Signal watcher functionality with test

bindings/cpp/Makefile

@@ -41,6 +41,10 @@ else
 $(error Expected value of THREADING to be single/pthread/std)
 endif
 
+ifneq "$(THREADING)" "std"
+override POSIX_SUPPORT = "0"
+endif
+
 # Required flag customizations.
 override CPPFLAGS += -Iinclude
 override CPPFLAGS += -I$(GTEST_DIR)/include
@@ -67,6 +71,10 @@ PLATFORM_HEADERS := \
 	include/wtf/platform/platform_myriad2sparc_impl.h \
 	include/wtf/platform/platform_myriad2sparc_inl.h
 
+ifeq "$(POSIX_SUPPORT)" "1"
+LIBRARY_HEADERS += include/wtf/posix_utils.h
+endif
+
 ALL_HEADERS := $(LIBRARY_HEADERS) $(PLATFORM_HEADERS)
 
 LIBRARY_SOURCES := \
@@ -81,6 +89,11 @@ TEST_SOURCES := \
 	runtime_test.cc \
 	threaded_torture_test.cc
 
+ifeq "$(POSIX_SUPPORT)" "1"
+LIBRARY_SOURCES += posix_utils.cc
+TEST_SOURCES += posix_utils_test.cc
+endif
+
 LIBRARY_OBJECTS := $(LIBRARY_SOURCES:%.cc=%.o)
 
 .PHONY: clean all test
@@ -113,7 +126,13 @@ clean:
 		$(wildcard tmp*.wtf-trace)
 
 ### TESTING.
+ifneq "$(POSIX_SUPPORT)" "1"
 test: buffer_test macros_test runtime_test threaded_torture_test
+else
+test: buffer_test macros_test runtime_test threaded_torture_test posix_utils_test
+	@echo "Running posix_utils_test"
+	./posix_utils_test
+endif
 	@echo "Running buffer_test"
 	./buffer_test
 	@echo "Running macros_test"
@@ -138,6 +157,9 @@ macros_test: macros_test.o gtest.o libwtf.a
 runtime_test: runtime_test.o gtest.o libwtf.a
 	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -o $@ $+ $(LDLIBS)
 
+posix_utils_test: posix_utils_test.o gtest.o libwtf.a
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -o $@ $+ $(LDLIBS)
+
 ### THREADED TORTURE TEST
 ifneq "$(THREADING)" "single"
 threaded_torture_test: threaded_torture_test.o libwtf.a

bindings/cpp/include/wtf/posix_utils.h

@@ -0,0 +1,12 @@
+#ifndef POSIX_UTILS_H
+#define POSIX_UTILS_H
+
+namespace wtf {
+namespace posix_utils {
+
+    void InstallSignalHandler(int number, char const* filename);
+
+} // namespace posix_utils
+} // namespace wtf
+
+#endif // POSIX_UTILS_H

bindings/cpp/posix_utils.cc

@@ -0,0 +1,52 @@
+#include <wtf/runtime.h>
+#include <signal.h>
+
+#include <thread>
+#include <condition_variable>
+
+namespace {
+
+std::condition_variable gCv;
+std::mutex gMutex;
+std::string gFilename;
+
+void WtfOnSignal(int) {
+  gCv.notify_all();
+};
+
+void WtfSignalWatcherThread () {
+  std::unique_lock<std::mutex> lock { gMutex };
+  while (true) {
+    gCv.wait(lock);
+    wtf::Runtime::GetInstance()->SaveToFile(gFilename.c_str());
+  }
+}
+
+} // namespace
+
+namespace wtf {
+namespace posix_utils {
+
+void InstallSignalHandler(int number, char const* filename) {
+  if (!filename) {
+    fprintf(stderr, "%s: Error: filename can't be null\n", __PRETTY_FUNCTION__);
+    return;
+  }
+
+  static std::atomic<bool> only_once {false};
+  bool expected = false;
+  if (only_once.compare_exchange_strong(expected, true)) {
+
+    gFilename = filename;
+    std::thread thread { WtfSignalWatcherThread };
+
+    signal(number, WtfOnSignal);
+
+    thread.detach();
+
+  }
+
+}
+
+} // namespace posix_utils
+} // namespace wtf

bindings/cpp/posix_utils_test.cc

@@ -0,0 +1,47 @@
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "wtf/posix_utils.h"
+#include "wtf/macros.h"
+
+#include "gtest/gtest.h"
+
+const char kSignalWatcherFilename[] { "./tmptstsignal_watcher.wtf-trace" };
+
+namespace wtf {
+
+class PosixUtilsTest : public ::testing::Test {
+protected:
+  void TearDown() override {
+    wtf::Runtime::GetInstance()->DisableCurrentThread();
+    wtf::Runtime::GetInstance()->ResetForTesting();
+  }
+
+};
+
+
+TEST_F(PosixUtilsTest, SignalWatcher) {
+  unlink(kSignalWatcherFilename);
+  // watch SIGALRM
+  wtf::posix_utils::InstallSignalHandler(14, kSignalWatcherFilename);
+  WTF_EVENT0("MacrosTest#SignalWatcher");
+
+  alarm(1);
+
+  const int second = 1000;
+  usleep(5000 * second);
+
+  alarm(0);
+  // allow the thread to finish it's work
+  usleep(1000 * second);
+  struct stat buffer;
+
+  EXPECT_TRUE(stat(kSignalWatcherFilename, &buffer) == 0);
+  EXPECT_TRUE(buffer.st_size > 0);
+}
+} // namespace wtf
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}