ClockVector *currClock) {
        uint64_t * shadow=lookupAddressEntry(location);
        uint64_t shadowval=*shadow;
@@ -140,6 +153,7 @@ void raceCheckWrite(thread_id_t thread, void *location, ClockVector *currClock)
        *shadow = ENCODEOP(0, 0, threadid, ourClock);
 }
 
+/** This function does race detection on a read for an expanded record. */
 void fullRaceCheckRead(thread_id_t thread, uint64_t * shadow, ClockVector *currClock) {
        struct RaceRecord * record=(struct RaceRecord *) (*shadow);
 
@@ -161,9 +175,13 @@ void fullRaceCheckRead(thread_id_t thread, uint64_t * shadow, ClockVector *currC
                modelclock_t readClock = record->readClock[i];
                thread_id_t readThread = record->thread[i];
 
-               /* TODO: should this have different logic than all the other
-                * 'clock_may_race' calls? */
-               if (readThread != thread && currClock->getClock(readThread) <= readClock) {
+               /*  Note that is not really a datarace check as reads cannott
+                               actually race.  It is just determining that this read subsumes
+                               another in the sense that either this read races or neither
+                               read races. Note that readClock can't actually be zero, so it
+                               could be optimized.  */
+
+               if (clock_may_race(currClock, thread, readClock, readThread)) {
                        /* Still need this read in vector */
                        if (copytoindex!=i) {
                                record->readClock[copytoindex]=record->readClock[i];
@@ -193,6 +211,7 @@ void fullRaceCheckRead(thread_id_t thread, uint64_t * shadow, ClockVector *currC
        record->numReads=copytoindex+1;
 }
 
+/** This function does race detection on a read. */
 void raceCheckRead(thread_id_t thread, void *location, ClockVector *currClock) {
        uint64_t * shadow=lookupAddressEntry(location);
        uint64_t shadowval=*shadow;