71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
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#include <assert.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <unistd.h>
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static void test_anonymous(void)
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{
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int pagesize = getpagesize();
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char *page;
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int ret;
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page = mmap(NULL, pagesize, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
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assert(page != MAP_FAILED);
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/* Check that mprotect() does not interfere with MADV_DONTNEED. */
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ret = mprotect(page, pagesize, PROT_READ | PROT_WRITE);
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assert(ret == 0);
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/* Check that MADV_DONTNEED clears the page. */
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*page = 42;
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ret = madvise(page, pagesize, MADV_DONTNEED);
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assert(ret == 0);
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assert(*page == 0);
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ret = munmap(page, pagesize);
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assert(ret == 0);
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}
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static void test_file(void)
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{
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char tempname[] = "/tmp/.cmadviseXXXXXX";
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int pagesize = getpagesize();
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ssize_t written;
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char c = 42;
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char *page;
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int ret;
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int fd;
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fd = mkstemp(tempname);
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assert(fd != -1);
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ret = unlink(tempname);
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assert(ret == 0);
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written = write(fd, &c, sizeof(c));
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assert(written == sizeof(c));
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page = mmap(NULL, pagesize, PROT_READ, MAP_PRIVATE, fd, 0);
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assert(page != MAP_FAILED);
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/* Check that mprotect() does not interfere with MADV_DONTNEED. */
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ret = mprotect(page, pagesize, PROT_READ | PROT_WRITE);
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assert(ret == 0);
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/* Check that MADV_DONTNEED resets the page. */
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*page = 0;
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ret = madvise(page, pagesize, MADV_DONTNEED);
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assert(ret == 0);
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assert(*page == c);
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ret = munmap(page, pagesize);
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assert(ret == 0);
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ret = close(fd);
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assert(ret == 0);
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}
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int main(void)
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{
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test_anonymous();
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test_file();
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return EXIT_SUCCESS;
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}
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