Baron: removed PL as not supported. Added signal handling/propagation.

solvers/baronmp/baronmpbackend.cc

@@ -6,6 +6,12 @@
 #include "mp/flat/model_api_base.h"
 #include "baronmpbackend.h"
 
+
+#ifndef WIN32
+#include <csignal>  // for kill()
+#endif
+
+
 extern "C" {
   #include "baronmp-ampls-c-api.h"    // Baronmp AMPLS C API
 }
@@ -15,12 +21,18 @@ namespace {
 
 
 bool InterruptBaronmp(void* prob) {
-
-  //return BARONMP_Interrupt((baronmp_prob*)prob);
+  #ifndef WIN32
+  kill(mp::BaronmpCommon::pid, SIGINT);
+  #else
+  if (!GenerateConsoleCtrlEvent(CTRL_C_EVENT, mp::BaronmpCommon::pid)) {
+        std::cerr << "GenerateConsoleCtrlEvent failed (" << GetLastError() << ").\n";
+        return false;
+    }
+  #endif
   return true;
 }
 
-}  // namespace {}
+}  
 
 std::unique_ptr<mp::BasicBackend> CreateBaronmpBackend() {
   return std::unique_ptr<mp::BasicBackend>{new mp::BaronmpBackend()};
@@ -121,8 +133,6 @@ int BaronmpBackend::BarrierIterations() const {
 
 void BaronmpBackend::SetInterrupter(mp::Interrupter *inter) {
   inter->SetHandler(InterruptBaronmp, lp());
-  // TODO Check interrupter
-  //BARONMP_CCALL( CPXsetterminate (env(), &terminate_flag) );
 }
 
 void BaronmpBackend::Solve() {

solvers/baronmp/baronmpcommon.cc

@@ -39,6 +39,7 @@ namespace mp {
 #else
   constexpr const char* EXENAME = "baronin";
   char SEP = '/';
+  volatile pid_t BaronmpCommon::pid=-5;
 #endif
 
 int BaronmpCommon::runBaron(const std::string& arg) {
@@ -102,11 +103,12 @@ int BaronmpCommon::run(const std::vector<std::string>& args) {
   ZeroMemory(&pi, sizeof(pi));
 
   // Create the process
-  if (!CreateProcess(NULL, cmdline.data(), NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)) {
+  if (!CreateProcess(NULL, cmdline.data(), NULL, 
+  NULL, TRUE, CREATE_NEW_PROCESS_GROUP, NULL, NULL, &si, &pi)) {
     fmt::print(stderr, "CreateProcess failed ({})\n", GetLastError());
     return -1;
   }
-
+  pid = pi.dwProcessId;
   // Wait until the process exits
   WaitForSingleObject(pi.hProcess, INFINITE);
 
@@ -126,7 +128,7 @@ int BaronmpCommon::run(const std::vector<std::string>& args) {
   char **environ= *_NSGetEnviron();
 #endif
   // Unix-like system implementation using fork and execve
-  pid_t pid = fork();
+  pid = fork();
 
   if (pid == -1) {
     fmt::print(stderr, "fork failed: {}\n", strerror(errno));
@@ -147,17 +149,17 @@ int BaronmpCommon::run(const std::vector<std::string>& args) {
   else {
     // Parent process: wait for the child to complete
     int status;
-    if (waitpid(pid, &status, 0) == -1) {
-      fmt::print(stderr, "waitpid failed: {}\n", strerror(errno));
-      return -1;
-    }
+    do {
+          pid = waitpid(pid, &status, 0);
+    } while (pid == -1 && errno == EINTR);  // Retry if interrupted by a signal
+
 
     if (WIFEXITED(status)) {
       return WEXITSTATUS(status);
     }
     else if (WIFSIGNALED(status)) {
       fmt::print(stderr, "Process terminated by signal {}\n", WTERMSIG(status));
-      return -1;
+      return 0;
     }
   }
 #endif

solvers/baronmp/baronmpcommon.h

@@ -298,6 +298,11 @@ class BaronmpCommon :
     public Backend2ModelAPIConnector<BaronmpCommonInfo> {
 public:
 
+#ifndef WIN32
+  static volatile pid_t pid;
+  #else 
+  DWORD pid;
+#endif
   static constexpr double Infinity() { return INFINITY;  }
   static constexpr double MinusInfinity() { return -INFINITY; }
   const std::string FILENAME_BAR = "amplmodel.bar";
@@ -402,6 +407,9 @@ class ResFileData {
 
 
   double ObjectiveValue() const {
+
+    if(objective_values.size() == 0)
+    return 0;
     return objective_values[objective_values.size() - 1];
   }
 

solvers/baronmp/baronmpmodelapi.cc

@@ -110,19 +110,29 @@ namespace mp {
     nVarsInteger(indicesInt.size());
   }
 
+  void addCoefficient(fmt::MemoryWriter &w, double coeff, bool first)
+  {
+    if (coeff > 0) {
+        if (!first) w << " + ";
+        // Omit '1*' for positive coefficient 1
+        if (coeff != 1) 
+            w << coeff << "*";
+    } 
+    else { // Coefficient is negative
+        // If the coefficient is -1, just print ' - ', otherwise print the coefficient
+        if (coeff == -1)  w << " - ";
+         else  w << coeff << "*";
+    }
+  }
 
   void appendLinearTerm(fmt::MemoryWriter &w, double coeff, const char* vname, bool first = false)
   {
-    if ((!first) && (coeff > 0))
-      w << "+";
-    if (std::fabs(coeff) != 1.0) w << coeff << "*";
+    addCoefficient(w, coeff, first);
     w << vname;
   }
   void appendQuadTerm(fmt::MemoryWriter &w, double coeff, const char* v1, const char* v2=nullptr, bool first = false)
   {
-    if ((!first) && (coeff > 0))
-      w << " +";
-    if (std::fabs(coeff) != 1.0) w << coeff << "*";
+    addCoefficient(w, coeff, first);
     if(v2)
       w << v1 << "*" << v2;
     else
@@ -303,31 +313,30 @@ void BaronmpModelAPI::AddConstraint(const LogConstraint& cc) {
 }
 
 void BaronmpModelAPI::AddConstraint(const ExpAConstraint& cc) {
-  // TODO
-  fmt::print("Adding ExpA constraint \"{}\"\n", cc.GetName());
+  // a^v
+  fmt::MemoryWriter w;
+  w<< createConName(cc.GetName()) << ": ";
+  w << fmt::format("{} = {} ^ {};\n",  varName(cc.GetResultVar()), cc.GetParameters()[0],varName( cc.GetArguments()[0]));
+  cons.push_back(w.str());
 }
 
-
-
 void BaronmpModelAPI::AddConstraint(const LogAConstraint& cc) {
-  // TODO
-  fmt::print("Adding LogA constraint \"{}\"\n", cc.GetName());
+  fmt::MemoryWriter w;
+  w<< createConName(cc.GetName()) << ": ";
+  w << fmt::format("{} = log({})/log({});\n", varName(cc.GetResultVar()), 
+    varName( cc.GetArguments()[0]), cc.GetParameters()[0]);
+  cons.push_back(w.str());
 }
 
 void BaronmpModelAPI::AddConstraint(const PowConstraint& cc) {
-  // TODO
-}
-
-
-
-void BaronmpModelAPI::AddConstraint(const PLConstraint& plc) {
-  fmt::print("Adding PL constraint \"{}\"\n", plc.GetName());
-  // todo
+  // v ^ a
+   fmt::MemoryWriter w;
+  w<< createConName(cc.GetName()) << ": ";
+  w << fmt::format("{} = {} ^ {};\n",  varName(cc.GetResultVar()),varName( cc.GetArguments()[0]), cc.GetParameters()[0]);
+  cons.push_back(w.str());
 }
 
-
 template <int SENSE> void BaronmpModelAPI::addTopLevel(const NLBaseAssign<SENSE>& c) {
-    fmt::print("addTopLevel(const NLBaseAssign)\n");
   const auto var = GetVariable(c);
   fmt::MemoryWriter w;
   w << createConName(c.GetName()) << ": ";
@@ -336,7 +345,6 @@ template <int SENSE> void BaronmpModelAPI::addTopLevel(const NLBaseAssign<SENSE>
   const auto& frm = GetExpression(c);
   w << frm.ToString(false); 
   w << ";\n";
-    fmt::print("{}\n", w.str());
   cons.push_back(w.str());
 }
 

solvers/baronmp/baronmpmodelapi.h

@@ -297,8 +297,6 @@ class BaronmpModelAPI :
 
   /// Some non linear constraints.
   /// See constr_std.h for more.
-  ACCEPT_CONSTRAINT(PLConstraint, Recommended, CG_General)
-  void AddConstraint(const PLConstraint& cc);
   ACCEPT_CONSTRAINT(MaxConstraint, Recommended, CG_General)
     void AddConstraint(const MaxConstraint& mc);
   ACCEPT_CONSTRAINT(MinConstraint, Recommended, CG_General)