diff --git a/include/myclib/hashmap/myhashmap.c b/include/myclib/hashmap/myhashmap.c
index 4208413..ddaf5cb 100644
--- a/include/myclib/hashmap/myhashmap.c
+++ b/include/myclib/hashmap/myhashmap.c
@@ -1,9 +1,12 @@
 #include "myhashmap.h"
 
+#include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+static size_t mcl_get_mutex(mcl_hashmap *hashmap, size_t hash) { return hash % hashmap->num_locks; }
+
 static size_t mcl_get_bucket_index(mcl_hashmap *hashmap, void *key) {
 	unsigned int hash = hashmap->hash_fn(key);
 	return hash % MYCLIB_HASHMAP_SIZE;
@@ -62,6 +65,28 @@ mcl_hashmap *mcl_hm_init(mcl_hash_fn *hash_fn, mcl_equal_fn *equal_fn, mcl_free_
 	hashmap->key_size = key_size;
 	hashmap->value_size = value_size;
 
+	hashmap->num_locks = 64;
+	hashmap->locks = malloc(sizeof(pthread_mutex_t) * hashmap->num_locks);
+	if (hashmap->locks == NULL) {
+		free(hashmap);
+
+		return NULL;
+	}
+
+	int ret;
+	for (size_t i = 0; i < hashmap->num_locks; ++i) {
+		ret = pthread_mutex_init(&(hashmap->locks[i]), NULL);
+		if (ret != 0) {
+			/* Mutex failed */
+			for (size_t j = 0; j < i; ++j) {
+				pthread_mutex_destroy(&(hashmap->locks[j]));
+			}
+
+			free(hashmap->locks);
+			free(hashmap);
+		}
+	}
+
 	memset(hashmap->map, 0, sizeof(hashmap->map));
 
 	return hashmap;
@@ -91,15 +116,35 @@ void mcl_hm_free(mcl_hashmap *hashmap) {
 		}
 	}
 
+	/* Free the mutex */
+	for (size_t i = 0; i < hashmap->num_locks; ++i) {
+		pthread_mutex_destroy(&(hashmap->locks[i]));
+	}
+	free(hashmap->locks);
+
 	/* Free the hash map structure itself */
 	free(hashmap);
 }
 
+void mcl_hm_free_bucket(mcl_bucket *bucket) {
+	if (bucket == NULL) {
+		return;
+	}
+
+	free(bucket->key);
+	free(bucket->value);
+	free(bucket);
+}
+
 bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 	if (hashmap == NULL || key == NULL || value == NULL) {
 		return false;
 	}
 
+	size_t mutex_id = mcl_get_mutex(hashmap, hashmap->hash_fn(key));
+	pthread_mutex_t *mutex = &(hashmap->locks[mutex_id]);
+	pthread_mutex_lock(mutex);
+
 	mcl_bucket *prev;
 	mcl_bucket *existing = mcl_find_bucket(hashmap, key, &prev);
 
@@ -111,9 +156,14 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 
 		existing->value = malloc(hashmap->value_size);
 		if (existing->value == NULL) {
+			pthread_mutex_unlock(mutex);
+
 			return false;
 		}
+
 		memcpy(existing->value, value, hashmap->value_size);
+		pthread_mutex_unlock(mutex);
+
 		return true;
 	}
 
@@ -125,6 +175,8 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 		/* First bucket is empty, use it */
 		bucket->key = malloc(hashmap->key_size);
 		if (bucket->key == NULL) {
+			pthread_mutex_unlock(mutex);
+
 			return false;
 		}
 
@@ -132,24 +184,32 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 		if (bucket->value == NULL) {
 			free(bucket->key);
 			bucket->key = NULL;
+			pthread_mutex_unlock(mutex);
+
 			return false;
 		}
 
 		memcpy(bucket->key, key, hashmap->key_size);
 		memcpy(bucket->value, value, hashmap->value_size);
 		bucket->next = NULL;
+		pthread_mutex_unlock(mutex);
+
 		return true;
 	}
 
 	/* Create new bucket and insert at head of collision chain */
 	mcl_bucket *new_bucket = malloc(sizeof(mcl_bucket));
 	if (new_bucket == NULL) {
+		pthread_mutex_unlock(mutex);
+
 		return false;
 	}
 
 	new_bucket->key = malloc(hashmap->key_size);
 	if (new_bucket->key == NULL) {
 		free(new_bucket);
+		pthread_mutex_unlock(mutex);
+
 		return false;
 	}
 
@@ -157,6 +217,8 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 	if (new_bucket->value == NULL) {
 		free(new_bucket->key);
 		free(new_bucket);
+		pthread_mutex_unlock(mutex);
+
 		return false;
 	}
 
@@ -164,17 +226,61 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value) {
 	memcpy(new_bucket->value, value, hashmap->value_size);
 	new_bucket->next = bucket->next;
 	bucket->next = new_bucket;
+	pthread_mutex_unlock(mutex);
 
 	return true;
 }
 
+static mcl_bucket *mcl_get_bucket_copy(mcl_bucket *from, size_t key_size, size_t value_size) {
+	mcl_bucket *copy = malloc(sizeof(mcl_bucket));
+	if (copy == NULL) {
+		return NULL;
+	}
+	memcpy(copy, from, sizeof(mcl_bucket));
+
+	copy->key = malloc(key_size);
+	if (copy->key == NULL) {
+		free(copy);
+
+		return NULL;
+	}
+	memcpy(copy->key, from->key, key_size);
+
+	copy->value = malloc(value_size);
+	if (copy->value == NULL) {
+		free(copy->key);
+		free(copy);
+
+		return NULL;
+	}
+	memcpy(copy->value, from->value, value_size);
+
+	return copy;
+}
+
 mcl_bucket *mcl_hm_get(mcl_hashmap *hashmap, void *key) {
 	if (hashmap == NULL || key == NULL) {
 		return NULL;
 	}
 
+	size_t mutex_id = mcl_get_mutex(hashmap, hashmap->hash_fn(key));
+	pthread_mutex_t *mutex = &(hashmap->locks[mutex_id]);
+	pthread_mutex_lock(mutex);
+
 	mcl_bucket *prev;
-	return mcl_find_bucket(hashmap, key, &prev);
+	mcl_bucket *found = mcl_find_bucket(hashmap, key, &prev);
+
+	if (found) {
+		mcl_bucket *copy = mcl_get_bucket_copy(found, hashmap->key_size, hashmap->value_size);
+
+		pthread_mutex_unlock(mutex);
+
+		return copy;
+	}
+
+	pthread_mutex_unlock(mutex);
+
+	return NULL;
 }
 
 bool mcl_hm_remove(mcl_hashmap *hashmap, void *key) {
@@ -182,10 +288,16 @@ bool mcl_hm_remove(mcl_hashmap *hashmap, void *key) {
 		return false;
 	}
 
+	size_t mutex_id = mcl_get_mutex(hashmap, hashmap->hash_fn(key));
+	pthread_mutex_t *mutex = &(hashmap->locks[mutex_id]);
+	pthread_mutex_lock(mutex);
+
 	mcl_bucket *prev;
 	mcl_bucket *to_remove = mcl_find_bucket(hashmap, key, &prev);
 
 	if (to_remove == NULL) {
+		pthread_mutex_unlock(mutex);
+
 		return false;
 	}
 
@@ -214,5 +326,7 @@ bool mcl_hm_remove(mcl_hashmap *hashmap, void *key) {
 		free(to_remove);
 	}
 
+	pthread_mutex_unlock(mutex);
+
 	return true;
 }
diff --git a/include/myclib/hashmap/myhashmap.h b/include/myclib/hashmap/myhashmap.h
index b1e546f..3826603 100644
--- a/include/myclib/hashmap/myhashmap.h
+++ b/include/myclib/hashmap/myhashmap.h
@@ -1,6 +1,7 @@
 #ifndef MYCLIB_HASHMAP_H
 #define MYCLIB_HASHMAP_H
 
+#include <pthread.h>
 #include <stdbool.h>
 #include <stddef.h>
 
@@ -63,6 +64,8 @@ typedef struct mcl_hashmap_t {
 	size_t key_size;					 /**< Size in bytes of the key */
 	size_t value_size;					 /**< Size in bytes of the value */
 	mcl_bucket map[MYCLIB_HASHMAP_SIZE]; /**< Array of bucket chains */
+	pthread_mutex_t *locks;				 /**< Mutex array */
+	size_t num_locks;					 /**< Number of mutex */
 } mcl_hashmap;
 
 /**
@@ -93,6 +96,13 @@ mcl_hashmap *mcl_hm_init(mcl_hash_fn *hash_fn, mcl_equal_fn *equal_fn, mcl_free_
  */
 void mcl_hm_free(mcl_hashmap *hashmap);
 
+/**
+ * @brief Free a bucket returned by mcl_hm_get()
+ *
+ * @param[in] bucket Pointer to the bucket to free
+ */
+void mcl_hm_free_bucket(mcl_bucket *bucket);
+
 /**
  * @brief Insert or update a key-value pair in the hash map
  *
@@ -115,7 +125,7 @@ bool mcl_hm_set(mcl_hashmap *hashmap, void *key, void *value);
  *
  * @param[in] hashmap Pointer to the hash map
  * @param[in] key Pointer to the key to search for
- * @return Pointer to the found bucket, or NULL if not found or on invalid input
+ * @return Pointer to the copy of the bucket, to avoid race conditions, or NULL if not found or on invalid input
  */
 mcl_bucket *mcl_hm_get(mcl_hashmap *hashmap, void *key);
 
diff --git a/include/myclib/queue/myqueue.c b/include/myclib/queue/myqueue.c
new file mode 100644
index 0000000..49fe73e
--- /dev/null
+++ b/include/myclib/queue/myqueue.c
@@ -0,0 +1,89 @@
+#include "myqueue.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+mcl_queue *mcl_queue_init(size_t queue_size, size_t elem_size) {
+	mcl_queue *queue = malloc(sizeof(mcl_queue));
+	if (queue == NULL) {
+		return NULL;
+	}
+
+	queue->buffer = malloc(queue_size * elem_size);
+	if (queue->buffer == NULL) {
+		free(queue);
+
+		return NULL;
+	}
+
+	queue->front = 0;
+	queue->rear = 0;
+	queue->size = 0;
+	queue->capacity = queue_size;
+	queue->elem_size = elem_size;
+
+	return queue;
+}
+
+int mcl_queue_push(mcl_queue *queue, const void *elem) {
+	if (queue->size == queue->capacity) {
+		/* Queue full */
+		return -1;
+	}
+
+	/* Copy the elem in the buffer */
+	void *dest = (void *)queue->buffer + (queue->rear * queue->elem_size);
+	memcpy(dest, elem, queue->elem_size);
+
+	queue->size++;
+	queue->rear = (queue->rear + 1) % queue->capacity;
+
+	return 0;
+}
+
+int mcl_queue_pop(mcl_queue *queue, void *out_elem) {
+	if (queue->size == 0) {
+		/* Queue empty */
+		return -1;
+	}
+
+	void *src = (void *)queue->buffer + (queue->front * queue->elem_size);
+	memcpy(out_elem, src, queue->elem_size);
+
+	queue->front = (queue->front + 1) % queue->capacity;
+	queue->size--;
+
+	return 0;
+}
+
+void *mcl_queue_get_front(mcl_queue *queue) {
+	if (queue->size == 0) {
+		return NULL;
+	}
+
+	return (void *)queue->buffer + (queue->front * queue->elem_size);
+}
+
+void *mcl_queue_get_rear(mcl_queue *queue) {
+	if (queue->size == 0) {
+		return NULL;
+	}
+
+	size_t rear_index;
+	if (queue->rear == 0) {
+		rear_index = queue->capacity - 1;
+	} else {
+		rear_index = queue->rear - 1;
+	}
+
+	return (void *)queue->buffer + (rear_index * queue->elem_size);
+}
+
+void mcl_queue_free(mcl_queue *queue) {
+	if (queue == NULL) {
+		return;
+	}
+
+	free(queue->buffer);
+	free(queue);
+}
diff --git a/include/myclib/queue/myqueue.h b/include/myclib/queue/myqueue.h
new file mode 100644
index 0000000..42d4bfd
--- /dev/null
+++ b/include/myclib/queue/myqueue.h
@@ -0,0 +1,68 @@
+#ifndef MYCLIB_QUEUE_H
+#define MYCLIB_QUEUE_H
+
+#include <stddef.h>
+
+/**
+ * @brief A generic circular queue (ring buffer).
+ */
+typedef struct mcl_queue_t {
+	size_t front;	  /**< Index of the first element (read position). */
+	size_t rear;	  /**< Index where the next element will be written (write position). */
+	size_t size;	  /**< Current number of elements in the queue. */
+	size_t capacity;  /**< Maximum number of elements the queue can hold. */
+	size_t elem_size; /**< Size in bytes of each element in the queue. */
+	void *buffer;	  /**< Pointer to the memory buffer that stores the elements. */
+} mcl_queue;
+
+/**
+ * @brief Create and initialize a new queue.
+ *
+ * @param queue_size Number of elements the queue can hold.
+ * @param elem_size Size (in bytes) of each element in the queue.
+ * @return Pointer to the new queue, or NULL if allocation fails.
+ */
+mcl_queue *mcl_queue_init(size_t queue_size, size_t elem_size);
+
+/**
+ * @brief Add an element to the queue.
+ *
+ * @param queue Pointer to the queue.
+ * @param elem Pointer to the element to insert.
+ * @return 0 on success, -1 if the queue is full.
+ */
+int mcl_queue_push(mcl_queue *queue, const void *elem);
+
+/**
+ * @brief Remove an element from the queue.
+ *
+ * @param queue Pointer to the queue.
+ * @param out_elem Pointer where the removed element will be copied.
+ * @return 0 on success, -1 if the queue is empty.
+ */
+int mcl_queue_pop(mcl_queue *queue, void *out_elem);
+
+/**
+ * @brief Get a pointer to the front element of the queue (oldest one).
+ *
+ * @param queue Pointer to the queue.
+ * @return Pointer to the front element, or NULL if the queue is empty.
+ */
+void *mcl_queue_get_front(mcl_queue *queue);
+
+/**
+ * @brief Get a pointer to the rear element of the queue (most recently added).
+ *
+ * @param queue Pointer to the queue.
+ * @return Pointer to the rear element, or NULL if the queue is empty.
+ */
+void *mcl_queue_get_rear(mcl_queue *queue);
+
+/**
+ * @brief Free all memory used by the queue.
+ *
+ * @param queue Pointer to the queue to free.
+ */
+void mcl_queue_free(mcl_queue *queue);
+
+#endif
diff --git a/include/myclib/string/mystring.c b/include/myclib/string/mystring.c
index 2e979fc..fbc3400 100644
--- a/include/myclib/string/mystring.c
+++ b/include/myclib/string/mystring.c
@@ -1,17 +1,26 @@
 #include "mystring.h"
 
 #include <math.h>
+#include <pthread.h>
 #include <stdlib.h>
 #include <string.h>
 
 mcl_string *mcl_string_new(const char *text, long initial_capacity) {
-	if (!text) {
+	if (text == NULL) {
 		return NULL;
 	}
 
 	/* Allocate string struct */
 	mcl_string *str = malloc(sizeof(mcl_string));
-	if (!str) {
+	if (str == NULL) {
+		return NULL;
+	}
+
+	/* Init pthread mutex */
+	int ret = pthread_mutex_init(&str->lock, NULL);
+	if (ret != 0) {
+		free(str);
+
 		return NULL;
 	}
 
@@ -20,6 +29,8 @@ mcl_string *mcl_string_new(const char *text, long initial_capacity) {
 	size_t capacity = initial_capacity;
 
 	if (capacity != -1 && capacity - 1 < str->size) {
+		free(str);
+
 		return NULL;
 	}
 
@@ -31,7 +42,7 @@ mcl_string *mcl_string_new(const char *text, long initial_capacity) {
 
 	/* Allocate data buffer */
 	str->data = malloc(sizeof(char) * str->capacity);
-	if (!str->data) {
+	if (str->data == NULL) {
 		free(str);
 
 		return NULL;
@@ -46,13 +57,21 @@ mcl_string *mcl_string_new(const char *text, long initial_capacity) {
 }
 
 int mcl_string_append(mcl_string *string, const char *text) {
-	if (!string || !text) {
+	if (string == NULL || text == NULL) {
+		return -1;
+	}
+
+	/* Lock resource */
+	int ret = pthread_mutex_lock(&string->lock);
+	if (ret != 0) {
 		return -1;
 	}
 
 	/* Handle empty case */
 	size_t text_len = strlen(text);
 	if (text_len == 0) {
+		pthread_mutex_unlock(&string->lock);
+
 		return 0;
 	}
 
@@ -64,6 +83,8 @@ int mcl_string_append(mcl_string *string, const char *text) {
 		/* Reallocate the buffer */
 		void *new_data = realloc(string->data, sizeof(char) * new_capacity);
 		if (!new_data) {
+			pthread_mutex_unlock(&string->lock);
+
 			return -1;
 		}
 
@@ -79,11 +100,22 @@ int mcl_string_append(mcl_string *string, const char *text) {
 	string->size = new_size;
 	string->data[string->size] = '\0';
 
+	/* Unlock resource */
+	ret = pthread_mutex_unlock(&string->lock);
+	if (ret != 0) {
+		return -1;
+	}
+
 	return 0;
 }
 
 void mcl_string_free(mcl_string *string) {
-	if (!string) {
+	if (string == NULL) {
+		return;
+	}
+
+	int ret = pthread_mutex_lock(&string->lock);
+	if (ret != 0) {
 		return;
 	}
 
@@ -91,29 +123,59 @@ void mcl_string_free(mcl_string *string) {
 		free(string->data);
 	}
 
+	pthread_mutex_unlock(&string->lock);
+	pthread_mutex_destroy(&string->lock);
+
 	free(string);
 }
 
-size_t mcl_string_length(const mcl_string *string) {
-	if (!string) {
+size_t mcl_string_length(mcl_string *string) {
+	if (string == NULL) {
 		return 0;
 	}
 
-	return string->size;
-}
-
-size_t mcl_string_capacity(const mcl_string *string) {
-	if (!string) {
+	int ret = pthread_mutex_lock(&string->lock);
+	if (ret != 0) {
 		return 0;
 	}
 
-	return string->capacity;
+	size_t len = string->size;
+
+	pthread_mutex_unlock(&string->lock);
+
+	return len;
 }
 
-const char *mcl_string_cstr(const mcl_string *string) {
-	if (!string || !string->data) {
+size_t mcl_string_capacity(mcl_string *string) {
+	if (string == NULL) {
+		return 0;
+	}
+
+	int ret = pthread_mutex_lock(&string->lock);
+	if (ret != 0) {
+		return 0;
+	}
+
+	size_t cap = string->capacity;
+
+	pthread_mutex_unlock(&string->lock);
+
+	return cap;
+}
+
+const char *mcl_string_cstr(mcl_string *string) {
+	if (string == NULL || string->data == NULL) {
 		return "";
 	}
 
-	return string->data;
+	int ret = pthread_mutex_lock(&string->lock);
+	if (ret != 0) {
+		return NULL;
+	}
+
+	char *data = string->data;
+
+	pthread_mutex_unlock(&string->lock);
+
+	return data;
 }
diff --git a/include/myclib/string/mystring.h b/include/myclib/string/mystring.h
index f6daa54..b13d40b 100644
--- a/include/myclib/string/mystring.h
+++ b/include/myclib/string/mystring.h
@@ -1,25 +1,27 @@
 #ifndef MYCLIB_STRING_H
 #define MYCLIB_STRING_H
 
+#include <pthread.h>
 #include <stddef.h>
 
 /**
- * @brief String structure
+ * @brief Thread-safe dynamic string structure
  */
 typedef struct mcl_string_t {
-	size_t size;	 /**< Length of the string (excluding null terminator) */
-	size_t capacity; /**< Total allocated capacity */
-	char *data;		 /**< Pointer to the string data */
+	size_t size;		  /**< Current length of the string (excluding null terminator) */
+	size_t capacity;	  /**< Allocated capacity */
+	char *data;			  /**< Pointer to string data */
+	pthread_mutex_t lock; /**< Mutex for thread safety */
 } mcl_string;
 
 /**
- * @brief Create a new string
+ * @brief Create a new string initialized with given text
  *
- * @param text The text to initialize from
- * @param initial_capacity The initial capacity, pass -1 to retrieve it from the text
- * @return Pointer to the new string, or NULL on failure
+ * @param text Initial text (cannot be NULL)
+ * @param initial_capacity Initial buffer capacity; pass -1 to auto-calculate
+ * @return Pointer to new string, or NULL on failure
  *
- * @note The caller is responsible for freeing the returned string with mcl_string_free() and to pass the right inital_capacity
+ * @note Caller must free the string with mcl_string_free()
  */
 mcl_string *mcl_string_new(const char *text, long initial_capacity);
 
@@ -27,47 +29,45 @@ mcl_string *mcl_string_new(const char *text, long initial_capacity);
  * @brief Append text to an existing string
  *
  * @param string The string to append to
- * @param text The string to append (can be empty)
+ * @param text Text to append (can be empty)
  * @return 0 on success, -1 on failure
  *
- * @note If it fails, the original string remains unchanged
+ * @note Original string remains unchanged if append fails
  */
 int mcl_string_append(mcl_string *string, const char *text);
 
 /**
- * @brief Free a string
+ * @brief Free a string and its resources
  *
- * @param string The string to free
- *
- * @note This function is safe to call with NULL pointers
+ * @param string String to free (NULL is safe)
  */
 void mcl_string_free(mcl_string *string);
 
 /**
  * @brief Get the current length of the string
  *
- * @param string The string to query
- * @return The length of the string, or 0 if string is NULL
+ * @param string String to query
+ * @return Length of string, or 0 if NULL
  */
-size_t mcl_string_length(const mcl_string *string);
+size_t mcl_string_length(mcl_string *string);
 
 /**
- * @brief Get the current capacity of the string
+ * @brief Get the current capacity of the string buffer
  *
- * @param string The string to query
- * @return The capacity of the string buffer, or 0 if string is NULL
+ * @param string String to query
+ * @return Capacity, or 0 if NULL
  */
-size_t mcl_string_capacity(const mcl_string *string);
+size_t mcl_string_capacity(mcl_string *string);
 
 /**
- * @brief Get a read-only string representation
+ * @brief Get a read-only C-string pointer
  *
- * @param string The string to access
- * @return Pointer to null-terminated string data, or empty string "" if string is NULL
+ * @param string String to access
+ * @return Null-terminated string pointer, or "" if NULL
  *
- * @warning The returned pointer should not be modified directly and may become
- *          invalid after any modification operation on the string
+ * @warning Do not modify returned pointer.
+ *          Pointer may become invalid after string modifications.
  */
-const char *mcl_string_cstr(const mcl_string *string);
+const char *mcl_string_cstr(mcl_string *string);
 
 #endif /* MYCLIB_STRING_H */
diff --git a/include/server/server.h b/include/server/server.h
index 828827b..986c3fb 100644
--- a/include/server/server.h
+++ b/include/server/server.h
@@ -44,11 +44,19 @@ typedef enum cws_server_ret_t {
 	CWS_SERVER_REQUEST_TOO_LARGE,
 } cws_server_ret;
 
+/* TODO: use last_activity as keep-alive */
 typedef struct cws_client_t {
 	struct sockaddr_storage addr;
 	time_t last_activity;
 } cws_client;
 
+typedef struct cws_pthread_data_t {
+	int client_fd;
+	int epfd;
+	cws_config *config;
+	mcl_hashmap *clients;
+} cws_pthread_data;
+
 /**
  * @brief Setups hints object
  *
@@ -114,6 +122,6 @@ int cws_server_accept_client(int sockfd, struct sockaddr_storage *their_sa, sock
 void cws_server_close_client(int epfd, int client_fd, mcl_hashmap *hashmap);
 
 cws_server_ret cws_server_handle_new_client(int sockfd, int epfd, mcl_hashmap *clients);
-cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashmap *clients, cws_config *config);
+void *cws_server_handle_client_data(void *arg);
 
 #endif
diff --git a/include/server/threadpool.h b/include/server/threadpool.h
new file mode 100644
index 0000000..b23b51c
--- /dev/null
+++ b/include/server/threadpool.h
@@ -0,0 +1,34 @@
+#ifndef CWS_THREADPOOL_H
+#define CWS_THREADPOOL_H
+
+#include "myclib/hashmap/myhashmap.h"
+#include "server.h"
+#include "utils/config.h"
+
+#define CWS_MAX_QUEUE_TASKS 16
+#define CWS_MAX_THREADS 16
+
+typedef struct cws_task_t {
+	int client_fd;
+	int epfd;
+	mcl_hashmap *clients;
+	cws_config *config;
+} cws_task;
+
+typedef struct cws_threadpool_t {
+	cws_task queue[CWS_MAX_QUEUE_TASKS];
+	int front, rear;
+
+	pthread_mutex_t lock;
+	pthread_cond_t cond;
+	pthread_t threads[CWS_MAX_THREADS];
+
+	int shutdown;
+} cws_threadpool;
+
+cws_threadpool *cws_threadpool_init();
+cws_server_ret cws_threadpool_add_task(cws_threadpool *pool, cws_task *task);
+cws_server_ret cws_threadpool_worker(cws_threadpool *pool);
+cws_server_ret cws_threadpool_destroy(cws_threadpool *pool);
+
+#endif
diff --git a/src/http/http.c b/src/http/http.c
index 1f0d9fb..f60b516 100644
--- a/src/http/http.c
+++ b/src/http/http.c
@@ -64,7 +64,7 @@ cws_http *cws_http_parse(mcl_string *request_str, int sockfd, cws_config *config
 
 		return NULL;
 	}
-	//CWS_LOG_DEBUG("method: %s", pch);
+	// CWS_LOG_DEBUG("method: %s", pch);
 
 	int ret = cws_http_parse_method(request, pch);
 	if (ret < 0) {
@@ -85,7 +85,7 @@ cws_http *cws_http_parse(mcl_string *request_str, int sockfd, cws_config *config
 
 		return NULL;
 	}
-	//CWS_LOG_DEBUG("location: %s", pch);
+	// CWS_LOG_DEBUG("location: %s", pch);
 	mcl_string_append(request->location, pch);
 	mcl_string_append(request->location_path, config->www);
 
@@ -95,7 +95,7 @@ cws_http *cws_http_parse(mcl_string *request_str, int sockfd, cws_config *config
 	} else {
 		mcl_string_append(request->location_path, mcl_string_cstr(request->location));
 	}
-	//CWS_LOG_DEBUG("location path: %s", mcl_string_cstr(request->location_path));
+	// CWS_LOG_DEBUG("location path: %s", mcl_string_cstr(request->location_path));
 
 	/* Parse HTTP version */
 	pch = strtok_r(NULL, " \r\n", &saveptr);
@@ -105,7 +105,7 @@ cws_http *cws_http_parse(mcl_string *request_str, int sockfd, cws_config *config
 
 		return NULL;
 	}
-	//CWS_LOG_DEBUG("version: %s", pch);
+	// CWS_LOG_DEBUG("version: %s", pch);
 	mcl_string_append(request->http_version, pch);
 
 	/* Parse headers until a \r\n */
diff --git a/src/server/server.c b/src/server/server.c
index e707bdf..0fa6abc 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -83,6 +83,7 @@ cws_server_ret cws_server_start(cws_config *config) {
 }
 
 cws_server_ret cws_server_loop(int sockfd, cws_config *config) {
+	/* Make the server loop multi-thread */
 	mcl_hashmap *clients = mcl_hm_init(my_int_hash_fn, my_int_equal_fn, my_int_free_key_fn, my_str_free_fn, sizeof(int), sizeof(cws_client));
 	if (!clients) {
 		return CWS_SERVER_HASHMAP_INIT;
@@ -116,9 +117,7 @@ cws_server_ret cws_server_loop(int sockfd, cws_config *config) {
 	}
 
 	while (cws_server_run) {
-		CWS_LOG_DEBUG("Waiting for epoll events...");
 		int nfds = epoll_wait(epfd, revents, CWS_SERVER_EPOLL_MAXEVENTS, CWS_SERVER_EPOLL_TIMEOUT);
-		CWS_LOG_DEBUG("epoll_wait returned %d events", nfds);
 
 		if (nfds == 0) {
 			/* TODO: Check for inactive clients */
@@ -132,10 +131,27 @@ cws_server_ret cws_server_loop(int sockfd, cws_config *config) {
 					CWS_LOG_DEBUG("Handle new client: %d", ret);
 				}
 			} else {
-				ret = cws_server_handle_client_data(revents[i].data.fd, epfd, clients, config);
-				if (ret != CWS_SERVER_OK) {
-					CWS_LOG_DEBUG("Handle client data: %d", ret);
+				cws_pthread_data *thread_data = malloc(sizeof(cws_pthread_data));
+				if (!thread_data) {
+					continue;
 				}
+				pthread_t client_thread;
+
+				int client_fd = revents[i].data.fd;
+				thread_data->client_fd = client_fd;
+				thread_data->clients = clients;
+				thread_data->config = config;
+				thread_data->epfd = epfd;
+
+				ret = pthread_create(&client_thread, NULL, cws_server_handle_client_data, thread_data);
+				CWS_LOG_DEBUG("Started client thread for fd: %d", client_fd);
+				if (ret != 0) {
+					free(thread_data);
+					cws_server_close_client(epfd, client_fd, clients);
+					continue;
+				}
+
+				pthread_detach(client_thread);
 			}
 		}
 	}
@@ -173,7 +189,14 @@ cws_server_ret cws_server_handle_new_client(int sockfd, int epfd, mcl_hashmap *c
 	return CWS_SERVER_OK;
 }
 
-cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashmap *clients, cws_config *config) {
+void *cws_server_handle_client_data(void *arg) {
+	cws_pthread_data *thread_data = (cws_pthread_data *)arg;
+
+	int client_fd = thread_data->client_fd;
+	int epfd = thread_data->epfd;
+	mcl_hashmap *clients = thread_data->clients;
+	cws_config *config = thread_data->config;
+
 	char tmp_data[1024];
 	memset(tmp_data, 0, sizeof(tmp_data));
 	char ip[INET_ADDRSTRLEN] = {0};
@@ -187,8 +210,9 @@ cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashma
 		if (total_bytes > CWS_SERVER_MAX_REQUEST_SIZE) {
 			mcl_string_free(data);
 			cws_server_close_client(epfd, client_fd, clients);
+			free(thread_data);
 
-			return CWS_SERVER_REQUEST_TOO_LARGE;
+			return NULL;
 		}
 		mcl_string_append(data, tmp_data);
 		memset(tmp_data, 0, sizeof(tmp_data));
@@ -199,8 +223,9 @@ cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashma
 		CWS_LOG_ERROR("recv(): %s", strerror(errno));
 		mcl_string_free(data);
 		cws_server_close_client(epfd, client_fd, clients);
+		free(thread_data);
 
-		return CWS_SERVER_CLIENT_DISCONNECTED_ERROR;
+		return NULL;
 	}
 
 	/* Retrieve client ip */
@@ -210,8 +235,9 @@ cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashma
 		mcl_string_free(data);
 		cws_epoll_del(epfd, client_fd);
 		close(client_fd);
+		free(thread_data);
 
-		return CWS_SERVER_CLIENT_NOT_FOUND;
+		return NULL;
 	}
 	cws_client *client_info = (cws_client *)client->value;
 	cws_utils_get_client_ip(&client_info->addr, ip);
@@ -222,8 +248,9 @@ cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashma
 		CWS_LOG_INFO("Client (%s) disconnected", ip);
 		mcl_string_free(data);
 		cws_server_close_client(epfd, client_fd, clients);
+		free(thread_data);
 
-		return CWS_SERVER_CLIENT_DISCONNECTED;
+		return NULL;
 	}
 
 	/* Parse HTTP request */
@@ -233,19 +260,23 @@ cws_server_ret cws_server_handle_client_data(int client_fd, int epfd, mcl_hashma
 	if (request == NULL) {
 		CWS_LOG_INFO("Client (%s) disconnected (request NULL)", ip);
 		cws_server_close_client(epfd, client_fd, clients);
+		free(thread_data);
 
-		return CWS_SERVER_HTTP_PARSE_ERROR;
+		return NULL;
 	}
 
 	int keepalive = cws_http_send_resource(request);
 	cws_http_free(request);
 
 	/* Only close connection if not keep-alive */
+	/* TODO: fix */
 	if (keepalive <= 0) {
 		cws_server_close_client(epfd, client_fd, clients);
 	}
 
-	return CWS_SERVER_OK;
+	free(thread_data);
+
+	return NULL;
 }
 
 cws_server_ret cws_epoll_add(int epfd, int sockfd, uint32_t events) {
@@ -298,6 +329,8 @@ int cws_server_accept_client(int sockfd, struct sockaddr_storage *their_sa, sock
 }
 
 void cws_server_close_client(int epfd, int client_fd, mcl_hashmap *hashmap) {
-	cws_epoll_del(epfd, client_fd);
-	mcl_hm_remove(hashmap, &client_fd);
+	if (fcntl(client_fd, F_GETFD) != -1) {
+		cws_epoll_del(epfd, client_fd);
+		mcl_hm_remove(hashmap, &client_fd);
+	}
 }
diff --git a/src/server/threadpool.c b/src/server/threadpool.c
new file mode 100644
index 0000000..f80e7ef
--- /dev/null
+++ b/src/server/threadpool.c
@@ -0,0 +1,49 @@
+#include "server/threadpool.h"
+
+#include <stdlib.h>
+
+cws_threadpool *cws_threadpool_init() {
+	cws_threadpool *pool = malloc(sizeof(cws_threadpool));
+	if (pool == NULL) {
+		return NULL;
+	}
+
+	int ret;
+
+	ret = pthread_mutex_init(&pool->lock, NULL);
+	if (ret != 0) {
+		free(pool);
+		return NULL;
+	}
+
+	ret = pthread_cond_init(&pool->cond, NULL);
+	if (ret != 0) {
+		free(pool);
+		return NULL;
+	}
+
+	pool->front = 0;
+	pool->rear = 0;
+	pool->shutdown = 0;
+
+	return pool;
+}
+
+cws_server_ret cws_threadpool_add_task(cws_threadpool *pool, cws_task *task) {
+	pthread_mutex_lock(&pool->lock);
+
+	/* ? */
+
+	pthread_mutex_unlock(&pool->lock);
+
+	return CWS_SERVER_OK;
+}
+
+cws_server_ret cws_threadpool_worker(cws_threadpool *pool) { return CWS_SERVER_OK; }
+
+cws_server_ret cws_threadpool_destroy(cws_threadpool *pool) {
+	pthread_mutex_destroy(&pool->lock);
+	pthread_cond_destroy(&pool->cond);
+
+	return CWS_SERVER_OK;
+}