Limit the number of startup hints in SCC

runtime/nls/shrc/j9shr.nls

@@ -6957,3 +6957,36 @@ J9NLS_SHRC_SHRINIT_FAILURE_CREATE_ROMTORAMMUTEX.explanation=The system is unable
 J9NLS_SHRC_SHRINIT_FAILURE_CREATE_ROMTORAMMUTEX.system_action=The JVM terminates, unless you have specified the nonfatal option with "-Xshareclasses:nonfatal", in which case the JVM attempts to start up without using Shared Classes.
 J9NLS_SHRC_SHRINIT_FAILURE_CREATE_ROMTORAMMUTEX.user_response=System is running low on memory resource for the JVM to start up properly. Check system memory configuration. If the situation persists, contact your service representative.
 # END NON-TRANSLATABLE
+
+J9NLS_SHRC_SHRINIT_HELPTEXT_EXTRA_STARTUPHINTS_EQUALS=Adjust the number of additional startup hints allowed to be stored into the shared classes cache to <number>.
+# START NON-TRANSLATABLE
+J9NLS_SHRC_SHRINIT_HELPTEXT_EXTRA_STARTUPHINTS_EQUALS.explanation=NOTAG
+J9NLS_SHRC_SHRINIT_HELPTEXT_EXTRA_STARTUPHINTS_EQUALS.system_action=
+J9NLS_SHRC_SHRINIT_HELPTEXT_EXTRA_STARTUPHINTS_EQUALS.user_response=
+# END NON-TRANSLATABLE
+
+J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM=Invalid parameter passed to option \"%s\".
+# START NON-TRANSLATABLE
+J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM.sample_input_1=extraStartupHints=
+J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM.explanation=An incorrect parameter has been used in the command-line option
+J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM.system_action=The JVM terminates.
+J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM.user_response=Correct or remove the invalid command-line option and rerun.
+# END NON-TRANSLATABLE
+
+J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET=The number of additional startup hints that can be stored into the shared cache is set to %u.
+# START NON-TRANSLATABLE
+J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET.sample_input_1=64
+J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET.explanation=The number of additional startup hints allowed to be stored to the shared classes cache has been adjusted.
+J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET.system_action=The JVM continues.
+J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET.user_response=No action required. This message is for information only.
+# END NON-TRANSLATABLE
+
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS=additional startup hints allowed    %*.c= %u
+# START NON-TRANSLATABLE
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.sample_input_1=0
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.sample_input_2=
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.sample_input_3=8
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.explanation=NOTAG
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.system_action=
+J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS.user_response=
+# END NON-TRANSLATABLE

runtime/oti/j9nonbuilder.h

@@ -1221,6 +1221,7 @@ typedef struct J9SharedClassJavacoreDataDescriptor {
 	UDATA startupHintBytes;
 	UDATA nattach;
 	UDATA currentOSPageSize; /* memory page size of the current running OS */
+	U_32 extraStartupHints;
 } J9SharedClassJavacoreDataDescriptor;
 
 typedef struct J9SharedStringFarm {
@@ -1271,7 +1272,7 @@ typedef struct J9SharedCacheHeader {
 	J9WSRP corruptFlagPtr;
 	J9SRP sharedStringHead;
 	J9SRP sharedStringTail;
-	J9SRP unused1;
+	U_32 extraStartupHints; /* Number of addtional startup hints allowed to be stored into the shared cache */
 	U_32 totalSharedStringNodes;
 	U_32 totalSharedStringWeight;
 	U_32 readWriteFlags;
@@ -1354,6 +1355,7 @@ typedef struct J9SharedCacheAPI {
 #if defined(J9VM_OPT_JITSERVER)
 	U_8 usingJITServerAOTCacheLayer;
 #endif /* defined(J9VM_OPT_JITSERVER) */
+	I_32 newStartupHints;
 } J9SharedCacheAPI;
 
 typedef struct J9SharedClassConfig {

runtime/shared/shrclssup.c

@@ -184,6 +184,7 @@ IDATA J9VMDllMain(J9JavaVM* vm, IDATA stage, void* reserved)
 		vm->sharedCacheAPI->minJIT = -1;
 		vm->sharedCacheAPI->maxJIT = -1;
 		vm->sharedCacheAPI->layer = -1;
+		vm->sharedCacheAPI->newStartupHints = -1;
 		if (index >= 0) {
 			/* -Xshareclasses is specified */
 			char optionsBuffer[SHR_SUBOPT_BUFLEN];

runtime/shared_common/CacheMap.cpp

@@ -3890,6 +3890,7 @@ SH_CacheMap::storeSharedData(J9VMThread* currentThread, const char* key, UDATA k
 	UDATA dataNotIndexed = (data != NULL) ? (data->flags & J9SHRDATA_NOT_INDEXED) : 0;
 	SH_ByteDataManager* localBDM;
 	bool overwrite = false;
+	U_32 extraStartupHints = 0;
 
 	PORT_ACCESS_FROM_VMC(currentThread);
 
@@ -3989,6 +3990,14 @@ SH_CacheMap::storeSharedData(J9VMThread* currentThread, const char* key, UDATA k
 	}
 
 _addData:
+	if (J9SHR_DATA_TYPE_STARTUP_HINTS == data->type) {
+		extraStartupHints = _ccHead->getExtraStartupHints();
+		if (0 == extraStartupHints) {
+			result = NULL;
+			Trc_SHR_CM_storeSharedData_NoMoreStartupHintsAllowed(currentThread);
+			goto _done;
+		}
+	}
 	/* If data is NULL or datalen <= 0, mark the original item(s) stale, but don't store anything */
 	if ((data != NULL) && (data->length > 0) && ((data->address != NULL) || (data->flags & J9SHRDATA_ALLOCATE_ZEROD_MEMORY))) {
 		const J9UTF8* tokenKey = NULL;
@@ -4021,6 +4030,12 @@ SH_CacheMap::storeSharedData(J9VMThread* currentThread, const char* key, UDATA k
 			}
 		}
 		result = (const U_8*)addByteDataToCache(currentThread, localBDM, tokenKey, data, NULL, false);
+		if (NULL != result) {
+			if (J9SHR_DATA_TYPE_STARTUP_HINTS == data->type) {
+				Trc_SHR_Assert_True(extraStartupHints > 0);
+				_ccHead->setExtraStartupHints(currentThread, extraStartupHints - 1);
+			}
+		}
 	}
 
 _done:
@@ -5043,7 +5058,11 @@ SH_CacheMap::printCacheStatsTopLayerStatsHelper(J9VMThread* currentThread, UDATA
 	if (J9_ARE_ALL_BITS_SET(runtimeFlags, J9SHR_RUNTIMEFLAG_ENABLE_DETAILED_STATS)) {
 		CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_SUMMARY_METADATA_STARTADDRESS, javacoreData->metadataStart);
 		CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_RUNTIME_FLAGS, javacoreData->runtimeFlags);
+		CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS, javacoreData->extraStartupHints);
 		CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_CACHE_GEN, javacoreData->cacheGen);
+	} else if (J9_ARE_ALL_BITS_SET(showFlags, PRINTSTATS_SHOW_STARTUPHINT)) {
+		CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_STARTUP_HINTS, javacoreData->extraStartupHints);
+		j9tty_printf(_portlib, "\n");
 	}
 
 	CACHEMAP_FMTPRINT1(J9NLS_DO_NOT_PRINT_MESSAGE_TAG, J9NLS_SHRC_CM_PRINTSTATS_CACHE_LAYER, javacoreData->topLayer);
@@ -7088,3 +7107,18 @@ SH_CacheMap::getDataFromByteDataWrapper(const ByteDataWrapper* bdw)
 	}
 	return ret;
 }
+
+void
+SH_CacheMap::setExtraStartupHints(J9VMThread* currentThread)
+{
+	PORT_ACCESS_FROM_PORT(_portlib);
+	const char* fnName = "setExtraStartupHints";
+	U_32 val = (U_32)currentThread->javaVM->sharedCacheAPI->newStartupHints;
+	if (_ccHead->enterWriteMutex(currentThread, false, fnName) != 0) {
+		CACHEMAP_TRACE(J9SHR_VERBOSEFLAG_ENABLE_VERBOSE_DEFAULT, J9NLS_ERROR, J9NLS_SHRC_CM_FAILED_ENTER_WRITE_MUTEX);
+		return;
+	}
+	_ccHead->setExtraStartupHints(currentThread, val);
+	CACHEMAP_TRACE1(J9SHR_VERBOSEFLAG_ENABLE_VERBOSE_DEFAULT, J9NLS_INFO, J9NLS_SHRC_CC_EXTRA_STARTUPHINTS_SET, val);
+	_ccHead->exitWriteMutex(currentThread, fnName);
+}

runtime/shared_common/CacheMap.hpp

@@ -281,6 +281,8 @@ class SH_CacheMap : public SH_SharedCache, public SH_CacheMapStats
 
 	bool isAddressInCache(const void *address, UDATA length, bool includeHeaderReadWriteArea, bool useCcHeadOnly) const;
 
+	void setExtraStartupHints(J9VMThread* currentThread);
+
 private:
 	SH_CompositeCacheImpl* _cc;					/* current cache */
 

runtime/shared_common/CompositeCache.cpp

@@ -38,6 +38,7 @@
 #include "CompositeCacheImpl.hpp"
 
 #define SEMSUFFIX "SHSEM"
+#define DEFAULT_STARTUPHINTS 64
 
 /**
  * CACHE AREAS
@@ -157,6 +158,7 @@ SH_CompositeCacheImpl::SH_SharedCacheHeaderInit::init(BlockPtr data, U_32 len, I
 	ca->writerCount = 0;
 	ca->softMaxBytes = softMaxBytes;
 	ca->cacheFullFlags = 0;
+	ca->extraStartupHints = DEFAULT_STARTUPHINTS;
 	ca->unused8 = 0;
 	ca->unused9 = 0;
 	ca->unused10 = 0;
@@ -4488,6 +4490,7 @@ SH_CompositeCacheImpl::getJavacoreData(J9JavaVM *vm, J9SharedClassJavacoreDataDe
 		descriptor->maxJIT = _theca->maxJIT;
 		descriptor->softMaxBytes = (UDATA)((U_32)-1 == _theca->softMaxBytes ? descriptor->cacheSize : _theca->softMaxBytes);
 		descriptor->currentOSPageSize = getOSPageSize();
+		descriptor->extraStartupHints = getExtraStartupHints();
 #if defined(J9VM_OPT_JITSERVER)
 		descriptor->usingJITServerAOTCacheLayer = vm->sharedCacheAPI->usingJITServerAOTCacheLayer;
 #endif /* defined(J9VM_OPT_JITSERVER) */
@@ -6784,3 +6787,29 @@ SH_CompositeCacheImpl::updateMsyncRuntimeFlags(void)
 	}
 }
 #endif /* defined(J9VM_OPT_SHR_MSYNC_SUPPORT) */
+
+U_32
+SH_CompositeCacheImpl::getExtraStartupHints(void) const
+{
+	if (!_started) {
+		Trc_SHR_Assert_ShouldNeverHappen();
+		return 0;
+	}
+	return _theca->extraStartupHints;
+}
+
+void
+SH_CompositeCacheImpl::setExtraStartupHints(J9VMThread* currentThread, U_32 val)
+{
+	if (!_started) {
+		Trc_SHR_Assert_ShouldNeverHappen();
+		return;
+	}
+	if (_readOnlyOSCache) {
+		Trc_SHR_Assert_ShouldNeverHappen();
+		return;
+	}
+	Trc_SHR_Assert_True(hasWriteMutex(currentThread));
+	_theca->extraStartupHints = val;
+	Trc_SHR_CC_setExtraStartupHints_Event(currentThread, val);
+}

runtime/shared_common/CompositeCacheImpl.hpp

@@ -397,6 +397,10 @@ class SH_CompositeCacheImpl : public SH_CompositeCache, public AbstractMemoryPer
 
 	bool hasReadMutex(J9VMThread* currentThread) const;
 
+	U_32 getExtraStartupHints(void) const;
+
+	void setExtraStartupHints(J9VMThread* currentThread, U_32 val);
+
 private:
 	J9SharedClassConfig* _sharedClassConfig;
 	SH_OSCache* _oscache;
@@ -581,4 +585,3 @@ class SH_CompositeCacheImpl : public SH_CompositeCache, public AbstractMemoryPer
 };
 
 #endif /* !defined(COMPOSITECACHEIMPL_H_INCLUDED) */
-

runtime/shared_common/j9shr.tdf

@@ -3006,3 +3006,5 @@ TraceEvent=Trc_SHR_OSC_Mmap_startup_jitserverlayergooddelete NoEnv Overhead=1 Le
 TraceException=Trc_SHR_OSC_Mmap_startup_jitserverlayerbaddelete NoEnv Overhead=1 Level=1 Template="SH_OSCachemmap::startup: deleteCacheFile failed for cache path name = %s, file handle %zd"
 
 TraceEvent=Trc_SHR_CC_OSPAGE_SIZE_MISMATCH_V1 Overhead=1 Level=1 Template="Mismatch in layer %d composite cache osPageSize value. CompositeCache = %p, _theca->osPageSize = %zu, _osPageSize = %zu, _theca->roundedPagesFlag is %u, _readOnlyOSCache is %d"
+TraceEvent=Trc_SHR_CC_setExtraStartupHints_Event Overhead=1 Level=6 Template="CC setExtraStartupHints: set extraStartupHints in the header to %u"
+TraceEvent=Trc_SHR_CM_storeSharedData_NoMoreStartupHintsAllowed Overhead=1 Level=1 Template="CM storeSharedData: No more startup hints are allowed to be stored"

runtime/shared_common/shrinit.cpp

@@ -250,6 +250,7 @@ J9SharedClassesHelpText J9SHAREDCLASSESHELPTEXT[] = {
 	{HELPTEXT_ADJUST_MAXAOT_EQUALS, J9NLS_SHRC_SHRINIT_HELPTEXT_ADJUST_MAXAOT_EQUALS, 0, 0},
 	{HELPTEXT_ADJUST_MINJITDATA_EQUALS, J9NLS_SHRC_SHRINIT_HELPTEXT_ADJUST_MINJIT_EQUALS, 0, 0},
 	{HELPTEXT_ADJUST_MAXJITDATA_EQUALS, J9NLS_SHRC_SHRINIT_HELPTEXT_ADJUST_MAXJIT_EQUALS, 0, 0},
+	{HELPTEXT_OPTION_EXTRA_STARTUPHINTS_EQUALS, J9NLS_SHRC_SHRINIT_HELPTEXT_EXTRA_STARTUPHINTS_EQUALS, 0, 0},
 #if defined(J9VM_OPT_MULTI_LAYER_SHARED_CLASS_CACHE)
 	HELPTEXT_NEWLINE,
 	{HELPTEXT_LAYER_EQUALS,J9NLS_SHRC_SHRINIT_HELPTEXT_LAYER_EQUALS, 0, 0},
@@ -385,6 +386,7 @@ J9SharedClassesOptions J9SHAREDCLASSESOPTIONS[] = {
 #endif /* defined(J9ZOS39064) */
 	{ OPTION_TEST_DOUBLE_PAGESIZE, PARSE_TYPE_EXACT, RESULT_DO_ADD_RUNTIMEFLAG2, J9SHR_RUNTIMEFLAG2_TEST_DOUBLE_PAGESIZE},
 	{ OPTION_TEST_HALF_PAGESIZE, PARSE_TYPE_EXACT, RESULT_DO_ADD_RUNTIMEFLAG2, J9SHR_RUNTIMEFLAG2_TEST_HALF_PAGESIZE},
+	{ OPTION_EXTRA_STARTUPHINTS_EQUALS, PARSE_TYPE_STARTSWITH, RESULT_DO_SET_EXTRA_STARTUPHINTS, 0},
 	{ NULL, 0, 0 }
 };
 
@@ -707,6 +709,26 @@ parseArgs(J9JavaVM* vm, char* options, U_64* runtimeFlags, U_64* runtimeFlags2,
 			options += strlen(OPTION_LAYER_EQUALS)+ (cursor - layerString) +1;
 			continue;
 		}
+		case RESULT_DO_SET_EXTRA_STARTUPHINTS:
+		{
+			UDATA temp = 0;
+			char* optString = options + strlen(OPTION_EXTRA_STARTUPHINTS_EQUALS);
+			char* cursor = optString;
+			if (J9_ARE_ALL_BITS_SET(*runtimeFlags, J9SHR_RUNTIMEFLAG_ENABLE_READONLY)) {
+				*runtimeFlags &= ~J9SHR_RUNTIMEFLAG_ENABLE_READONLY;
+				SHRINIT_WARNING_TRACE3(verboseFlags, J9NLS_SHRC_SHRINIT_OPTION_IGNORED_WARNING, OPTION_READONLY, OPTION_EXTRA_STARTUPHINTS_EQUALS, OPTION_READONLY);
+			}
+			if (scan_udata(&cursor, &temp) == 0) {
+				vm->sharedCacheAPI->newStartupHints = (I_32)temp;
+			} else {
+				SHRINIT_ERR_TRACE1(1, J9NLS_SHRC_SHRINIT_OPTION_INVALID_PARAM, OPTION_EXTRA_STARTUPHINTS_EQUALS);
+				return RESULT_PARSE_FAILED;
+			}
+			options += strlen(OPTION_EXTRA_STARTUPHINTS_EQUALS) + (cursor - optString) + 1;
+			returnAction = J9SHAREDCLASSESOPTIONS[i].action;
+			*runtimeFlags |= J9SHR_RUNTIMEFLAG_DO_NOT_CREATE_CACHE;
+			continue;
+		}
 		case RESULT_DO_CREATE_LAYER:
 		{
 			vm->sharedCacheAPI->layer = SHRINIT_CREATE_NEW_LAYER;
@@ -2641,6 +2663,7 @@ performSharedClassesCommandLineAction(J9JavaVM* vm, J9SharedClassConfig* sharedC
 	case RESULT_DO_ADJUST_MAXAOT_EQUALS:
 	case RESULT_DO_ADJUST_MINJITDATA_EQUALS:
 	case RESULT_DO_ADJUST_MAXJITDATA_EQUALS:
+	case RESULT_DO_SET_EXTRA_STARTUPHINTS:
 		if (1 == checkIfCacheExists(vm, sharedClassConfig->ctrlDirName, cacheDirName, cacheName, &versionData, cacheType, layer)) {
 			return J9VMDLLMAIN_OK;
 		}
@@ -3869,10 +3892,12 @@ j9shr_init(J9JavaVM *vm, UDATA loadFlags, UDATA* nonfatal)
  		 * will be printed out inside tryAdjustMinMaxSizes() no matter whether the softmx/minAOT/maxAOT/minJIT/maxJIT has been adjusted as requested */
 		cm->tryAdjustMinMaxSizes(currentThread);
 		returnVal = J9VMDLLMAIN_SILENT_EXIT_VM;
+	} else if (RESULT_DO_SET_EXTRA_STARTUPHINTS == parseResult) {
+		cm->setExtraStartupHints(currentThread);
+		returnVal = J9VMDLLMAIN_SILENT_EXIT_VM;
 	}
 
 	return returnVal;
-
 _error:
 	/* This needs to be done before freeing vm->sharedClassConfig */
 	if ((doPrintStats) && (-2 == rcStartup)) {

runtime/shared_common/shrinit.h

@@ -198,6 +198,7 @@ typedef struct J9SharedClassesOptions {
 #define OPTION_MAP31 "map31"
 #define OPTION_TEST_DOUBLE_PAGESIZE "testDoublePageSize"
 #define OPTION_TEST_HALF_PAGESIZE "testHalfPageSize"
+#define OPTION_EXTRA_STARTUPHINTS_EQUALS "extraStartupHints="
 
 /* public options for printallstats= and printstats=  */
 #define SUB_OPTION_PRINTSTATS_ALL "all"
@@ -279,6 +280,7 @@ typedef struct J9SharedClassesOptions {
 #define RESULT_DO_PRINT_TOP_LAYER_STATS 53
 #define RESULT_DO_PRINT_TOP_LAYER_STATS_EQUALS 54
 #define RESULT_DO_ADD_RUNTIMEFLAG2 55
+#define RESULT_DO_SET_EXTRA_STARTUPHINTS 56
 
 #define PARSE_TYPE_EXACT 1
 #define PARSE_TYPE_STARTSWITH 2
@@ -311,6 +313,7 @@ typedef struct J9SharedClassesOptions {
 #define HELPTEXT_ADJUST_MINJITDATA_EQUALS OPTION_ADJUST_MINJITDATA_EQUALS"<size>"
 #define HELPTEXT_ADJUST_MAXJITDATA_EQUALS OPTION_ADJUST_MAXJITDATA_EQUALS"<size>"
 #define HELPTEXT_LAYER_EQUALS OPTION_LAYER_EQUALS "<number>"
+#define HELPTEXT_OPTION_EXTRA_STARTUPHINTS_EQUALS OPTION_EXTRA_STARTUPHINTS_EQUALS"<number>"
 
 #define HELPTEXT_NEWLINE {"", 0, 0, 0, 0}