5 files changed, 68 insertions, 69 deletions

diff --git a/src/cancel.cpp b/src/cancel.cpp
index 81f25d5..73e50f5 100644
--- a/src/cancel.cpp
+++ b/src/cancel.cpp
@@ -53,11 +53,11 @@ THE SOFTWARE.
 * Returns CANCEL_SOFT/HARD if any locks are to be exited, and 'cancel_error()' called,
 * to make execution of the lane end.
 */
-static inline enum e_cancel_request cancel_test( lua_State* L)
+static inline CancelRequest cancel_test(lua_State* L)
 {
     Lane* const s = get_lane_from_registry( L);
     // 's' is nullptr for the original main state (and no-one can cancel that)
-    return s ? s->cancel_request : CANCEL_NONE;
+    return s ? s->cancel_request : CancelRequest::None;
 }
 
 // ################################################################################################
@@ -70,19 +70,18 @@ static inline enum e_cancel_request cancel_test( lua_State* L)
 //
 LUAG_FUNC( cancel_test)
 {
-    enum e_cancel_request test = cancel_test( L);
-    lua_pushboolean( L, test != CANCEL_NONE);
+    CancelRequest test{ cancel_test(L) };
+    lua_pushboolean(L, test != CancelRequest::None);
     return 1;
 }
 
 // ################################################################################################
 // ################################################################################################
 
-static void cancel_hook( lua_State* L, lua_Debug* ar)
+static void cancel_hook( lua_State* L, [[maybe_unused]] lua_Debug* ar)
 {
-    (void)ar;
     DEBUGSPEW_CODE( fprintf( stderr, "cancel_hook\n"));
-    if( cancel_test( L) != CANCEL_NONE)
+    if (cancel_test(L) != CancelRequest::None)
     {
         lua_sethook( L, nullptr, 0, 0);
         cancel_error( L);
@@ -112,40 +111,40 @@ static void cancel_hook( lua_State* L, lua_Debug* ar)
 
 // ################################################################################################
 
-static cancel_result thread_cancel_soft( Lane* s, double secs_, bool wake_lindas_)
+static CancelResult thread_cancel_soft(Lane* s, double secs_, bool wake_lindas_)
 {
-    s->cancel_request = CANCEL_SOFT; // it's now signaled to stop
+    s->cancel_request = CancelRequest::Soft; // it's now signaled to stop
     // negative timeout: we don't want to truly abort the lane, we just want it to react to cancel_test() on its own
     if( wake_lindas_) // wake the thread so that execution returns from any pending linda operation if desired
     {
-        SIGNAL_T *waiting_on = s->waiting_on;
+        SIGNAL_T* waiting_on = s->waiting_on;
         if( s->status == WAITING && waiting_on != nullptr)
         {
             SIGNAL_ALL( waiting_on);
         }
     }
 
-    return THREAD_WAIT( &s->thread, secs_, &s->done_signal, &s->done_lock, &s->status) ? CR_Cancelled : CR_Timeout;
+    return THREAD_WAIT(&s->thread, secs_, &s->done_signal, &s->done_lock, &s->status) ? CancelResult::Cancelled : CancelResult::Timeout;
 }
 
 // ################################################################################################
 
-static cancel_result thread_cancel_hard( lua_State* L, Lane* s, double secs_, bool force_, double waitkill_timeout_)
+static CancelResult thread_cancel_hard(lua_State* L, Lane* s, double secs_, bool force_, double waitkill_timeout_)
 {
-    cancel_result result;
+    CancelResult result;
 
-    s->cancel_request = CANCEL_HARD;    // it's now signaled to stop
+    s->cancel_request = CancelRequest::Hard; // it's now signaled to stop
     {
-        SIGNAL_T *waiting_on = s->waiting_on;
+        SIGNAL_T* waiting_on = s->waiting_on;
         if( s->status == WAITING && waiting_on != nullptr)
         {
             SIGNAL_ALL( waiting_on);
         }
     }
 
-    result = THREAD_WAIT( &s->thread, secs_, &s->done_signal, &s->done_lock, &s->status) ? CR_Cancelled : CR_Timeout;
+    result = THREAD_WAIT(&s->thread, secs_, &s->done_signal, &s->done_lock, &s->status) ? CancelResult::Cancelled : CancelResult::Timeout;
 
-    if( (result == CR_Timeout) && force_)
+    if ((result == CancelResult::Timeout) && force_)
     {
         // Killing is asynchronous; we _will_ wait for it to be done at
         // GC, to make sure the data structure can be released (alternative
@@ -156,8 +155,8 @@ static cancel_result thread_cancel_hard( lua_State* L, Lane* s, double secs_, bo
 #if THREADAPI == THREADAPI_PTHREAD
         // pthread: make sure the thread is really stopped!
         // note that this may block forever if the lane doesn't call a cancellation point and pthread doesn't honor PTHREAD_CANCEL_ASYNCHRONOUS
-        result = THREAD_WAIT( &s->thread, waitkill_timeout_, &s->done_signal, &s->done_lock, &s->status) ? CR_Killed : CR_Timeout;
-        if( result == CR_Timeout)
+        result = THREAD_WAIT(&s->thread, waitkill_timeout_, &s->done_signal, &s->done_lock, &s->status) ? CancelResult::Killed : CancelResult::Timeout;
+        if (result == CancelResult::Timeout)
         {
             (void) luaL_error( L, "force-killed lane failed to terminate within %f second%s", waitkill_timeout_, waitkill_timeout_ > 1 ? "s" : "");
         }
@@ -165,29 +164,29 @@ static cancel_result thread_cancel_hard( lua_State* L, Lane* s, double secs_, bo
         (void) waitkill_timeout_; // unused
         (void) L; // unused
 #endif // THREADAPI == THREADAPI_PTHREAD
-        s->mstatus = KILLED; // mark 'gc' to wait for it
+        s->mstatus = ThreadStatus::Killed; // mark 'gc' to wait for it
         // note that s->status value must remain to whatever it was at the time of the kill
         // because we need to know if we can lua_close() the Lua State or not.
-        result = CR_Killed;
+        result = CancelResult::Killed;
     }
     return result;
 }
 
 // ################################################################################################
 
-cancel_result thread_cancel( lua_State* L, Lane* s, CancelOp op_, double secs_, bool force_, double waitkill_timeout_)
+CancelResult thread_cancel(lua_State* L, Lane* s, CancelOp op_, double secs_, bool force_, double waitkill_timeout_)
 {
     // remember that lanes are not transferable: only one thread can cancel a lane, so no multithreading issue here
     // We can read 's->status' without locks, but not wait for it (if Posix no PTHREAD_TIMEDJOIN)
-    if( s->mstatus == KILLED)
+    if (s->mstatus == ThreadStatus::Killed)
     {
-        return CR_Killed;
+        return CancelResult::Killed;
     }
 
     if( s->status >= DONE)
     {
         // say "ok" by default, including when lane is already done
-        return CR_Cancelled;
+        return CancelResult::Cancelled;
     }
 
     // signal the linda the wake up the thread so that it can react to the cancel query
@@ -281,17 +280,17 @@ LUAG_FUNC( thread_cancel)
 
         switch( thread_cancel( L, s, op, secs, force, forcekill_timeout))
         {
-            case CR_Timeout:
+            case CancelResult::Timeout:
             lua_pushboolean( L, 0);
             lua_pushstring( L, "timeout");
             return 2;
 
-            case CR_Cancelled:
+            case CancelResult::Cancelled:
             lua_pushboolean( L, 1);
             push_thread_status( L, s);
             return 2;
 
-            case CR_Killed:
+            case CancelResult::Killed:
             lua_pushboolean( L, 1);
             push_thread_status( L, s);
             return 2;
diff --git a/src/cancel.h b/src/cancel.h
index be4d781..9a20774 100644
--- a/src/cancel.h
+++ b/src/cancel.h
@@ -20,18 +20,18 @@ struct Lane; // forward
 /*
  * Lane cancellation request modes
  */
-enum e_cancel_request
+enum class CancelRequest
 {
-    CANCEL_NONE, // no pending cancel request
-    CANCEL_SOFT, // user wants the lane to cancel itself manually on cancel_test()
-    CANCEL_HARD  // user wants the lane to be interrupted (meaning code won't return from those functions) from inside linda:send/receive calls
+    None, // no pending cancel request
+    Soft, // user wants the lane to cancel itself manually on cancel_test()
+    Hard  // user wants the lane to be interrupted (meaning code won't return from those functions) from inside linda:send/receive calls
 };
 
-enum cancel_result
+enum class CancelResult
 {
-    CR_Timeout,
-    CR_Cancelled,
-    CR_Killed
+    Timeout,
+    Cancelled,
+    Killed
 };
 
 enum CancelOp
@@ -51,7 +51,7 @@ static constexpr UniqueKey CANCEL_ERROR{ 0xe97d41626cc97577ull }; // 'cancel_err
 // crc64/we of string "CANCEL_TEST_KEY" generated at http://www.nitrxgen.net/hashgen/
 static constexpr UniqueKey CANCEL_TEST_KEY{ 0xe66f5960c57d133aull }; // used as registry key
 
-cancel_result thread_cancel( lua_State* L, Lane* s, CancelOp op_, double secs_, bool force_, double waitkill_timeout_);
+CancelResult thread_cancel(lua_State* L, Lane* s, CancelOp op_, double secs_, bool force_, double waitkill_timeout_);
 
 static inline int cancel_error( lua_State* L)
 {
diff --git a/src/lanes.cpp b/src/lanes.cpp
index e3f53c0..acfa0dc 100644
--- a/src/lanes.cpp
+++ b/src/lanes.cpp
@@ -456,7 +456,7 @@ static int selfdestruct_gc( lua_State* L)
             while( s != SELFDESTRUCT_END)
             {
                 // attempt a regular unforced hard cancel with a small timeout
-                bool const cancelled = THREAD_ISNULL( s->thread) || thread_cancel( L, s, CO_Hard, 0.0001, false, 0.0);
+                bool const cancelled = THREAD_ISNULL( s->thread) || thread_cancel( L, s, CO_Hard, 0.0001, false, 0.0) != CancelResult::Timeout;
                 // if we failed, and we know the thread is waiting on a linda
                 if( cancelled == false && s->status == WAITING && s->waiting_on != nullptr)
                 {
@@ -501,7 +501,7 @@ static int selfdestruct_gc( lua_State* L)
                         Lane* s = U->selfdestruct_first;
                         while( s != SELFDESTRUCT_END)
                         {
-                            if( s->cancel_request == CANCEL_HARD)
+                            if (s->cancel_request == CancelRequest::Hard)
                                 ++ n;
                             s = s->selfdestruct_next;
                         }
@@ -1239,13 +1239,13 @@ LUAG_FUNC( lane_new)
     s->status = PENDING;
     s->waiting_on = nullptr;
     s->debug_name = "<unnamed>";
-    s->cancel_request = CANCEL_NONE;
+    s->cancel_request = CancelRequest::None;
 
 #if THREADWAIT_METHOD == THREADWAIT_CONDVAR
     MUTEX_INIT( &s->done_lock);
     SIGNAL_INIT( &s->done_signal);
 #endif // THREADWAIT_METHOD == THREADWAIT_CONDVAR
-    s->mstatus = NORMAL;
+    s->mstatus = ThreadStatus::Normal;
     s->selfdestruct_next = nullptr;
 #if HAVE_LANE_TRACKING()
     s->tracking_next = nullptr;
@@ -1322,8 +1322,8 @@ LUAG_FUNC( thread_gc)
     }
 
     // We can read 's->status' without locks, but not wait for it
-    // test KILLED state first, as it doesn't need to enter the selfdestruct chain
-    if( s->mstatus == KILLED)
+    // test Killed state first, as it doesn't need to enter the selfdestruct chain
+    if (s->mstatus == ThreadStatus::Killed)
     {
         // Make sure a kill has proceeded, before cleaning up the data structure.
         //
@@ -1392,7 +1392,7 @@ static char const * thread_status_string( Lane* s)
 {
     enum e_status st = s->status;    // read just once (volatile)
     char const* str =
-        (s->mstatus == KILLED) ? "killed" : // new to v3.3.0!
+        (s->mstatus == ThreadStatus::Killed) ? "killed" : // new to v3.3.0!
         (st == PENDING) ? "pending" :
         (st == RUNNING) ? "running" :    // like in 'co.status()'
         (st == WAITING) ? "waiting" :
@@ -1438,7 +1438,7 @@ LUAG_FUNC( thread_join)
     STACK_CHECK( L, 0);
     // Thread is DONE/ERROR_ST/CANCELLED; all ours now
 
-    if( s->mstatus == KILLED) // OS thread was killed if thread_cancel was forced
+    if (s->mstatus == ThreadStatus::Killed) // OS thread was killed if thread_cancel was forced
     {
         // in that case, even if the thread was killed while DONE/ERROR_ST/CANCELLED, ignore regular return values
         STACK_GROW( L, 2);
@@ -1548,7 +1548,7 @@ LUAG_FUNC( thread_index)
                 switch( s->status)
                 {
                     default:
-                    if( s->mstatus != KILLED)
+                    if (s->mstatus != ThreadStatus::Killed)
                     {
                         // this is an internal error, we probably never get here
                         lua_settop( L, 0);
diff --git a/src/lanes_private.h b/src/lanes_private.h
index cd0c388..75607b9 100644
--- a/src/lanes_private.h
+++ b/src/lanes_private.h
@@ -4,10 +4,10 @@
 #include "cancel.h"
 #include "universe.h"
 
-enum ThreadStatus
+enum class ThreadStatus
 {
-    NORMAL,         // normal master side state
-    KILLED          // issued an OS kill
+    Normal, // normal master side state
+    Killed  // issued an OS kill
 };
 
 // NOTE: values to be changed by either thread, during execution, without
@@ -37,7 +37,7 @@ struct Lane
     //
     // When status is WAITING, points on the linda's signal the thread waits on, else nullptr
 
-    volatile enum e_cancel_request cancel_request;
+    volatile CancelRequest cancel_request;
     //
     // M: sets to false, flags true for cancel request
     // S: reads to see if cancel is requested
@@ -54,9 +54,9 @@ struct Lane
     // lane status changes to DONE/ERROR_ST/CANCELLED.
 #endif // THREADWAIT_METHOD == THREADWAIT_CONDVAR
 
-    volatile enum ThreadStatus mstatus;
+    volatile ThreadStatus mstatus;
     //
-    // M: sets to NORMAL, if issued a kill changes to KILLED
+    // M: sets to Normal, if issued a kill changes to Killed
     // S: not used
 
     Lane* volatile selfdestruct_next;
diff --git a/src/linda.cpp b/src/linda.cpp
index 10ee08b..ff3d543 100644
--- a/src/linda.cpp
+++ b/src/linda.cpp
@@ -53,7 +53,7 @@ struct s_Linda
     SIGNAL_T write_happened;
     Universe* U; // the universe this linda belongs to
     ptrdiff_t group; // a group to control keeper allocation between lindas
-    enum e_cancel_request simulate_cancel;
+    CancelRequest simulate_cancel;
     char name[1];
 };
 #define LINDA_KEEPER_HASHSEED( linda) (linda->group ? linda->group : (ptrdiff_t)linda)
@@ -122,7 +122,7 @@ LUAG_FUNC( linda_send)
 {
     struct s_Linda* linda = lua_toLinda( L, 1);
     bool ret{ false };
-    enum e_cancel_request cancel = CANCEL_NONE;
+    CancelRequest cancel{ CancelRequest::None };
     int pushed;
     time_d timeout = -1.0;
     int key_i = 2; // index of first key, if timeout not there
@@ -178,9 +178,9 @@ LUAG_FUNC( linda_send)
             {
                 cancel = s->cancel_request;
             }
-            cancel = (cancel != CANCEL_NONE) ? cancel : linda->simulate_cancel;
+            cancel = (cancel != CancelRequest::None) ? cancel : linda->simulate_cancel;
             // if user wants to cancel, or looped because of a timeout, the call returns without sending anything
-            if( !try_again || cancel != CANCEL_NONE)
+            if (!try_again || cancel != CancelRequest::None)
             {
                 pushed = 0;
                 break;
@@ -241,12 +241,12 @@ LUAG_FUNC( linda_send)
 
     switch( cancel)
     {
-        case CANCEL_SOFT:
+        case CancelRequest::Soft:
         // if user wants to soft-cancel, the call returns lanes.cancel_error
         CANCEL_ERROR.push(L);
         return 1;
 
-        case CANCEL_HARD:
+        case CancelRequest::Hard:
         // raise an error interrupting execution only in case of hard cancel
         return cancel_error( L); // raises an error and doesn't return
 
@@ -273,7 +273,7 @@ LUAG_FUNC( linda_receive)
 {
     struct s_Linda* linda = lua_toLinda( L, 1);
     int pushed, expected_pushed_min, expected_pushed_max;
-    enum e_cancel_request cancel = CANCEL_NONE;
+    CancelRequest cancel{ CancelRequest::None };
     keeper_api_t keeper_receive;
     
     time_d timeout = -1.0;
@@ -335,9 +335,9 @@ LUAG_FUNC( linda_receive)
             {
                 cancel = s->cancel_request;
             }
-            cancel = (cancel != CANCEL_NONE) ? cancel : linda->simulate_cancel;
+            cancel = (cancel != CancelRequest::None) ? cancel : linda->simulate_cancel;
             // if user wants to cancel, or looped because of a timeout, the call returns without sending anything
-            if( !try_again || cancel != CANCEL_NONE)
+            if (!try_again || cancel != CancelRequest::None)
             {
                 pushed = 0;
                 break;
@@ -395,12 +395,12 @@ LUAG_FUNC( linda_receive)
 
     switch( cancel)
     {
-        case CANCEL_SOFT:
+        case CancelRequest::Soft:
         // if user wants to soft-cancel, the call returns CANCEL_ERROR
         CANCEL_ERROR.push(L);
         return 1;
 
-        case CANCEL_HARD:
+        case CancelRequest::Hard:
         // raise an error interrupting execution only in case of hard cancel
         return cancel_error( L); // raises an error and doesn't return
 
@@ -430,7 +430,7 @@ LUAG_FUNC( linda_set)
     {
         Keeper* K = which_keeper( linda->U->keepers, LINDA_KEEPER_HASHSEED( linda));
 
-        if( linda->simulate_cancel == CANCEL_NONE)
+        if (linda->simulate_cancel == CancelRequest::None)
         {
             if( has_value)
             {
@@ -511,7 +511,7 @@ LUAG_FUNC( linda_get)
     {
         Keeper* K = which_keeper( linda->U->keepers, LINDA_KEEPER_HASHSEED( linda));
 
-        if( linda->simulate_cancel == CANCEL_NONE)
+        if (linda->simulate_cancel == CancelRequest::None)
         {
             pushed = keeper_call( linda->U, K->L, KEEPER_API( get), L, linda, 2);
             if( pushed > 0)
@@ -557,7 +557,7 @@ LUAG_FUNC( linda_limit)
     {
         Keeper* K = which_keeper( linda->U->keepers, LINDA_KEEPER_HASHSEED( linda));
 
-        if( linda->simulate_cancel == CANCEL_NONE)
+        if (linda->simulate_cancel == CancelRequest::None)
         {
             pushed = keeper_call( linda->U, K->L, KEEPER_API( limit), L, linda, 2);
             ASSERT_L( pushed == 0 || pushed == 1); // no error, optional boolean value saying if we should wake blocked writer threads
@@ -592,7 +592,7 @@ LUAG_FUNC( linda_cancel)
     // make sure we got 3 arguments: the linda, a key and a limit
     luaL_argcheck( L, lua_gettop( L) <= 2, 2, "wrong number of arguments");
 
-    linda->simulate_cancel = CANCEL_SOFT;
+    linda->simulate_cancel = CancelRequest::Soft;
     if( strcmp( who, "both") == 0) // tell everyone writers to wake up
     {
         SIGNAL_ALL( &linda->write_happened);
@@ -600,7 +600,7 @@ LUAG_FUNC( linda_cancel)
     }
     else if( strcmp( who, "none") == 0) // reset flag
     {
-        linda->simulate_cancel = CANCEL_NONE;
+        linda->simulate_cancel = CancelRequest::None;
     }
     else if( strcmp( who, "read") == 0) // tell blocked readers to wake up
     {
@@ -802,7 +802,7 @@ static void* linda_id( lua_State* L, DeepOp op_)
                 SIGNAL_INIT( &s->read_happened);
                 SIGNAL_INIT( &s->write_happened);
                 s->U = universe_get( L);
-                s->simulate_cancel = CANCEL_NONE;
+                s->simulate_cancel = CancelRequest::None;
                 s->group = linda_group << KEEPER_MAGIC_SHIFT;
                 s->name[0] = 0;
                 memcpy( s->name, linda_name, name_len ? name_len + 1 : 0);