From ecc63d70476ad0bda0c0e80ec0f23c0216d93f23 Mon Sep 17 00:00:00 2001
From: ac-stef <ac_stef@users.sf.net>
Date: Tue, 15 Sep 2015 02:58:02 +0200
Subject: [PATCH] more thread wrapper functions

Add code to detach threads without losing any ressources.
(use POSIX libs when SDL is not available)
---
 source/src/tools.cpp | 75 ++++++++++++++++++++++++++++++++++++++++++--
 source/src/tools.h   |  3 ++
 2 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/source/src/tools.cpp b/source/src/tools.cpp
index 940acce4..9fbd49c8 100644
--- a/source/src/tools.cpp
+++ b/source/src/tools.cpp
@@ -594,15 +594,21 @@ void sl_semaphore::post()
 
 // (wrapping threads is slightly ugly, since SDL threads use a different return value (int) than pthreads (void *) - and that can't be solved with a typecast)
 #ifdef AC_USE_SDL_THREADS
-struct sl_threadinfo { int (*fn)(void *); void *data; SDL_Thread *handle; };
+struct sl_threadinfo { int (*fn)(void *); void *data; SDL_Thread *handle; volatile char done; };
 
-static int sl_thread_indir(void *info) { return (*((sl_threadinfo*)info)->fn)(((sl_threadinfo*)info)->data); }
+static int sl_thread_indir(void *info)
+{
+    int res = (*((sl_threadinfo*)info)->fn)(((sl_threadinfo*)info)->data);
+    ((sl_threadinfo*)info)->done = 1;
+    return res;
+}
 
 void *sl_createthread(int (*fn)(void *), void *data)
 {
     sl_threadinfo *ti = new sl_threadinfo;
     ti->data = data;
     ti->fn = fn;
+    ti->done = 0;
     ti->handle = SDL_CreateThread(sl_thread_indir, ti);
     return (void *) ti;
 }
@@ -614,13 +620,41 @@ int sl_waitthread(void *ti)
     delete (sl_threadinfo *) ti;
     return res;
 }
+
+static vector<sl_threadinfo *> oldthreads;
+static sl_semaphore sem_oldthreads(1, NULL);
+
+void sl_detachthread(void *ti) // SDL can't actually detach threads, so this is manual cleanup
+{
+    if(ti && sl_pollthread(ti))
+    {
+        SDL_WaitThread(((sl_threadinfo *)ti)->handle, NULL);
+        delete (sl_threadinfo *) ti;
+        ti = NULL;
+    }
+    if(ti || sem_oldthreads.getvalue() > 0)
+    {
+        sem_oldthreads.wait();
+        if(ti) oldthreads.add((sl_threadinfo *)ti);
+        loopvrev(oldthreads)
+        {
+            if(oldthreads[i]->done)
+            {
+                SDL_WaitThread(oldthreads[i]->handle, NULL);
+                delete oldthreads.remove(i);
+            }
+        }
+        sem_oldthreads.post();
+    }
+}
 #else
-struct sl_threadinfo { int (*fn)(void *); void *data; pthread_t handle; int res; };
+struct sl_threadinfo { int (*fn)(void *); void *data; pthread_t handle; int res; volatile char done; };
 
 static void *sl_thread_indir(void *info)
 {
     sl_threadinfo *ti = (sl_threadinfo*) info;
     ti->res = (ti->fn)(ti->data);
+    ti->done = 1;
     return &ti->res;
 }
 
@@ -629,6 +663,7 @@ void *sl_createthread(int (*fn)(void *), void *data)
     sl_threadinfo *ti = new sl_threadinfo;
     ti->data = data;
     ti->fn = fn;
+    ti->done = 0;
     pthread_create(&(ti->handle), NULL, sl_thread_indir, ti);
     return (void *) ti;
 }
@@ -641,6 +676,40 @@ int sl_waitthread(void *ti)
     delete (sl_threadinfo *) ti;
     return ires;
 }
+
+static vector<sl_threadinfo *> oldthreads;
+static sl_semaphore sem_oldthreads(1, NULL);
+
+void sl_detachthread(void *ti)
+{
+    if(ti) pthread_detach(((sl_threadinfo *)ti)->handle);
+    if(ti || sem_oldthreads.getvalue() > 0)
+    {
+        sem_oldthreads.wait();
+        if(ti) oldthreads.add((sl_threadinfo *)ti);
+        loopvrev(oldthreads) if(oldthreads[i]->done) delete oldthreads.remove(i);
+        sem_oldthreads.post();
+    }
+}
+#endif
+
+bool sl_pollthread(void *ti)
+{
+    return ((sl_threadinfo*)ti)->done != 0;
+}
+
+// platform dependent stuff not covered by enet (use POSIX or, if possible, SDL)
+#ifdef AC_USE_SDL_THREADS
+void sl_sleep(int duration)
+{
+    SDL_Delay(duration);
+}
+#else
+void sl_sleep(int duration)
+{
+    struct timespec t = { duration / 1000, (duration % 1000) * 1000000 };
+    nanosleep(&t, NULL);
+}
 #endif
 
 void parseupdatelist(hashtable<const char *, int> &ht, char *buf, const char *prefix, const char *suffix)
diff --git a/source/src/tools.h b/source/src/tools.h
index 88d12ddc..fa9f10f5 100644
--- a/source/src/tools.h
+++ b/source/src/tools.h
@@ -1010,6 +1010,9 @@ struct sl_semaphore
 
 extern void *sl_createthread(int (*fn)(void *), void *data);
 extern int sl_waitthread(void *ti);
+extern bool sl_pollthread(void *ti);
+extern void sl_detachthread(void *ti);
+extern void sl_sleep(int duration);
 
 #endif