exec and waitpid work with lua table for each child

git-svn-id: https://svn.spreadspace.org/gcsd/trunk@56 ac14a137-c7f1-4531-abe0-07747231d213

3 files changed, 55 insertions, 118 deletions

diff --git a/src/l_util.c b/src/l_util.c
index 9b87beb..41bfcdd 100644
--- a/src/l_util.c
+++ b/src/l_util.c
@@ -220,118 +220,48 @@ void free_ptrptr(char** ptrptr)
   free(ptrptr);
 }
 
-struct child_struct {
-  pid_t pid_;
-  int fd_;
-  struct child_struct* next_;
-};
-typedef struct child_struct child_t;
-
-child_t* child_get_last(child_t* first)
-{
-  if(!first)
-    return NULL;
-
-  while(first->next_) {
-    first = first->next_;
-  }
-  return first;
-}
-
-int child_add(lua_State *L, pid_t pid, int fd)
-{
-  lua_getglobal(L, LUA_UTILLIBNAME);
-  lua_getfield(L, -1, LUA_UTILCHLIDRENNAME);
-  child_t* first = lua_touserdata(L, -1);
-  lua_pop(L, 1);
-
-  child_t* new_child = malloc(sizeof(child_t));
-  if(!new_child)
-    return -1;
-
-  new_child->pid_ = pid;
-  new_child->fd_ = fd;
-  new_child->next_ = NULL;
-  if(!first) {
-    lua_pushlightuserdata(L, new_child);
-    lua_setfield(L, -2, LUA_UTILCHLIDRENNAME);    
-    lua_pop(L, 1);
-    return 0;
-  }
-  child_get_last(first)->next_ = new_child;
-  lua_pop(L, 1);
-  return 0;
-}
-
-void child_remove(lua_State *L, pid_t pid)
+static int child_add(lua_State *L, pid_t pid, int fd)
 {
   lua_getglobal(L, LUA_UTILLIBNAME);
   lua_getfield(L, -1, LUA_UTILCHLIDRENNAME);
-  child_t* first = lua_touserdata(L, -1);
-  if(!first) {
-    lua_pop(L, 2);
-    return;
-  }
-  lua_pop(L, 1);
-
-  child_t* deletee = first;
-  if(first->pid_ == pid) {
-    lua_pushlightuserdata(L, first->next_);
-    lua_setfield(L, -2, LUA_UTILCHLIDRENNAME);    
-    lua_pop(L, 1);
-    close(deletee->fd_);
-    free(deletee);
-    return;
-  }
-  lua_pop(L, 1);
-  child_t* prev = deletee;
-  deletee = deletee->next_;
-  while(deletee) {
-    if(deletee->pid_ == pid) {
-      prev->next_ = deletee->next_;
-      close(deletee->fd_);
-      free(deletee);
-      return;
-    }
-    prev = deletee;
-    deletee = deletee->next_;
-  }
+  lua_remove(L, -2);
+  lua_newtable(L);
+  lua_pushinteger(L, pid);
+  lua_setfield(L, -2, "pid");
+  lua_pushinteger(L, fd);
+  lua_setfield(L, -2, "errfd");
+  lua_pushinteger(L, pid);
+  lua_pushvalue(L, -2);
+  lua_settable(L, -4);
+  lua_remove(L, -2);
 }
 
-child_t* child_find(lua_State *L, pid_t pid)
+static void child_remove(lua_State *L, pid_t pid)
 {
   lua_getglobal(L, LUA_UTILLIBNAME);
   lua_getfield(L, -1, LUA_UTILCHLIDRENNAME);
-  child_t* first = lua_touserdata(L, -1);
+  lua_pushinteger(L, pid);
+  lua_pushnil(L);
+  lua_settable(L, -3);
   lua_pop(L, 2);
-
-  if(!first)
-    return NULL;
-  
-  while(first) {
-    if(first->pid_ == pid)
-      return first;
-
-    first = first->next_;
-  }
-  return NULL;
 }
 
-void child_clear(lua_State *L, pid_t pid)
+static int child_find(lua_State *L, pid_t pid)
 {
   lua_getglobal(L, LUA_UTILLIBNAME);
   lua_getfield(L, -1, LUA_UTILCHLIDRENNAME);
-  child_t* first = lua_touserdata(L, -1);
-  lua_pop(L, 1);
-  lua_pushlightuserdata(L, NULL);
-  lua_setfield(L, -2, LUA_UTILCHLIDRENNAME);  
-
-  while(first) {
-    child_t* tmp = first;
-    first = tmp->next_;
-    close(tmp->fd_);
-    free(tmp);
+  lua_pushinteger(L, pid);
+  lua_gettable(L, -2);
+  if(lua_isnil(L, -1)) {
+    lua_pop(L, 3);
+    return -1;
   }
+  lua_getfield(L, -1, "errfd");
+  int fd = luaL_checkint(L, -1);
+  lua_pop(L, 1);
+  lua_remove(L, -2);
+  lua_remove(L, -3);
+  return fd;
 }
 
 static void prepare_fds(lua_State *L, int *child_stdio, int pipefd)
@@ -400,8 +330,6 @@ static int l_util_exec(lua_State *L)
   }
   close(pipefd[1]);
   child_add(L, pid, pipefd[0]);
-
-  lua_pushinteger(L, pid);
   return 1;
 }
 
@@ -410,7 +338,7 @@ static int l_util_waitpid(lua_State *L)
   int status = 0;
   pid_t pid = waitpid(-1, &status, WNOHANG);
   if(!pid || (pid < 0 && (errno == ECHILD))) {
-    lua_pushinteger(L, 0);
+    lua_pushnil(L);
     return 1;
   }
   if(pid < 0) {
@@ -419,17 +347,21 @@ static int l_util_waitpid(lua_State *L)
     return 2;
   }
 
-  lua_pushinteger(L, pid);
-  child_t* child = child_find(L, pid);
-  if(child) {
+  int errfd = child_find(L, pid);
+  if(errfd != -1) {
+    child_remove(L, pid);
     int err = 0;
-    if(read(child->fd_, (void*)(&err), sizeof(err)) >= sizeof(err)) {
+    if(read(errfd, (void*)(&err), sizeof(err)) >= sizeof(err)) {
       lua_pushliteral(L, "error");
       lua_pushstring(L, strerror(err)); // FIXXXXXME: strerror is not threadsafe!!!
-      child_remove(L, pid);
+      close(errfd);
       return 3;
     }
-    child_remove(L, pid);
+    close(errfd);
+  } else {
+    lua_pushnil(L);
+    lua_pushliteral(L, "unknown child pid returned");
+    return 2;
   }
   if(WIFEXITED(status)) {
     lua_pushliteral(L, "exit");
@@ -531,7 +463,7 @@ static const struct luaL_reg util_funcs [] = {
 LUALIB_API int luaopen_util(lua_State *L) 
 {
   luaL_register(L, LUA_UTILLIBNAME, util_funcs);
-  lua_pushlightuserdata(L, NULL);
+  lua_newtable(L);
   lua_setfield(L, -2, LUA_UTILCHLIDRENNAME);
   return 1;
 }
diff --git a/src/main_loop.lua b/src/main_loop.lua
index 3211660..22809aa 100644
--- a/src/main_loop.lua
+++ b/src/main_loop.lua
@@ -85,11 +85,14 @@ function main_loop(opt)
       local readable, writeable, err = util.select({ sig, unpack(get_readables()) }, get_writeables(), 10)
       if(err) then
          if(err == "timeout") then
-            local pid, reason, status = util.waitpid()
-            if(pid == nil) then
-               log.printf(log.DEBUG, "waitpid failed: " .. reason)
-            elseif(pid > 0) then
-               log.printf(log.DEBUG, "child with pid %d stopped, reason: %s, code: %s", pid, reason, tostring(status))
+            local child, reason, status = util.waitpid()
+            if(child == nil) then
+               if(reason ~= nil) then
+                  log.printf(log.DEBUG, "waitpid failed: " .. reason)
+               end
+            else
+               log.printf(log.DEBUG, "child with pid %d stopped, reason: %s, code: %s", child.pid, reason, tostring(status))
+               if(child.cleanup ~= nil) then child:cleanup() end
             end
          elseif(err == "signal") then
             -- ignore this
diff --git a/src/modules/exec.lua b/src/modules/exec.lua
index 765fdb6..239248f 100644
--- a/src/modules/exec.lua
+++ b/src/modules/exec.lua
@@ -36,6 +36,7 @@ local defines = require("defines")
 local exec = {}
 exec.properties = { type=defines.INOUT_MODULE, name="exec", max_instances=-1 }
 exec.defaults = { script = "exec.sh" }
+exec.next_id = 0
 
 -- create new instance of exec module class
 function exec:new(config)
@@ -43,7 +44,8 @@ function exec:new(config)
    inst.class = self.properties.name
    inst.config = config
    if(config.name == nil or config.name == "") then
-      inst.name = self.properties.name
+      inst.name = self.properties.name .. self.next_id
+      self.next_id = self.next_id + 1
    else
       inst.name = config.name
    end
@@ -59,13 +61,13 @@ function exec:new(config)
       log.printf(log.ERROR, inst.name .. ": pipe failed: %s", reader_child)
       return nil
    end
-   local pid, err = util.exec(config.script, nil, nil, reader_child, writer_child)
-   if(pid == nil) then
+   local child, err = util.exec(config.script, nil, nil, reader_child, writer_child)
+   if(child == nil) then
       log.printf(log.ERROR, inst.name .. ": exec failed: %s", error)
       return nil
    end
    
-   log.printf(log.NOTICE, inst.name .. ": child spawned with pid %d", pid)
+   log.printf(log.NOTICE, inst.name .. ": child spawned with pid %d", child.pid)
 
    local in_handle = {}
    in_handle.fd = reader
@@ -114,7 +116,7 @@ function exec:new(config)
    local client = {}
    client.module_instance = inst
    client.name = inst.name .. "#0"
-   client.pid = pid
+   client.pid = child.pid
    function client:process_response() end
    function client:process_timeout() end
    function client:get_read_handles() 
@@ -128,7 +130,7 @@ function exec:new(config)
       end
    end
    function client:cleanup() 
-      util.kill(pid)
+      util.kill(self.pid)
    end
    in_handle.client_instance = client
    out_handle.client_instance = client