Print actual string arguments with -Xtrace (part 2)

The changes reflect the feature request #16416. Adding cmdline option to specify string argument length. -Xtrace:methodstrarglen=[1-128] methodStrArgLen takes an unsigned integer value from 1 to 128 If methodStrArgLen = 0 or unspecified, default to 32. Other invalid inputs result in the input error. There will be subsequent PR for tests (part 3). Signed-off-by: Nick Kamal <[email protected]>
eclipse-openj9 · Nov 28, 2024 · 2a77535 · 2a77535
1 parent 4ee9b77
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Showing 5 changed files with 62 additions and 9 deletions.
diff --git a/runtime/oti/j9trace.h b/runtime/oti/j9trace.h
@@ -63,6 +63,7 @@ typedef struct RasGlobalStorage {
 	void *  traceMethodTable;
 	int     stackdepth;
 	unsigned int    stackCompressionLevel;
+	unsigned int    methodStrArgLength;
 	ConfigureTraceFunction configureTraceEngine;
 #if defined(J9VM_OPT_CRIU_SUPPORT)
 	CRIURestoreInitializeTrace criuRestoreInitializeTrace;

diff --git a/runtime/rastrace/j9rastrace.h b/runtime/rastrace/j9rastrace.h
@@ -48,12 +48,13 @@ extern "C" {
  *  Keywords for options added by J9VM layer.
  * =============================================================================
  */
-#define RAS_METHODS_KEYWORD             "METHODS"
-#define RAS_DEBUG_KEYWORD               "DEBUG"
-#define RAS_TRIGGER_KEYWORD             "TRIGGER"
-#define RAS_STACKDEPTH_KEYWORD          "STACKDEPTH"
-#define RAS_SLEEPTIME_KEYWORD           "SLEEPTIME"
-#define RAS_COMPRESSION_LEVEL_KEYWORD   "STACKCOMPRESSIONLEVEL"
+#define RAS_METHODS_KEYWORD                 "METHODS"
+#define RAS_DEBUG_KEYWORD                   "DEBUG"
+#define RAS_TRIGGER_KEYWORD                 "TRIGGER"
+#define RAS_STACKDEPTH_KEYWORD              "STACKDEPTH"
+#define RAS_SLEEPTIME_KEYWORD               "SLEEPTIME"
+#define RAS_COMPRESSION_LEVEL_KEYWORD       "STACKCOMPRESSIONLEVEL"
+#define RAS_METHOD_STRING_LENGTH_KEYWORD    "METHODSTRARGLEN"
 
 /*
  * ======================================================================
@@ -130,6 +131,7 @@ omr_error_t processTriggerMethodClause(OMR_VMThread *, char *, BOOLEAN atRuntime
 void doTriggerActionJstacktrace(OMR_VMThread *thr);
 omr_error_t setStackDepth(J9JavaVM *thr, const char * value, BOOLEAN atRuntime);
 omr_error_t setStackCompressionLevel(J9JavaVM * vm, const char *str, BOOLEAN atRuntime);
+omr_error_t setMethodStrArgLength(J9JavaVM * vm, const char *str, BOOLEAN atRuntime);
 
 /*
  * =============================================================================

diff --git a/runtime/rastrace/method_trace.c b/runtime/rastrace/method_trace.c
@@ -30,6 +30,9 @@
 #undef UT_MODULE_UNLOADED
 #include "ut_mt.h"
 
+#define DEFAULT_BUFFER_LENGTH 128
+#define DEFAULT_STRING_LENGTH 32
+
 static void hookRAMClassLoad(J9HookInterface** hook, UDATA eventNum, void* eventData, void* userData);
 static void traceMethodArgInt (J9VMThread *thr, UDATA* arg0EA, char* cursor, UDATA length, char* type); 
 static void traceMethodArgDouble (J9VMThread *thr, UDATA* arg0EA, char* cursor, UDATA length);
@@ -476,12 +479,16 @@ traceMethodArgObject(J9VMThread *thr, UDATA* arg0EA, char* cursor, UDATA length)
 	} else {
 		J9Class *clazz = J9OBJECT_CLAZZ(thr, object);
 		J9JavaVM *vm = thr->javaVM;
+		const unsigned int methodStrArgLength = ((RasGlobalStorage *)thr->javaVM->j9rasGlobalStorage)->methodStrArgLength;
+		unsigned int strArgLength = methodStrArgLength == 0 ? DEFAULT_STRING_LENGTH : methodStrArgLength;
 
 		if (clazz == J9VMJAVALANGSTRING_OR_NULL(vm)) {
 			/* string argument */
 #define DEFAULT_STRING_LENGTH 32
 			char utf8Buffer[128];
 			UDATA utf8Length = 0;
+			const unsigned int methodStrArgLength = ((RasGlobalStorage *)thr->javaVM->j9rasGlobalStorage)->methodStrArgLength;
+			unsigned int strArgLength = methodStrArgLength == 0 ? DEFAULT_STRING_LENGTH : methodStrArgLength;
 
 			char *utf8String = vm->internalVMFunctions->copyStringToUTF8WithMemAlloc(
 					thr,

diff --git a/runtime/rastrace/method_trigger.c b/runtime/rastrace/method_trigger.c
@@ -60,7 +60,6 @@ static const StackTraceFormattingFunction stackTraceFormattingFunctions[] = {
 
 #define NUM_STACK_TRACE_FORMATTING_FUNCTIONS (sizeof(stackTraceFormattingFunctions) / sizeof(stackTraceFormattingFunctions[0]))
 
-
 /**************************************************************************
  * name        - rasSetTriggerTrace
  * description - Called whenever a class is loaded.
@@ -547,6 +546,49 @@ decimalString2Int(J9PortLibrary* portLibrary, const char *decString, I_32 signed
 	return num;
 }
 
+/**************************************************************************
+ * name        - setMethodStrArgLength
+ * description - Set method string argument length
+ * parameters  - thr, trace options, atRuntime flag
+ * returns     - JNI return code
+ *************************************************************************/
+omr_error_t
+setMethodStrArgLength(J9JavaVM *vm, const char *str, BOOLEAN atRuntime)
+{
+#define MAX_STRING_LENGTH 128
+	PORT_ACCESS_FROM_JAVAVM(vm);
+	int value, length;
+	omr_error_t rc = OMR_ERROR_NONE;
+	const char *p;
+
+	if (getParmNumber(str) != 1) {
+		goto err;
+	}
+
+	p = getPositionalParm(1, str, &length);
+
+	if (length > 3) {
+		goto err;
+	}
+
+	value = decimalString2Int(PORTLIB, p, FALSE, &rc);
+	if (OMR_ERROR_NONE != rc) {
+		goto err;
+	}
+
+	if ((0 > value) ||
+			(MAX_STRING_LENGTH < value)) {
+		goto err;
+	}
+
+	RAS_GLOBAL_FROM_JAVAVM(methodStrArgLength,vm) = (unsigned int)value;
+	return OMR_ERROR_NONE;
+err:
+	vaReportJ9VMCommandLineError(PORTLIB, "methodstrarglen takes an unsigned integer value from 1 to %d", MAX_STRING_LENGTH);
+	return OMR_ERROR_INTERNAL;
+#undef MAX_STRING_LENGTH 128
+}
+
 /**************************************************************************
  * name        - addTriggeredMethodSpec
  * description - Take a user specified method trigger rule (from the
@@ -654,12 +696,12 @@ addTriggeredMethodSpec(J9VMThread *thr, const char *ptrMethodSpec, const struct
 		}
 
 		if (methodRule->entryAction != NULL && methodRule->entryAction->name != NULL
-		    && j9_cmdla_stricmp((char *)methodRule->entryAction->name, "jstacktrace") == 0) {
+			&& j9_cmdla_stricmp((char *)methodRule->entryAction->name, "jstacktrace") == 0) {
 			/* set up the current method spec to be enabled for trace */
 			setMethod(thr->javaVM, ptrMethodSpec, FALSE);
 		}
 		if (methodRule->exitAction != NULL && methodRule->exitAction->name != NULL
-		    && j9_cmdla_stricmp((char *)methodRule->exitAction->name, "jstacktrace") == 0) {
+			&& j9_cmdla_stricmp((char *)methodRule->exitAction->name, "jstacktrace") == 0) {
 			/* set up the current method spec to be enabled for trace */
 			setMethod(thr->javaVM, ptrMethodSpec, FALSE);
 		}

diff --git a/runtime/rastrace/trcengine.c b/runtime/rastrace/trcengine.c
@@ -117,6 +117,7 @@ const struct traceOption TRACE_OPTIONS[] =
 	{RAS_METHODS_KEYWORD, FALSE, setMethod},
 	{RAS_STACKDEPTH_KEYWORD, TRUE, setStackDepth},
 	{RAS_COMPRESSION_LEVEL_KEYWORD, TRUE, setStackCompressionLevel},
+	{RAS_METHOD_STRING_LENGTH_KEYWORD, FALSE, setMethodStrArgLength},
 };
 
 #define NUMBER_OF_TRACE_OPTIONS ( sizeof(TRACE_OPTIONS) / sizeof(struct traceOption))