Test system-wide semaphore limits.

1 files changed, 16 insertions, 2 deletions

diff --git a/test/syscalls/linux/semaphore.cc b/test/syscalls/linux/semaphore.cc
index 2ce8f836c..54cbda19d 100644
--- a/test/syscalls/linux/semaphore.cc
+++ b/test/syscalls/linux/semaphore.cc
@@ -22,12 +22,12 @@
 #include <ctime>
 #include <set>
 
-#include "gmock/gmock.h"
-#include "gtest/gtest.h"
 #include "absl/base/macros.h"
 #include "absl/memory/memory.h"
 #include "absl/synchronization/mutex.h"
 #include "absl/time/clock.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
 #include "test/util/capability_util.h"
 #include "test/util/test_util.h"
 #include "test/util/thread_util.h"
@@ -49,6 +49,9 @@ constexpr int kSemAem = 32767;
 
 class AutoSem {
  public:
+  // Creates a new private semaphore.
+  AutoSem() : id_(semget(IPC_PRIVATE, 1, 0)) {}
+
   explicit AutoSem(int id) : id_(id) {}
   ~AutoSem() {
     if (id_ >= 0) {
@@ -101,6 +104,17 @@ TEST(SemaphoreTest, SemGet) {
   EXPECT_NE(sem3.get(), sem2.get());
 }
 
+// Tests system-wide limits for semget.
+TEST(SemaphoreTest, SemGetSystemLimits) {
+  // Exceed number of semaphores per set.
+  EXPECT_THAT(semget(IPC_PRIVATE, kSemMsl + 1, 0),
+              SyscallFailsWithErrno(EINVAL));
+
+  // Exceed system-wide limit for semaphore sets by 1.
+  AutoSem sems[kSemMni];
+  EXPECT_THAT(semget(IPC_PRIVATE, 1, 0), SyscallFailsWithErrno(ENOSPC));
+}
+
 // Tests simple operations that shouldn't block in a single-thread.
 TEST(SemaphoreTest, SemOpSingleNoBlock) {
   AutoSem sem(semget(IPC_PRIVATE, 1, 0600 | IPC_CREAT));