Implement GetThreadCount for Linux.android-cts_7.1_r1android-cts-7.1_r9android-cts-7.1_r8android-cts-7.1_r7android-cts-7.1_r6android-cts-7.1_r5android-cts-7.1_r4android-cts-7.1_r3android-cts-7.1_r29android-cts-7.1_r28android-cts-7.1_r27android-cts-7.1_r26android-cts-7.1_r25android-cts-7.1_r24android-cts-7.1_r23android-cts-7.1_r22android-cts-7.1_r21android-cts-7.1_r20android-cts-7.1_r2android-cts-7.1_r19android-cts-7.1_r18android-cts-7.1_r17android-cts-7.1_r16android-cts-7.1_r15android-cts-7.1_r14android-cts-7.1_r13android-cts-7.1_r12android-cts-7.1_r11android-cts-7.1_r10android-cts-7.1_r1android-cts-7.0_r9android-cts-7.0_r8android-cts-7.0_r7android-cts-7.0_r6android-cts-7.0_r5android-cts-7.0_r4android-cts-7.0_r33android-cts-7.0_r32android-cts-7.0_r31android-cts-7.0_r30android-cts-7.0_r3android-cts-7.0_r29android-cts-7.0_r28android-cts-7.0_r27android-cts-7.0_r26android-cts-7.0_r25android-cts-7.0_r24android-cts-7.0_r23android-cts-7.0_r22android-cts-7.0_r21android-cts-7.0_r20android-cts-7.0_r2android-cts-7.0_r19android-cts-7.0_r18android-cts-7.0_r17android-cts-7.0_r16android-cts-7.0_r15android-cts-7.0_r14android-cts-7.0_r13android-cts-7.0_r12android-cts-7.0_r11android-cts-7.0_r10android-cts-7.0_r1android-7.1.2_r9android-7.1.2_r8android-7.1.2_r6android-7.1.2_r5android-7.1.2_r4android-7.1.2_r39android-7.1.2_r38android-7.1.2_r37android-7.1.2_r36android-7.1.2_r33android-7.1.2_r32android-7.1.2_r30android-7.1.2_r3android-7.1.2_r29android-7.1.2_r28android-7.1.2_r27android-7.1.2_r25android-7.1.2_r24android-7.1.2_r23android-7.1.2_r2android-7.1.2_r19android-7.1.2_r18android-7.1.2_r17android-7.1.2_r16android-7.1.2_r15android-7.1.2_r14android-7.1.2_r13android-7.1.2_r12android-7.1.2_r11android-7.1.2_r10android-7.1.2_r1android-7.1.1_r9android-7.1.1_r8android-7.1.1_r7android-7.1.1_r61android-7.1.1_r60android-7.1.1_r6android-7.1.1_r59android-7.1.1_r58android-7.1.1_r57android-7.1.1_r56android-7.1.1_r55android-7.1.1_r54android-7.1.1_r53android-7.1.1_r52android-7.1.1_r51android-7.1.1_r50android-7.1.1_r49android-7.1.1_r48android-7.1.1_r47android-7.1.1_r46android-7.1.1_r45android-7.1.1_r44android-7.1.1_r43android-7.1.1_r42android-7.1.1_r41android-7.1.1_r40android-7.1.1_r4android-7.1.1_r39android-7.1.1_r38android-7.1.1_r35android-7.1.1_r33android-7.1.1_r32android-7.1.1_r31android-7.1.1_r3android-7.1.1_r28android-7.1.1_r27android-7.1.1_r26android-7.1.1_r25android-7.1.1_r24android-7.1.1_r23android-7.1.1_r22android-7.1.1_r21android-7.1.1_r20android-7.1.1_r2android-7.1.1_r17android-7.1.1_r16android-7.1.1_r15android-7.1.1_r14android-7.1.1_r13android-7.1.1_r12android-7.1.1_r11android-7.1.1_r10android-7.1.1_r1android-7.1.0_r7android-7.1.0_r6android-7.1.0_r5android-7.1.0_r4android-7.1.0_r3android-7.1.0_r2android-7.1.0_r1android-7.0.0_r9android-7.0.0_r8android-7.0.0_r7android-7.0.0_r6android-7.0.0_r5android-7.0.0_r4android-7.0.0_r36android-7.0.0_r35android-7.0.0_r34android-7.0.0_r33android-7.0.0_r32android-7.0.0_r31android-7.0.0_r30android-7.0.0_r3android-7.0.0_r29android-7.0.0_r28android-7.0.0_r27android-7.0.0_r24android-7.0.0_r21android-7.0.0_r19android-7.0.0_r17android-7.0.0_r15android-7.0.0_r14android-7.0.0_r13android-7.0.0_r12android-7.0.0_r11android-7.0.0_r10android-7.0.0_r1afw-test-harness-2.1nougat-releasenougat-mr2.3-releasenougat-mr2.2-releasenougat-mr2.1-releasenougat-mr2-security-releasenougat-mr2-releasenougat-mr2-pixel-releasenougat-mr2-devnougat-mr1.8-releasenougat-mr1.7-releasenougat-mr1.6-releasenougat-mr1.5-releasenougat-mr1.4-releasenougat-mr1.3-releasenougat-mr1.2-releasenougat-mr1.1-releasenougat-mr1-volantis-releasenougat-mr1-security-releasenougat-mr1-releasenougat-mr1-flounder-releasenougat-mr1-devnougat-mr1-cts-releasenougat-mr0.5-releasenougat-dr1-releasenougat-devnougat-cts-releasenougat-bugfix-release

(cherry picked from commit 34114d43af2ef5c5fdf773abe8080ca504737e23)

2 files changed, 47 insertions, 32 deletions

diff --git a/src/gtest-port.cc b/src/gtest-port.cc
index 28fa09a..4847ddc 100644
--- a/src/gtest-port.cc
+++ b/src/gtest-port.cc
@@ -36,6 +36,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <fstream>
 
 #if GTEST_OS_WINDOWS_MOBILE
 # include <windows.h>  // For TerminateProcess()
@@ -83,10 +84,31 @@ const int kStdOutFileno = STDOUT_FILENO;
 const int kStdErrFileno = STDERR_FILENO;
 #endif  // _MSC_VER
 
-#if GTEST_OS_MAC
+#if GTEST_OS_LINUX
+
+namespace {
+template <typename T>
+T ReadProcFileField(const string& filename, int field) {
+  std::string dummy;
+  std::ifstream file(filename.c_str());
+  while (field-- > 0) {
+    file >> dummy;
+  }
+  T output = 0;
+  file >> output;
+  return output;
+}
+}  // namespace
+
+// Returns the number of active threads, or 0 when there is an error.
+size_t GetThreadCount() {
+  const string filename =
+      (Message() << "/proc/" << getpid() << "/stat").GetString();
+  return ReadProcFileField<int>(filename, 19);
+}
+
+#elif GTEST_OS_MAC
 
-// Returns the number of threads running in the process, or 0 to indicate that
-// we cannot detect it.
 size_t GetThreadCount() {
   const task_t task = mach_task_self();
   mach_msg_type_number_t thread_count;
@@ -132,7 +154,7 @@ size_t GetThreadCount() {
   return 0;
 }
 
-#endif  // GTEST_OS_MAC
+#endif  // GTEST_OS_LINUX
 
 #if GTEST_USES_POSIX_RE
 
diff --git a/test/gtest-port_test.cc b/test/gtest-port_test.cc
index 43f1f20..9240996 100644
--- a/test/gtest-port_test.cc
+++ b/test/gtest-port_test.cc
@@ -304,58 +304,51 @@ TEST(FormatCompilerIndependentFileLocationTest, FormatsUknownFileAndLine) {
   EXPECT_EQ("unknown file", FormatCompilerIndependentFileLocation(NULL, -1));
 }
 
-#if GTEST_OS_MAC || GTEST_OS_QNX
+#if GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_QNX
 void* ThreadFunc(void* data) {
-  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data);
-  pthread_mutex_lock(mutex);
-  pthread_mutex_unlock(mutex);
+  internal::Mutex* mutex = static_cast<internal::Mutex*>(data);
+  mutex->Lock();
+  mutex->Unlock();
   return NULL;
 }
 
 TEST(GetThreadCountTest, ReturnsCorrectValue) {
-  EXPECT_EQ(1U, GetThreadCount());
-  pthread_mutex_t mutex;
-  pthread_attr_t  attr;
+  const size_t starting_count = GetThreadCount();
   pthread_t       thread_id;
 
-  // TODO(vladl@google.com): turn mutex into internal::Mutex for automatic
-  // destruction.
-  pthread_mutex_init(&mutex, NULL);
-  pthread_mutex_lock(&mutex);
-  ASSERT_EQ(0, pthread_attr_init(&attr));
-  ASSERT_EQ(0, pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE));
-
-  const int status = pthread_create(&thread_id, &attr, &ThreadFunc, &mutex);
-  ASSERT_EQ(0, pthread_attr_destroy(&attr));
-  ASSERT_EQ(0, status);
-  EXPECT_EQ(2U, GetThreadCount());
-  pthread_mutex_unlock(&mutex);
+  internal::Mutex mutex;
+  {
+    internal::MutexLock lock(&mutex);
+    pthread_attr_t  attr;
+    ASSERT_EQ(0, pthread_attr_init(&attr));
+    ASSERT_EQ(0, pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE));
+
+    const int status = pthread_create(&thread_id, &attr, &ThreadFunc, &mutex);
+    ASSERT_EQ(0, pthread_attr_destroy(&attr));
+    ASSERT_EQ(0, status);
+    EXPECT_EQ(starting_count + 1, GetThreadCount());
+  }
 
   void* dummy;
   ASSERT_EQ(0, pthread_join(thread_id, &dummy));
 
-# if GTEST_OS_MAC
-
-  // MacOS X may not immediately report the updated thread count after
+  // The OS may not immediately report the updated thread count after
   // joining a thread, causing flakiness in this test. To counter that, we
   // wait for up to .5 seconds for the OS to report the correct value.
   for (int i = 0; i < 5; ++i) {
-    if (GetThreadCount() == 1)
+    if (GetThreadCount() == starting_count)
       break;
 
     SleepMilliseconds(100);
   }
 
-# endif  // GTEST_OS_MAC
-
-  EXPECT_EQ(1U, GetThreadCount());
-  pthread_mutex_destroy(&mutex);
+  EXPECT_EQ(starting_count, GetThreadCount());
 }
 #else
 TEST(GetThreadCountTest, ReturnsZeroWhenUnableToCountThreads) {
   EXPECT_EQ(0U, GetThreadCount());
 }
-#endif  // GTEST_OS_MAC || GTEST_OS_QNX
+#endif  // GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_QNX
 
 TEST(GtestCheckDeathTest, DiesWithCorrectOutputOnFailure) {
   const bool a_false_condition = false;