Merge branch 'q3k/lock-2-electric-boogaloo' into 'master'

Basic locking and threading for Arch/GUI

See merge request SymbioticEDA/nextpnr!10

3 files changed, 154 insertions, 72 deletions

diff --git a/common/nextpnr.h b/common/nextpnr.h
index c8915c19..d89eb15b 100644
--- a/common/nextpnr.h
+++ b/common/nextpnr.h
@@ -2,6 +2,7 @@
  *  nextpnr -- Next Generation Place and Route
  *
  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@symbioticeda.com>
  *
  *  Permission to use, copy, modify, and/or distribute this software for any
  *  purpose with or without fee is hereby granted, provided that the above
@@ -19,7 +20,10 @@
 
 #include <algorithm>
 #include <assert.h>
+#include <condition_variable>
 #include <memory>
+#include <mutex>
+#include <pthread.h>
 #include <stdexcept>
 #include <stdint.h>
 #include <string>
@@ -270,19 +274,87 @@ struct CellInfo : ArchCellInfo
     std::unordered_map<IdString, IdString> pins;
 };
 
-struct BaseCtx
+struct DeterministicRNG
 {
-    // --------------------------------------------------------------
+    uint64_t rngstate;
 
-    mutable std::unordered_map<std::string, int> *idstring_str_to_idx;
-    mutable std::vector<const std::string *> *idstring_idx_to_str;
+    DeterministicRNG() : rngstate(0x3141592653589793) {}
 
-    IdString id(const std::string &s) const { return IdString(this, s); }
+    uint64_t rng64()
+    {
+        // xorshift64star
+        // https://arxiv.org/abs/1402.6246
 
-    IdString id(const char *s) const { return IdString(this, s); }
+        uint64_t retval = rngstate * 0x2545F4914F6CDD1D;
 
-    // --------------------------------------------------------------
+        rngstate ^= rngstate >> 12;
+        rngstate ^= rngstate << 25;
+        rngstate ^= rngstate >> 27;
+
+        return retval;
+    }
+
+    int rng() { return rng64() & 0x3fffffff; }
+
+    int rng(int n)
+    {
+        assert(n > 0);
+
+        // round up to power of 2
+        int m = n - 1;
+        m |= (m >> 1);
+        m |= (m >> 2);
+        m |= (m >> 4);
+        m |= (m >> 8);
+        m |= (m >> 16);
+        m += 1;
+
+        while (1) {
+            int x = rng64() & (m - 1);
+            if (x < n)
+                return x;
+        }
+    }
+
+    void rngseed(uint64_t seed)
+    {
+        rngstate = seed ? seed : 0x3141592653589793;
+        for (int i = 0; i < 5; i++)
+            rng64();
+    }
+
+    template <typename T> void shuffle(std::vector<T> &a)
+    {
+        for (size_t i = 0; i != a.size(); i++) {
+            size_t j = i + rng(a.size() - i);
+            if (j > i)
+                std::swap(a[i], a[j]);
+        }
+    }
 
+    template <typename T> void sorted_shuffle(std::vector<T> &a)
+    {
+        std::sort(a.begin(), a.end());
+        shuffle(a);
+    }
+};
+
+struct BaseCtx
+{
+    // Lock to perform mutating actions on the Context.
+    std::mutex mutex;
+    pthread_t mutex_owner;
+
+    // Lock to be taken by UI when wanting to access context - the yield()
+    // method will lock/unlock it when its' released the main mutex to make
+    // sure the UI is not starved.
+    std::mutex ui_mutex;
+
+    // ID String database.
+    mutable std::unordered_map<std::string, int> *idstring_str_to_idx;
+    mutable std::vector<const std::string *> *idstring_idx_to_str;
+
+    // Placed nets and cells.
     std::unordered_map<IdString, std::unique_ptr<NetInfo>> nets;
     std::unordered_map<IdString, std::unique_ptr<CellInfo>> cells;
 
@@ -300,13 +372,57 @@ struct BaseCtx
         delete idstring_idx_to_str;
     }
 
+    // Must be called before performing any mutating changes on the Ctx/Arch.
+    void lock(void)
+    {
+        mutex.lock();
+        mutex_owner = pthread_self();
+    }
+
+    void unlock(void)
+    {
+        NPNR_ASSERT(pthread_equal(pthread_self(), mutex_owner) != 0);
+        mutex.unlock();
+    }
+
+    // Must be called by the UI before rendering data. This lock will be
+    // prioritized when processing code calls yield().
+    void lock_ui(void)
+    {
+        ui_mutex.lock();
+        mutex.lock();
+    }
+
+    void unlock_ui(void)
+    {
+        mutex.unlock();
+        ui_mutex.unlock();
+    }
+
+    // Yield to UI by unlocking the main mutex, flashing the UI mutex and
+    // relocking the main mutex. Call this when you're performing a
+    // long-standing action while holding a lock to let the UI show
+    // visualization updates.
+    // Must be called with the main lock taken.
+    void yield(void)
+    {
+        unlock();
+        ui_mutex.lock();
+        ui_mutex.unlock();
+        lock();
+    }
+
+    IdString id(const std::string &s) const { return IdString(this, s); }
+
+    IdString id(const char *s) const { return IdString(this, s); }
+
     Context *getCtx() { return reinterpret_cast<Context *>(this); }
 
     const Context *getCtx() const { return reinterpret_cast<const Context *>(this); }
 
     // --------------------------------------------------------------
 
-    bool allUiReload = false;
+    bool allUiReload = true;
     bool frameUiReload = false;
     std::unordered_set<BelId> belUiReload;
     std::unordered_set<WireId> wireUiReload;
@@ -332,7 +448,7 @@ NEXTPNR_NAMESPACE_END
 
 NEXTPNR_NAMESPACE_BEGIN
 
-struct Context : Arch
+struct Context : Arch, DeterministicRNG
 {
     bool verbose = false;
     bool debug = false;
@@ -349,66 +465,6 @@ struct Context : Arch
 
     // --------------------------------------------------------------
 
-    uint64_t rngstate = 0x3141592653589793;
-
-    uint64_t rng64()
-    {
-        // xorshift64star
-        // https://arxiv.org/abs/1402.6246
-
-        uint64_t retval = rngstate * 0x2545F4914F6CDD1D;
-
-        rngstate ^= rngstate >> 12;
-        rngstate ^= rngstate << 25;
-        rngstate ^= rngstate >> 27;
-
-        return retval;
-    }
-
-    int rng() { return rng64() & 0x3fffffff; }
-
-    int rng(int n)
-    {
-        assert(n > 0);
-
-        // round up to power of 2
-        int m = n - 1;
-        m |= (m >> 1);
-        m |= (m >> 2);
-        m |= (m >> 4);
-        m |= (m >> 8);
-        m |= (m >> 16);
-        m += 1;
-
-        while (1) {
-            int x = rng64() & (m - 1);
-            if (x < n)
-                return x;
-        }
-    }
-
-    void rngseed(uint64_t seed)
-    {
-        rngstate = seed ? seed : 0x3141592653589793;
-        for (int i = 0; i < 5; i++)
-            rng64();
-    }
-
-    template <typename T> void shuffle(std::vector<T> &a)
-    {
-        for (size_t i = 0; i != a.size(); i++) {
-            size_t j = i + rng(a.size() - i);
-            if (j > i)
-                std::swap(a[i], a[j]);
-        }
-    }
-
-    template <typename T> void sorted_shuffle(std::vector<T> &a)
-    {
-        std::sort(a.begin(), a.end());
-        shuffle(a);
-    }
-
     uint32_t checksum() const;
 
     void check() const;
diff --git a/common/placer1.cc b/common/placer1.cc
index 74a11040..025c7c15 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;
@@ -169,6 +175,7 @@ class SAPlacer
                         try_swap_position(cell, try_bel);
                 }
             }
+
             // Heuristic to improve placement on the 8k
             if (improved)
                 n_no_progress = 0;
@@ -178,6 +185,7 @@ 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 +240,12 @@ class SAPlacer
                 metrics[net.first] = wl;
                 curr_metric += wl;
             }
+
+            // Let the UI show visualization updates.
+            ctx->yield();
         }
         // Final post-pacement validitiy check
+        ctx->lock();
         for (auto bel : ctx->getBels()) {
             IdString cell = ctx->getBoundBelCell(bel);
             if (!ctx->isBelLocationValid(bel)) {
@@ -251,6 +263,7 @@ class SAPlacer
                 }
             }
         }
+        ctx->unlock();
         return true;
     }
 
@@ -436,7 +449,9 @@ 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 1ea50448..a171374f 100644
--- a/common/router1.cc
+++ b/common/router1.cc
@@ -695,6 +695,7 @@ bool router1(Context *ctx)
 
         log_break();
         log_info("Routing..\n");
+        ctx->lock();
 
         std::unordered_map<IdString, std::vector<bool>> jobCache;
         std::priority_queue<RouteJob, std::vector<RouteJob>, RouteJob::Greater> jobQueue;
@@ -766,15 +767,19 @@ bool router1(Context *ctx)
                     normalRouteNets.insert(net_name);
                 }
 
-                if ((ctx->verbose || iterCnt == 1) && !printNets && (jobCnt % 100 == 0))
+                if ((ctx->verbose || iterCnt == 1) && !printNets && (jobCnt % 100 == 0)) {
                     log_info("  processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
+                    ctx->yield();
+                }
             }
 
             NPNR_ASSERT(jobQueue.empty());
             jobCache.clear();
 
-            if ((ctx->verbose || iterCnt == 1) && (jobCnt % 100 != 0))
+            if ((ctx->verbose || iterCnt == 1) && (jobCnt % 100 != 0)) {
                 log_info("  processed %d jobs. (%d routed, %d failed)\n", jobCnt, jobCnt - failedCnt, failedCnt);
+                ctx->yield();
+            }
 
             if (ctx->verbose)
                 log_info("  visited %d PIPs (%.2f%% revisits, %.2f%% overtime "
@@ -828,8 +833,10 @@ bool router1(Context *ctx)
 
                     ripCnt += router.rippedNets.size();
 
-                    if ((ctx->verbose || iterCnt == 1) && !printNets && (netCnt % 100 == 0))
+                    if ((ctx->verbose || iterCnt == 1) && !printNets && (netCnt % 100 == 0)) {
                         log_info("  routed %d nets, ripped %d nets.\n", netCnt, ripCnt);
+                        ctx->yield();
+                    }
                 }
 
                 if ((ctx->verbose || iterCnt == 1) && (netCnt % 100 != 0))
@@ -857,6 +864,8 @@ bool router1(Context *ctx)
 
             if (iterCnt == 8 || iterCnt == 16 || iterCnt == 32 || iterCnt == 64 || iterCnt == 128)
                 ripup_penalty += ctx->getRipupDelayPenalty();
+
+            ctx->yield();
         }
 
         log_info("routing complete after %d iterations.\n", iterCnt);
@@ -888,11 +897,13 @@ bool router1(Context *ctx)
         log_info("Checksum: 0x%08x\n", ctx->checksum());
 #ifndef NDEBUG
         ctx->check();
+        ctx->unlock();
 #endif
         return true;
     } catch (log_execution_error_exception) {
 #ifndef NDEBUG
         ctx->check();
+        ctx->unlock();
 #endif
         return false;
     }