Add GNU make jobserver client support

CMakeLists.txt

@@ -118,6 +118,7 @@ add_library(libninja OBJECT
 	src/state.cc
 	src/status.cc
 	src/string_piece_util.cc
+	src/tokenpool-gnu-make.cc
 	src/util.cc
 	src/version.cc
 )
@@ -129,13 +130,17 @@ if(WIN32)
 		src/msvc_helper_main-win32.cc
 		src/getopt.c
 		src/minidump-win32.cc
+		src/tokenpool-gnu-make-win32.cc
 	)
 	# Build getopt.c, which can be compiled as either C or C++, as C++
 	# so that build environments which lack a C compiler, but have a C++
 	# compiler may build ninja.
 	set_source_files_properties(src/getopt.c PROPERTIES LANGUAGE CXX)
 else()
-	target_sources(libninja PRIVATE src/subprocess-posix.cc)
+	target_sources(libninja PRIVATE
+		src/subprocess-posix.cc
+		src/tokenpool-gnu-make-posix.cc
+	)
 	if(CMAKE_SYSTEM_NAME STREQUAL "OS400" OR CMAKE_SYSTEM_NAME STREQUAL "AIX")
 		target_sources(libninja PRIVATE src/getopt.c)
 		# Build getopt.c, which can be compiled as either C or C++, as C++
@@ -224,6 +229,7 @@ if(BUILD_TESTING)
     src/string_piece_util_test.cc
     src/subprocess_test.cc
     src/test.cc
+    src/tokenpool_test.cc
     src/util_test.cc
   )
   if(WIN32)

configure.py

@@ -538,11 +538,13 @@ def has_re2c():
              'state',
              'status',
              'string_piece_util',
+             'tokenpool-gnu-make',
              'util',
              'version']:
     objs += cxx(name, variables=cxxvariables)
 if platform.is_windows():
     for name in ['subprocess-win32',
+                 'tokenpool-gnu-make-win32',
                  'includes_normalize-win32',
                  'msvc_helper-win32',
                  'msvc_helper_main-win32']:
@@ -551,7 +553,9 @@ def has_re2c():
         objs += cxx('minidump-win32', variables=cxxvariables)
     objs += cc('getopt')
 else:
-    objs += cxx('subprocess-posix')
+    for name in ['subprocess-posix',
+                 'tokenpool-gnu-make-posix']:
+        objs += cxx(name)
 if platform.is_aix():
     objs += cc('getopt')
 if platform.is_msvc():
@@ -609,6 +613,7 @@ def has_re2c():
              'string_piece_util_test',
              'subprocess_test',
              'test',
+             'tokenpool_test',
              'util_test']:
     objs += cxx(name, variables=cxxvariables)
 if platform.is_windows():

src/build.cc

@@ -35,6 +35,7 @@
 #include "state.h"
 #include "status.h"
 #include "subprocess.h"
+#include "tokenpool.h"
 #include "util.h"
 
 using namespace std;
@@ -47,8 +48,9 @@ struct DryRunCommandRunner : public CommandRunner {
 
   // Overridden from CommandRunner:
   virtual bool CanRunMore() const;
+  virtual bool AcquireToken();
   virtual bool StartCommand(Edge* edge);
-  virtual bool WaitForCommand(Result* result);
+  virtual bool WaitForCommand(Result* result, bool more_ready);
 
  private:
   queue<Edge*> finished_;
@@ -58,12 +60,16 @@ bool DryRunCommandRunner::CanRunMore() const {
   return true;
 }
 
+bool DryRunCommandRunner::AcquireToken() {
+  return true;
+}
+
 bool DryRunCommandRunner::StartCommand(Edge* edge) {
   finished_.push(edge);
   return true;
 }
 
-bool DryRunCommandRunner::WaitForCommand(Result* result) {
+bool DryRunCommandRunner::WaitForCommand(Result* result, bool more_ready) {
    if (finished_.empty())
      return false;
 
@@ -149,7 +155,7 @@ void Plan::EdgeWanted(const Edge* edge) {
 }
 
 Edge* Plan::FindWork() {
-  if (ready_.empty())
+  if (!more_ready())
     return NULL;
   EdgeSet::iterator e = ready_.begin();
   Edge* edge = *e;
@@ -448,19 +454,39 @@ void Plan::Dump() const {
 }
 
 struct RealCommandRunner : public CommandRunner {
-  explicit RealCommandRunner(const BuildConfig& config) : config_(config) {}
-  virtual ~RealCommandRunner() {}
+  explicit RealCommandRunner(const BuildConfig& config);
+  virtual ~RealCommandRunner();
   virtual bool CanRunMore() const;
+  virtual bool AcquireToken();
   virtual bool StartCommand(Edge* edge);
-  virtual bool WaitForCommand(Result* result);
+  virtual bool WaitForCommand(Result* result, bool more_ready);
   virtual vector<Edge*> GetActiveEdges();
   virtual void Abort();
 
   const BuildConfig& config_;
+  // copy of config_.max_load_average; can be modified by TokenPool setup
+  double max_load_average_;
   SubprocessSet subprocs_;
+  TokenPool* tokens_;
   map<const Subprocess*, Edge*> subproc_to_edge_;
 };
 
+RealCommandRunner::RealCommandRunner(const BuildConfig& config) : config_(config) {
+  max_load_average_ = config.max_load_average;
+  if ((tokens_ = TokenPool::Get()) != NULL) {
+    if (!tokens_->Setup(config_.parallelism_from_cmdline,
+                        config_.verbosity == BuildConfig::VERBOSE,
+                        max_load_average_)) {
+      delete tokens_;
+      tokens_ = NULL;
+    }
+  }
+}
+
+RealCommandRunner::~RealCommandRunner() {
+  delete tokens_;
+}
+
 vector<Edge*> RealCommandRunner::GetActiveEdges() {
   vector<Edge*> edges;
   for (map<const Subprocess*, Edge*>::iterator e = subproc_to_edge_.begin();
@@ -471,34 +497,57 @@ vector<Edge*> RealCommandRunner::GetActiveEdges() {
 
 void RealCommandRunner::Abort() {
   subprocs_.Clear();
+  if (tokens_)
+    tokens_->Clear();
 }
 
 bool RealCommandRunner::CanRunMore() const {
-  size_t subproc_number =
-      subprocs_.running_.size() + subprocs_.finished_.size();
-  return (int)subproc_number < config_.parallelism
-    && ((subprocs_.running_.empty() || config_.max_load_average <= 0.0f)
-        || GetLoadAverage() < config_.max_load_average);
+  bool parallelism_limit_not_reached =
+    tokens_ || // ignore config_.parallelism
+    ((int) (subprocs_.running_.size() +
+            subprocs_.finished_.size()) < config_.parallelism);
+  return parallelism_limit_not_reached
+    && (subprocs_.running_.empty() ||
+        (max_load_average_ <= 0.0f ||
+         GetLoadAverage() < max_load_average_));
+}
+
+bool RealCommandRunner::AcquireToken() {
+  return (!tokens_ || tokens_->Acquire());
 }
 
 bool RealCommandRunner::StartCommand(Edge* edge) {
   string command = edge->EvaluateCommand();
   Subprocess* subproc = subprocs_.Add(command, edge->use_console());
   if (!subproc)
     return false;
+  if (tokens_)
+    tokens_->Reserve();
   subproc_to_edge_.insert(make_pair(subproc, edge));
 
   return true;
 }
 
-bool RealCommandRunner::WaitForCommand(Result* result) {
+bool RealCommandRunner::WaitForCommand(Result* result, bool more_ready) {
   Subprocess* subproc;
-  while ((subproc = subprocs_.NextFinished()) == NULL) {
-    bool interrupted = subprocs_.DoWork();
+  subprocs_.ResetTokenAvailable();
+  while (((subproc = subprocs_.NextFinished()) == NULL) &&
+         !subprocs_.IsTokenAvailable()) {
+    bool interrupted = subprocs_.DoWork(more_ready ? tokens_ : NULL);
     if (interrupted)
       return false;
   }
 
+  // token became available
+  if (subproc == NULL) {
+    result->status = ExitTokenAvailable;
+    return true;
+  }
+
+  // command completed
+  if (tokens_)
+    tokens_->Release();
+
   result->status = subproc->Finish();
   result->output = subproc->GetOutput();
 
@@ -628,45 +677,54 @@ bool Builder::Build(string* err) {
   // command runner.
   // Second, we attempt to wait for / reap the next finished command.
   while (plan_.more_to_do()) {
-    // See if we can start any more commands.
-    if (failures_allowed && command_runner_->CanRunMore()) {
-      if (Edge* edge = plan_.FindWork()) {
-        if (edge->GetBindingBool("generator")) {
+    // See if we can start any more commands...
+    bool can_run_more =
+        failures_allowed   &&
+        plan_.more_ready() &&
+        command_runner_->CanRunMore();
+
+    // ... but we also need a token to do that.
+    if (can_run_more && command_runner_->AcquireToken()) {
+      Edge* edge = plan_.FindWork();
+      if (edge->GetBindingBool("generator")) {
           scan_.build_log()->Close();
         }
 
-        if (!StartEdge(edge, err)) {
+      if (!StartEdge(edge, err)) {
+        Cleanup();
+        status_->BuildFinished();
+        return false;
+      }
+
+      if (edge->is_phony()) {
+        if (!plan_.EdgeFinished(edge, Plan::kEdgeSucceeded, err)) {
           Cleanup();
           status_->BuildFinished();
           return false;
         }
-
-        if (edge->is_phony()) {
-          if (!plan_.EdgeFinished(edge, Plan::kEdgeSucceeded, err)) {
-            Cleanup();
-            status_->BuildFinished();
-            return false;
-          }
-        } else {
-          ++pending_commands;
-        }
-
-        // We made some progress; go back to the main loop.
-        continue;
+      } else {
+        ++pending_commands;
       }
+
+      // We made some progress; go back to the main loop.
+      continue;
     }
 
     // See if we can reap any finished commands.
     if (pending_commands) {
       CommandRunner::Result result;
-      if (!command_runner_->WaitForCommand(&result) ||
+      if (!command_runner_->WaitForCommand(&result, can_run_more) ||
           result.status == ExitInterrupted) {
         Cleanup();
         status_->BuildFinished();
         *err = "interrupted by user";
         return false;
       }
 
+      // We might be able to start another command; start the main loop over.
+      if (result.status == ExitTokenAvailable)
+        continue;
+
       --pending_commands;
       if (!FinishCommand(&result, err)) {
         Cleanup();

src/build.h

@@ -52,6 +52,9 @@ struct Plan {
   /// Returns true if there's more work to be done.
   bool more_to_do() const { return wanted_edges_ > 0 && command_edges_ > 0; }
 
+  /// Returns true if there's more edges ready to start
+  bool more_ready() const { return !ready_.empty(); }
+
   /// Dumps the current state of the plan.
   void Dump() const;
 
@@ -136,6 +139,7 @@ struct Plan {
 struct CommandRunner {
   virtual ~CommandRunner() {}
   virtual bool CanRunMore() const = 0;
+  virtual bool AcquireToken() = 0;
   virtual bool StartCommand(Edge* edge) = 0;
 
   /// The result of waiting for a command.
@@ -147,15 +151,18 @@ struct CommandRunner {
     bool success() const { return status == ExitSuccess; }
   };
   /// Wait for a command to complete, or return false if interrupted.
-  virtual bool WaitForCommand(Result* result) = 0;
+  /// If more_ready is true then the optional TokenPool is monitored too
+  /// and we return when a token becomes available.
+  virtual bool WaitForCommand(Result* result, bool more_ready) = 0;
 
   virtual std::vector<Edge*> GetActiveEdges() { return std::vector<Edge*>(); }
   virtual void Abort() {}
 };
 
 /// Options (e.g. verbosity, parallelism) passed to a build.
 struct BuildConfig {
-  BuildConfig() : verbosity(NORMAL), dry_run(false), parallelism(1),
+  BuildConfig() : verbosity(NORMAL), dry_run(false),
+                  parallelism(1), parallelism_from_cmdline(false),
                   failures_allowed(1), max_load_average(-0.0f) {}
 
   enum Verbosity {
@@ -167,6 +174,7 @@ struct BuildConfig {
   Verbosity verbosity;
   bool dry_run;
   int parallelism;
+  bool parallelism_from_cmdline;
   int failures_allowed;
   /// The maximum load average we must not exceed. A negative value
   /// means that we do not have any limit.