diff --git a/common/nextpnr.h b/common/nextpnr.h
index 1f75434d..e9cda565 100644
--- a/common/nextpnr.h
+++ b/common/nextpnr.h
@@ -20,6 +20,7 @@
 
 #include <algorithm>
 #include <assert.h>
+#include <condition_variable>
 #include <memory>
 #include <mutex>
 #include <pthread.h>
@@ -346,8 +347,9 @@ class BaseCtx : public IdStringDB
 {
   private:
     std::mutex mutex;
-    bool mutex_owned;
     pthread_t mutex_owner;
+    
+    std::mutex generation_mutex;
 
   public:
     std::unordered_map<IdString, std::unique_ptr<NetInfo>> nets;
@@ -360,6 +362,7 @@ class BaseCtx : public IdStringDB
     {
         mutex.lock();
         mutex_owner = pthread_self();
+
     }
 
     void unlock(void)
@@ -368,6 +371,14 @@ class BaseCtx : public IdStringDB
         mutex.unlock();
     }
 
+    // TODO(q3k): get rid of this hack
+    void yield(void)
+    {
+        for (int i = 0; i < 10; i++) {
+            pthread_yield();
+        }
+    }
+
     Context *getCtx() { return reinterpret_cast<Context *>(this); }
 
     const Context *getCtx() const { return reinterpret_cast<const Context *>(this); }
diff --git a/common/placer1.cc b/common/placer1.cc
index b58893ce..c8ba71a4 100644
--- a/common/placer1.cc
+++ b/common/placer1.cc
@@ -29,7 +29,6 @@
 #include <list>
 #include <map>
 #include <ostream>
-#include <pthread.h>
 #include <queue>
 #include <set>
 #include <stdarg.h>
@@ -157,14 +156,7 @@ class SAPlacer
 
         // Main simulated annealing loop
         for (int iter = 1;; iter++) {
-            // TODO(q3k): unwat
-            pthread_yield();
-            pthread_yield();
-            pthread_yield();
-            pthread_yield();
-            pthread_yield();
-            pthread_yield();
-            pthread_yield();
+            ctx->yield();
             ctx->lock();
             n_move = n_accept = 0;
             improved = false;
diff --git a/common/router1.cc b/common/router1.cc
index bde3be31..3a0aa19b 100644
--- a/common/router1.cc
+++ b/common/router1.cc
@@ -495,6 +495,7 @@ bool router1(Context *ctx)
 #endif
                 return false;
             }
+            ctx->yield();
             ctx->lock();
 
             iterCnt++;