main thread initial layout

assignment1/partb/550server.cpp

@@ -7,6 +7,7 @@
 #include <cstring>
 #include <sys/poll.h>
 #include <fcntl.h>
+#include <unordered_map>
 
 #include "server_util.h"
 #include "threadpool.h"
@@ -37,6 +38,7 @@ int main(int argc, char **argv) {
   int num_fds = 1;
   int poll_timeout = -1; // -1 is same as infinite timeout
   bool resize_events_arr = false;
+  unordered_map<int, Work*> worker_to_client;  // read end of a worker -> work to do map
 
   // Check for valid number of arguments
   if (argc != 3)
@@ -137,33 +139,57 @@ int main(int argc, char **argv) {
           // TODO: clean up;
           continue;
         }
+        
+        Work *thread_work = new Work;
+        thread_work->filepath = req_file_path;
+        // pipe_fds[1] is write end of pipe
+        thread_work->pipe_fd = pipe_fds[1];
+        thread_work->written = 0;
+        thread_work->client_fd = new_client_fd;
 
         // add pollfd 
-        events[num_fds].fd = new_client_fd;
+        events[num_fds].fd = pipe_fds[0];
         events[num_fds].events = POLLIN;
         num_fds++;
 
         // dispatch thread
         HttpServerTask *worker_task = new HttpServerTask(HttpServer_ThrFn);
+        worker_task-> work = thread_work;
 
+        worker_to_client[pipe_fds[0]] = thread_work;
 
         tp.Dispatch(worker_task);
       } else {
         // this is probably a worker thread done with the work
+        Work *thread_work = worker_to_client[events[i].fd];
+        if (thread_work == nullptr) {
+          cerr << "   worker_to_client mapping corrupted for fd: " << events[i].fd << "\n";
+          // TODO: need some action
+        }
+        // return data to client
+        int written_bytes = WrappedWrite(thread_work->client_fd, (unsigned char*)(thread_work->buffer), thread_work->written);
+        if (written_bytes != thread_work->written) {
+          cerr << "   actual written: " << written_bytes << ", expected: " << thread_work->written << "\n";
+        }
 
+        // clean up resource: pipes, client socket, work struct
+        close(thread_work->client_fd);
+        close(events[i].fd);
+        close(thread_work->pipe_fd);
+
+        delete thread_work;
+        
+        events[i].fd = -1;
+        resize_events_arr = true;
       }
     }
 
-
-  if (resize_events_arr)
-    {
+    // at least 1 event has been deleted, need to resize
+    if (resize_events_arr) {
       resize_events_arr = false;
-      for (int i = 0; i < num_fds; i++)
-      {
-        if (events[i].fd == -1)
-        {
-          for(int j = i; j < num_fds; j++)
-          {
+      for (int i = 0; i < num_fds; i++) {
+        if (events[i].fd == -1) {
+          for(int j = i; j < num_fds; j++) {
             events[j].fd = events[j+1].fd;
           }
           i--;
@@ -171,35 +197,6 @@ int main(int argc, char **argv) {
         }
       }
     }
-    // TODO: initialize shared data structure
-    // TODO: modify logic to add threapool 
-    // TODO: use server_socket class
-    /*
-        1) accept client connection
-        2) initialize stuff for communication with threadpool
-        3) read from client and write to thread
-        4) get back info from thread
-    
-    
-    
-    */
-
-    // read from client fd and write to stdout
-    while (1) {
-        int rlen = WrappedRead(client_fd, buf, BUFFER_SIZE);
-        // check for reading failure
-        // on error, clean up and exit with failure
-        if (rlen <= 0) {
-        break;
-        }
-
-        int wlen = WrappedWrite(STDOUT_FILENO, buf, rlen);
-        // check that we wrote the same amount as we read in
-        // on error, clean up and exit with failure
-        if (wlen != rlen) {
-        break;
-        }
-    }
   }
 
   return EXIT_SUCCESS;

assignment1/partb/threadpool.h

@@ -79,7 +79,9 @@ class HttpServerTask : public ThreadPool::Task {
 struct Work {
     string filepath;
     char buffer[FILE_BUFFER_SIZE]; // Buffer for main thread to read file contents from worker thread
+    int written;  // Number of bytes (char) that the worker thread has written to the buffer
     int pipe_fd; // Write end for the pipe. Used to notify main thread that the worker is done writing the file contents.
+    int client_fd; // Client that this work is for
 };
 
 #endif  // THREADPOOL_H_