Generalize the worker setup/runloop/teardown logic by adding a smol ot_worker helper

1 files changed, 75 insertions, 0 deletions

diff --git a/ot_worker.c b/ot_worker.c
new file mode 100644
index 0000000..97eaeb2
--- /dev/null
+++ b/ot_worker.c
@@ -0,0 +1,75 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever.
+
+   $id$ */
+
+/* System */
+#include <pthread.h>
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* Opentracker */
+#include "ot_worker.h"
+#include "trackerlogic.h"
+
+static struct ot_worker **g_workers;
+static size_t             g_worker_count;
+
+/* Everything a worker needs doing around its own loop, in one place, so that
+   a new kind of worker cannot miss a piece of it. */
+static void *worker_trampoline(void *args) {
+  struct ot_worker *me = args;
+
+  if (workstruct_init(&me->ws) == -1)
+    fprintf(stderr, "Warning: a worker could not get its buffers and will not run.\n");
+  else {
+    me->run(me);
+    workstruct_deinit(&me->ws);
+  }
+
+  atomic_store(&me->left, 1);
+  return NULL;
+}
+
+int worker_start(ot_worker_run run, int64_t sock) {
+  struct ot_worker **grown = realloc(g_workers, (g_worker_count + 1) * sizeof(*g_workers));
+  struct ot_worker  *worker;
+
+  if (!grown)
+    return -1;
+  g_workers = grown;
+
+  if (!(worker = calloc(1, sizeof(*worker))))
+    return -1;
+  worker->sock = sock;
+  worker->run  = run;
+
+  if (pthread_create(&worker->thread, NULL, worker_trampoline, worker)) {
+    free(worker);
+    return -1;
+  }
+  g_workers[g_worker_count++] = worker;
+  return 0;
+}
+
+void worker_stop_all(void) {
+  size_t i;
+
+  for (i = 0; i < g_worker_count; ++i) {
+    struct ot_worker *worker = g_workers[i];
+
+    /* Repeated because a signal only interrupts a call already under way */
+    while (!atomic_load(&worker->left)) {
+      pthread_kill(worker->thread, OT_SIGNAL_WAKE);
+      usleep(1000);
+    }
+    pthread_join(worker->thread, NULL);
+    free(worker);
+  }
+
+  free(g_workers);
+  g_workers      = NULL;
+  g_worker_count = 0;
+}