From 2d5d798c24286f10c1bffd5ea4ac466c2c3a12fa Mon Sep 17 00:00:00 2001
From: Benoit Germain <bnt.germain@gmail.com>
Date: Wed, 30 Mar 2011 19:16:39 +0200
Subject: 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

---
 CHANGES         |   5 +++
 docs/index.html |  37 +++++++++++++--
 src/keeper.lua  |  22 +++++++--
 src/lanes.c     | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 src/lanes.lua   |   9 +++-
 5 files changed, 197 insertions(+), 12 deletions(-)

diff --git a/CHANGES b/CHANGES
index 58b6061..31ca342 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,11 @@ CHANGES:
 
 CHANGE X:
 
+CHANGE 30 BGe 30-Mar-2011
+* 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
+
 CHANGE 29 BGe 1-Mar-2011
     fixed potential crash at application shutdown when calling lua_close() on a killed thread's VM.
     exposed cancel_test() in the lanes to enable manual testing for cancellation requests.
diff --git a/docs/index.html b/docs/index.html
index ba25515..7d61d96 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -263,6 +263,19 @@ also in the new lanes.
     Implementation and dependability of priorities varies
     by platform. Especially Linux kernel 2.6 is not supporting priorities in user mode.
     </td></tr>
+
+    <tr valign="top">
+      <td width="40">
+        <td>
+          <code>.packagepath</code>
+          <br/><code>.packagecpath</code>
+        </td>
+        <td>
+          <code>package.path</code> and <code>package.cpath</code> overrides, if needed.
+          Specifying these when <code>libs_str</code> doesn't cause the <code>package</code> library to be loaded will generate an error.
+          <br>
+    </td>
+    </tr>
   </table>
   <p>Each lane also gets a function <tt>set_debug_threadname()</tt> that it can use anytime to do as the name says.
 Supported debuggers are Microsoft Visual Studio (for the C side) and Decoda (for the Lua side).
@@ -547,7 +560,18 @@ They can be used for making shared tables of storage among the lanes.
 Writing to a slot overwrites existing value, and clears any possible queued
 entries. Table access and <tt>send</tt>/<tt>receive</tt> can be used together;
 reading a slot essentially peeks the next outcoming value of a queue.
-</p>
+</p><p>
+
+    <table border="1" bgcolor="#E0E0FF" cellpadding="10">
+      <tr>
+        <td>
+          <code>[val]= linda_h:keys()</code>
+        </table>
+
+  </p>
+  <p>
+    A way to examine the slots in which a linda contains some pending data to be read.
+  </p>
 
 <!--
 <p>
@@ -961,8 +985,15 @@ its actual value.
 
 <p>
 
-Mar-2011 (2.1.0)
-<ul>
+  Mar-2011 (not yet versioned)
+  <ul>
+    <li>linda honors __tostring and __concat</li>
+    <li>new accessor linda:keys(), to retrieve the list of keys with pending data inside a linda</li>
+    <li>new lanes options packagepath and packagecpath, in case one needs to set them differently than the default</li>
+  </ul>
+
+  Mar-2011 (2.1.0)
+  <ul>
   <li>fixed potential crash at application shutdown when calling lua_close() on a killed thread's VM.</li>
   <li>exposed cancel_test() in the lanes to enable manual testing for cancellation requests.</li>
   <li>removed kludgy {globals={threadName}} support, replaced with a new function set_debug_threadname().</li>
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(...)
@@ -229,6 +230,21 @@ function get( ud, key )
 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 )
 --
@@ -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
@@ -536,6 +536,33 @@ 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 )
 *
@@ -607,6 +634,57 @@ 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.
 * 
@@ -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 ===---
 
-- 
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