changeset 4879:7875ea94bea5

8017308: Remove unused breakpoint relocation type Summary: remove unused breakpoint relocation type Reviewed-by: kvn
author goetz
date Mon, 24 Jun 2013 11:53:54 -0700
parents fc8a1a5de78e
children a023da4ffc15
files src/cpu/sparc/vm/macroAssembler_sparc.cpp src/cpu/sparc/vm/relocInfo_sparc.cpp src/cpu/x86/vm/relocInfo_x86.cpp src/cpu/zero/vm/relocInfo_zero.cpp src/share/vm/code/nmethod.cpp src/share/vm/code/relocInfo.cpp src/share/vm/code/relocInfo.hpp
diffstat 7 files changed, 3 insertions(+), 349 deletions(-) [+]
line wrap: on
line diff
--- a/src/cpu/sparc/vm/macroAssembler_sparc.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/cpu/sparc/vm/macroAssembler_sparc.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -1161,12 +1161,6 @@
   while (offset() % modulus != 0) nop();
 }
 
-
-void MacroAssembler::safepoint() {
-  relocate(breakpoint_Relocation::spec(breakpoint_Relocation::safepoint));
-}
-
-
 void RegistersForDebugging::print(outputStream* s) {
   FlagSetting fs(Debugging, true);
   int j;
--- a/src/cpu/sparc/vm/relocInfo_sparc.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/cpu/sparc/vm/relocInfo_sparc.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -193,36 +193,6 @@
   return *(address*)addr();
 }
 
-
-int Relocation::pd_breakpoint_size() {
-  // minimum breakpoint size, in short words
-  return NativeIllegalInstruction::instruction_size / sizeof(short);
-}
-
-void Relocation::pd_swap_in_breakpoint(address x, short* instrs, int instrlen) {
-  Untested("pd_swap_in_breakpoint");
-  // %%% probably do not need a general instrlen; just use the trap size
-  if (instrs != NULL) {
-    assert(instrlen * sizeof(short) == NativeIllegalInstruction::instruction_size, "enough instrlen in reloc. data");
-    for (int i = 0; i < instrlen; i++) {
-      instrs[i] = ((short*)x)[i];
-    }
-  }
-  NativeIllegalInstruction::insert(x);
-}
-
-
-void Relocation::pd_swap_out_breakpoint(address x, short* instrs, int instrlen) {
-  Untested("pd_swap_out_breakpoint");
-  assert(instrlen * sizeof(short) == sizeof(int), "enough buf");
-  union { int l; short s[1]; } u;
-  for (int i = 0; i < instrlen; i++) {
-    u.s[i] = instrs[i];
-  }
-  NativeInstruction* ni = nativeInstruction_at(x);
-  ni->set_long_at(0, u.l);
-}
-
 void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 }
 
--- a/src/cpu/x86/vm/relocInfo_x86.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/cpu/x86/vm/relocInfo_x86.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -177,30 +177,6 @@
   return *pd_address_in_code();
 }
 
-int Relocation::pd_breakpoint_size() {
-  // minimum breakpoint size, in short words
-  return NativeIllegalInstruction::instruction_size / sizeof(short);
-}
-
-void Relocation::pd_swap_in_breakpoint(address x, short* instrs, int instrlen) {
-  Untested("pd_swap_in_breakpoint");
-  if (instrs != NULL) {
-    assert(instrlen * sizeof(short) == NativeIllegalInstruction::instruction_size, "enough instrlen in reloc. data");
-    for (int i = 0; i < instrlen; i++) {
-      instrs[i] = ((short*)x)[i];
-    }
-  }
-  NativeIllegalInstruction::insert(x);
-}
-
-
-void Relocation::pd_swap_out_breakpoint(address x, short* instrs, int instrlen) {
-  Untested("pd_swap_out_breakpoint");
-  assert(NativeIllegalInstruction::instruction_size == sizeof(short), "right address unit for update");
-  NativeInstruction* ni = nativeInstruction_at(x);
-  *(short*)ni->addr_at(0) = instrs[0];
-}
-
 void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 #ifdef _LP64
   if (!Assembler::is_polling_page_far()) {
--- a/src/cpu/zero/vm/relocInfo_zero.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/cpu/zero/vm/relocInfo_zero.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -52,22 +52,6 @@
   return (address *) addr();
 }
 
-int Relocation::pd_breakpoint_size() {
-  ShouldNotCallThis();
-}
-
-void Relocation::pd_swap_in_breakpoint(address x,
-                                       short*  instrs,
-                                       int     instrlen) {
-  ShouldNotCallThis();
-}
-
-void Relocation::pd_swap_out_breakpoint(address x,
-                                        short*  instrs,
-                                        int     instrlen) {
-  ShouldNotCallThis();
-}
-
 void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src,
                                                 CodeBuffer*       dst) {
   ShouldNotCallThis();
--- a/src/share/vm/code/nmethod.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/share/vm/code/nmethod.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -1081,11 +1081,6 @@
       metadata_Relocation* reloc = iter.metadata_reloc();
       reloc->fix_metadata_relocation();
     }
-
-    // There must not be any interfering patches or breakpoints.
-    assert(!(iter.type() == relocInfo::breakpoint_type
-             && iter.breakpoint_reloc()->active()),
-           "no active breakpoint");
   }
 }
 
--- a/src/share/vm/code/relocInfo.cpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/share/vm/code/relocInfo.cpp	Mon Jun 24 11:53:54 2013 -0700
@@ -338,31 +338,6 @@
   _limit = limit;
 }
 
-
-void PatchingRelocIterator:: prepass() {
-  // turn breakpoints off during patching
-  _init_state = (*this);        // save cursor
-  while (next()) {
-    if (type() == relocInfo::breakpoint_type) {
-      breakpoint_reloc()->set_active(false);
-    }
-  }
-  (RelocIterator&)(*this) = _init_state;        // reset cursor for client
-}
-
-
-void PatchingRelocIterator:: postpass() {
-  // turn breakpoints back on after patching
-  (RelocIterator&)(*this) = _init_state;        // reset cursor again
-  while (next()) {
-    if (type() == relocInfo::breakpoint_type) {
-      breakpoint_Relocation* bpt = breakpoint_reloc();
-      bpt->set_active(bpt->enabled());
-    }
-  }
-}
-
-
 // All the strange bit-encodings are in here.
 // The idea is to encode relocation data which are small integers
 // very efficiently (a single extra halfword).  Larger chunks of
@@ -704,51 +679,6 @@
   _target  = address_from_scaled_offset(offset, base);
 }
 
-
-void breakpoint_Relocation::pack_data_to(CodeSection* dest) {
-  short* p = (short*) dest->locs_end();
-  address point = dest->locs_point();
-
-  *p++ = _bits;
-
-  assert(_target != NULL, "sanity");
-
-  if (internal())  normalize_address(_target, dest);
-
-  jint target_bits =
-    (jint)( internal() ? scaled_offset           (_target, point)
-                       : runtime_address_to_index(_target) );
-  if (settable()) {
-    // save space for set_target later
-    p = add_jint(p, target_bits);
-  } else {
-    p = add_var_int(p, target_bits);
-  }
-
-  for (int i = 0; i < instrlen(); i++) {
-    // put placeholder words until bytes can be saved
-    p = add_short(p, (short)0x7777);
-  }
-
-  dest->set_locs_end((relocInfo*) p);
-}
-
-
-void breakpoint_Relocation::unpack_data() {
-  _bits = live_bits();
-
-  int targetlen = datalen() - 1 - instrlen();
-  jint target_bits = 0;
-  if (targetlen == 0)       target_bits = 0;
-  else if (targetlen == 1)  target_bits = *(data()+1);
-  else if (targetlen == 2)  target_bits = relocInfo::jint_from_data(data()+1);
-  else                      { ShouldNotReachHere(); }
-
-  _target = internal() ? address_from_scaled_offset(target_bits, addr())
-                       : index_to_runtime_address  (target_bits);
-}
-
-
 //// miscellaneous methods
 oop* oop_Relocation::oop_addr() {
   int n = _oop_index;
@@ -933,81 +863,6 @@
   return target;
 }
 
-
-breakpoint_Relocation::breakpoint_Relocation(int kind, address target, bool internal) {
-  bool active    = false;
-  bool enabled   = (kind == initialization);
-  bool removable = (kind != safepoint);
-  bool settable  = (target == NULL);
-
-  int bits = kind;
-  if (enabled)    bits |= enabled_state;
-  if (internal)   bits |= internal_attr;
-  if (removable)  bits |= removable_attr;
-  if (settable)   bits |= settable_attr;
-
-  _bits = bits | high_bit;
-  _target = target;
-
-  assert(this->kind()      == kind,      "kind encoded");
-  assert(this->enabled()   == enabled,   "enabled encoded");
-  assert(this->active()    == active,    "active encoded");
-  assert(this->internal()  == internal,  "internal encoded");
-  assert(this->removable() == removable, "removable encoded");
-  assert(this->settable()  == settable,  "settable encoded");
-}
-
-
-address breakpoint_Relocation::target() const {
-  return _target;
-}
-
-
-void breakpoint_Relocation::set_target(address x) {
-  assert(settable(), "must be settable");
-  jint target_bits =
-    (jint)(internal() ? scaled_offset           (x, addr())
-                      : runtime_address_to_index(x));
-  short* p = &live_bits() + 1;
-  p = add_jint(p, target_bits);
-  assert(p == instrs(), "new target must fit");
-  _target = x;
-}
-
-
-void breakpoint_Relocation::set_enabled(bool b) {
-  if (enabled() == b) return;
-
-  if (b) {
-    set_bits(bits() | enabled_state);
-  } else {
-    set_active(false);          // remove the actual breakpoint insn, if any
-    set_bits(bits() & ~enabled_state);
-  }
-}
-
-
-void breakpoint_Relocation::set_active(bool b) {
-  assert(!b || enabled(), "cannot activate a disabled breakpoint");
-
-  if (active() == b) return;
-
-  // %%% should probably seize a lock here (might not be the right lock)
-  //MutexLockerEx ml_patch(Patching_lock, true);
-  //if (active() == b)  return;         // recheck state after locking
-
-  if (b) {
-    set_bits(bits() | active_state);
-    if (instrlen() == 0)
-      fatal("breakpoints in original code must be undoable");
-    pd_swap_in_breakpoint (addr(), instrs(), instrlen());
-  } else {
-    set_bits(bits() & ~active_state);
-    pd_swap_out_breakpoint(addr(), instrs(), instrlen());
-  }
-}
-
-
 //---------------------------------------------------------------------------------
 // Non-product code
 
--- a/src/share/vm/code/relocInfo.hpp	Fri Jun 21 00:59:12 2013 -0700
+++ b/src/share/vm/code/relocInfo.hpp	Mon Jun 24 11:53:54 2013 -0700
@@ -49,9 +49,6 @@
 //    RelocIterator
 //      A StackObj which iterates over the relocations associated with
 //      a range of code addresses.  Can be used to operate a copy of code.
-//    PatchingRelocIterator
-//      Specialized subtype of RelocIterator which removes breakpoints
-//      temporarily during iteration, then restores them.
 //    BoundRelocation
 //      An _internal_ type shared by packers and unpackers of relocations.
 //      It pastes together a RelocationHolder with some pointers into
@@ -204,15 +201,6 @@
 //   immediate field must not straddle a unit of memory coherence.
 //   //%note reloc_3
 //
-// relocInfo::breakpoint_type -- a conditional breakpoint in the code
-//   Value:  none
-//   Instruction types: any whatsoever
-//   Data:  [b [T]t  i...]
-//   The b is a bit-packed word representing the breakpoint's attributes.
-//   The t is a target address which the breakpoint calls (when it is enabled).
-//   The i... is a place to store one or two instruction words overwritten
-//   by a trap, so that the breakpoint may be subsequently removed.
-//
 // relocInfo::static_stub_type -- an extra stub for each static_call_type
 //   Value:  none
 //   Instruction types: a virtual call:  { set_oop; jump; }
@@ -271,8 +259,8 @@
     section_word_type       =  9, // internal, but a cross-section reference
     poll_type               = 10, // polling instruction for safepoints
     poll_return_type        = 11, // polling instruction for safepoints at return
-    breakpoint_type         = 12, // an initialization barrier or safepoint
-    metadata_type           = 13, // metadata that used to be oops
+    metadata_type           = 12, // metadata that used to be oops
+    yet_unused_type_1       = 13, // Still unused
     yet_unused_type_2       = 14, // Still unused
     data_prefix_tag         = 15, // tag for a prefix (carries data arguments)
     type_mask               = 15  // A mask which selects only the above values
@@ -312,7 +300,6 @@
     visitor(internal_word) \
     visitor(poll) \
     visitor(poll_return) \
-    visitor(breakpoint) \
     visitor(section_word) \
 
 
@@ -454,7 +441,7 @@
  public:
   enum {
     // Conservatively large estimate of maximum length (in shorts)
-    // of any relocation record (probably breakpoints are largest).
+    // of any relocation record.
     // Extended format is length prefix, data words, and tag/offset suffix.
     length_limit       = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1,
     have_format        = format_width > 0
@@ -571,8 +558,6 @@
 
   void initialize(nmethod* nm, address begin, address limit);
 
-  friend class PatchingRelocIterator;
-  // make an uninitialized one, for PatchingRelocIterator:
   RelocIterator() { initialize_misc(); }
 
  public:
@@ -779,9 +764,6 @@
   void       pd_verify_data_value    (address x, intptr_t off) { pd_set_data_value(x, off, true); }
   address    pd_call_destination     (address orig_addr = NULL);
   void       pd_set_call_destination (address x);
-  void       pd_swap_in_breakpoint   (address x, short* instrs, int instrlen);
-  void       pd_swap_out_breakpoint  (address x, short* instrs, int instrlen);
-  static int pd_breakpoint_size      ();
 
   // this extracts the address of an address in the code stream instead of the reloc data
   address* pd_address_in_code       ();
@@ -1302,87 +1284,6 @@
   void     fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest);
 };
 
-
-class breakpoint_Relocation : public Relocation {
-  relocInfo::relocType type() { return relocInfo::breakpoint_type; }
-
-  enum {
-    // attributes which affect the interpretation of the data:
-    removable_attr = 0x0010,   // buffer [i...] allows for undoing the trap
-    internal_attr  = 0x0020,   // the target is an internal addr (local stub)
-    settable_attr  = 0x0040,   // the target is settable
-
-    // states which can change over time:
-    enabled_state  = 0x0100,   // breakpoint must be active in running code
-    active_state   = 0x0200,   // breakpoint instruction actually in code
-
-    kind_mask      = 0x000F,   // mask for extracting kind
-    high_bit       = 0x4000    // extra bit which is always set
-  };
-
- public:
-  enum {
-    // kinds:
-    initialization = 1,
-    safepoint      = 2
-  };
-
-  // If target is NULL, 32 bits are reserved for a later set_target().
-  static RelocationHolder spec(int kind, address target = NULL, bool internal_target = false) {
-    RelocationHolder rh = newHolder();
-    new(rh) breakpoint_Relocation(kind, target, internal_target);
-    return rh;
-  }
-
- private:
-  // We require every bits value to NOT to fit into relocInfo::datalen_width,
-  // because we are going to actually store state in the reloc, and so
-  // cannot allow it to be compressed (and hence copied by the iterator).
-
-  short   _bits;                  // bit-encoded kind, attrs, & state
-  address _target;
-
-  breakpoint_Relocation(int kind, address target, bool internal_target);
-
-  friend class RelocIterator;
-  breakpoint_Relocation() { }
-
-  short    bits()       const { return _bits; }
-  short&   live_bits()  const { return data()[0]; }
-  short*   instrs()     const { return data() + datalen() - instrlen(); }
-  int      instrlen()   const { return removable() ? pd_breakpoint_size() : 0; }
-
-  void set_bits(short x) {
-    assert(live_bits() == _bits, "must be the only mutator of reloc info");
-    live_bits() = _bits = x;
-  }
-
- public:
-  address  target()     const;
-  void set_target(address x);
-
-  int  kind()           const { return  bits() & kind_mask; }
-  bool enabled()        const { return (bits() &  enabled_state) != 0; }
-  bool active()         const { return (bits() &   active_state) != 0; }
-  bool internal()       const { return (bits() &  internal_attr) != 0; }
-  bool removable()      const { return (bits() & removable_attr) != 0; }
-  bool settable()       const { return (bits() &  settable_attr) != 0; }
-
-  void set_enabled(bool b);     // to activate, you must also say set_active
-  void set_active(bool b);      // actually inserts bpt (must be enabled 1st)
-
-  // data is packed as 16 bits, followed by the target (1 or 2 words), followed
-  // if necessary by empty storage for saving away original instruction bytes.
-  void pack_data_to(CodeSection* dest);
-  void unpack_data();
-
-  // during certain operations, breakpoints must be out of the way:
-  void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
-    assert(!active(), "cannot perform relocation on enabled breakpoints");
-  }
-};
-
-
 // We know all the xxx_Relocation classes, so now we can define these:
 #define EACH_CASE(name)                                         \
 inline name##_Relocation* RelocIterator::name##_reloc() {       \
@@ -1401,25 +1302,4 @@
   initialize(nm, begin, limit);
 }
 
-// if you are going to patch code, you should use this subclass of
-// RelocIterator
-class PatchingRelocIterator : public RelocIterator {
- private:
-  RelocIterator _init_state;
-
-  void prepass();               // deactivates all breakpoints
-  void postpass();              // reactivates all enabled breakpoints
-
-  // do not copy these puppies; it would have unpredictable side effects
-  // these are private and have no bodies defined because they should not be called
-  PatchingRelocIterator(const RelocIterator&);
-  void        operator=(const RelocIterator&);
-
- public:
-  PatchingRelocIterator(nmethod* nm, address begin = NULL, address limit = NULL)
-    : RelocIterator(nm, begin, limit)                { prepass();  }
-
-  ~PatchingRelocIterator()                           { postpass(); }
-};
-
 #endif // SHARE_VM_CODE_RELOCINFO_HPP