From 2f5b94fe309619c221c3e1ea5aa48a4523bd3156 Mon Sep 17 00:00:00 2001
From: Serge Bazanski <serge@bazanski.pl>
Date: Tue, 17 Jul 2018 16:27:50 +0100
Subject: [PATCH] Add basic external locking, lock from P&R

---
 common/nextpnr.h  | 19 +++++++++++++++++++
 common/placer1.cc | 14 ++++++++++++++
 common/router1.cc |  7 +++++++
 3 files changed, 40 insertions(+)

diff --git a/common/nextpnr.h b/common/nextpnr.h
index e53e4d01..7aa5b100 100644
--- a/common/nextpnr.h
+++ b/common/nextpnr.h
@@ -21,6 +21,8 @@
 #include <algorithm>
 #include <assert.h>
 #include <memory>
+#include <mutex>
+#include <pthread.h>
 #include <stdexcept>
 #include <stdint.h>
 #include <string>
@@ -337,6 +339,11 @@ class DeterministicRNG
 
 class BaseCtx : public IdStringDB, public DeterministicRNG
 {
+  private:
+    std::mutex mutex;
+    bool mutex_owned;
+    pthread_t mutex_owner;
+
   public:
     std::unordered_map<IdString, std::unique_ptr<NetInfo>> nets;
     std::unordered_map<IdString, std::unique_ptr<CellInfo>> cells;
@@ -344,6 +351,18 @@ class BaseCtx : public IdStringDB, public DeterministicRNG
     BaseCtx() {}
     ~BaseCtx() {}
 
+    void lock(void)
+    {
+        mutex.lock();
+        mutex_owner = pthread_self();
+    }
+
+    void unlock(void)
+    {
+        NPNR_ASSERT(pthread_equal(pthread_self(), mutex_owner) != 0);
+        mutex.unlock();
+    }
+
     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 74a11040..b229616c 100644
--- a/common/placer1.cc
+++ b/common/placer1.cc
@@ -80,6 +80,7 @@ class SAPlacer
 
         size_t placed_cells = 0;
         // Initial constraints placer
+        ctx->lock();
         for (auto &cell_entry : ctx->cells) {
             CellInfo *cell = cell_entry.second.get();
             auto loc = cell->attrs.find(ctx->id("BEL"));
@@ -118,16 +119,19 @@ class SAPlacer
         }
         std::sort(autoplaced.begin(), autoplaced.end(), [](CellInfo *a, CellInfo *b) { return a->name < b->name; });
         ctx->shuffle(autoplaced);
+        ctx->unlock();
 
         // Place cells randomly initially
         log_info("Creating initial placement for remaining %d cells.\n", int(autoplaced.size()));
 
         for (auto cell : autoplaced) {
+            ctx->lock();
             place_initial(cell);
             placed_cells++;
             if ((placed_cells - constr_placed_cells) % 500 == 0)
                 log_info("  initial placement placed %d/%d cells\n", int(placed_cells - constr_placed_cells),
                          int(autoplaced.size()));
+            ctx->unlock();
         }
         if ((placed_cells - constr_placed_cells) % 500 != 0)
             log_info("  initial placement placed %d/%d cells\n", int(placed_cells - constr_placed_cells),
@@ -136,6 +140,7 @@ class SAPlacer
         log_info("Running simulated annealing placer.\n");
 
         // Calculate metric after initial placement
+        ctx->lock();
         curr_metric = 0;
         curr_tns = 0;
         for (auto &net : ctx->nets) {
@@ -143,6 +148,7 @@ class SAPlacer
             metrics[net.first] = wl;
             curr_metric += wl;
         }
+        ctx->unlock();
 
         int n_no_progress = 0;
         double avg_metric = curr_metric;
@@ -150,6 +156,7 @@ class SAPlacer
 
         // Main simulated annealing loop
         for (int iter = 1;; iter++) {
+            ctx->lock();
             n_move = n_accept = 0;
             improved = false;
 
@@ -169,6 +176,7 @@ class SAPlacer
                         try_swap_position(cell, try_bel);
                 }
             }
+
             // Heuristic to improve placement on the 8k
             if (improved)
                 n_no_progress = 0;
@@ -178,6 +186,7 @@ class SAPlacer
             if (temp <= 1e-3 && n_no_progress >= 5) {
                 if (iter % 5 != 0)
                     log_info("  at iteration #%d: temp = %f, cost = %f\n", iter, temp, double(curr_metric));
+                ctx->unlock();
                 break;
             }
 
@@ -232,8 +241,10 @@ class SAPlacer
                 metrics[net.first] = wl;
                 curr_metric += wl;
             }
+            ctx->unlock();
         }
         // Final post-pacement validitiy check
+        ctx->lock();
         for (auto bel : ctx->getBels()) {
             IdString cell = ctx->getBoundBelCell(bel);
             if (!ctx->isBelLocationValid(bel)) {
@@ -251,6 +262,7 @@ class SAPlacer
                 }
             }
         }
+        ctx->unlock();
         return true;
     }
 
@@ -436,7 +448,9 @@ bool placer1(Context *ctx)
         placer.place();
         log_info("Checksum: 0x%08x\n", ctx->checksum());
 #ifndef NDEBUG
+        ctx->lock();
         ctx->check();
+        ctx->unlock();
 #endif
         return true;
     } catch (log_execution_error_exception) {
diff --git a/common/router1.cc b/common/router1.cc
index 94c7070e..a85de7c6 100644
--- a/common/router1.cc
+++ b/common/router1.cc
@@ -414,6 +414,7 @@ bool router1(Context *ctx)
 
         std::unordered_set<IdString> netsQueue;
 
+        ctx->lock();
         for (auto &net_it : ctx->nets) {
             auto net_name = net_it.first;
             auto net_info = net_it.second.get();
@@ -478,6 +479,7 @@ bool router1(Context *ctx)
                 estimatedTotalDelayCnt++;
             }
         }
+        ctx->unlock();
 
         log_info("estimated total wire delay: %.2f (avg %.2f)\n", float(estimatedTotalDelay),
                  float(estimatedTotalDelay) / estimatedTotalDelayCnt);
@@ -493,6 +495,7 @@ bool router1(Context *ctx)
 #endif
                 return false;
             }
+            ctx->lock();
 
             iterCnt++;
             if (ctx->verbose)
@@ -621,6 +624,8 @@ bool router1(Context *ctx)
 
             if (iterCnt == 8 || iterCnt == 16 || iterCnt == 32 || iterCnt == 64 || iterCnt == 128)
                 ripup_penalty += ctx->getRipupDelayPenalty();
+
+            ctx->unlock();
         }
 
         log_info("routing complete after %d iterations.\n", iterCnt);
@@ -637,7 +642,9 @@ bool router1(Context *ctx)
         return true;
     } catch (log_execution_error_exception) {
 #ifndef NDEBUG
+        ctx->lock();
         ctx->check();
+        ctx->unlock();
 #endif
         return false;
     }