From 021afcb8e4aa4fbc7905f527089c415108c86c75 Mon Sep 17 00:00:00 2001
From: Stefan Zabka <zabkaste@hu-berlin.de>
Date: Thu, 18 Jun 2020 15:04:54 +0200
Subject: Switched to slotmap

---
 04_exercise/threadpool.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

(limited to '04_exercise/threadpool.c')

diff --git a/04_exercise/threadpool.c b/04_exercise/threadpool.c
index d4ee8bb..9d73013 100644
--- a/04_exercise/threadpool.c
+++ b/04_exercise/threadpool.c
@@ -1,8 +1,8 @@
 #include "threadpool.h"
-#include "arena_list.h"
 #include "array.h"
 
 #include <pthread.h>
+#include <slotmap.h>
 #include <stdatomic.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -19,8 +19,8 @@ typedef struct ThreadPool {
     /* TODO: benötigte Attribute hinzufügen */
     size_t size;
     Thread *threads;
-    Node arena[MAX_FUTURES];
-    AtomicArenaList al;
+    smEntry slab [MAX_FUTURES];
+    smHeader header;
 } ThreadPool;
 
 ThreadPool threadPool;
@@ -31,31 +31,32 @@ bool isFutureWaiting(void const *vFuture) {
     //This is racy but we'll CAS it later to make sure it's safe
     return status == FUT_WAITING;
 }
-
-void tryRunningFuture(Future *future) {
+//TODO Document the behaviour of this function
+bool tryRunningFuture(Future *  const future) {
     char expected = FUT_WAITING;
     // This can happen if multiple threads found the same Future
     if (!atomic_compare_exchange_strong(&future->status, &expected, FUT_IN_PROGRESS)) {
-        return;
+        return false;
     }
-
+    smDeleteValue(& threadPool.header, future);
     future->fn(future);
-    expected = FUT_IN_PROGRESS;
-    if (!atomic_compare_exchange_strong(&future->status, &expected, FUT_DONE)) {
+
+    if (atomic_exchange(&future->status, FUT_DONE) != FUT_IN_PROGRESS) {
         perror("The future got marked as done by another thread");
         exit(-1);
     }
+    return true;
 }
 /* TODO: interne Hilfsfunktionen hinzufügen */
 
 bool tryDoingWork() {
-    Future *future = alFindLastElem(&threadPool.al, &isFutureWaiting);
-    if (future == NULL) {
+    smEntry *entry = smFindEntry(&threadPool.header, &isFutureWaiting);
+    if (entry == NULL) {
         return false;
     }
+    Future * fut = (Future *) entry->value;
     // This will just return if some other thread was first
-    tryRunningFuture(future);
-    return true;
+    return tryRunningFuture(fut);
 }
 /** @brief worker function running in the threadpool
  */
@@ -78,10 +79,9 @@ _Noreturn void *poolWorkerFunc(void *v_index) {
 
 int tpInit(size_t size) {
     threadPool.size = size;
-    arrayInit(threadPool.threads);
-    threadPool.al = alInit(threadPool.arena, MAX_FUTURES);
+    threadPool.threads = malloc(sizeof(Thread)*size);
+    threadPool.header = smInit((smEntry *)&threadPool.slab, MAX_FUTURES);
     for (size_t i = 0; i < size; ++i) {
-        arrayPush(threadPool.threads);
         int status;
         threadPool.threads[i].index = i;
         if ((status = pthread_create(&threadPool.threads[i].pthread, NULL,
@@ -107,13 +107,12 @@ void tpRelease(void) {
             exit(status);
         }
     }
-    arrayRelease(threadPool.threads);
+    free(threadPool.threads);
 }
 
 void tpAsync(Future *future) {
-    if (alPush(&threadPool.al, (void *)future) < -1) {
-        perror("Push failed");
-        exit(-1);
+    while (smInsert(&threadPool.header, (void *)future) < 0) {
+        tryDoingWork();
     }
 }
 
@@ -125,5 +124,4 @@ void tpAwait(Future *future) {
     while (atomic_load(&future->status) != FUT_DONE) {
         tryDoingWork();
     }
-    alRemoveElem(&threadPool.al, (void *)future);
 }
-- 
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