New features

* linda honors __tostring and __concat
* new accessor linda:keys(), to retrieve the list of keys with pending data inside a linda
* new lanes options packagepath and packagecpath, in case one needs to set them differently than the default

3 files changed, 158 insertions, 9 deletions

diff --git a/src/keeper.lua b/src/keeper.lua
index 2c38c0b..4bb181a 100644
--- a/src/keeper.lua
+++ b/src/keeper.lua
@@ -40,8 +40,9 @@ assert( nil_sentinel )
 
 -- We only need to have base and table libraries (and io for debugging)
 --
-local table_remove= assert( table.remove )
-local table_concat= assert( table.concat )
+local table_concat = assert( table.concat)
+local table_insert = assert( table.insert)
+local table_remove = assert( table.remove)
 
 --[[
 local function WR(...)
@@ -230,6 +231,21 @@ end
 
 
 -----
+-- [val]= keys( linda_deep_ud)
+--
+function keys( ud)
+
+    local data,_,_= tables(ud)
+
+    local out = {}
+    for key, v in pairs( data) do
+        table_insert( out, key)
+    end
+    return (#out > 0) and out or nil
+end
+
+
+-----
 -- void= clear( linda_deep_ud )
 --
 -- Clear the data structures used for a Linda (at its destructor)
@@ -240,5 +256,3 @@ function clear( ud )
     _incoming[ud]= nil
     _limits[ud]= nil
 end
-
-
diff --git a/src/lanes.c b/src/lanes.c
index 0c943aa..e06d367 100644
--- a/src/lanes.c
+++ b/src/lanes.c
@@ -537,6 +537,33 @@ LUAG_FUNC( linda_set)
 
 
 /*
+* [val]= linda_keys( linda_ud)
+*
+* Get the list of keys with pending data in the linda
+*/
+LUAG_FUNC( linda_keys)
+{
+        struct s_Linda *linda= lua_toLinda( L, 1);
+        int pushed;
+        luaL_argcheck( L, linda, 1, "expected a linda object!");
+
+        {
+                struct s_Keeper *K = keeper_acquire( linda);
+                pushed = keeper_call( K->L, "keys", L, linda, 2);
+                ASSERT_L( pushed==0 || pushed==1 );
+                keeper_release(K);
+                // must trigger error after keeper state has been released
+                if( pushed < 0)
+                {
+                        luaL_error( L, "tried to copy unsupported types");
+                }
+        }
+
+        return pushed;
+}
+
+
+/*
 * [val]= linda_get( linda_ud, key_num|str|bool|lightuserdata )
 *
 * Get a value from Linda.
@@ -608,6 +635,57 @@ LUAG_FUNC( linda_deep ) {
 
 
 /*
+* string = linda:__tostring( linda_ud)
+*
+* Return the stringification of a linda
+*
+* Useful for concatenation or debugging purposes
+*/
+LUAG_FUNC( linda_tostring)
+{
+        char text[32];
+        struct s_Linda *linda = lua_toLinda( L, 1);
+        luaL_argcheck( L, linda, 1, "expected a linda object!");
+        sprintf( text, "linda: %p", linda);
+        lua_pushstring( L, text);
+        return 1;
+}
+
+
+/*
+* string = linda:__concat( a, b)
+*
+* Return the concatenation of a pair of items, one of them being a linda
+*
+* Useful for concatenation or debugging purposes
+*/
+LUAG_FUNC( linda_concat)
+{
+        struct s_Linda *linda1 = lua_toLinda( L, 1);
+        struct s_Linda *linda2 = lua_toLinda( L, 2);
+        // lua semantics should enforce that one of the parameters we got is a linda
+        luaL_argcheck( L, linda1 || linda2, 1, "expected a linda object!");
+        // replace the lindas by their string equivalents in the stack
+        if ( linda1)
+        {
+                char text[32];
+                sprintf( text, "linda: %p", linda1);
+                lua_pushstring( L, text);
+                lua_replace( L, 1);
+        }
+        if ( linda2)
+        {
+                char text[32];
+                sprintf( text, "linda: %p", linda2);
+                lua_pushstring( L, text);
+                lua_replace( L, 2);
+        }
+        // concat the result
+        lua_concat( L, 2);
+        return 1;
+}
+
+/*
 * Identity function of a shared userdata object.
 * 
 *   lightuserdata= linda_id( "new" [, ...] )
@@ -678,17 +756,28 @@ static void linda_id( lua_State *L, char const * const which)
         // metatable is its own index
         lua_pushvalue( L, -1);
         lua_setfield( L, -2, "__index");
+
         // protect metatable from external access
         lua_pushboolean( L, 0);
         lua_setfield( L, -2, "__metatable");
+
+        lua_pushcfunction( L, LG_linda_tostring);
+        lua_setfield( L, -2, "__tostring");
+
+        lua_pushcfunction( L, LG_linda_concat);
+        lua_setfield( L, -2, "__concat");
+
         //
         // [-1]: linda metatable
         lua_pushcfunction( L, LG_linda_send );
         lua_setfield( L, -2, "send" );
-    
+
         lua_pushcfunction( L, LG_linda_receive );
         lua_setfield( L, -2, "receive" );
-    
+
+        lua_pushcfunction( L, LG_linda_keys );
+        lua_setfield( L, -2, "keys" );
+
         lua_pushcfunction( L, LG_linda_limit );
         lua_setfield( L, -2, "limit" );
 
@@ -1359,6 +1448,7 @@ LUAG_FUNC( set_debug_threadname)
 //                          [cancelstep_uint=0], 
 //                          [prio_int=0],
 //                          [globals_tbl],
+//                          [packagepath],
 //                          [... args ...] )
 //
 // Upvalues: metatable to use for 'lane_ud'
@@ -1373,8 +1463,10 @@ LUAG_FUNC( thread_new )
         uint_t cs= luaG_optunsigned( L, 3,0);
         int prio= (int)luaL_optinteger( L, 4,0);
         uint_t glob= luaG_isany(L,5) ? 5:0;
+        uint_t ppath = luaG_isany(L,6) ? 6:0;
+        uint_t pcpath = luaG_isany(L,7) ? 7:0;
 
-#define FIXED_ARGS (5)
+#define FIXED_ARGS (7)
         uint_t args= lua_gettop(L) - FIXED_ARGS;
 
         if (prio < THREAD_PRIO_MIN || prio > THREAD_PRIO_MAX)
@@ -1424,6 +1516,44 @@ LUAG_FUNC( thread_new )
                 serialize_require( L2 );
         }
 
+        // package.path
+        STACK_CHECK(L2)
+        if( ppath)
+        {
+                if (lua_type(L,ppath) != LUA_TSTRING)
+                        luaL_error( L, "expected packagepath as string, got %s", luaG_typename(L,ppath));
+                lua_getglobal( L2, "package");
+                if( lua_isnil( L2, -1))
+                {
+                        lua_pop( L2, 1);
+                        luaL_error( L, "specifying a new path for packages, but lane doesn't load package library");
+                }
+                lua_pushvalue( L, ppath);
+                luaG_inter_move( L, L2, 1);     // moves the new path to L2
+                lua_setfield( L2, -2, "path"); // set package.path
+                lua_pop( L2, 1);
+        }
+        STACK_END(L2,0)
+
+        // package.cpath
+        STACK_CHECK(L2)
+        if( pcpath)
+        {
+                if (lua_type(L,pcpath) != LUA_TSTRING)
+                        luaL_error( L, "expected packagecpath as string, got %s", luaG_typename(L,pcpath));
+                lua_getglobal( L2, "package");
+                if( lua_isnil( L2, -1))
+                {
+                        lua_pop( L2, 1);
+                        luaL_error( L, "specifying a new cpath for packages, but lane doesn't load package library");
+                }
+                lua_pushvalue( L, pcpath);
+                luaG_inter_move( L, L2, 1);     // moves the new cpath to L2
+                lua_setfield( L2, -2, "cpath"); // set package.cpath
+                lua_pop( L2, 1);
+        }
+        STACK_END(L2,0)
+
         // Lane main function
         //
         STACK_CHECK(L)
diff --git a/src/lanes.lua b/src/lanes.lua
index 05c2ff1..252d151 100644
--- a/src/lanes.lua
+++ b/src/lanes.lua
@@ -204,7 +204,7 @@ function gen( ... )
         end
     end
     
-    local prio, cs, g_tbl
+    local prio, cs, g_tbl, packagepath, packagecpath
 
     for k,v in pairs(opt) do
             if k=="priority" then prio= v
@@ -213,6 +213,8 @@ function gen( ... )
                                         type(v)=="number" and v or
                                         error( "Bad cancelstep: "..tostring(v), lev )
         elseif k=="globals" then g_tbl= v
+        elseif k=="packagepath" then packagepath= v
+        elseif k=="packagecpath" then packagecpath= v
         --..
         elseif k==1 then error( "unkeyed option: ".. tostring(v), lev )
         else error( "Bad option: ".. tostring(k), lev )
@@ -222,7 +224,7 @@ function gen( ... )
     -- Lane generator
     --
     return function(...)
-              return thread_new( func, libs, cs, prio, g_tbl, ...)     -- args
+              return thread_new( func, libs, cs, prio, g_tbl, packagepath, packagecpath, ...)     -- args
            end
 end
 
@@ -237,6 +239,8 @@ linda = mm.linda
 
 
 ---=== Timers ===---
+local want_timers = true
+if want_timers then
 
 local timer_gateway= assert( mm.timer_gateway )
 --
@@ -452,6 +456,7 @@ function timer( linda, key, a, period )
     timer_gateway:send( TGW_KEY, linda, key, wakeup_at, period )
 end
 
+end -- want_timers
 
 ---=== Lock & atomic generators ===---