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8224974: Implement JEP 352

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Non-Volatile Mapped Byte Buffers

Reviewed-by: alanb, kvn, bpb, gromero, darcy, shade, bulasevich, dchuyko
This commit is contained in:
Andrew Dinn 2019-08-20 10:11:53 +01:00
parent db359f11b5
commit 047b8bfeb7
53 changed files with 1400 additions and 69 deletions
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38
src/java.base/unix/native/libnio/ch/FileChannelImpl.c
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@ -48,6 +48,7 @@
#include "nio_util.h"
#include "sun_nio_ch_FileChannelImpl.h"
#include "java_lang_Integer.h"
#include <assert.h>
static jfieldID chan_fd; /* jobject 'fd' in sun.nio.ch.FileChannelImpl */
@ -73,7 +74,7 @@ handle(JNIEnv *env, jlong rv, char *msg)
JNIEXPORT jlong JNICALL
Java_sun_nio_ch_FileChannelImpl_map0(JNIEnv *env, jobject this,
jint prot, jlong off, jlong len)
jint prot, jlong off, jlong len, jboolean map_sync)
{
void *mapAddress = 0;
jobject fdo = (*env)->GetObjectField(env, this, chan_fd);
@ -81,6 +82,9 @@ Java_sun_nio_ch_FileChannelImpl_map0(JNIEnv *env, jobject this,
int protections = 0;
int flags = 0;
// should never be called with map_sync and prot == PRIVATE
assert((prot != sun_nio_ch_FileChannelImpl_MAP_PV) || !map_sync);
if (prot == sun_nio_ch_FileChannelImpl_MAP_RO) {
protections = PROT_READ;
flags = MAP_SHARED;
@ -92,6 +96,33 @@ Java_sun_nio_ch_FileChannelImpl_map0(JNIEnv *env, jobject this,
flags = MAP_PRIVATE;
}
// if MAP_SYNC and MAP_SHARED_VALIDATE are not defined then it is
// best to define them here. This ensures the code compiles on old
// OS releases which do not provide the relevant headers. If run
// on the same machine then it will work if the kernel contains
// the necessary support otherwise mmap should fail with an
// invalid argument error
#ifndef MAP_SYNC
#define MAP_SYNC 0x80000
#endif
#ifndef MAP_SHARED_VALIDATE
#define MAP_SHARED_VALIDATE 0x03
#endif
if (map_sync) {
// ensure
// 1) this is Linux on AArch64 or x86_64
// 2) the mmap APIs are available/ at compile time
#if !defined(LINUX) || ! (defined(aarch64) || (defined(amd64) && defined(_LP64)))
// TODO - implement for solaris/AIX/BSD/WINDOWS and for 32 bit
JNU_ThrowInternalError(env, "should never call map on platform where MAP_SYNC is unimplemented");
return IOS_THROWN;
#else
flags |= MAP_SYNC | MAP_SHARED_VALIDATE;
#endif
}
mapAddress = mmap64(
0, /* Let OS decide location */
len, /* Number of bytes to map */
@ -101,6 +132,11 @@ Java_sun_nio_ch_FileChannelImpl_map0(JNIEnv *env, jobject this,
off); /* Offset into file */
if (mapAddress == MAP_FAILED) {
if (map_sync && errno == ENOTSUP) {
JNU_ThrowIOExceptionWithLastError(env, "map with mode MAP_SYNC unsupported");
return IOS_THROWN;
}
if (errno == ENOMEM) {
JNU_ThrowOutOfMemoryError(env, "Map failed");
return IOS_THROWN;