From a9e77155aee17d9e66603f970a964bee83f62248 Mon Sep 17 00:00:00 2001
From: bdemsky <bdemsky@uci.edu>
Date: Tue, 16 Jul 2019 17:03:54 -0700
Subject: [PATCH] Track whether a write was from an atomic

---
 datarace.cc | 27 ++++++++++++++-------------
 datarace.h  |  8 ++++++--
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/datarace.cc b/datarace.cc
index b3ce8abe..4a6b8d81 100644
--- a/datarace.cc
+++ b/datarace.cc
@@ -93,14 +93,15 @@ static void expandRecord(uint64_t *shadow)
 	record->writeClock = writeClock;
 
 	if (readClock != 0) {
-		record->capacity = INITCAPACITY;
-		record->thread = (thread_id_t *)snapshot_malloc(sizeof(thread_id_t) * record->capacity);
-		record->readClock = (modelclock_t *)snapshot_malloc(sizeof(modelclock_t) * record->capacity);
+		record->thread = (thread_id_t *)snapshot_malloc(sizeof(thread_id_t) * INITCAPACITY);
+		record->readClock = (modelclock_t *)snapshot_malloc(sizeof(modelclock_t) * INITCAPACITY);
 		record->numReads = 1;
 		ASSERT(readThread >= 0);
 		record->thread[0] = readThread;
 		record->readClock[0] = readClock;
 	}
+	if (shadowval & ATOMICMASK)
+		record->isAtomic = 1;
 	*shadow = (uint64_t) record;
 }
 
@@ -201,6 +202,7 @@ struct DataRace * fullRaceCheckWrite(thread_id_t thread, void *location, uint64_
 Exit:
 	record->numReads = 0;
 	record->writeThread = thread;
+	record->isAtomic = 0;
 	modelclock_t ourClock = currClock->getClock(thread);
 	record->writeClock = ourClock;
 	return race;
@@ -278,6 +280,7 @@ void fullRecordWrite(thread_id_t thread, void *location, uint64_t *shadow, Clock
 	record->writeThread = thread;
 	modelclock_t ourClock = currClock->getClock(thread);
 	record->writeClock = ourClock;
+	record->isAtomic = 1;
 }
 
 /** This function just updates metadata on atomic write. */
@@ -301,7 +304,7 @@ void recordWrite(thread_id_t thread, void *location) {
 		return;
 	}
 
-	*shadow = ENCODEOP(0, 0, threadid, ourClock);
+	*shadow = ENCODEOP(0, 0, threadid, ourClock) | ATOMICMASK;
 }
 
 
@@ -346,23 +349,21 @@ struct DataRace * fullRaceCheckRead(thread_id_t thread, const void *location, ui
 		}
 	}
 
-	if (copytoindex >= record->capacity) {
-		if (record->capacity == 0) {
+	if (__builtin_popcount(copytoindex) <= 1) {
+		if (copytoindex == 0) {
 			int newCapacity = INITCAPACITY;
 			record->thread = (thread_id_t *)snapshot_malloc(sizeof(thread_id_t) * newCapacity);
 			record->readClock = (modelclock_t *)snapshot_malloc(sizeof(modelclock_t) * newCapacity);
-			record->capacity = newCapacity;
-		} else {
-			int newCapacity = record->capacity * 2;
+		} else if (copytoindex>=INITCAPACITY) {
+			int newCapacity = copytoindex * 2;
 			thread_id_t *newthread = (thread_id_t *)snapshot_malloc(sizeof(thread_id_t) * newCapacity);
 			modelclock_t *newreadClock = (modelclock_t *)snapshot_malloc(sizeof(modelclock_t) * newCapacity);
-			std::memcpy(newthread, record->thread, record->capacity * sizeof(thread_id_t));
-			std::memcpy(newreadClock, record->readClock, record->capacity * sizeof(modelclock_t));
+			std::memcpy(newthread, record->thread, copytoindex * sizeof(thread_id_t));
+			std::memcpy(newreadClock, record->readClock, copytoindex * sizeof(modelclock_t));
 			snapshot_free(record->readClock);
 			snapshot_free(record->thread);
 			record->readClock = newreadClock;
 			record->thread = newthread;
-			record->capacity = newCapacity;
 		}
 	}
 
@@ -424,7 +425,7 @@ ShadowExit:
 			}
 		}
 
-		*shadow = ENCODEOP(threadid, ourClock, id_to_int(writeThread), writeClock);
+		*shadow = ENCODEOP(threadid, ourClock, id_to_int(writeThread), writeClock) | (shadowval & ATOMICMASK);
 	}
 Exit:
 	if (race) {
diff --git a/datarace.h b/datarace.h
index 7c841215..67d58e7c 100644
--- a/datarace.h
+++ b/datarace.h
@@ -55,8 +55,8 @@ void assert_race(struct DataRace *race);
 struct RaceRecord {
 	modelclock_t *readClock;
 	thread_id_t *thread;
-	int capacity;
-	int numReads;
+	int numReads : 31;
+	int isAtomic : 1;
 	thread_id_t writeThread;
 	modelclock_t writeClock;
 };
@@ -78,6 +78,9 @@ bool race_equals(struct DataRace *r1, struct DataRace *r2);
 #define WRITEMASK READMASK
 #define WRITEVECTOR(x) (((x)>>38)&WRITEMASK)
 
+#define ATOMICMASK (0x1ULL << 63)
+#define NONATOMICMASK ~(0x1ULL << 63)
+
 /**
  * The basic encoding idea is that (void *) either:
  *  -# points to a full record (RaceRecord) or
@@ -88,6 +91,7 @@ bool race_equals(struct DataRace *r1, struct DataRace *r2);
  *     - next 25 bits are read clock vector
  *     - next 6 bits are write thread id
  *     - next 25 bits are write clock vector
+ *     - highest bit is 1 if the write is from an atomic
  */
 #define ENCODEOP(rdthread, rdtime, wrthread, wrtime) (0x1ULL | ((rdthread)<<1) | ((rdtime) << 7) | (((uint64_t)wrthread)<<32) | (((uint64_t)wrtime)<<38))
 
-- 
2.34.1