From: Florian Forster <octo@leeloo.lan.home.verplant.org>
Date: Mon, 17 Aug 2009 08:39:55 +0000 (+0200)
Subject: java plugin: Wait with the configuration until the daemon has forked.
X-Git-Tag: collectd-4.7.3~11
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=de38c1a6e44cadfc88fc6e1d0919663f0c08bbdc;p=collectd.git

java plugin: Wait with the configuration until the daemon has forked.

Passing the configuration to Java-based plugins requires the JVM to be
active and running. However, the JVM starts some threads that are lost
when the daemon forks to the background.

This patch changes the behavior of the Java plugin to copy the
configuration blocks found to a local variable and run the configuration
of the Java-based plugins from the `init' callback, because it is
invoked after the daemon has forked to the background.
---

diff --git a/src/java.c b/src/java.c
index 6a98d823..1d762219 100644
--- a/src/java.c
+++ b/src/java.c
@@ -93,6 +93,8 @@ static cjni_callback_info_t *java_callbacks      = NULL;
 static size_t                java_callbacks_num  = 0;
 static pthread_mutex_t       java_callbacks_lock = PTHREAD_MUTEX_INITIALIZER;
 
+static oconfig_item_t       *config_block = NULL;
+
 /*
  * Prototypes
  *
@@ -2304,7 +2306,7 @@ static int cjni_config_plugin_block (oconfig_item_t *ci) /* {{{ */
   return (0);
 } /* }}} int cjni_config_plugin_block */
 
-static int cjni_config (oconfig_item_t *ci) /* {{{ */
+static int cjni_config_perform (oconfig_item_t *ci) /* {{{ */
 {
   int success;
   int errors;
@@ -2359,7 +2361,55 @@ static int cjni_config (oconfig_item_t *ci) /* {{{ */
   }
 
   return (0);
-} /* }}} int cjni_config */
+} /* }}} int cjni_config_perform */
+
+/* Copy the children of `ci' to the global `config_block' variable. */
+static int cjni_config_callback (oconfig_item_t *ci) /* {{{ */
+{
+  oconfig_item_t *ci_copy;
+  oconfig_item_t *tmp;
+
+  assert (ci != NULL);
+  if (ci->children_num == 0)
+    return (0); /* nothing to do */
+
+  ci_copy = oconfig_clone (ci);
+  if (ci_copy == NULL)
+  {
+    ERROR ("java plugin: oconfig_clone failed.");
+    return (-1);
+  }
+
+  if (config_block == NULL)
+  {
+    config_block = ci_copy;
+    return (0);
+  }
+
+  tmp = realloc (config_block->children,
+      (config_block->children_num + ci_copy->children_num) * sizeof (*tmp));
+  if (tmp == NULL)
+  {
+    ERROR ("java plugin: realloc failed.");
+    oconfig_free (ci_copy);
+    return (-1);
+  }
+  config_block->children = tmp;
+
+  /* Copy the pointers */
+  memcpy (config_block->children + config_block->children_num,
+      ci_copy->children,
+      ci_copy->children_num * sizeof (*ci_copy->children));
+
+  /* Delete the pointers from the copy, so `oconfig_free' can't free them. */
+  memset (ci_copy->children, 0,
+      ci_copy->children_num * sizeof (*ci_copy->children));
+  ci_copy->children_num = 0;
+
+  oconfig_free (ci_copy);
+
+  return (0);
+} /* }}} int cjni_config_callback */
 
 /* Free the data contained in the `user_data_t' pointer passed to `cjni_read'
  * and `cjni_write'. In particular, delete the global reference to the Java
@@ -2995,6 +3045,22 @@ static int cjni_init (void) /* {{{ */
 {
   JNIEnv *jvm_env;
 
+  if ((config_block == NULL) && (jvm == NULL))
+  {
+    ERROR ("java plugin: cjni_init: No configuration block for "
+        "the java plugin was found.");
+    return (-1);
+  }
+
+  if (config_block != NULL)
+  {
+    int status;
+
+    status = cjni_config_perform (config_block);
+    oconfig_free (config_block);
+    config_block = NULL;
+  }
+
   if (jvm == NULL)
   {
     ERROR ("java plugin: cjni_init: jvm == NULL");
@@ -3013,7 +3079,7 @@ static int cjni_init (void) /* {{{ */
 
 void module_register (void)
 {
-  plugin_register_complex_config ("java", cjni_config);
+  plugin_register_complex_config ("java", cjni_config_callback);
   plugin_register_init ("java", cjni_init);
   plugin_register_shutdown ("java", cjni_shutdown);
 } /* void module_register (void) */