Add JFR InitialEnvironmentVariable support

Signed-off-by: Gengchen Tuo <[email protected]>
eclipse-openj9 · Nov 20, 2024 · 7a84785 · 7a84785
1 parent 9464ff3
commit 7a84785
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Showing 2 changed files with 58 additions and 0 deletions.
diff --git a/runtime/vm/JFRChunkWriter.cpp b/runtime/vm/JFRChunkWriter.cpp
@@ -815,4 +815,52 @@ VM_JFRChunkWriter::writeInitialSystemPropertyEvents(J9JavaVM *vm)
 	}
 }
 
+void
+VM_JFRChunkWriter::writeInitialEnvironmentVariableEvents()
+{
+	J9SysinfoEnvIteratorState envState;
+	memset(&envState, 0, sizeof(envState));
+
+	/* Call init with zero length buffer to get the required buffer size */
+	int32_t result = j9sysinfo_env_iterator_init(&envState, NULL, 0);
+
+	if (result >= 0) {
+		int32_t bufferSize = result;
+		void *buffer = j9mem_allocate_memory(bufferSize, OMRMEM_CATEGORY_VM);
+
+		if (NULL != buffer) {
+			J9SysinfoEnvElement envElement = {NULL};
+
+			result = j9sysinfo_env_iterator_init(&envState, buffer, bufferSize);
+
+			if (result >= 0) {
+				while (j9sysinfo_env_iterator_hasNext(&envState)) {
+					result = j9sysinfo_env_iterator_next(&envState, &envElement);
+
+					if (0 == result) {
+						/* reserve size field */
+						U_8 *dataStart = _bufferWriter->getAndIncCursor(sizeof(U_32));
+						const char *equalChar = strchr(envElement.nameAndValue, '=');
+
+						/* write event type */
+						_bufferWriter->writeLEB128(InitialEnvironmentVariableID);
+
+						/* write start time */
+						_bufferWriter->writeLEB128(j9time_nano_time());
+						/* write key */
+						writeUTF8String((U_8 *)envElement.nameAndValue, equalChar - envElement.nameAndValue);
+
+						/* write value */
+						writeStringLiteral(equalChar + 1);
+
+						/* write size */
+						_bufferWriter->writeLEB128PaddedU32(dataStart, _bufferWriter->getCursor() - dataStart);
+					}
+				}
+			}
+
+			j9mem_free_memory(buffer);
+		}
+	}
+}
 #endif /* defined(J9VM_OPT_JFR) */
diff --git a/runtime/vm/JFRChunkWriter.hpp b/runtime/vm/JFRChunkWriter.hpp
@@ -70,6 +70,7 @@ enum MetadataTypeID {
 	OSInformationID = 87,
 	VirtualizationInformationID = 88,
 	InitialSystemPropertyID = 89,
+	InitialEnvironmentVariableID = 90,
 	CPUInformationID = 92,
 	CPULoadID = 94,
 	ThreadCPULoadID = 95,
@@ -162,6 +163,7 @@ class VM_JFRChunkWriter {
 	static constexpr int INITIAL_SYSTEM_PROPERTY_EVENT_SIZE = 6000;
 	static constexpr int CPU_LOAD_EVENT_SIZE = (3 * sizeof(float)) + (3 * sizeof(I_64));
 	static constexpr int THREAD_CPU_LOAD_EVENT_SIZE = (2 * sizeof(float)) + (4 * sizeof(I_64));
+	static constexpr int INITIAL_ENVIRONMENT_VARIABLE_EVENT_SIZE = 6000;
 
 	static constexpr int METADATA_ID = 1;
 
@@ -347,6 +349,8 @@ class VM_JFRChunkWriter {
 				writeOSInformationEvent();
 
 				writeInitialSystemPropertyEvents(_vm);
+
+				writeInitialEnvironmentVariableEvents();
 			}
 
 			writePhysicalMemoryEvent();
@@ -625,6 +629,8 @@ class VM_JFRChunkWriter {
 
 	void writeStringLiteral(const char *string);
 
+	void writeStringLiteral(const char *string, UDATA len);
+
 	U_8 *writeThreadStateCheckpointEvent();
 
 	U_8 *writePackageCheckpointEvent();
@@ -659,6 +665,8 @@ class VM_JFRChunkWriter {
 
 	void writeInitialSystemPropertyEvents(J9JavaVM *vm);
 
+	void writeInitialEnvironmentVariableEvents();
+
 	UDATA
 	calculateRequiredBufferSize()
 	{
@@ -713,6 +721,8 @@ class VM_JFRChunkWriter {
 
 		requiredBufferSize += INITIAL_SYSTEM_PROPERTY_EVENT_SIZE;
 
+		requiredBufferSize += INITIAL_ENVIRONMENT_VARIABLE_EVENT_SIZE;
+
 		requiredBufferSize += _constantPoolTypes.getCPULoadCount() * CPU_LOAD_EVENT_SIZE;
 
 		requiredBufferSize += _constantPoolTypes.getThreadCPULoadCount() * THREAD_CPU_LOAD_EVENT_SIZE;