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OMRCodeCache.cpp
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/*******************************************************************************
* Copyright IBM Corp. and others 2000
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at https://www.eclipse.org/legal/epl-2.0/
* or the Apache License, Version 2.0 which accompanies this distribution
* and is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] https://openjdk.org/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
*******************************************************************************/
#include "runtime/CodeCache.hpp"
#include <algorithm>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "AtomicSupport.hpp"
#include "env/FrontEnd.hpp"
#include "control/Options.hpp"
#include "control/Options_inlines.hpp"
#include "env/CompilerEnv.hpp"
#include "env/IO.hpp"
#include "env/defines.h"
#include "env/jittypes.h"
#include "env/VerboseLog.hpp"
#include "il/DataTypes.hpp"
#include "infra/Assert.hpp"
#include "infra/CriticalSection.hpp"
#include "infra/Monitor.hpp"
#include "omrformatconsts.h"
#include "runtime/CodeCache.hpp"
#include "runtime/CodeCacheManager.hpp"
#include "runtime/CodeCacheMemorySegment.hpp"
#include "runtime/CodeCacheConfig.hpp"
#include "runtime/Runtime.hpp"
#ifdef LINUX
#include <elf.h>
#include <unistd.h>
#endif
namespace TR { class CodeGenerator; }
/*****************************************************************************
* Multi Code Cache page management
*/
/**
* \page CodeCache Code Cache Layout:
*
* Basic layout of the code cache memory (capitalized names are fixed, others
* move)
*
*
* TRAMPOLINEBASE TEMPTRAMPOLINETOP
* | TEMPTRAMPOLINEBASE |
* | | |
* warmCodeAlloc coldCodeAlloc | | HELPERBASE HELPERTOP
* |--> <--| | | | |
* |_____v_________________v______v_______________v___________v_________v
* warm cold
* \ /
* ----> Method Bodies<--- ^ Trampolines ^ TempTramps^ Helpers
*
* (Low memory) ---------------------------------------> (High memory)
*
*
* * There are a fixed number of helper trampolines. Each helper has an index into
* these trampolines.
* * There are a fixed number of temporary trampoline slots. `_tempTrampolineNext`
* goes from `_tempTrampolineBase`, allocating to `tempTrampolineMax.`
* * There are a fixed number of permanent trampoline slots.
* ** `_trampolineReservationMark` goes from `_tempTrampolineBase` to `_trampolineBase`
* backwards, reserving trampoline slots.
* ** `_trampolineAllocationMark` goes from `_tempTrampolineBase` to
* `_trampolineReservationMark` filling in the trampoline slots.
*
* When there is no more room for trampolines the code cache is full.
*
* 5% of the code cache is allocated to the above trampolines. The rest is used
* for method bodies. Regular parts of method bodies are allocated from the
* heapBase forwards, and cold parts of method bodies are allocated from
* `_trampolineBase` backwards. When the two meet, the code cache is full.
*
*/
OMR::CodeCache::CacheCriticalSection::CacheCriticalSection(TR::CodeCache *codeCache)
: CriticalSection(codeCache->_mutex)
{
}
TR::CodeCache *
OMR::CodeCache::self()
{
return static_cast<TR::CodeCache *>(this);
}
void
OMR::CodeCache::destroy(TR::CodeCacheManager *manager)
{
while (_hashEntrySlab)
{
CodeCacheHashEntrySlab *slab = _hashEntrySlab;
_hashEntrySlab = slab->_next;
slab->free(manager);
}
#if defined(TR_HOST_POWER)
if (_trampolineSyncList)
{
if (_trampolineSyncList->_hashEntryArray)
manager->freeMemory(_trampolineSyncList->_hashEntryArray);
manager->freeMemory(_trampolineSyncList);
}
#endif
if (manager->codeCacheConfig().needsMethodTrampolines())
{
if (_resolvedMethodHT)
{
if (_resolvedMethodHT->_buckets)
manager->freeMemory(_resolvedMethodHT->_buckets);
manager->freeMemory(_resolvedMethodHT);
}
if (_unresolvedMethodHT)
{
if (_unresolvedMethodHT->_buckets)
manager->freeMemory(_unresolvedMethodHT->_buckets);
manager->freeMemory(_unresolvedMethodHT);
}
}
}
uint8_t *
OMR::CodeCache::getCodeAlloc()
{
return _segment->segmentAlloc();
}
uint8_t *
OMR::CodeCache::getCodeBase()
{
return _segment->segmentBase();
}
uint8_t *
OMR::CodeCache::getCodeTop()
{
return _segment->segmentTop();
}
void
OMR::CodeCache::reserve(int32_t reservingCompThreadID)
{
_reserved = true;
_reservingCompThreadID = reservingCompThreadID;
}
void
OMR::CodeCache::unreserve()
{
_reserved = false;
_reservingCompThreadID = -2;
}
void
OMR::CodeCache::writeMethodHeader(void *freeBlock, size_t size, bool isCold)
{
omrthread_jit_write_protect_disable();
CodeCacheMethodHeader * block = (CodeCacheMethodHeader *)freeBlock;
block->_size = static_cast<uint32_t>(size);
TR::CodeCacheConfig & config = _manager->codeCacheConfig();
if (!isCold)
memcpy(block->_eyeCatcher, config.warmEyeCatcher(), sizeof(block->_eyeCatcher));
else
memcpy(block->_eyeCatcher, config.coldEyeCatcher(), sizeof(block->_eyeCatcher));
block->_metaData = NULL;
omrthread_jit_write_protect_enable();
}
bool
OMR::CodeCache::trimCodeMemoryAllocation(void *codeMemoryStart, size_t actualSizeInBytes)
{
if (actualSizeInBytes == 0) return false; // nothing to resize, just return
TR::CodeCacheConfig & config = _manager->codeCacheConfig();
size_t round = config.codeCacheAlignment() - 1;
codeMemoryStart = (uint8_t *) codeMemoryStart - sizeof(CodeCacheMethodHeader); // Do we always have a header?
actualSizeInBytes = (actualSizeInBytes + sizeof(CodeCacheMethodHeader) + round) & ~round;
CodeCacheMethodHeader *cacheHeader = (CodeCacheMethodHeader *) codeMemoryStart;
// sanity check, the eyecatcher must be there
TR_ASSERT(cacheHeader->_eyeCatcher[0] == config.warmEyeCatcher()[0], "Missing eyecatcher during trimCodeMemoryAllocation");
size_t oldSize = cacheHeader->_size;
if (actualSizeInBytes >= oldSize)
return false;
size_t shrinkage = oldSize - actualSizeInBytes;
uint8_t *expectedHeapAlloc = (uint8_t *) codeMemoryStart + oldSize;
if (config.verboseReclamation())
{
TR_VerboseLog::writeLineLocked(TR_Vlog_CODECACHE,"--trimCodeMemoryAllocation-- CC=%p cacheHeader=%p oldSize=%u actualSizeInBytes=%d shrinkage=%u", this, cacheHeader, oldSize, actualSizeInBytes, shrinkage);
}
if (expectedHeapAlloc == _warmCodeAlloc)
{
_manager->decreaseCurrTotalUsedInBytes(shrinkage);
_warmCodeAlloc -= shrinkage;
omrthread_jit_write_protect_disable();
cacheHeader->_size = static_cast<uint32_t>(actualSizeInBytes);
omrthread_jit_write_protect_enable();
return true;
}
else // the allocation could have been from a free block or from the cold portion
{
if (shrinkage >= MIN_SIZE_BLOCK)
{
// addFreeBlock needs to be done with VM access because the GC may also
// change the list of free blocks
if (self()->addFreeBlock2((uint8_t *) codeMemoryStart+actualSizeInBytes, (uint8_t *)expectedHeapAlloc))
{
//fprintf(stderr, "---ccr--- addFreeBlock due to shrinkage\n");
}
omrthread_jit_write_protect_disable();
cacheHeader->_size = static_cast<uint32_t>(actualSizeInBytes);
omrthread_jit_write_protect_enable();
return true;
}
}
//fprintf(stderr, "--ccr-- shrink code by %d\n", shrinkage);
return false;
}
// Initialize a code cache
//
bool
OMR::CodeCache::initialize(TR::CodeCacheManager *manager,
TR::CodeCacheMemorySegment *codeCacheSegment,
size_t allocatedCodeCacheSizeInBytes)
{
_manager = manager;
// heapSize can be calculated as (codeCache->helperTop - codeCacheSegment->heapBase), which is equal to segmentSize
// If codeCachePadKB is set, this will make the system believe that we allocated segmentSize bytes,
// instead of _jitConfig->codeCachePadKB * 1024 bytes
// If codeCachePadKB is not set, heapSize is segmentSize anyway
_segment = codeCacheSegment;
// helperTop is heapTop, usually
// When codeCachePadKB > segmentSize, the helperTop is not at the very end of the segemnt
_helperTop = _segment->segmentBase() + allocatedCodeCacheSizeInBytes;
TR::CodeCacheConfig &config = manager->codeCacheConfig();
// Allocate the CodeCacheHashEntrySlab object and the initial slab
//
_hashEntrySlab = CodeCacheHashEntrySlab::allocate(manager, config.codeCacheHashEntryAllocatorSlabSize());
if (!_hashEntrySlab)
{
return false;
}
// FIXME: try to provide different names to the mutex based on the codecache
if (!(_mutex = TR::Monitor::create("JIT-CodeCacheMonitor-??")))
{
_hashEntrySlab->free(manager);
return false;
}
_hashEntryFreeList = NULL;
_freeBlockList = NULL;
_flags = 0;
_CCPreLoadedCodeInitialized = false;
self()->unreserve();
_almostFull = TR_no;
_sizeOfLargestFreeColdBlock = 0;
_sizeOfLargestFreeWarmBlock = 0;
_lastAllocatedBlock = NULL; // MP
_warmCodeAlloc = _segment->segmentBase() + sizeof(this);
_warmCodeAlloc = (uint8_t *)align((size_t)_warmCodeAlloc, config.codeCacheAlignment());
if (!config.trampolineCodeSize())
{
// _helperTop is heapTop
_trampolineBase = _helperTop;
_helperBase = _helperTop;
_trampolineReservationMark = _trampolineAllocationMark = _trampolineBase;
// set the pre loaded per Cache Helper slab
_CCPreLoadedCodeTop = (uint8_t *)(((size_t)_trampolineBase) & (~config.codeCacheHelperAlignmentMask()));
_CCPreLoadedCodeBase = _CCPreLoadedCodeTop - config.ccPreLoadedCodeSize();
TR_ASSERT( (((size_t)_CCPreLoadedCodeBase) & config.codeCacheHelperAlignmentMask()) == 0, "Per-code cache helper sizes do not account for alignment requirements." );
_coldCodeAlloc = _CCPreLoadedCodeBase;
_trampolineSyncList = NULL;
}
else // Trampolines are needed
{
// Helpers are located at the top of the code cache (offset N), growing down towards the base (offset 0)
size_t trampolineSpaceSize = config.trampolineCodeSize() * config.numRuntimeHelpers();
// _helperTop is heapTop
_helperBase = _helperTop - trampolineSpaceSize;
_helperBase = (uint8_t *)(((size_t)_helperBase) & (~config.codeCacheTrampolineAlignmentBytes()));
if (!config.needsMethodTrampolines())
{
// There is no need in method trampolines when there is going to be
// only one code cache segment
//
_trampolineBase = _helperBase;
_tempTrampolinesMax = 0;
}
else
{
// _helperTop is heapTop
// (_helperTop - segment->heapBase) is heapSize
_trampolineBase = _helperBase -
((_helperBase - _segment->segmentBase())*config.trampolineSpacePercentage()/100);
// Grab the configuration details from the JIT platform code
//
// (_helperTop - segment->heapBase) is heapSize
config.mccCallbacks().codeCacheConfig(static_cast<int32_t>(_helperTop - _segment->segmentBase()), &_tempTrampolinesMax);
}
mcc_printf("mcc_initialize: trampoline base %p\n", _trampolineBase);
// set the temporary trampoline slab right under the helper trampolines, should be already aligned
_tempTrampolineTop = _helperBase;
_tempTrampolineBase = _tempTrampolineTop - (config.trampolineCodeSize() * _tempTrampolinesMax);
_tempTrampolineNext = _tempTrampolineBase;
// Check if we have enough space in the code cache to contain the trampolines
if (_trampolineBase >= _tempTrampolineNext && config.needsMethodTrampolines())
{
_hashEntrySlab->free(manager);
return false;
}
// set the allocation pointer to right after the temporary trampolines
_trampolineAllocationMark = _tempTrampolineBase;
_trampolineReservationMark = _trampolineAllocationMark;
// set the pre loaded per Cache Helper slab
_CCPreLoadedCodeTop = (uint8_t *)(((size_t)_trampolineBase) & (~config.codeCacheHelperAlignmentMask()));
_CCPreLoadedCodeBase = _CCPreLoadedCodeTop - config.ccPreLoadedCodeSize();
TR_ASSERT( (((size_t)_CCPreLoadedCodeBase) & config.codeCacheHelperAlignmentMask()) == 0, "Per-code cache helper sizes do not account for alignment requirements." );
_coldCodeAlloc = _CCPreLoadedCodeBase;
// Set helper trampoline table available
//
config.mccCallbacks().createHelperTrampolines((uint8_t *)_helperBase, config.numRuntimeHelpers());
_trampolineSyncList = NULL;
if (_tempTrampolinesMax)
{
// Initialize temporary trampoline synchronization list
if (!self()->allocateTempTrampolineSyncBlock())
{
_hashEntrySlab->free(manager);
return false;
}
}
if (config.needsMethodTrampolines())
{
// Initialize hashtables to hold trampolines for resolved and unresolved methods
_resolvedMethodHT = CodeCacheHashTable::allocate(manager);
_unresolvedMethodHT = CodeCacheHashTable::allocate(manager);
if (_resolvedMethodHT==NULL || _unresolvedMethodHT==NULL)
{
_hashEntrySlab->free(manager);
return false;
}
}
}
// Before returning, let's adjust the free space seen by VM.
// Usable space is between _warmCodeAlloc and _trampolineBase. Everything else is overhead
size_t spaceLost = (_warmCodeAlloc - _segment->segmentBase()) + (_segment->segmentTop() - _trampolineBase);
_manager->increaseCurrTotalUsedInBytes(spaceLost);
// Now that we have initialized the code cache, (including _warmCodeAlloc and _coldCodeAlloc)
// write a pointer to this cache at the beginning of the segment
VM_AtomicSupport::writeBarrier();
omrthread_jit_write_protect_disable();
*((TR::CodeCache **)(_segment->segmentBase())) = self();
omrthread_jit_write_protect_enable();
return true;
}
/*****************************************************************************
* Trampoline Reservation
*/
// Allocate a trampoline in given code cache
//
// An allocation MUST be preceeded by at least one reservation. If we get a case
// where we dont have reserved space, abort
//
OMR::CodeCacheTrampolineCode *
OMR::CodeCache::allocateTrampoline()
{
CodeCacheTrampolineCode *trampoline = NULL;
if (_trampolineAllocationMark > _trampolineReservationMark)
{
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
_trampolineAllocationMark -= config.trampolineCodeSize();
trampoline = (CodeCacheTrampolineCode *) _trampolineAllocationMark;
}
else
{
//TR_ASSERT(0);
}
return trampoline;
}
// Allocate a temporary trampoline
//
OMR::CodeCacheTrampolineCode *
OMR::CodeCache::allocateTempTrampoline()
{
CodeCacheTrampolineCode *freeTrampolineSlot;
if (_tempTrampolineNext >= _tempTrampolineTop)
return NULL;
freeTrampolineSlot = _tempTrampolineNext;
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
_tempTrampolineNext += config.trampolineCodeSize();
return freeTrampolineSlot;
}
OMR::CodeCacheErrorCode::ErrorCode
OMR::CodeCache::reserveSpaceForTrampoline_bridge(int32_t numTrampolines)
{
return self()->reserveSpaceForTrampoline(numTrampolines);
}
OMR::CodeCacheErrorCode::ErrorCode
OMR::CodeCache::reserveSpaceForTrampoline(int32_t numTrampolines)
{
CacheCriticalSection ReserveSpaceForTrampoline(self());
CodeCacheErrorCode::ErrorCode status = CodeCacheErrorCode::ERRORCODE_SUCCESS;
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
size_t size = numTrampolines * config.trampolineCodeSize();
if (size)
{
// See if we are hitting against the method body allocation pointer
// indicating that there is no more free space left in this code cache
//
if (_trampolineReservationMark >= _trampolineBase + size)
{
_trampolineReservationMark -= size;
}
else
{
status = CodeCacheErrorCode::ERRORCODE_INSUFFICIENTSPACE;
_almostFull = TR_yes;
if (config.verboseCodeCache())
{
TR_VerboseLog::writeLineLocked(TR_Vlog_CODECACHE, "CodeCache %p marked as full in reserveSpaceForTrampoline", self());
}
}
}
return status;
}
void
OMR::CodeCache::unreserveSpaceForTrampoline()
{
// sanity check, should never have the reservation mark dip past the
// allocation mark
//TR_ASSERT(_trampolineReservationMark < _trampolineAllocationMark);
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
_trampolineReservationMark += config.trampolineCodeSize();
}
//------------------------------ reserveResolvedTrampoline ------------------
// Find or create a reservation for an resolved method trampoline.
// Method must be called with VM access in hand to prevent unloading
// Returns 0 on success or a negative error code on failure
//---------------------------------------------------------------------------
int32_t
OMR::CodeCache::reserveResolvedTrampoline(TR_OpaqueMethodBlock *method,
bool inBinaryEncoding)
{
int32_t retValue = CodeCacheErrorCode::ERRORCODE_SUCCESS; // assume success
TR_ASSERT(_reserved, "CodeCache %p is not reserved when calling reservedResolvedTrampoline\n", this);
// does the platform need trampolines at all?
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
if (!config.needsMethodTrampolines())
return retValue;
// scope for cache critical section
{
CacheCriticalSection reserveTrampoline(self());
// see if a reservation for this method already exists, return corresponding
// code cache if thats the case
CodeCacheHashEntry *entry = _resolvedMethodHT->findResolvedMethod(method);
if (!entry)
{
// Reserve a new trampoline since there is not an active reservation for given method
//
retValue = self()->reserveSpaceForTrampoline();
if (retValue == OMR::CodeCacheErrorCode::ERRORCODE_SUCCESS)
{
// add hashtable entry
if (!self()->addResolvedMethod(method))
retValue = CodeCacheErrorCode::ERRORCODE_FATALERROR; // couldn't allocate memory from VM
}
}
}
return retValue;
}
// Trampoline lookup for resolved methods
//
OMR::CodeCacheTrampolineCode *
OMR::CodeCache::findTrampoline(TR_OpaqueMethodBlock * method)
{
CodeCacheTrampolineCode *trampoline;
// scope for critical section
{
CacheCriticalSection resolveAndCreateTrampoline(self());
CodeCacheHashEntry *entry = _resolvedMethodHT->findResolvedMethod(method);
trampoline = entry->_info._resolved._currentTrampoline;
if (!trampoline)
{
void *newPC = (void *) TR::Compiler->mtd.startPC(method);
trampoline = self()->allocateTrampoline();
self()->createTrampoline(trampoline, newPC, method);
entry->_info._resolved._currentTrampoline = trampoline;
entry->_info._resolved._currentStartPC = newPC;
}
}
return trampoline;
}
// Trampoline lookup for helper methods
//
OMR::CodeCacheTrampolineCode *
OMR::CodeCache::findTrampoline(int32_t helperIndex)
{
CodeCacheTrampolineCode *trampoline;
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
trampoline = (CodeCacheTrampolineCode *) (_helperBase + (config.trampolineCodeSize() * helperIndex));
//TR_ASSERT(trampoline < _helperTop);
return trampoline;
}
// Replace a trampoline
//
OMR::CodeCacheTrampolineCode *
OMR::CodeCache::replaceTrampoline(TR_OpaqueMethodBlock *method,
void *oldTrampoline,
void *oldTargetPC,
void *newTargetPC,
bool needSync)
{
CodeCacheTrampolineCode *trampoline = oldTrampoline;
CodeCacheHashEntry *entry;
entry = _resolvedMethodHT->findResolvedMethod(method);
//suspicious that this assertion is commented out...
//TR_ASSERT(entry);
if (oldTrampoline == NULL)
{
// A trampoline has not been created. Simply allocate a new one.
//
trampoline = self()->allocateTrampoline();
entry->_info._resolved._currentTrampoline = trampoline;
}
else
{
if (needSync)
{
// Trampoline CANNOT be safely modified in place
// We have to allocate a new temporary trampoline
// and rely on the sync later on to update the old one using the
// temporary data
//
// A permanent trampoline already exists, create a temporary one,
// This might fail due to lack of free slots
//
trampoline = self()->allocateTempTrampoline();
// Save the temporary trampoline entry for future temp->parm synchronization
self()->saveTempTrampoline(entry);
if (!trampoline)
{
// Unable to fulfill the replacement request, no temp space left
return NULL;
}
}
}
// update the hash entry for this method
entry->_info._resolved._currentStartPC = newTargetPC;
return trampoline;
}
// Synchronize all temporary trampolines in given code cache
//
void
OMR::CodeCache::syncTempTrampolines()
{
if (_flags & CODECACHE_FULL_SYNC_REQUIRED)
{
for (uint32_t entryIdx = 0; entryIdx < _resolvedMethodHT->_size; entryIdx++)
{
for (CodeCacheHashEntry *entry = _resolvedMethodHT->_buckets[entryIdx]; entry; entry = entry->_next)
{
void *newPC = (void *) TR::Compiler->mtd.startPC(entry->_info._resolved._method);
void *trampoline = entry->_info._resolved._currentTrampoline;
bool forceCreateTrampoline = false;
if (reinterpret_cast<intptr_t>(newPC) == 0)
{
newPC = entry->_info._resolved._currentStartPC;
forceCreateTrampoline = true;
}
if (trampoline && (forceCreateTrampoline || (entry->_info._resolved._currentStartPC != newPC)))
{
self()->createTrampoline(trampoline,
newPC,
entry->_info._resolved._method);
entry->_info._resolved._currentStartPC = newPC;
}
}
}
for (CodeCacheTempTrampolineSyncBlock *syncBlock = _trampolineSyncList; syncBlock; syncBlock = syncBlock->_next)
syncBlock->_entryCount = 0;
_flags &= ~CODECACHE_FULL_SYNC_REQUIRED;
}
else
{
CodeCacheTempTrampolineSyncBlock *syncBlock = NULL;
// Traverse the list of trampoline synchronization blocks
for (syncBlock = _trampolineSyncList; syncBlock; syncBlock = syncBlock->_next)
{
//TR_ASSERT(syncBlock->_entryCount <= syncBlock->_entryListSize);
// Synchronize all stored sync requests
for (auto entryIdx = 0; entryIdx < syncBlock->_entryCount; entryIdx++)
{
CodeCacheHashEntry *entry = syncBlock->_hashEntryArray[entryIdx];
void *newPC = (void *) TR::Compiler->mtd.startPC(entry->_info._resolved._method);
if (reinterpret_cast<intptr_t>(newPC) == 0)
{
newPC = entry->_info._resolved._currentStartPC;
}
// call the codegen to perform the trampoline code modification
self()->createTrampoline(entry->_info._resolved._currentTrampoline,
newPC,
entry->_info._resolved._method);
entry->_info._resolved._currentStartPC = newPC;
}
syncBlock->_entryCount = 0;
}
}
_tempTrampolineNext = _tempTrampolineBase;
}
// Patch the address of a method in this code cache's trampolines
//
void
OMR::CodeCache::patchCallPoint(TR_OpaqueMethodBlock *method,
void *callSite,
void *newStartPC,
void *extraArg)
{
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
// the name is still the same. The logic of callPointPatching is as follow:
// look up the right codeCache,
// search for the hashEntry for the method,
// grab its current trampoline plus its current pointed-at address (if no trampoline, both are NULL).
// Then, call code_patching with these things as argument.
// scope to patch trampoline
{
CacheCriticalSection patching(self());
CodeCacheTrampolineCode *resolvedTramp = NULL;
void *methodRunAddress = NULL;
if (config.needsMethodTrampolines())
{
CodeCacheHashEntry *entry = _resolvedMethodHT->findResolvedMethod(method);
if (entry)
{
resolvedTramp = entry->_info._resolved._currentTrampoline;
if (resolvedTramp)
methodRunAddress = entry->_info._resolved._currentStartPC;
}
}
else if (TR::Options::getCmdLineOptions()->getOption(TR_UseGlueIfMethodTrampolinesAreNotNeeded))
{
// Safety measure, return to the old behaviour of always going through the glue
return;
}
if (TR::Options::getCmdLineOptions()->getVerboseOption(TR_VerbosePatching))
{
TR_VerboseLog::writeLineLocked(TR_Vlog_PATCH, "Patching callsite=0x%p using j9method=0x%p,resolvedTramp=0x%p,methodRunAddress=0x%p,newStartPC=0x%p,extraArg=0x%p",
callSite,
method,
resolvedTramp,
methodRunAddress,
newStartPC,
extraArg);
}
// Patch the code for a method trampoline
int32_t rc = _manager->codeCacheConfig().mccCallbacks().patchTrampoline(method, callSite, methodRunAddress, resolvedTramp, newStartPC, extraArg);
}
}
// Create code for a method trampoline at indicated address
//
// Calls platform dependent code to create a trampoline code snippet at the
// specified address and initialize it to jump to targetStartPC.
//
void
OMR::CodeCache::createTrampoline(CodeCacheTrampolineCode *trampoline,
void *targetStartPC,
TR_OpaqueMethodBlock *method)
{
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
config.mccCallbacks().createMethodTrampoline(trampoline, targetStartPC, method);
}
bool
OMR::CodeCache::saveTempTrampoline(CodeCacheHashEntry *entry)
{
CodeCacheTempTrampolineSyncBlock *freeSyncBlock = NULL;
CodeCacheTempTrampolineSyncBlock *syncBlock;
for (syncBlock = _trampolineSyncList; syncBlock; syncBlock = syncBlock->_next)
{
// See if the entry already exists in the block.
// If so, don't add another copy.
//
for (int32_t i = 0; i < syncBlock->_entryCount; i++)
{
if (syncBlock->_hashEntryArray[i] == entry)
return true;
}
// Remember the first sync block that has some free slots
//
if (syncBlock->_entryCount < syncBlock->_entryListSize && !freeSyncBlock)
freeSyncBlock = syncBlock;
}
if (!freeSyncBlock)
{
// Allocate a new temp trampoline sync block
//
if (!self()->allocateTempTrampolineSyncBlock())
{
// Can't allocate another block, mark the code cache as needing a
// full/slow sync during a safe point
//
_flags |= CODECACHE_FULL_SYNC_REQUIRED;
return false;
}
// New block is now at the at head of list
//
freeSyncBlock = _trampolineSyncList;
}
freeSyncBlock->_hashEntryArray[freeSyncBlock->_entryCount] = entry;
freeSyncBlock->_entryCount++;
return true;
}
// Allocate a new temp trampoline sync block and add it to the head of the list
// of such blocks.
//
bool
OMR::CodeCache::allocateTempTrampolineSyncBlock()
{
CodeCacheTempTrampolineSyncBlock *block = static_cast<CodeCacheTempTrampolineSyncBlock*>(_manager->getMemory(sizeof(CodeCacheTempTrampolineSyncBlock)));
if (!block)
return false;
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
block->_hashEntryArray = static_cast<CodeCacheHashEntry**>(_manager->getMemory(sizeof(CodeCacheHashEntry *) * config.codeCacheTempTrampolineSyncArraySize()));
if (!block->_hashEntryArray)
{
_manager->freeMemory(block);
return false;
}
mcc_printf("mcc_temptrampolinesyncblock: trampolineSyncList = %p\n", _trampolineSyncList);
mcc_printf("mcc_temptrampolinesyncblock: block = %p\n", block);
block->_entryCount = 0;
block->_entryListSize = static_cast<int32_t>(config.codeCacheTempTrampolineSyncArraySize());
block->_next = _trampolineSyncList;
_trampolineSyncList = block;
return true;
}
// Allocate a trampoline hash entry
//
OMR::CodeCacheHashEntry *
OMR::CodeCache::allocateHashEntry()
{
CodeCacheHashEntry *entry;
CodeCacheHashEntrySlab *slab = _hashEntrySlab;
// Do we have any free entries that were previously allocated from (perhaps)
// a slab or this list and were released onto it?
if (_hashEntryFreeList)
{
entry = _hashEntryFreeList;
_hashEntryFreeList = entry->_next;
return entry;
}
// Look for a slab with free hash entries
if ((slab->_heapAlloc + sizeof(CodeCacheHashEntry)) > slab->_heapTop)
{
TR::CodeCacheConfig & config = _manager->codeCacheConfig();
slab = CodeCacheHashEntrySlab::allocate(_manager, config.codeCacheHashEntryAllocatorSlabSize());
if (slab == NULL)
return NULL;
slab->_next = _hashEntrySlab;
_hashEntrySlab = slab;
}
entry = (CodeCacheHashEntry *) slab->_heapAlloc;
slab->_heapAlloc += sizeof(CodeCacheHashEntry);
return entry;
}
// Release an unused trampoline hash entry back onto the free list
//
void
OMR::CodeCache::freeHashEntry(CodeCacheHashEntry *entry)
{
// put it back onto the first slabs free list, see comment above
entry->_next = _hashEntryFreeList;
_hashEntryFreeList = entry;
}
// Add a resolved method to the trampoline hash table
//
bool
OMR::CodeCache::addResolvedMethod(TR_OpaqueMethodBlock *method)
{
CodeCacheHashEntry *entry = self()->allocateHashEntry();
if (!entry)
return false;
entry->_key = _resolvedMethodHT->hashResolvedMethod(method);
entry->_info._resolved._method = method;
entry->_info._resolved._currentStartPC = NULL;
entry->_info._resolved._currentTrampoline = NULL;
_resolvedMethodHT->add(entry);
return true;
}
// empty by default
OMR::CodeCacheMethodHeader *
OMR::CodeCache::addFreeBlock(void * metaData)
{
return NULL;
}
// May add the block between start and end to freeBlockList.
// returns false if block is not added
// No lock is needed because this operation is performed at GC points
// when GC has exclusive access; This is why the allocation (by the compilation
// thread needs to be done with VM access
// It can also be done by a compilation thread that performs a resize, but we
// also take VM access around resize.
bool
OMR::CodeCache::addFreeBlock2WithCallSite(uint8_t *start,
uint8_t *end,
const char *file,
uint32_t lineNumber)
{
TR::CodeCacheConfig &config = _manager->codeCacheConfig();
// align start on a code cache alignment boundary
uint8_t *start_o = start;
uint32_t round = static_cast<uint32_t>(config.codeCacheAlignment());
start = (uint8_t *)align((size_t)start, round);
// make sure aligning start didn't push it past end
if (end <= (start+sizeof(CodeCacheFreeCacheBlock)))
{
if (config.verboseReclamation())
{
TR_VerboseLog::writeLineLocked(TR_Vlog_FAILURE,"addFreeBlock2[%s.%d]: failed to add free block. start = 0x%016x end = 0x%016x alignment = 0x%04x sizeof(CodeCacheFreeCacheBlock) = 0x%08x",
file, lineNumber, start_o, end, config.codeCacheAlignment(), sizeof(CodeCacheFreeCacheBlock));
}
return false;
}
omrthread_jit_write_protect_disable();
uint64_t size = end - start; // Size of space to be freed
// Destroy the eyeCatcher; note that there might not be an eyecatcher at all
//
if (size >= sizeof(CodeCacheMethodHeader))
((CodeCacheMethodHeader*)start)->_eyeCatcher[0] = 0;