Allow arbitrary number of connections (#13)

* refactor plasma to use an event loop

* unify comment style

* Clean up Makefile flags.

* Randomize socket names in tests so multiple copies of the tests can be run in parallel without conflict.

src/event_loop.c

@@ -0,0 +1,85 @@
+#include "event_loop.h"
+
+#include <assert.h>
+#include <unistd.h>
+
+UT_icd item_icd = { sizeof(event_loop_item), NULL, NULL, NULL };
+UT_icd poll_icd = { sizeof(struct pollfd), NULL, NULL, NULL };
+
+/* Initializes the event loop.
+ * This function needs to be called before any other event loop function. */
+void event_loop_init(event_loop *loop) {
+  utarray_new(loop->items, &item_icd);
+  utarray_new(loop->waiting, &poll_icd);
+}
+
+/* Add a new file descriptor fd to the event loop.
+ * This function sets a user defined type and id for the file descriptor
+ * which can be queried using event_loop_type and event_loop_id. The parameter
+ * events is the same as in http://linux.die.net/man/2/poll.
+ * Returns the index of the item in the event loop. */
+int64_t event_loop_attach(event_loop *loop, int type, data_connection* connection, int fd, int events) {
+  assert(utarray_len(loop->items) == utarray_len(loop->waiting));
+  int64_t index = utarray_len(loop->items);
+  event_loop_item item = { .type = type };
+  if (connection) {
+    item.connection = *connection;
+  }
+  utarray_push_back(loop->items, &item );
+  struct pollfd waiting = { .fd = fd, .events = events };
+  utarray_push_back(loop->waiting, &waiting);
+  return index;
+}
+
+/* Detach a file descriptor from the event loop.
+ * This invalidates all other indices into the event loop items, but leaves
+ * the ids of the event loop items valid. */
+void event_loop_detach(event_loop *loop, int64_t index, int shall_close) {
+  struct pollfd *waiting_item = (struct pollfd*) utarray_eltptr(loop->waiting, index);
+  struct pollfd *waiting_back = (struct pollfd*) utarray_back(loop->waiting);
+  if (shall_close) {
+    close(waiting_item->fd);
+  }
+  *waiting_item = *waiting_back;
+  utarray_pop_back(loop->waiting);
+
+  event_loop_item *items_item = (event_loop_item*) utarray_eltptr(loop->items, index);
+  event_loop_item *items_back = (event_loop_item*) utarray_back(loop->items);
+  *items_item = *items_back;
+  utarray_pop_back(loop->items);
+}
+
+/* Poll the file descriptors associated to this event loop.
+ * See http://linux.die.net/man/2/poll */
+int event_loop_poll(event_loop *loop) {
+  return poll((struct pollfd*) utarray_front(loop->waiting), utarray_len(loop->waiting), -1);
+}
+
+/* Get the total number of file descriptors participating in the event loop. */
+int64_t event_loop_size(event_loop *loop) {
+  return utarray_len(loop->waiting);
+}
+
+/* Get the pollfd structure associated to a file descriptor participating in the event loop. */
+struct pollfd *event_loop_get(event_loop *loop, int64_t index) {
+  return (struct pollfd*) utarray_eltptr(loop->waiting, index);
+}
+
+/* Set the data connection information for participant in the event loop. */
+void event_loop_set_connection(event_loop *loop, int64_t index, const data_connection* conn) {
+  event_loop_item *item = (event_loop_item*) utarray_eltptr(loop->items, index);
+  item->connection = *conn;
+}
+
+/* Get the data connection information for participant in the event loop. */
+data_connection* event_loop_get_connection(event_loop *loop, int64_t index) {
+  event_loop_item *item = (event_loop_item*) utarray_eltptr(loop->items, index);
+  return &item->connection;
+}
+
+/* Free the space associated to the event loop.
+ * Does not free the event_loop datastructure itself. */
+void event_loop_free(event_loop *loop) {
+  utarray_free(loop->items);
+  utarray_free(loop->waiting);
+}