atomic.h: Rename gettid() -> mdbm_gettid() to avoid conflicts (#11)

* atomic.h: Rename gettid() -> mdbm_gettid() to avoid conflicts

Recent versions of glibc contain a gettid syscall wrapper, starting
with 2.30. This causes the following compile error on anything that
includes it, such as Ubuntu LTS 20.04. Rename the function to fix it.
This should also return a int32_t instead of uint32_t to match the
actual kernel and glibc definitions.

In file included from mdbm.c:47:
atomic.h:102:24: error: conflicting types for 'gettid'
  102 | static inline uint32_t gettid() {
      |                        ^~~~~~
In file included from /usr/include/unistd.h:1170,
                 from mdbm.c:29:
/usr/include/x86_64-linux-gnu/bits/unistd_ext.h:34:16: note: previous declaration of 'gettid' was here
   34 | extern __pid_t gettid (void) __THROW;
      |                ^~~~~~

* Add missing rename (OOPS)

Author: evanj

src/lib/atomic.h

@@ -94,23 +94,27 @@ static inline void atomic_pause() {
 }
 
 
-/* returns (linux-specific) thread-id (for single-thread processes it's just PID) */
-static inline uint32_t gettid() {
-  /* AUTO_TSC("gettid()"); */
+/*
+returns (linux-specific) thread-id (for single-thread processes it's just PID).
+Renamed to not conflict with glibc 2.30's gettid wrapper.
+On Linux gettid returns pid_t which is int32_t.
+*/
+static inline int32_t mdbm_gettid() {
+  /* AUTO_TSC("mdbm_gettid()"); */
 #ifdef __linux__
   return syscall(SYS_gettid);
 #else
   /* Horrible hack, but pthread_self is not unique across processes, */
   /* and some OS don't expose any other unique id. */
   /* xor-fold pthread_self() pointer down to 16-bits */
-  uint32_t tid;
+  uint32_t tid_unsigned;
   uint64_t pself = (uint64_t)pthread_self();
   pself = pself ^ (pself >> 32);
   pself = pself ^ (pself >> 16);
   /* add in PID to help unique-ify */
   /* NOTE: tiger and later OSX have PID #s up to 10k. */
   tid = ((pself & 0xffff) << 16) + getpid();
-  return tid;
+  return (int32_t) tid_unsigned;
 #endif
 }
 

src/lib/log.c

@@ -157,7 +157,7 @@ int mdbm_log_vlog_at (const char* file, int line, int level, const char* format,
 
     gettimeofday(&tv, NULL);
 #ifdef __linux__
-    pid = gettid();
+    pid = mdbm_gettid();
 #else
     pid = getpid();
 #endif

src/lib/mdbm.c

@@ -8267,7 +8267,7 @@ open_tmp_test_file(const char *file, uint32_t siz, char *buf)
 {
     int created = 0, fd = -1;
 
-    snprintf(buf, MAXPATHLEN, "%s%d.map", file, gettid()); /* assuming buf is big enough */
+    snprintf(buf, MAXPATHLEN, "%s%d.map", file, mdbm_gettid()); /* assuming buf is big enough */
 
     fd = open(buf, O_RDWR|O_NOATIME);
     if (fd < 0) {

src/lib/mdbm_lock.cc

@@ -473,7 +473,7 @@ do_lock_x(MDBM* db, int pageno, int nonblock, int check)
         int do_check = 0; /* If an integrity check needs to be done. */
         int upgraded = 0; /* If the lock was implicitly upgraded (prev EXCL owner died). */
         int part_num = -1;
-        //fprintf(stderr, "@@@ do_lock_x pid:%d tid:%d, excl_nest:%d part_nest:%d part_count:%d pageno:%d\n", getpid(), gettid(), exclusive_nest, part_nest, part_count, pageno); 
+        //fprintf(stderr, "@@@ do_lock_x pid:%d tid:%d, excl_nest:%d part_nest:%d part_count:%d pageno:%d\n", getpid(), mdbm_gettid(), exclusive_nest, part_nest, part_count, pageno);
         /*fprintf(stderr, "do_lock_x, part_count:%d\n", part_count); */
         if (part_count > 1) { /* shared/indexed locking (vs single-lock) */
             if (pageno == MDBM_LOCK_EXCLUSIVE || pageno == MDBM_LOCK_SHARED) {
@@ -485,11 +485,11 @@ do_lock_x(MDBM* db, int pageno, int nonblock, int check)
 
             if (pageno == MDBM_LOCK_EXCLUSIVE || exclusive_nest > 0) {
                 if (!exclusive_nest && part_nest>0) {
-                    //fprintf(stderr, "@@@ do_lock_x-upgrade pid:%d tid:%d, \n", getpid(), gettid()); 
+                    //fprintf(stderr, "@@@ do_lock_x-upgrade pid:%d tid:%d, \n", getpid(), mdbm_gettid());
                     /*NOTE("Upgrade(TRY)"); */
                     TRY_OR_LOCK_TIMED_ERR(MLOCK_UPGRADE, part_num, "mlock_upgrade()");
                 } else { /* exclusive lock already held, bump count */
-                    //fprintf(stderr, "@@@ do_lock_x-exclusive pid:%d tid:%d\n",getpid(), gettid());
+                    //fprintf(stderr, "@@@ do_lock_x-exclusive pid:%d tid:%d\n",getpid(), mdbm_gettid());
                     /*NOTE("Lock(ASYNC) EXCLUSIVE"); */
                     TRY_OR_LOCK_TIMED_ERR(MLOCK_EXCLUSIVE, part_num, "mlock_lock(exclusive)");
                     if (1 == locks->getHeldCount(MLOCK_EXCLUSIVE, true)) {
@@ -505,27 +505,27 @@ do_lock_x(MDBM* db, int pageno, int nonblock, int check)
                         exclusive_nest, part_nest, part_count);
                     return -1;
                 } else {
-                    /*fprintf(stderr, "@@@ do_lock_x-part pid:%d tid:%d, part_num:%d\n", getpid(), gettid(), part_num); */
+                    /*fprintf(stderr, "@@@ do_lock_x-part pid:%d tid:%d, part_num:%d\n", getpid(), mdbm_gettid(), part_num); */
                     /* don't worry about blocking... should already be held... */
                     locks->lock(MLOCK_INDEX, MLOCK_BLOCK, part_num, do_check, upgraded);
                 }
             } else {
                 if (pageno == MDBM_LOCK_SHARED) {
                     /*NOTE("Lock(ASYNC) ANY SHARED"); */
-                    //fprintf(stderr, "@@@ do_lock_x-shared pid:%d tid:%d, \n", getpid(), gettid()); 
+                    //fprintf(stderr, "@@@ do_lock_x-shared pid:%d tid:%d, \n", getpid(), mdbm_gettid());
                     TRY_OR_LOCK_TIMED_ERR(MLOCK_SHARED, MLOCK_ANY, "mlock_lock(shared)");
                 } else {
                     /*NOTE("Lock(ASYNC) PART"); */
                     /*lock_error(db,"Lock(ASYNC) Part (page:%d part:%d)",pageno,part_num); */
                     /*print_trace(); */
-                    /*fprintf(stderr, "@@@ do_lock_x-index pid:%d tid:%d part_num:%d, \n", getpid(), gettid(), part_num); */
+                    /*fprintf(stderr, "@@@ do_lock_x-index pid:%d tid:%d part_num:%d, \n", getpid(), mdbm_gettid(), part_num); */
                     TRY_OR_LOCK_TIMED_ERR(MLOCK_INDEX, part_num, "mlock_lock(index)");
                 }
                 prot = 1;
             }
         } else { /* Single lock (not partitioned/shared) */
             /*NOTE("Lock(ASYNC) SINGLE"); */
-            //fprintf(stderr, "@@@ do_lock_x-single pid:%d tid:%d, \n", getpid(), gettid()); 
+            //fprintf(stderr, "@@@ do_lock_x-single pid:%d tid:%d, \n", getpid(), mdbm_gettid());
             TRY_OR_LOCK_TIMED_ERR(MLOCK_EXCLUSIVE, part_num, "mlock_lock(single)");
             if (locks->getHeldCount(MLOCK_EXCLUSIVE, true) == 1) {
                 prot = 1;
@@ -777,7 +777,7 @@ do_unlock_x(MDBM* db)
       int exclusive_nest = locks->getHeldCount(MLOCK_EXCLUSIVE, true);
       int part_nest = locks->getHeldCount(MLOCK_INDEX, true);
       int share_nest = locks->getHeldCount(MLOCK_SHARED, true);
-      //fprintf(stderr, "@@@ do_unlock_x pid:%d tid:%d, excl_nest:%d part_nest:%d share_nest:%d\n", getpid(), gettid(), exclusive_nest, part_nest, share_nest);
+      //fprintf(stderr, "@@@ do_unlock_x pid:%d tid:%d, excl_nest:%d part_nest:%d share_nest:%d\n", getpid(), mdbm_gettid(), exclusive_nest, part_nest, share_nest);
       if (exclusive_nest > 0) {
         /* exclusive lock is held... release it */
         if (locks->unlock(MLOCK_EXCLUSIVE) < 0) {

src/lib/multi_lock.cc

@@ -93,7 +93,7 @@ class TlsData {
       TlsEntry *te = (TlsEntry*)pthread_getspecific(key_);
       if (!te) {
         te = new TlsEntry;
-        te->tid = gettid();
+        te->tid = mdbm_gettid();
         //fprintf(stderr, "TlsData tid:%llu \n", tid);
         install_atfork();
         pthread_setspecific(key_, (void*)te);
@@ -301,7 +301,7 @@ inline int PMutex::Lock(bool blocking, owner_t tid) {
 //  PRINT_LOCK_TRACE(blocking?"TRY Lock(BLOCK)":"TRY Lock(ASYNC)");
 //#endif
 //  CHECKPOINTV("  Lock(%s) any:%u owner:" OWNER_FMT " %p", blocking?"BLOCK":"ASYNC", rec->count, rec->owner, rec);
-  //uint32_t tid = gettid();
+  //int32_t tid = mdbm_gettid();
   //owner_t tid = get_thread_id();
   int ret = -1;
   if (tid == rec->owner) {
@@ -357,7 +357,7 @@ inline int PMutex::Lock(bool blocking, owner_t tid) {
 
 inline int PMutex::Unlock(owner_t tid) {
   AUTO_TSC("PMutex::Unlock()");
-  //uint32_t tid = gettid();
+  //int32_t tid = mdbm_gettid();
   //owner_t tid = get_thread_id();
 //#ifdef TRACE_LOCKS
 //  PRINT_LOCK_TRACE("TRY Unlock()");
@@ -1507,7 +1507,7 @@ void MLock::DumpLockState(FILE* file) {
   if (!file) {
     file = stderr;
   }
-  fprintf(file, "Begin Lock state (for non-zero locks) (pid:%d, tid:%d self:%llx uuid:" OWNER_FMT " ):\n", getpid(), gettid(), (long long unsigned)pthread_self(), get_thread_id());
+  fprintf(file, "Begin Lock state (for non-zero locks) (pid:%d, tid:%d self:%llx uuid:" OWNER_FMT " ):\n", getpid(), mdbm_gettid(), (long long unsigned)pthread_self(), get_thread_id());
   fprintf(file, "  BaseLocks:%d Core:%d Shared/Partitioned:%d mode:%s (%d)\n", base, 1, parts, MLockTypeToStr(GetLockType()), GetLockType());
   for (int i=0; i<base; ++i) {
     local = locks.locks[i]->GetLocalCount();

src/test/unit-test/test_lockbase.cc

@@ -964,7 +964,7 @@ LockBaseTestSuite::parChildLockPartitions(CommonParams &params, const string &db
                      << " child locker got ret="<<ret<< " expected=" << params.expectedRet()
                      << " dbName=" << dbName
                      << " pid=" << getpid()
-                     << " tid=" << gettid()
+                     << " tid=" << mdbm_gettid()
                      << endl << flush;
 
         if (ret == params.expectedRet()) {

src/test/unit-test/test_lockv3.cc

@@ -2228,7 +2228,7 @@ void* LockV3TestSuite::LockV3TestSuite::thrdIterates(void *arg)
 
     // iterate the DB - when done send an ACK to the parent
     MDBM_ITER iter;
-    //fprintf(stderr, "@@@ === child pid:%d tid:%d about to iterate\n", getpid(), gettid());
+    //fprintf(stderr, "@@@ === child pid:%d tid:%d about to iterate\n", getpid(), mdbm_gettid());
     //mdbm_lock_dump(params->dbh());
     datum     key = mdbm_firstkey_r(params->dbh(), &iter);
     while (key.dsize != 0) {
@@ -2281,7 +2281,7 @@ LockV3TestSuite::thrdLockAndChildIterates(CommonParams &parParams, int childOpen
         CPPUNIT_ASSERT_MESSAGE(errMsg.insert(0, prefix), (ret == parParams.expectedRet()));
     }
 
-    //fprintf(stderr, "@@@ === parent pid:%d tid:%d about to tell child to iterate\n", getpid(), gettid());
+    //fprintf(stderr, "@@@ === parent pid:%d tid:%d about to tell child to iterate\n", getpid(), mdbm_gettid());
     //mdbm_lock_dump(dbh);
     // tell child to iterate
     parSendFD.sendMsg(_Continue);

src/test/unit-test/test_other.cc

@@ -1188,7 +1188,7 @@ void MdbmUnitTestOther::testMLock() {
   //    MDBM* db = (MDBM*)mdbm;
   //    struct mdbm_locks *db_locks = db->db_locks;
   //    mlock_t* locks = db_locks->db_mlocks;
-  //    uint32_t tid = gettid();
+  //    int32_t tid = mdbm_gettid();
 
       CPPUNIT_ASSERT(0 == db_part_owned(mdbm));
       CPPUNIT_ASSERT(0 == db_multi_part_locked(mdbm));