From e57688a7742b07fb88b40a3db59e8ed54feba92e Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Thu, 17 Dec 2015 22:45:45 -0500
Subject: [PATCH] Added thread start/end functions to runtime

---
 gc.c                      |  1 +
 include/cyclone/runtime.h |  2 ++
 runtime.c                 | 60 +++++++++++++++++++++++++++++++--------
 3 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/gc.c b/gc.c
index 82fa9971..2c0b7150 100644
--- a/gc.c
+++ b/gc.c
@@ -1181,6 +1181,7 @@ void *collector_main(void *arg)
     }
     nanosleep(&tim, NULL);
   }
+  return NULL;
 }
 
 static pthread_t collector_thread;
diff --git a/include/cyclone/runtime.h b/include/cyclone/runtime.h
index 4db8d288..ade5fac2 100644
--- a/include/cyclone/runtime.h
+++ b/include/cyclone/runtime.h
@@ -186,7 +186,9 @@ object equalp(object,object);
 object memberp(void *,object,list);
 object memqp(void *,object,list);
 
+object Cyc_spawn_thread(object thunk);
 void Cyc_start_thread(gc_thread_data *thd);
+void Cyc_end_thread(gc_thread_data *thd);
 void GC(void *,closure,object*,int);
 
 void Cyc_st_add(void *data, char *frame);
diff --git a/runtime.c b/runtime.c
index 568bf50b..a43fa31a 100644
--- a/runtime.c
+++ b/runtime.c
@@ -2475,19 +2475,46 @@ void Cyc_apply_from_buf(void *data, int argc, object prim, object *buf) {
 // longjmp(jmp_main,1); /* Return globals gc_cont, gc_ans. */
 //}
 
-void Cyc_setup_thread(thunk)
+/**
+ * Thread initialization function only called from within the runtime
+ */
+void *Cyc_init_thread(object thunk)
 {
-  // TODO: how to use pthread? need to run this in a pthread, I think. when/how to do that?
-  // TODO: this function should be start_thread, call below one run_thread
-  // TODO:
+  long stack_start;
   gc_thread_data *thd;
-  // malloc thread, init it
-  // setup gc_cont, args
-  // gc_add_mutator
-  // Cyc_start_thread(thd)
-  
+// TODO: I don't think we want a closure here, but rather want to 
+// init the end-thread primitive, and call into that instead. that way
+// we can explicitly provide the thread_data argument.
+  mclosure0(clo_end, Cyc_end_thread);
+  thd = malloc(sizeof(gc_thread_data));
+  gc_thread_data_init(thd, 0, (char *) &stack_start, global_stack_size);
+  thd->gc_cont = thunk;
+  thd->gc_num_args = 1;
+  thd->gc_args[0] = &clo_end;
+  gc_add_mutator(thd);
+  Cyc_start_thread(thd);
+  return NULL;
 }
 
+/**
+ * Spawn a new thread to execute the given thunk
+ */
+object Cyc_spawn_thread(object thunk)
+{
+  pthread_t thread;
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+  if (pthread_create(&thread, NULL, Cyc_init_thread, thunk)) {
+    fprintf(stderr, "Error creating a new thread\n");
+    exit(1);
+  }
+  return boolean_t;
+}
+
+/**
+ * Start a thread's trampoline
+ */
 void Cyc_start_thread(gc_thread_data *thd)
 {
   /* Tank, load the jump program... */
@@ -2507,10 +2534,19 @@ void Cyc_start_thread(gc_thread_data *thd)
   exit(0);
 }
 
-void Cyc_end_thread(gc_thread_data *thd) {
-  // TODO:  call pthread_exit?
+/**
+ * Terminate a thread
+ */
+void Cyc_end_thread(gc_thread_data *thd) 
+{
   // alternatively could call longjmp with a null continuation, but that seems
-  // more complicated than necessary
+  // more complicated than necessary. or does it... see next comment:
+  
+  // TODO: what if there are any locals from the thread's stack still being
+  // referenced? might want to do one more minor GC to clear the stack before
+  // terminating the thread
+
+  pthread_exit(NULL); // For now, just a proof of concept
 }
 
 // Mark globals as part of the tracing collector