Limit to an unique enventor instance.

Now, Enventor allows only one enventor instance.
This is sort of a limited way, but it would be better while enventor supports
multiple file editing.

Unless it perfectly covers scenarios that overwrite editor code from other
process, Enventor will limit its process count.

src/bin/base_gui.c

@@ -266,7 +266,7 @@ void
 base_gui_term(void)
 {
    base_data *bd = g_bd;
-   EINA_SAFETY_ON_NULL_RETURN(bd);
+   if (!bd) return;
 
    ecore_timer_del(bd->edc_navi_update_timer);
    file_browser_term();

src/bin/config_data.c

@@ -94,19 +94,22 @@ static void
 config_save(config_data *cd)
 {
    char buf[PATH_MAX];
+   const char *config_home = efreet_config_home_get();
+   if (!config_home) return;
 
    //Create config home directory if it doesn't exist.
-   if (!ecore_file_exists(efreet_config_home_get()))
+   if (!ecore_file_exists(config_home))
      {
-        Eina_Bool success = ecore_file_mkdir(efreet_config_home_get());
+        Eina_Bool success = ecore_file_mkdir(config_home);
         if (!success)
           {
-             EINA_LOG_ERR(_("Cannot create a config folder \"%s\""), efreet_config_home_get());
+             EINA_LOG_ERR(_("Cannot create a config folder \"%s\""),
+                          config_home);
              return;
           }
      }
 
-   snprintf(buf, sizeof(buf), "%s/enventor", efreet_config_home_get());
+   snprintf(buf, sizeof(buf), "%s/enventor", config_home);
 
    //Create enventor config folder if it doesn't exist.
    if (!ecore_file_exists(buf))
@@ -114,14 +117,14 @@ config_save(config_data *cd)
         Eina_Bool success = ecore_file_mkdir(buf);
         if (!success)
           {
-             EINA_LOG_ERR(_("Cannot create a config folder \"%s\""), buf);
+             EINA_LOG_ERR(_("Cannot create a enventor config folder \"%s\""),
+                          buf);
              return;
           }
      }
 
    //Save config file.
-   snprintf(buf, sizeof(buf), "%s/enventor/config.eet",
-            efreet_config_home_get());
+   snprintf(buf, sizeof(buf), "%s/enventor/config.eet", config_home);
    Eet_File *ef = eet_open(buf, EET_FILE_MODE_WRITE);
    if (!ef)
      {
@@ -395,6 +398,7 @@ void
 config_term(void)
 {
    config_data *cd = g_cd;
+   if (!cd) return;
 
    config_save(cd);
 

src/bin/file_mgr.c

@@ -228,7 +228,7 @@ void
 file_mgr_term(void)
 {
    file_mgr_data *fmd = g_fmd;
-   EINA_SAFETY_ON_NULL_RETURN(fmd);
+   if (!fmd) return;
 
    free(fmd);
 }

src/bin/live_edit.c

@@ -2345,7 +2345,7 @@ void
 live_edit_term(void)
 {
    live_data *ld = g_ld;
-   EINA_SAFETY_ON_NULL_RETURN(ld);
+   if (!ld) return;
 
    live_edit_cancel(EINA_FALSE);
 

src/bin/main.c

@@ -13,6 +13,8 @@ typedef struct app_s
    Eina_Bool lazy_save : 1;
 } app_data;
 
+static Eina_Bool own_lock = EINA_FALSE;  //lock file owner?
+
 int main(int argc, char **argv);
 
 static void
@@ -912,6 +914,150 @@ keygrabber_init(app_data *ad)
    GRAB_ADD("Down", modifier);
 }
 
+static Eina_Bool
+enventor_lock_create(void)
+{
+   const char *config_home = efreet_config_home_get();
+
+   //Exception 1
+   //Create config home directory if it doesn't exist.
+   if (!config_home)
+     {
+        EINA_LOG_ERR("No config home directory?! = %s", config_home);
+        return EINA_TRUE;
+     }
+
+   //Exception 2
+   //Create config home directory if it doesn't exist.
+   if (!ecore_file_exists(config_home))
+     {
+        Eina_Bool success = ecore_file_mkdir(efreet_config_home_get());
+        if (!success)
+          {
+             EINA_LOG_ERR(_("Cannot create a config folder \"%s\""),
+                          config_home);
+             return EINA_TRUE;
+          }
+     }
+
+   char buf[PATH_MAX];
+   snprintf(buf, sizeof(buf), "%s/enventor", config_home);
+
+   //Exception 3
+   //Create enventor config folder if it doesn't exist.
+   if (!ecore_file_exists(buf))
+     {
+        Eina_Bool success = ecore_file_mkdir(buf);
+        if (!success)
+          {
+             EINA_LOG_ERR(_("Cannot create a enventor config folder \"%s\""),
+                          buf);
+             return EINA_TRUE;
+          }
+     }
+
+   snprintf(buf, sizeof(buf), "%s/enventor/"ENVENTOR_LOCK_FILE, config_home);
+
+   //Is there any other Enventor instance?
+   if (ecore_file_exists(buf))
+     {
+        fprintf(stdout, "Enventor program is already running!\n\n"
+                        "If you are really stuck in launching enventor due to "
+                        "this,\nTry removing a file \"%s\"\n", buf);
+        return EINA_FALSE;
+     }
+
+   //Ok, this is an unique instance!
+   FILE *fp = fopen(buf, "w");
+   if (!fp)
+     {
+        EINA_LOG_ERR("Failed to open file \"%s\"", buf);
+        return EINA_TRUE;
+     }
+   fputs("x", fp);
+   fclose(fp);
+
+   own_lock = EINA_TRUE;
+
+   return EINA_TRUE;
+}
+
+static void
+enventor_lock_remove()
+{
+   //You are not the owner of the lock.
+   if (!own_lock) return;
+
+   const char *config_home = efreet_config_home_get();
+   //Create config home directory if it doesn't exist.
+   if (!config_home || !ecore_file_exists(config_home))
+     {
+        EINA_LOG_ERR("No config home directory?! = %s", config_home);
+        return;
+     }
+
+   char buf[PATH_MAX];
+   snprintf(buf, sizeof(buf), "%s/enventor/"ENVENTOR_LOCK_FILE,
+            efreet_config_home_get());
+
+   //Just in case.
+   if (!ecore_file_exists(buf))
+     {
+        EINA_LOG_ERR("No enventor lock file?! = %s", buf);
+        return;
+     }
+
+   ecore_file_remove(buf);
+}
+
+static void
+crash_handler(int x EINA_UNUSED, siginfo_t *info EINA_UNUSED,
+              void *data EINA_UNUSED)
+{
+   EINA_LOG_ERR("Eeeek! Eventor is terminated abnormally!");
+   enventor_lock_remove();
+}
+
+static void
+sigaction_setup(void)
+{
+   //Just in case, if you are debugging using gdb,
+   //you can send signals like this. "handle SIGABRT pass"
+   //Use this for remove the enventor lock.
+
+   struct sigaction action;
+
+   memset(&action, 0x0, sizeof(action));
+   action.sa_handler = SIG_DFL;
+   action.sa_sigaction = crash_handler;
+   action.sa_flags = SA_NODEFER  | SA_RESETHAND | SA_SIGINFO;
+   sigemptyset(&action.sa_mask);
+
+   //Bus error (bad memory access)
+   sigaction(SIGBUS, &action, NULL);
+
+   //Floating pointer exception
+   sigaction(SIGFPE, &action, NULL);
+
+   //Illegal Instruction
+   sigaction(SIGILL, &action, NULL);
+
+   //Invalid memory reference
+   sigaction(SIGSEGV, &action, NULL);
+
+   //Kill
+   sigaction(SIGKILL, &action, NULL);
+
+   //Abort
+   sigaction(SIGABRT, &action, NULL);
+
+   //Stop
+   sigaction(SIGSTOP, &action, NULL);
+
+   //Interrupt from keyboard
+//   sigaction(SIGINT, &action, NULL);
+}
+
 static Eina_Bool
 init(app_data *ad, int argc, char **argv)
 {
@@ -922,9 +1068,12 @@ init(app_data *ad, int argc, char **argv)
 #endif /* set locale */
 
    elm_setup();
-
    enventor_init(argc, argv);
 
+   if (!enventor_lock_create()) return EINA_FALSE;
+   sigaction_setup();
+
+
    Eina_Bool template = EINA_FALSE;
    Eina_Bool default_edc = EINA_TRUE;
    if (!config_data_set(argc, argv, &default_edc, &template))
@@ -967,6 +1116,7 @@ term(void)
    base_gui_term();
    file_mgr_term();
    config_term();
+   enventor_lock_remove();
    enventor_shutdown();
 }
 

src/bin/statusbar.c

@@ -383,7 +383,7 @@ void
 stats_term(void)
 {
    stats_data *sd = g_sd;
-   EINA_SAFETY_ON_NULL_RETURN(sd);
+   if (!sd) return;
 
    eina_stringshare_del(sd->group_name);
    free(sd);

src/bin/tools.c

@@ -178,7 +178,7 @@ void
 tools_term(void)
 {
    tools_data *td = g_td;
-   assert(td);
+   if (!td) return;
    free(td);
 }
 

src/include/common.h

@@ -99,5 +99,6 @@ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\n"
    #define NGETTEXT(single, plur, n) (((n)==1)? (single):(plur))
 #endif /* localization */
 
+#define ENVENTOR_LOCK_FILE ".enventor.lock"
 
 #endif