implement posix_madvise
Bug: 18472477
Change-Id: I8183de6c281acf69ed5f7f88351b056b9827b162
diff --git a/libc/Android.mk b/libc/Android.mk
index 2270dc6..f04cf5c 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -153,6 +153,7 @@
bionic/poll.cpp \
bionic/posix_fadvise.cpp \
bionic/posix_fallocate.cpp \
+ bionic/posix_madvise.cpp \
bionic/posix_timers.cpp \
bionic/pthread_atfork.cpp \
bionic/pthread_attr.cpp \
diff --git a/libc/bionic/posix_madvise.cpp b/libc/bionic/posix_madvise.cpp
new file mode 100644
index 0000000..d77be01
--- /dev/null
+++ b/libc/bionic/posix_madvise.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <sys/mman.h>
+
+#include "private/ErrnoRestorer.h"
+
+int posix_madvise(void* addr, size_t len, int advice) {
+ ErrnoRestorer errno_restorer;
+
+ // Don't call madvise() on POSIX_MADV_DONTNEED, it will make the space not available.
+ if (advice == POSIX_MADV_DONTNEED) {
+ return 0;
+ }
+ return (madvise(addr, len, advice) == 0 ? 0 : errno);
+}
diff --git a/libc/include/machine/posix_limits.h b/libc/include/machine/posix_limits.h
index 939a1de..25887be 100644
--- a/libc/include/machine/posix_limits.h
+++ b/libc/include/machine/posix_limits.h
@@ -32,7 +32,7 @@
/* Any constant values here other than -1 or 200809L are explicitly specified by POSIX.1-2008. */
/* Keep it sorted. */
-#define _POSIX_ADVISORY_INFO -1 /* posix_madvise() not implemented */
+#define _POSIX_ADVISORY_INFO 200809L
#define _POSIX_AIO_LISTIO_MAX 2
#define _POSIX_AIO_MAX 1
#define _POSIX_ARG_MAX 4096
diff --git a/libc/include/sys/mman.h b/libc/include/sys/mman.h
index 09bf0d9..1663222 100644
--- a/libc/include/sys/mman.h
+++ b/libc/include/sys/mman.h
@@ -43,6 +43,12 @@
#define MREMAP_MAYMOVE 1
#define MREMAP_FIXED 2
+#define POSIX_MADV_NORMAL MADV_NORMAL
+#define POSIX_MADV_RANDOM MADV_RANDOM
+#define POSIX_MADV_SEQUENTIAL MADV_SEQUENTIAL
+#define POSIX_MADV_WILLNEED MADV_WILLNEED
+#define POSIX_MADV_DONTNEED MADV_DONTNEED
+
extern void* mmap(void*, size_t, int, int, int, off_t);
extern void* mmap64(void*, size_t, int, int, int, off64_t);
extern int munmap(void*, size_t);
@@ -61,6 +67,8 @@
extern int mincore(void*, size_t, unsigned char*);
+extern int posix_madvise(void*, size_t, int);
+
__END_DECLS
#endif /* _SYS_MMAN_H_ */
diff --git a/tests/sys_mman_test.cpp b/tests/sys_mman_test.cpp
index 75ccfa3..b0e40fd 100644
--- a/tests/sys_mman_test.cpp
+++ b/tests/sys_mman_test.cpp
@@ -172,3 +172,46 @@
ASSERT_STREQ(NEWPAGE2_MSG, buf);
ASSERT_STREQ(END_MSG, buf+pagesize-sizeof(END_MSG));
}
+
+TEST(sys_mman, posix_madvise) {
+ TemporaryFile tempfile;
+ size_t pagesize = sysconf(_SC_PAGESIZE);
+ char buf[pagesize];
+
+ // Prepare environment.
+ ASSERT_EQ(static_cast<ssize_t>(pagesize), write(tempfile.fd, buf, pagesize));
+ void* map = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, tempfile.fd, 0);
+ ASSERT_NE(MAP_FAILED, map);
+
+ // Verify different options of posix_madvise.
+ ASSERT_EQ(0, posix_madvise(map, pagesize, POSIX_MADV_NORMAL));
+ ASSERT_EQ(0, posix_madvise(map, pagesize, POSIX_MADV_SEQUENTIAL));
+ ASSERT_EQ(0, posix_madvise(map, pagesize, POSIX_MADV_RANDOM));
+ ASSERT_EQ(0, posix_madvise(map, pagesize, POSIX_MADV_WILLNEED));
+
+ ASSERT_EQ(0, munmap(map, pagesize));
+}
+
+// Verify that memory can still access after posix_madvise(POSIX_MADV_DONTNEED).
+// We should test on MAP_ANONYMOUS memory to verify whether the memory is discarded,
+// because the content of non MAP_ANONYMOUS memory can be reread from file.
+TEST(sys_mman, posix_madvise_POSIX_MADV_DONTNEED) {
+ size_t pagesize = sysconf(_SC_PAGESIZE);
+
+ void* map = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(MAP_FAILED, map);
+
+ int* int_ptr = reinterpret_cast<int*>(map);
+ for (int i = 0; i < static_cast<int>(pagesize / sizeof(int)); ++i) {
+ *int_ptr++ = i;
+ }
+
+ ASSERT_EQ(0, posix_madvise(map, pagesize, POSIX_MADV_DONTNEED));
+
+ int_ptr = reinterpret_cast<int*>(map);
+ for (int i = 0; i < static_cast<int>(pagesize / sizeof(int)); ++i) {
+ ASSERT_EQ(i, *int_ptr++);
+ }
+
+ ASSERT_EQ(0, munmap(map, pagesize));
+}
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index 34b7bf3..b37687f 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -523,6 +523,7 @@
// Verify according to POSIX.1-2008.
EXPECT_EQ(200809L, _POSIX_VERSION);
+ EXPECT_EQ(_POSIX_VERSION, _POSIX_ADVISORY_INFO);
EXPECT_GT(_POSIX_AIO_LISTIO_MAX, 0);
EXPECT_GT(_POSIX_AIO_MAX, 0);
EXPECT_GT(_POSIX_ARG_MAX, 0);
@@ -611,8 +612,7 @@
#if defined(__BIONIC__)
// These tests only pass on bionic, as bionic and glibc has different support on these macros.
- // Macros like _POSIX_ADVISORY_INFO are not supported on bionic yet.
- EXPECT_EQ(-1, _POSIX_ADVISORY_INFO);
+ // Macros like _POSIX_ASYNCHRONOUS_IO are not supported on bionic yet.
EXPECT_EQ(-1, _POSIX_ASYNCHRONOUS_IO);
EXPECT_EQ(-1, _POSIX_BARRIERS);
EXPECT_EQ(-1, _POSIX_MESSAGE_PASSING);
@@ -658,6 +658,7 @@
}
TEST(unistd, sysconf) {
+ VERIFY_SYSCONF_POSIX_VERSION(_SC_ADVISORY_INFO);
VERIFY_SYSCONF_POSITIVE(_SC_ARG_MAX);
VERIFY_SYSCONF_POSITIVE(_SC_BC_BASE_MAX);
VERIFY_SYSCONF_POSITIVE(_SC_BC_DIM_MAX);
@@ -773,7 +774,6 @@
#if defined(__BIONIC__)
// Tests can only run on bionic, as bionic and glibc have different support for these options.
// Below options are not supported on bionic yet.
- VERIFY_SYSCONF_NOT_SUPPORT(_SC_ADVISORY_INFO);
VERIFY_SYSCONF_NOT_SUPPORT(_SC_ASYNCHRONOUS_IO);
VERIFY_SYSCONF_NOT_SUPPORT(_SC_BARRIERS);
VERIFY_SYSCONF_NOT_SUPPORT(_SC_MESSAGE_PASSING);