8005076: Creating a CDS archive with one alignment and running another causes a crash.

Summary: Save the alignment when writing the CDS and compare it when reading the CDS.
Reviewed-by: kvn, coleenp

src/share/vm/memory/filemap.cpp

@@ -119,6 +119,7 @@ void FileMapInfo::populate_header(size_t alignment) {
   _header._magic = 0xf00baba2;
   _header._version = _current_version;
   _header._alignment = alignment;
+  _header._obj_alignment = ObjectAlignmentInBytes;
 
   // The following fields are for sanity checks for whether this archive
   // will function correctly with this JVM and the bootclasspath it's
@@ -473,6 +474,12 @@ bool FileMapInfo::validate() {
                   " version or build of HotSpot.");
     return false;
   }
+  if (_header._obj_alignment != ObjectAlignmentInBytes) {
+    fail_continue("The shared archive file's ObjectAlignmentInBytes of %d"
+                  " does not equal the current ObjectAlignmentInBytes of %d.",
+                  _header._obj_alignment, ObjectAlignmentInBytes);
+    return false;
+  }
 
   // Cannot verify interpreter yet, as it can only be created after the GC
   // heap has been initialized.

src/share/vm/memory/filemap.hpp

@@ -63,6 +63,7 @@ private:
     int    _magic;                    // identify file type.
     int    _version;                  // (from enum, above.)
     size_t _alignment;                // how shared archive should be aligned
+    int    _obj_alignment;            // value of ObjectAlignmentInBytes
 
     struct space_info {
       int    _file_offset;   // sizeof(this) rounded to vm page size

src/share/vm/runtime/arguments.cpp

@@ -1331,14 +1331,14 @@ bool verify_object_alignment() {
   // then a saved space from compressed oops.
   if ((int)ObjectAlignmentInBytes > 256) {
     jio_fprintf(defaultStream::error_stream(),
-                "error: ObjectAlignmentInBytes=%d must not be greater then 256\n",
+                "error: ObjectAlignmentInBytes=%d must not be greater than 256\n",
                 (int)ObjectAlignmentInBytes);
     return false;
   }
   // In case page size is very small.
   if ((int)ObjectAlignmentInBytes >= os::vm_page_size()) {
     jio_fprintf(defaultStream::error_stream(),
-                "error: ObjectAlignmentInBytes=%d must be less then page size %d\n",
+                "error: ObjectAlignmentInBytes=%d must be less than page size %d\n",
                 (int)ObjectAlignmentInBytes, os::vm_page_size());
     return false;
   }
@@ -2997,11 +2997,6 @@ void Arguments::set_shared_spaces_flags() {
     FLAG_SET_DEFAULT(UseLargePages, false);
   }
 
-  // Add 2M to any size for SharedReadOnlySize to get around the JPRT setting
-  if (DumpSharedSpaces && !FLAG_IS_DEFAULT(SharedReadOnlySize)) {
-    SharedReadOnlySize = 14*M;
-  }
-
   if (DumpSharedSpaces) {
     if (RequireSharedSpaces) {
       warning("cannot dump shared archive while using shared archive");

src/share/vm/runtime/globals.hpp

@@ -1830,7 +1830,7 @@ class CommandLineFlags {
                                                                             \
   product(intx, CMSIsTooFullPercentage, 98,                                 \
           "An absolute ceiling above which CMS will always consider the "   \
-          "perm gen ripe for collection")                                   \
+          "unloading of classes when class unloading is enabled")           \
                                                                             \
   develop(bool, CMSTestInFreeList, false,                                   \
           "Check if the coalesced range is already in the "                 \
@@ -1899,13 +1899,13 @@ class CommandLineFlags {
           "Metadata deallocation alot interval")                            \
                                                                             \
   develop(bool, TraceMetadataChunkAllocation, false,                        \
-          "Trace humongous metadata allocations")                           \
+          "Trace chunk metadata allocations")                               \
                                                                             \
   product(bool, TraceMetadataHumongousAllocation, false,                    \
           "Trace humongous metadata allocations")                           \
                                                                             \
   develop(bool, TraceMetavirtualspaceAllocation, false,                     \
-          "Trace humongous metadata allocations")                           \
+          "Trace virtual space metadata allocations")                       \
                                                                             \
   notproduct(bool, ExecuteInternalVMTests, false,                           \
           "Enable execution of internal VM tests.")                         \
@@ -3537,10 +3537,10 @@ class CommandLineFlags {
   /* Shared spaces */                                                       \
                                                                             \
   product(bool, UseSharedSpaces, true,                                      \
-          "Use shared spaces in the permanent generation")                  \
+          "Use shared spaces for metadata")                                 \
                                                                             \
   product(bool, RequireSharedSpaces, false,                                 \
-          "Require shared spaces in the permanent generation")              \
+          "Require shared spaces for metadata")                             \
                                                                             \
   product(bool, DumpSharedSpaces, false,                                    \
            "Special mode: JVM reads a class list, loads classes, builds "   \
@@ -3551,16 +3551,16 @@ class CommandLineFlags {
           "Print usage of shared spaces")                                   \
                                                                             \
   product(uintx, SharedReadWriteSize,  NOT_LP64(12*M) LP64_ONLY(16*M),      \
-          "Size of read-write space in permanent generation (in bytes)")    \
+          "Size of read-write space for metadata (in bytes)")               \
                                                                             \
   product(uintx, SharedReadOnlySize,  NOT_LP64(12*M) LP64_ONLY(16*M),       \
-          "Size of read-only space in permanent generation (in bytes)")     \
+          "Size of read-only space for metadata (in bytes)")                \
                                                                             \
   product(uintx, SharedMiscDataSize,    NOT_LP64(2*M) LP64_ONLY(4*M),       \
-          "Size of the shared data area adjacent to the heap (in bytes)")   \
+          "Size of the shared miscellaneous data area (in bytes)")          \
                                                                             \
   product(uintx, SharedMiscCodeSize,    120*K,                              \
-          "Size of the shared code area adjacent to the heap (in bytes)")   \
+          "Size of the shared miscellaneous code area (in bytes)")          \
                                                                             \
   product(uintx, SharedDummyBlockSize, 0,                                   \
           "Size of dummy block used to shift heap addresses (in bytes)")    \