From d2b6b96df63ac92e5456bc34f5c71ef464e023c3 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Fri, 25 Jan 2019 11:03:15 +0100
Subject: [PATCH] Explicitly use clientID for newOVerTimeClient() instead of
 using the private variable overTimeClientCount to avoid (possibly)
 error-prone double-entry bookkeeping.

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 datastructure.c |  7 ++++---
 routines.h      |  2 +-
 shmem.c         | 20 +++++++++-----------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/datastructure.c b/datastructure.c
index 18cb871a..a8dab52b 100644
--- a/datastructure.c
+++ b/datastructure.c
@@ -218,11 +218,12 @@ int findClientID(const char *client)
 	// to be done separately to be non-blocking
 	clients[clientID].new = true;
 	clients[clientID].namepos = 0;
-	// Increase counter by one
-	counters->clients++;
 
 	// Create new overTime client data
-	newOverTimeClient();
+	newOverTimeClient(clientID);
+
+	// Increase counter by one
+	counters->clients++;
 
 	return clientID;
 }
diff --git a/routines.h b/routines.h
index b4ad082b..49b518f3 100644
--- a/routines.h
+++ b/routines.h
@@ -119,7 +119,7 @@ void *enlarge_shmem_struct(char type);
  * Create a new overTime client shared memory block.
  * This also updates `overTimeClientData`.
  */
-void newOverTimeClient();
+void newOverTimeClient(int clientID);
 
 /**
  * Add a new overTime slot to each overTime client shared memory block.
diff --git a/shmem.c b/shmem.c
index dd7b1e6f..afbeb3d0 100644
--- a/shmem.c
+++ b/shmem.c
@@ -33,7 +33,6 @@ static SharedMemory shm_forwarded = { 0 };
 static SharedMemory shm_overTime = { 0 };
 
 static SharedMemory *shm_overTimeClients = NULL;
-static int overTimeClientCount = 0;
 
 typedef struct {
 	pthread_mutex_t lock;
@@ -88,33 +87,32 @@ static char *clientShmName(int id) {
 	return name;
 }
 
-void newOverTimeClient() {
+void newOverTimeClient(int clientID) {
 	// Get the name of the new shared memory.
 	// This will be used in the struct, so it should not be immediately freed.
-	char *name = clientShmName(overTimeClientCount);
+	char *name = clientShmName(clientID);
 
 	// Create the shared memory with enough space for the current overTime slots
 	shm_unlink(name);
 	SharedMemory shm = create_shm(name, (counters->overTime/pagesize + 1)*pagesize*sizeof(int));
 	if(shm.ptr == NULL) {
 		free(shm.name);
-		logg("Failed to initialize new overTime client %d", overTimeClientCount);
+		logg("Failed to initialize new overTime client %d", clientID);
 		return;
 	}
 
 	// Make space for the new shared memory
-	shm_overTimeClients = realloc(shm_overTimeClients, sizeof(SharedMemory) * (overTimeClientCount + 1));
-	overTimeClientCount++;
-	shm_overTimeClients[overTimeClientCount-1] = shm;
+	shm_overTimeClients = realloc(shm_overTimeClients, sizeof(SharedMemory) * (clientID + 1));
+	shm_overTimeClients[clientID] = shm;
 
 	// Add to overTimeClientData
-	overTimeClientData = realloc(overTimeClientData, sizeof(int*) * (overTimeClientCount));
-	overTimeClientData[overTimeClientCount-1] = shm.ptr;
+	overTimeClientData = realloc(overTimeClientData, sizeof(int*) * (clientID + 1));
+	overTimeClientData[clientID] = shm.ptr;
 }
 
 void addOverTimeClientSlot() {
 	// For each client slot, add pagesize overTime slots
-	for(int i = 0; i < overTimeClientCount; i++)
+	for(int i = 0; i < counters->clients; i++)
 	{
 		// Only increase the size of the shm object if needed
 		// shm_overTimeClients[i].size stores the size of the memory in bytes whereas
@@ -276,7 +274,7 @@ void destroy_shmem(void)
 	delete_shm(&shm_forwarded);
 	delete_shm(&shm_overTime);
 
-	for(int i = 0; i < overTimeClientCount; i++) {
+	for(int i = 0; i < counters->clients; i++) {
 		delete_shm(&shm_overTimeClients[i]);
 		free(shm_overTimeClients[i].name);
 	}