diff options
| -rw-r--r-- | llvm/unittests/Support/Path.cpp | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp index 3c0f7936030..750fd13db97 100644 --- a/llvm/unittests/Support/Path.cpp +++ b/llvm/unittests/Support/Path.cpp @@ -700,10 +700,18 @@ TEST_F(FileSystemTest, TempFileCollisions) { } }; - // We should be able to create exactly 16 temporary files. - for (int i = 0; i < 16; ++i) - EXPECT_TRUE(TryCreateTempFile()); - EXPECT_FALSE(TryCreateTempFile()); + // Our single-character template allows for 16 unique names. Check that + // calling TryCreateTempFile repeatedly results in 16 successes. + // Because the test depends on random numbers, it could theoretically fail. + // However, the probability of this happening is tiny: with 32 calls, each + // of which will retry up to 128 times, to not get a given digit we would + // have to fail at least 15 + 17 * 128 = 2191 attempts. The probability of + // 2191 attempts not producing a given hexadecimal digit is + // (1 - 1/16) ** 2191 or 3.88e-62. + int Successes = 0; + for (int i = 0; i < 32; ++i) + if (TryCreateTempFile()) ++Successes; + EXPECT_EQ(Successes, 16); for (fs::TempFile &T : TempFiles) cantFail(T.discard()); |
