Add test about pthread_mutex_t owner tid limit.

Bug: 19216648
Change-Id: I7b12955bdcad31c13bf8ec2740ff88ba15223ec0

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index cb32079..5dc60ee 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -27,6 +27,7 @@
 #include <malloc.h>
 #include <pthread.h>
 #include <signal.h>
+#include <stdio.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <time.h>
@@ -1092,3 +1093,14 @@ TEST(pthread, pthread_mutex_lock_RECURSIVE) {
   ASSERT_EQ(EPERM, pthread_mutex_unlock(&lock));
   ASSERT_EQ(0, pthread_mutex_destroy(&lock));
 }
+
+TEST(pthread, pthread_mutex_owner_tid_limit) {
+  FILE* fp = fopen("/proc/sys/kernel/pid_max", "r");
+  ASSERT_TRUE(fp != NULL);
+  long pid_max;
+  ASSERT_EQ(1, fscanf(fp, "%ld", &pid_max));
+  fclose(fp);
+  // Current pthread_mutex uses 16 bits to represent owner tid.
+  // Change the implementation if we need to support higher value than 65535.
+  ASSERT_LE(pid_max, 65536);
+}