Some random code cleanups, and implemented a naive lock manager. (Still need to tie it into LLADD...)

lladd/hash.h

@@ -3,7 +3,6 @@
 
 #ifndef __HASH_H
 #define __HASH_H
-/** @todo replace() powl in hash with something more efficient, if hash() becomes a bottleneck. */
 unsigned int max_bucket(unsigned char tableBits, unsigned long nextExtension);
 unsigned int hash(const void * val, long val_length, unsigned char tableBits, unsigned long nextExtension);
 #define twoToThe(x) (1 << (x))

lladd/lockManager.h

@@ -0,0 +1,9 @@
+#include <lladd/transactional.h>
+
+void lockManagerInit();
+
+int lockManagerReadLockRecord(int xid, recordid rid);
+int lockManagerWriteLockRecord(int xid, recordid rid);
+
+int lockManagerUnlockRecord(int xid, recordid rid);
+int lockManagerReleaseAll(int xid);

src/libdfa/rw.c

@@ -67,7 +67,7 @@ void writelock (rwl *lock, int d)
     /* printf ("writer %d blocked. %d readers, %d writers, %d waiting\n", d, lock->readers,  lock->writers, lock->waiting);  */
     pthread_cond_wait (lock->writeOK, lock->mut);
     /*    printf ("writer %d unblocked.\n", d);  */
-	}
+  }
   lock->waiting--;
   lock->writers++;
   pthread_mutex_unlock (lock->mut);
@@ -111,44 +111,13 @@ void unlock(rwl * lock) {
   pthread_mutex_unlock (lock->mut);
 }
 
-/*void readunlock(rwl *lock) {
-  writeunlock(lock);
-  }*/
 void readunlock(rwl * lock) {
   unlock(lock);
 }
 void writeunlock(rwl * lock) {
   unlock(lock);
 }
-/*
-  void readunlock (rwl *lock)
-  {
-  pthread_mutex_lock (lock->mut);
-  lock->readers--;
-  pthread_cond_signal (lock->writeOK); 
 
-  / * Don't need to broadcast, since only one writer can run at
-  once. * /
-  
-  / *  pthread_cond_broadcast (lock->writeOK);  * / 
-  
-  pthread_mutex_unlock (lock->mut);
-  / *  printf("readunlock done\n"); * /
-  }
-
-  void writeunlock (rwl *lock)
-   {
-   / * printf("writeunlock done\n"); 
-   fflush(NULL); * /
-   
-   pthread_mutex_lock (lock->mut);
-   lock->writers--;
-   / * Need this as well (in case there's another writer, which is blocking the all of the readers. * /
-   pthread_cond_signal (lock->writeOK); 
-   pthread_cond_broadcast (lock->readOK);
-   pthread_mutex_unlock (lock->mut);
-   }
-*/
 void deletelock (rwl *lock)
 {
 	pthread_mutex_destroy (lock->mut);

src/lladd/Makefile.am

@@ -5,11 +5,12 @@ lib_LIBRARIES=liblladd.a
 # removed: recovery.c transactional.c logger.c logger/logparser.c logger/logstreamer.c
 liblladd_a_SOURCES=crc32.c common.c stats.c io.c bufferManager.c linkedlist.c operations.c \
                    pageFile.c pageCache.c page.c blobManager.c recovery2.c transactional2.c \
-		   logger/logEntry.c logger/logWriter.c logger/logHandle.c logger/logger2.c \
+		   lockManager.c \
+	           logger/logEntry.c logger/logWriter.c logger/logHandle.c logger/logger2.c \
+		   page/slotted.c page/header.c page/fixed.c \
 	           operations/pageOperations.c page/indirect.c operations/decrement.c  \
 		   operations/increment.c  operations/prepare.c  operations/set.c \
 		   operations/alloc.c operations/noop.c operations/instantSet.c \
-		   page/slotted.c page/header.c page/fixed.c \
 		   operations/arrayList.c hash.c operations/linearHash.c \
 		   operations/naiveLinearHash.c operations/nestedTopActions.c \
 		   operations/linearHashNTA.c operations/linkedListNTA.c \

src/lladd/lockManager.c

@@ -0,0 +1,251 @@
+#include <pbl/pbl.h>
+#include <lladd/lockManager.h>
+#include <sys/time.h>
+#include <time.h>
+#include <pthread.h>
+#include <malloc.h>
+#include <errno.h>
+#include <stdio.h>
+#include <assert.h>
+
+#include <lladd/hash.h>
+
+
+#define MUTEX_COUNT 32
+// These next two correspond to MUTEX count, and are the appropriate values to pass into hash().
+#define MUTEX_BITS  5
+#define MUTEX_EXT   32 
+
+static pthread_mutex_t mutexes[MUTEX_COUNT];
+
+static pthread_mutex_t xid_table_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static pthread_mutex_t * getMutex(recordid rid) {
+  return &mutexes[hash(&rid, sizeof(recordid), MUTEX_BITS, MUTEX_EXT)];
+}
+
+static pblHashTable_t * xidLockTable;
+static pblHashTable_t * ridLockTable;
+
+typedef struct {
+  pthread_cond_t writeOK;
+  pthread_cond_t readOK;
+  int readers;
+  int writers;
+  int waiting;
+  int active;
+} lock;
+
+void lockManagerInit() {
+  int i = 0;
+  for(i = 0; i < MUTEX_COUNT; i++) {
+    pthread_mutex_init(&mutexes[i], NULL);
+  }
+  xidLockTable = pblHtCreate();
+  ridLockTable = pblHtCreate();
+  
+}
+/** @todo startTransaction needs a mutex!! */
+void startTransaction(int xid) {
+  pthread_mutex_lock(&xid_table_mutex);
+
+  pblHashTable_t * xidLocks = pblHtCreate();
+  pblHtInsert(xidLockTable, &xid, sizeof(int), xidLocks);
+  pthread_mutex_unlock(&xid_table_mutex);
+}
+
+lock* createLock(recordid rid) {
+  lock * ret = malloc(sizeof(lock));
+
+  if(!ret) { return NULL; }
+
+  //  pthread_mutex_init(&ret->mut, NULL);
+  pthread_cond_init(&ret->writeOK, NULL);
+  pthread_cond_init(&ret->readOK, NULL);
+  ret->readers = 0;
+  ret->writers = 0;
+  ret->waiting = 0;
+
+  pblHtInsert(ridLockTable, &rid, sizeof(recordid), ret);
+  return ret;
+}
+
+void destroyLock(recordid rid, lock * l) {
+  pthread_cond_destroy(&l->writeOK);
+  pthread_cond_destroy(&l->readOK);
+  free (l);
+  pblHtRemove(ridLockTable, &rid, sizeof(recordid));
+}
+
+#define LM_READLOCK 1
+#define LM_WRITELOCK 2
+
+int lockManagerReadLockRecord(int xid, recordid rid) {
+
+  pthread_mutex_lock(&xid_table_mutex);
+  pblHashTable_t * xidLocks = pblHtLookup(xidLockTable, &xid, sizeof(int));
+  if((int)pblHtLookup(xidLocks, &rid, sizeof(recordid)) >= LM_READLOCK) {
+    pthread_mutex_unlock(&xid_table_mutex);
+    return 0;
+  }
+  pthread_mutex_unlock(&xid_table_mutex);
+  pthread_mutex_t * mut = getMutex(rid);
+
+  pthread_mutex_lock(mut);
+
+  lock * ridLock = pblHtLookup(ridLockTable, &rid, sizeof(recordid));
+
+  if(!ridLock) {
+    ridLock = createLock(rid);
+  }
+
+  ridLock->active++;
+
+  if(ridLock->writers || ridLock->waiting) {
+    struct timeval tv;
+    int tod_ret = gettimeofday (&tv, NULL);
+    tv.tv_sec++; // Wait up to one second to obtain a lock before detecting deadlock.
+    struct timespec ts; 
+    ts.tv_sec = tv.tv_sec;
+    ts.tv_nsec = tv.tv_usec * 1000;
+    if(tod_ret != 0) {
+      perror("Could not get time of day");
+      return LLADD_INTERNAL_ERROR;
+    }
+    do {
+      int wait_ret = pthread_cond_timedwait(&ridLock->readOK, mut, &ts);
+      if(wait_ret == ETIMEDOUT) {
+	ridLock->active--;
+	pthread_mutex_unlock(mut);
+	return LLADD_DEADLOCK;
+      }
+    } while(ridLock->writers);
+  } 
+  ridLock->readers++;
+  ridLock->active--;
+  pthread_mutex_unlock(mut);
+  pblHtInsert(xidLocks, &rid, sizeof(recordid), (void*)LM_READLOCK);
+  return 0;
+}
+int lockManagerWriteLockRecord(int xid, recordid rid) {
+  pthread_mutex_lock(&xid_table_mutex);
+  pblHashTable_t * xidLocks = pblHtLookup(xidLockTable, &xid, sizeof(int));
+
+
+  int currentLockLevel = (int)pblHtLookup(xidLocks, &rid, sizeof(recordid));
+  int me = 0;
+  pthread_mutex_unlock(&xid_table_mutex);
+
+  if(currentLockLevel >= LM_WRITELOCK) {
+    return 0;
+  } else if(currentLockLevel == LM_READLOCK) {
+    me = 1;
+  }
+
+    pthread_mutex_t * mut = getMutex(rid);
+
+  pthread_mutex_lock(mut);
+  lock * ridLock = pblHtLookup(ridLockTable, &rid, sizeof(recordid));
+  if(!ridLock) {
+    ridLock = createLock(rid);
+  }
+
+  ridLock->active++;
+  ridLock->waiting++;
+  if(ridLock->writers || (ridLock->readers - me)) {
+    struct timeval tv;
+    int tod_ret = gettimeofday(&tv, NULL);
+    tv.tv_sec++;
+    struct timespec ts; 
+    ts.tv_sec = tv.tv_sec;
+    ts.tv_nsec = tv.tv_usec * 1000;
+    if(tod_ret != 0) {
+      perror("Could not get time of day");
+      return LLADD_INTERNAL_ERROR;
+    }
+    while(ridLock->writers || (ridLock->readers - me)) { 
+      int lockret = pthread_cond_timedwait(&ridLock->writeOK, mut, &ts);
+      if(lockret == ETIMEDOUT) {
+	ridLock->waiting--;
+	ridLock->active--;
+	pthread_mutex_unlock(mut);
+	return LLADD_DEADLOCK;
+      }
+    }
+  }
+  ridLock->waiting--;
+  if(currentLockLevel == 0) {
+    ridLock->readers++;
+  }
+  ridLock->writers++;
+  ridLock->active--;
+  pthread_mutex_unlock(mut);
+  pblHtInsert(xidLocks, &rid, sizeof(recordid), (void*)LM_WRITELOCK);
+  return 0;
+}
+
+int lockManagerUnlockRecord(int xid, recordid rid) {
+  pthread_mutex_lock(&xid_table_mutex);
+
+  pblHashTable_t * xidLocks = pblHtLookup(xidLockTable, &xid, sizeof(int));
+
+
+  int currentLevel = (int)pblHtLookup(xidLocks, &rid, sizeof(recordid));
+
+  if(currentLevel) {
+    pblHtRemove(xidLocks, &rid, sizeof(recordid));
+  }
+
+  pthread_mutex_unlock(&xid_table_mutex);
+  pthread_mutex_t * mut = getMutex(rid);
+  pthread_mutex_lock(mut);
+  lock * ridLock = pblHtLookup(ridLockTable, &rid, sizeof(recordid));
+  assert(ridLock);
+  ridLock->active++;
+
+  if(currentLevel == LM_WRITELOCK) {
+    ridLock->writers--;
+    ridLock->readers--;
+  } else if(currentLevel == LM_READLOCK) {
+    ridLock->readers--;
+  } else if(currentLevel == 0) {
+    assert(0); // Someone tried to release a lock they didn't own!
+  } else {
+    fprintf(stderr, "Unknown lock type encountered!");
+    ridLock->active--;
+    pthread_mutex_unlock(mut);
+    return LLADD_INTERNAL_ERROR;
+  }
+
+  ridLock->active--;
+
+  if(!(ridLock->active || ridLock->waiting || ridLock->readers || ridLock->writers)) {
+    destroyLock(rid, ridLock);
+  }
+
+  pthread_mutex_unlock(mut);
+
+  return 0;
+}
+
+int lockManagerReleaseAll(int xid) {
+
+  pthread_mutex_lock(&xid_table_mutex);
+
+  pblHashTable_t * xidLocks = pblHtLookup(xidLockTable, &xid, sizeof(int));
+
+  pthread_mutex_unlock(&xid_table_mutex);
+  void * data;
+  int ret = 0;
+  for(data = pblHtFirst(xidLocks); data; data = pblHtNext(xidLocks)) {
+    recordid rid = *(recordid*)pblHtCurrentKey(xidLocks);
+    int tmpret = lockManagerUnlockRecord(xid, rid);
+    // Pass any error(s) up to the user.
+    // (This logic relies on the fact that currently it only returns 0 and LLADD_INTERNAL_ERROR)
+    if(tmpret) {  
+      ret = tmpret;
+    }
+    pblHtRemove(xidLocks, &rid, sizeof(recordid));
+  }
+  return ret;
+}

src/lladd/page.h

@@ -136,8 +136,7 @@ struct Page_s {
   /** @todo The Page.LSN field seems extraneous.  Why do we need it? */
   long LSN;
   byte *memAddr;
-  /** @todo dirty pages currently aren't marked dirty! */
-  int dirty;
+  byte dirty;
   /** The next item in the replacement policy's queue */
   struct Page_s *next;
   /** The previous item in the replacement policy's queue. */
@@ -201,6 +200,7 @@ struct Page_s {
       
   */
   rwl * loadlatch;
+
 };
 
 /**

test/lladd/Makefile.am

@@ -1,12 +1,12 @@
 INCLUDES = @CHECK_CFLAGS@
 if HAVE_CHECK
 ## Had to disable check_lht because lht needs to be rewritten.
-TESTS = check_logEntry check_logWriter check_page check_operations check_transactional2 check_recovery check_blobRecovery check_bufferManager check_indirect check_pageOperations check_linearHash  check_logicalLinearHash check_header check_linkedListNTA check_linearHashNTA check_pageOrientedList
+TESTS = check_logEntry check_logWriter check_page check_operations check_transactional2 check_recovery check_blobRecovery check_bufferManager check_indirect check_pageOperations check_linearHash  check_logicalLinearHash check_header check_linkedListNTA check_linearHashNTA check_pageOrientedList check_lockManager
 #check_lladdhash
 else
 TESTS = 
 endif
 noinst_PROGRAMS = $(TESTS)
 LDADD = @CHECK_LIBS@ $(top_builddir)/src/lladd/liblladd.a $(top_builddir)/src/pbl/libpbl.a $(top_builddir)/src/libdfa/librw.a #-lefence
-CLEANFILES = check_lht.log check_logEntry.log storefile.txt logfile.txt blob0_file.txt blob1_file.txt check_blobRecovery.log check_logWriter.log check_operations.log check_recovery.log check_transactional2.log check_page.log check_bufferManager.log check_indirect.log check_bufferMananger.log check_lladdhash.log check_pageOperations.log check_linearhash.log check_linkedListNTA.log check_linearHashNTA.log check_pageOrientedListNTA.log
+CLEANFILES = check_lht.log check_logEntry.log storefile.txt logfile.txt blob0_file.txt blob1_file.txt check_blobRecovery.log check_logWriter.log check_operations.log check_recovery.log check_transactional2.log check_page.log check_bufferManager.log check_indirect.log check_bufferMananger.log check_lladdhash.log check_pageOperations.log check_linearhash.log check_linkedListNTA.log check_linearHashNTA.log check_pageOrientedListNTA.log check_lockManager.log
 AM_CFLAGS= -g -Wall -pedantic -std=gnu99

test/lladd/check_lockManager.c

@@ -0,0 +1,90 @@
+#include <lladd/transactional.h>
+#include <lladd/lockManager.h>
+#include <pthread.h>
+#include <config.h>
+#include <check.h>
+
+#include <lladd/transactional.h>
+#include <assert.h>
+#include "../check_includes.h"
+#include <stdlib.h>
+#define LOG_NAME   "check_lockManager.log"
+
+/** Needs to be formatted as a floating point */
+#define NUM_RECORDS 100000000.0
+#define THREAD_COUNT 100
+#define RIDS_PER_THREAD 10000
+
+void * workerThread(void * j) {
+
+  int xid = *(int*)j;
+  startTransaction(xid);
+  recordid rid;
+  rid.page = 0;
+  rid.size = 0;
+  int k;
+  int deadlocks = 0;
+  for(k = 0; k < RIDS_PER_THREAD; k++) {
+    rid.slot = (int) (NUM_RECORDS*random()/(RAND_MAX+1.0));
+    int rw = random() % 2;
+
+    if(rw) {
+      // readlock
+      
+      if(LLADD_DEADLOCK == lockManagerReadLockRecord(xid, rid)) {
+	deadlocks++;
+      }
+      
+      
+    } else {
+      // writelock
+      if(LLADD_DEADLOCK == lockManagerWriteLockRecord(xid, rid)) {
+	deadlocks++;
+      }
+
+    }
+  }
+  
+  printf("%2d ", deadlocks); fflush(stdout);
+
+  lockManagerReleaseAll(xid);
+
+  return NULL;
+
+}
+
+START_TEST(lockManagerTest) {
+
+  lockManagerInit();
+  pthread_t workers[THREAD_COUNT];
+  int i; 
+  for(i = 0; i < THREAD_COUNT; i++) {
+    int *j = malloc(sizeof(int));
+    *j = i;
+    pthread_create(&workers[i], NULL, workerThread, j);
+  }
+  for(i = 0; i < THREAD_COUNT; i++) {
+    pthread_join(workers[i], NULL);
+  }
+
+} END_TEST
+
+Suite * check_suite(void) {
+  Suite *s = suite_create("lockManager");
+  /* Begin a new test */
+  TCase *tc = tcase_create("multithreaded");
+
+  /* Sub tests are added, one per line, here */
+
+  tcase_add_test(tc, lockManagerTest); 
+
+  /* --------------------------------------------- */
+  
+  tcase_add_checked_fixture(tc, setup, teardown);
+
+
+  suite_add_tcase(s, tc);
+  return s;
+}
+
+#include "../check_setup.h"