f9cfecf3d4
This has been in the standard since C99, but we've never supported it before. It's apparently used by SPIRV-Tools. I tried implementing this the other way (with fcntl(2)) first, but eventually realized that that's more complicated and gives worse results. This implementation assumes that /proc is mounted, but so much of libc relies on that at this point that I don't think there's any realistic case where the fcntl(2) implementation would be preferable, and there are many where it's not. The fact that no-one's mentioned this until now suggests that it's not a heavily used feature anyway. I've also replaced AssertCloseOnExec() with a CloseOnExec() boolean-valued function instead, because it's really annoying getting assertion failures that don't point you at the test line in question, and instead point to some common helper code. Test: treehugger Change-Id: Ia2e53bf2664a4f782581042054ecd492830e2aed
94 lines
2.3 KiB
C++
94 lines
2.3 KiB
C++
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <gtest/gtest.h>
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#include <sys/eventfd.h>
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#include "utils.h"
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TEST(eventfd, smoke) {
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constexpr unsigned int kInitialValue = 2;
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int fd = eventfd(kInitialValue, EFD_NONBLOCK);
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ASSERT_NE(-1, fd);
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eventfd_t value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(kInitialValue, value);
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// Reading clears the counter.
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ASSERT_EQ(-1, eventfd_read(fd, &value));
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ASSERT_EQ(EAGAIN, errno);
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// Values written are added until the next read.
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ASSERT_EQ(0, eventfd_write(fd, 1));
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ASSERT_EQ(0, eventfd_write(fd, 1));
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ASSERT_EQ(0, eventfd_write(fd, 1));
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(3U, value);
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close(fd);
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}
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TEST(eventfd, cloexec) {
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constexpr unsigned int kInitialValue = 2;
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int fd = eventfd(kInitialValue, EFD_CLOEXEC);
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ASSERT_NE(-1, fd);
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ASSERT_TRUE(CloseOnExec(fd));
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eventfd_t value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(kInitialValue, value);
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close(fd);
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fd = eventfd(kInitialValue, EFD_NONBLOCK | EFD_CLOEXEC);
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ASSERT_NE(-1, fd);
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ASSERT_TRUE(CloseOnExec(fd));
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value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(kInitialValue, value);
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close(fd);
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}
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TEST(eventfd, semaphore) {
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int fd = eventfd(3, EFD_NONBLOCK | EFD_SEMAPHORE);
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ASSERT_NE(-1, fd);
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eventfd_t value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(1U, value);
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value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(1U, value);
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value = 123;
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ASSERT_EQ(0, eventfd_read(fd, &value));
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ASSERT_EQ(1U, value);
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// The counter is cleared after the initial value decrements to 0.
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ASSERT_EQ(-1, eventfd_read(fd, &value));
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ASSERT_EQ(EAGAIN, errno);
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close(fd);
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}
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