Finally finished

subprocess/request.go

@@ -12,7 +12,8 @@ import (
 )
 
 /* Stores a map between job ID and a string pointer. Nil for job not done yet */
-var waitingJobs map[string]*string = make (map[string]*string);
+var waitingJobs map[string]*string = make(map[string]*string);
+/* Mutex for waitingJobs list */
 var waitingJobsMutex sync.RWMutex;
 
 /* Method which module http calls to forward the request to the subprocess*/
@@ -23,6 +24,7 @@ func Request(body map[string]any) (responseJSON string, err error) {
 	}
 	
 	// Generate ID and store it
+	// 32 chars of base 64 is secure enough to assume no accidental collision
 	var id string = genID();
 	if len(id) == 0 {
 		err = errors.New("Error generating ID!");
@@ -42,35 +44,55 @@ func Request(body map[string]any) (responseJSON string, err error) {
 	waitingJobs[id] = nil;
 	waitingJobsMutex.Unlock();
 	
+	// Timeout waiting for response after 30 seconds
+	timeoutTime := time.Now().Add(time.Second * 30);
+	
 	// Wait for request to return
 	for {
+		// Check every milisecond
 		time.Sleep(time.Millisecond)
+		
+		// check if job is fufiled
 		waitingJobsMutex.RLock();
 		if waitingJobs[id] != nil {
 			waitingJobsMutex.RUnlock();
 			break;
 		}
 		waitingJobsMutex.RUnlock();
+		
+		// If request takes more than 30 seconds
+		/* This is technically a race condition, as the job could be fufiled
+		    between here and the job fufiled check, but it's the difference of
+			a milisecond or two out of 30 seconds */
+		if time.Now().After(timeoutTime) {
+			// Delete job from queue
+			waitingJobsMutex.Lock();
+			delete(waitingJobs, id)
+			waitingJobsMutex.Unlock();
+			return "", errors.New("Request timed out!");
+		}
 	}
 	
 	// Lock job when dequeueing
 	waitingJobsMutex.Lock();
 	responseJSON = *waitingJobs[id];
-	delete(waitingJobs, id)
+	delete(waitingJobs, id) // Remove job from "queue"
 	waitingJobsMutex.Unlock();
 	
-	err = nil;
+	err = nil; // No problems
 	return;
 }
 
 /* Handles putting a response into waitingJobs. Returns false on error */
 func handleResponse(body string, unmarshaledJSONMap map[string]any) {
+	waitingJobsMutex.RLock(); // Read lock
 	val, ok := unmarshaledJSONMap["id"];
+	waitingJobsMutex.RUnlock();
 	if !ok {return}
 	id, ok := val.(string)
 	if !ok {return}
 	
-	// Read-Write lock the mutex
+	// Read-Write lock the mutex when writing job result
 	waitingJobsMutex.Lock();
 	defer waitingJobsMutex.Unlock();