Fix mem leak

src/main.c

@@ -1,3 +1,12 @@
+/*
+ * Design Doc:
+ * The server is broken into the following files:
+ *  - main.c: Argument parsing and high-level control
+ *  - http.c: HTTP request parsing and response formatting
+ *  - server.c: Abstraction over sockets
+ *  - threadpool.c: Thread pool and wokr queue implementation
+ *  - util.c: Misc. utility functions
+ */
 #include "http.h"
 #include "server.h"
 #include "threadpool.h"
@@ -327,6 +336,10 @@ static void handle_connection(void *arg) {
     fclose(conn);
 }
 
+static void fclose_free_func(void *file) {
+    fclose(file);
+}
+
 int main(int argc, const char **argv) {
     setenv("POSIXLY_CORRECT", "1", true);
     GlobalFlags flags = DEFAULT_FLAGS;
@@ -367,7 +380,7 @@ int main(int argc, const char **argv) {
             close(conn_fd);
             continue;
         }
-        thread_pool_enqueue(pool, handle_connection, conn);
+        thread_pool_enqueue(pool, handle_connection, conn, fclose_free_func);
     }
     destroy_thread_pool(pool);
     destroy_server(server);

src/threadpool.c

@@ -8,6 +8,7 @@
 struct thread_pool_queue {
     Task task;
     void *arg;
+    FreeFunc ff;
     struct thread_pool_queue *next;
 };
 
@@ -91,15 +92,25 @@ void destroy_thread_pool(ThreadPool *pool) {
     free(pool->threads);
     pthread_mutex_destroy(&pool->queue_mtx);
     pthread_cond_destroy(&pool->queue_cnd);
+    struct thread_pool_queue *queue = pool->queue;
+    while (queue) {
+        struct thread_pool_queue *next = queue->next;
+        if (queue->ff) {
+            queue->ff(queue->arg);
+        }
+        free(queue);
+        queue = next;
+    }
     free(pool);
 }
 
-void thread_pool_enqueue(ThreadPool *pool, Task task, void *arg) {
+void thread_pool_enqueue(ThreadPool *pool, Task task, void *arg, FreeFunc ff) {
     pthread_mutex_lock(&pool->queue_mtx);
     struct thread_pool_queue *new =
         malloc_safe(sizeof(struct thread_pool_queue));
     new->task = task;
     new->arg = arg;
+    new->ff = ff;
     new->next = pool->queue;
     pool->queue = new;
     pthread_cond_signal(&pool->queue_cnd);

src/threadpool.h

@@ -6,11 +6,12 @@
 
 typedef struct _ThreadPool ThreadPool;
 typedef void (*Task)(void *);
+typedef void (*FreeFunc)(void *);
 
 ThreadPool *make_thread_pool(size_t parallelism, sigset_t sig_mask);
 
 void destroy_thread_pool(ThreadPool *pool);
 
-void thread_pool_enqueue(ThreadPool *pool, Task task, void *arg);
+void thread_pool_enqueue(ThreadPool *pool, Task task, void *arg, FreeFunc ff);
 
 #endif