Trying to find a bug where the database gets locked and never unlocks…

… again.

backoffice.go

@@ -535,13 +535,20 @@ func backofficeCommandsExec(w http.ResponseWriter, r *http.Request) {
 	content += "<p></p><h3>In-world results:</h3>"
 
 	// prepare the call to the agent (OpenSimulator NPC)
-	//  HTTP request as per http://moazzam-khan.com/blog/golang-make-http-requests/
-    body := []byte("command=" + r.Form.Get("command") + "&" + 
+    body := "command=" + r.Form.Get("command") + "&" + 
     	r.Form.Get("param1") + "=" + r.Form.Get("data1") + "&" +
-    	r.Form.Get("param2") + "=" + r.Form.Get("data2"))
+    	r.Form.Get("param2") + "=" + r.Form.Get("data2")
+
+    rsBody, err := callURL(r.Form.Get("PermURL"), body)
+    if (err != nil) {
+	    content += "<p class=\"text-danger\">" + rsBody + "</p>"
+    } else {
+	    content += "<p class=\"text-success\">" + rsBody + "</p>"
+    }
 
     log.Printf("Sending to in-world object %s ... %s\n", r.Form.Get("PermURL"), body) // debug
 
+    /*
     rs, err := http.Post(r.Form.Get("PermURL"), "body/type", bytes.NewBuffer(body))
     // Code to process response (written in Get request snippet) goes here
 
@@ -556,6 +563,7 @@ func backofficeCommandsExec(w http.ResponseWriter, r *http.Request) {
 	    log.Printf("Reply from in-world object %s\n", rsBody)
 		content += "<p class=\"text-success\">" + string(rsBody) + "</p>"
 	}
+	*/
 
 	tplParams := templateParameters{ "Title": "Gobot Administrator Panel - Commands Exec Result",
 		"Preamble": template.HTML("<p>Results coming from in-world object:</p>"),

engine.go

@@ -2,18 +2,20 @@
 package main
 
 import (
+	_ "github.com/mattn/go-sqlite3"
+	"bytes"	
 	"database/sql"
+	"encoding/json"
 	"fmt"
-	_ "github.com/mattn/go-sqlite3"
+	"golang.org/x/net/websocket"
+	"gopkg.in/guregu/null.v3/zero"
+	"html/template"
+	"io/ioutil"
 	"log"
 	"net/http"
-	"time"
-	"html/template"
-	"golang.org/x/net/websocket"
 	"strings"
-	"encoding/json"
-	"gopkg.in/guregu/null.v3/zero"
 	"sync/atomic" // used for sync'ing values across goroutines at a low level
+	"time"
 )
 
 // Define a communications procotol with the client, so that we can selectively
@@ -158,7 +160,7 @@ func backofficeEngine(w http.ResponseWriter, r *http.Request) {
 	rows, err = db.Query("SELECT Name, OwnerKey, Location, Position FROM Agents ORDER BY Name")
 	checkErr(err)
 
-	defer rows.Close()
+	// defer rows.Close() // already deferred above
 
 	var ownerKey, agentNames = "", ""
 
@@ -172,6 +174,7 @@ func backofficeEngine(w http.ResponseWriter, r *http.Request) {
 		agentNames += fmt.Sprintf("\t\t\t\t\t\t\t\t\t\t\t\t\t<option value=\"%s\">%s  (%s) [%s (%s,%s,%s)]</option>\n", ownerKey, name, ownerKey, regionName, xyz)
 	}
 
+	rows.Close() // closing after deferring to close is probably not good, but I'll try it anyway (20170723)
 	db.Close()
 
 	tplParams := templateParameters{ "Title": "Gobot Administrator Panel - engine",
@@ -301,11 +304,15 @@ func engine() {
 	db, err := sql.Open(PDO_Prefix, SQLiteDBFilename)
 	checkErr(err)
 
+	defer db.Close() // needed?
+
 	// load in Agents! We need them to call the movement algorithm for each one
 	// BUG(gwyneth): what if the number of agents _change_ while we're running the engine? We need a way to reset the engine somehow. We have a hack at the moment: send a SIGCONT, it will try to restart the engine in a new goroutine
 	rows, err := db.Query("SELECT * FROM Agents ORDER BY Name") // can't hurt much to let the DB engine sort it, that way we humans have an idea on how far we've progressed when adding agents
 	checkErr(err)
 
+	defer rows.Close() // needed?
+
 	for rows.Next() {
 		err = rows.Scan(
 			&Agent.UUID,
@@ -352,13 +359,14 @@ func engine() {
 				// We need to refresh all the data about cubes and positions again!
 
 				// do stuff while it runs, e.g. open databases, search for agents and so forth
-
+/*				
 				log.Println("Reloading database for Cubes (Positions) and Obstacles...")
 				
 				// Open database
 				db, err = sql.Open(PDO_Prefix, SQLiteDBFilename)
 				checkErr(err)
 				
+				defer db.Close() // needed?
 				
 				// Load in the 'special' objects (cubes). Because the Master Controllers can be somewhere in here, to save code.
 				//  and a database query, we simply skip all the Master Controllers until we get the most recent one, which gets saved
@@ -369,6 +377,8 @@ func engine() {
 				rows, err = db.Query("SELECT * FROM Positions ORDER BY LastUpdate ASC")
 				checkErr(err)
 						
+				defer rows.Close() // needed?
+						
 				for rows.Next() {
 					err = rows.Scan(
 						&Position.PermURL,
@@ -425,35 +435,17 @@ func engine() {
 					Objects = append(Objects, Object)
 				}
 				
-				// Debug stuff. Delete it after usage.
-				/*
-				var marshalled []byte = []byte("Kablooie! JSON blew up everything! No data available...")
-				marshalled, err = json.MarshalIndent(Objects, "", " ")
-				checkErr(err)
-				log.Println("Objects", marshalled)
-				sendMessageToBrowser("status", "info", fmt.Sprintf("Objects: %s<br />", marshalled), "")
-				marshalled, err = json.MarshalIndent(Agents, "", " ")
-				checkErr(err)
-				log.Println("Agents", marshalled)
-				sendMessageToBrowser("status", "info", fmt.Sprintf("Agents: %s<br />", marshalled ), "")
-				marshalled, err = json.MarshalIndent(Cubes, "", " ")
-				checkErr(err)
-				log.Println("Cubes", marshalled)
-				sendMessageToBrowser("status", "info", fmt.Sprintf("Cubes: %s<br />", marshalled), "")
-				marshalled, err = json.MarshalIndent(masterController, "", " ")
-				checkErr(err)
-				log.Println("Master Bot Controller", marshalled)
-				sendMessageToBrowser("status", "info", fmt.Sprintf("Master Bot Controller: %s<br />", marshalled), "")
-				*/
-				// debugging stuff ends here
-
 				// release DB resources before we start our job
 				rows.Close()
 				db.Close()
 				
 				// Do not trust the database with the exact Agent position: ask the master controller directly
-				log.Println(*masterController.PermURL.Ptr())
-
+				// log.Println(*masterController.PermURL.Ptr())
+*/				
+				log.Println(masterController, Position, Cubes, Object, Objects)
+				//curposResult, _ := callURL(*masterController.PermURL.Ptr(), "npc=" + *Agent.OwnerKey.Ptr() + "&command=osNpcGetPos");
+				//sendMessageToBrowser("status", "info", "<p class='box'>Grid reports that agent " + *Agent.Name.Ptr() + " is at position: " + curposResult + "</p>\n", "") 
+				//log.Println("Grid reports that agent", *Agent.Name.Ptr(), "is at position:", curposResult)
 
 				// output something to console so that we know this is being run in parallel
 			    fmt.Print("\r|")
@@ -499,4 +491,25 @@ func sendMessageToBrowser(msgType string, msgSubType string, msgText string, msg
 	    case <-time.After(time.Second * 10):
 	        fmt.Println("timeout after 10 seconds; coudn't send:", string(marshalled))
 	}
+}
+
+// callURL encapsulates a call to an URL. It exists as an analogy to the PHP version (20170723).
+func callURL(url string, encodedRequest string) (string, error) {
+	//  HTTP request as per http://moazzam-khan.com/blog/golang-make-http-requests/
+	body := []byte(encodedRequest)
+
+    rs, err := http.Post(url, "body/type", bytes.NewBuffer(body))
+    // Code to process response (written in Get request snippet) goes here
+
+	defer rs.Body.Close()
+
+	rsBody, err := ioutil.ReadAll(rs.Body)
+	if (err != nil) {
+		errMsg := fmt.Sprintf("Error response from in-world object: %s", err)
+		log.Println(errMsg)
+		return errMsg, err
+	} else {
+	    log.Printf("Reply from in-world object %s\n", rsBody)
+		return string(rsBody), err
+	}	
 }

gobot.go

@@ -2,19 +2,19 @@
 package main
 
 import (
+	_ "github.com/mattn/go-sqlite3"
 	"database/sql"
 	"fmt"
-	_ "github.com/mattn/go-sqlite3"
+	"github.com/Pallinder/go-randomdata"
 	"github.com/spf13/viper" // to read config files
-	"net/http"
+	"golang.org/x/net/websocket"
 	"log"
-	"os/user"
-	"path/filepath"
+	"net/http"
 	"os"
 	"os/signal"
+	"os/user"
+	"path/filepath"
 	"syscall"
-	"golang.org/x/net/websocket"
-	"github.com/Pallinder/go-randomdata"
 )
 
 

inworld.go

@@ -162,7 +162,6 @@ func registerPosition(w http.ResponseWriter, r *http.Request) {
 	checkErrPanicHTTP(w, http.StatusServiceUnavailable, funcName() + ": Extracting parameters failed: %s\n", err)
 	log.Println("Received: ", r)
 
-
 	if r.Header.Get("X-Secondlife-Object-Key") == "" {
 		// fmt.Printf("Got '%s'\n", r.Header["X-Secondlife-Object-Key"])
 		logErrHTTP(w, http.StatusForbidden, funcName() + ": Not called from within the virtual world.") 

ui.go

@@ -106,6 +106,7 @@ func uiObjects(w http.ResponseWriter, r *http.Request) {
 		rowArr = append(rowArr, Object)
 	}
 	checkErr(err)
+	defer rows.Close()
 
 	// produces neatly indented output; see https://blog.golang.org/json-and-go but especially http://stackoverflow.com/a/37084385/1035977
 	if data, err := json.MarshalIndent(rowArr, "", " "); err != nil {
@@ -232,6 +233,7 @@ func uiAgents(w http.ResponseWriter, r *http.Request) {
 		rowArr = append(rowArr, Agent)
 	}
 	checkErr(err)
+	defer rows.Close()
 
 	if data, err := json.MarshalIndent(rowArr, "", " "); err != nil {
 		checkErr(err)
@@ -343,6 +345,7 @@ func uiPositions(w http.ResponseWriter, r *http.Request) {
 		rowArr = append(rowArr, Position)
 	}
 	checkErr(err)
+	defer rows.Close()
 
 	if data, err := json.MarshalIndent(rowArr, "", " "); err != nil {
 		checkErr(err)
@@ -432,6 +435,7 @@ func uiInventory(w http.ResponseWriter, r *http.Request) {
 		rowArr = append(rowArr, Inventory)
 	}
 	checkErr(err)
+	defer rows.Close()
 
 	if data, err := json.MarshalIndent(rowArr, "", " "); err != nil {
 		checkErr(err)
@@ -514,6 +518,7 @@ func uiUserManagement(w http.ResponseWriter, r *http.Request) {
 		rowArr = append(rowArr, UserManagement)
 	}
 	checkErr(err)
+	defer rows.Close()
 
 	if data, err := json.MarshalIndent(rowArr, "", " "); err != nil {
 		checkErr(err)