Add an API for system processes

include_core/omrport.h

@@ -1905,6 +1905,7 @@ typedef struct J9Heap J9Heap;
 
 typedef uintptr_t (*omrsig_protected_fn)(struct OMRPortLibrary *portLib, void *handler_arg);
 typedef uintptr_t (*omrsig_handler_fn)(struct OMRPortLibrary *portLib, uint32_t gpType, void *gpInfo, void *handler_arg);
+typedef uintptr_t (*OMRProcessInfoCallback)(uintptr_t pid, const char *commandLine, void *userData);
 
 typedef struct OMRPortLibrary {
 	/** portGlobals*/
@@ -2007,6 +2008,8 @@ typedef struct OMRPortLibrary {
 	intptr_t (*sysinfo_get_CPU_utilization)(struct OMRPortLibrary *portLibrary, struct J9SysinfoCPUTime *cpuTime) ;
 	/** see @ref omrsysinfo.c::omrsysinfo_get_CPU_load "omrsysinfo_get_CPU_utilization"*/
 	intptr_t (*sysinfo_get_CPU_load)(struct OMRPortLibrary *portLibrary, double *load) ;
+	/** see @ref omrsysinfo.c::omrsysinfo_get_processes "omrsysinfo_get_processes" */
+	uintptr_t (*sysinfo_get_processes)(struct OMRPortLibrary *portLibrary, OMRProcessInfoCallback callback, void *userData);
 	/** see @ref omrsysinfo.c::omrsysinfo_limit_iterator_init "omrsysinfo_limit_iterator_init"*/
 	int32_t (*sysinfo_limit_iterator_init)(struct OMRPortLibrary *portLibrary, J9SysinfoLimitIteratorState *state) ;
 	/** see @ref omrsysinfo.c::omrsysinfo_limit_iterator_hasNext "omrsysinfo_limit_iterator_hasNext"*/
@@ -2907,6 +2910,7 @@ extern J9_CFUNC int32_t omrport_getVersion(struct OMRPortLibrary *portLibrary);
 #define omrsysinfo_env_iterator_hasNext(param1) privateOmrPortLibrary->sysinfo_env_iterator_hasNext(privateOmrPortLibrary, (param1))
 #define omrsysinfo_env_iterator_next(param1,param2) privateOmrPortLibrary->sysinfo_env_iterator_next(privateOmrPortLibrary, (param1), (param2))
 #define omrsysinfo_set_number_user_specified_CPUs(param1) privateOmrPortLibrary->sysinfo_set_number_user_specified_CPUs(privateOmrPortLibrary,(param1))
+#define omrsysinfo_get_processes(callback, userData) privateOmrPortLibrary->sysinfo_get_processes(privateOmrPortLibrary, callback, userData)
 #define omrfile_startup() privateOmrPortLibrary->file_startup(privateOmrPortLibrary)
 #define omrfile_shutdown() privateOmrPortLibrary->file_shutdown(privateOmrPortLibrary)
 #define omrfile_write(param1,param2,param3) privateOmrPortLibrary->file_write(privateOmrPortLibrary, (param1), (param2), (param3))

port/common/omrport.c

@@ -85,6 +85,7 @@ static OMRPortLibrary MainPortLibraryTable = {
 	omrsysinfo_get_load_average, /* sysinfo_get_load_average */
 	omrsysinfo_get_CPU_utilization, /* sysinfo_get_CPU_utilization */
 	omrsysinfo_get_CPU_load, /* sysinfo_get_CPU_load */
+	omrsysinfo_get_processes, /* sysinfo_get_processes */
 	omrsysinfo_limit_iterator_init, /* sysinfo_limit_iterator_next */
 	omrsysinfo_limit_iterator_hasNext, /* sysinfo_limit_iterator_hasNext */
 	omrsysinfo_limit_iterator_next, /* sysinfo_limit_iterator_next */

port/common/omrport.tdf

@@ -1635,3 +1635,5 @@ TraceEntry=Trc_PRT_sysinfo_get_process_start_time_enter Group=sysinfo Overhead=1
 TraceExit=Trc_PRT_sysinfo_get_process_start_time_exit Group=sysinfo Overhead=1 Level=1 NoEnv Template="Exit omrsysinfo_get_process_start_time, pid=%zu, processStartTimeInNanoseconds=%llu, rc=%d."
 
 TraceEvent=Trc_PRT_vmem_reserve_tempfile_not_created Group=mem Overhead=1 Level=5 NoEnv Template="reserve_memory cannot create temporary file %s of size %zu"
+
+TraceException=Trc_PRT_sysinfo_get_processes_failedOpeningProcFS Group=sysinfo Overhead=1 Level=1 NoEnv Template="omrsysinfo_get_processes failed opening /proc = %d."

port/common/omrsysinfo.c

@@ -1203,3 +1203,16 @@ omrsysinfo_get_number_context_switches(struct OMRPortLibrary *portLibrary, uint6
 {
 	return OMRPORT_ERROR_NOT_SUPPORTED_ON_THIS_PLATFORM;
 }
+
+/**
+ * Get the process ID and commandline for each process.
+ * @param[in] portLibrary The port library.
+ * @param[in] callback The function to be invoked for each process with the process ID and command info.
+ * @param[in] userData Data passed to the callback.
+ * @return 0 on success, or the first non-zero value returned by the callback.
+ */
+uintptr_t
+omrsysinfo_get_processes(struct OMRPortLibrary *portLibrary, OMRProcessInfoCallback callback, void *userData)
+{
+	return OMRPORT_ERROR_NOT_SUPPORTED_ON_THIS_PLATFORM;
+}

port/omrportpriv.h

@@ -617,6 +617,8 @@ extern J9_CFUNC intptr_t
 omrsysinfo_get_CPU_utilization(struct OMRPortLibrary *portLibrary, struct J9SysinfoCPUTime *cpuTime);
 extern J9_CFUNC intptr_t
 omrsysinfo_get_CPU_load(struct OMRPortLibrary *portLibrary, double *cpuLoad);
+extern J9_CFUNC uintptr_t
+omrsysinfo_get_processes(struct OMRPortLibrary *portLibrary, OMRProcessInfoCallback callback, void *userData);
 extern J9_CFUNC void
 omrsysinfo_set_number_user_specified_CPUs(struct OMRPortLibrary *portLibrary, uintptr_t number);
 extern J9_CFUNC intptr_t

port/unix/omrsysinfo.c

@@ -7557,3 +7557,118 @@ omrsysinfo_get_number_context_switches(struct OMRPortLibrary *portLibrary, uint6
 	return OMRPORT_ERROR_SYSINFO_NOT_SUPPORTED;
 #endif /* defined(LINUX) */
 }
+
+/*
+ * Get the process ID and commandline for each process.
+ * @param[in] portLibrary The port library.
+ * @param[in] callback The function to be invoked for each process with the process ID and command info.
+ * @param[in] userData Data passed to the callback.
+ * @return 0 on success, or the first non-zero value returned by the callback.
+ */
+uintptr_t
+omrsysinfo_get_processes(struct OMRPortLibrary *portLibrary, OMRProcessInfoCallback callback, void *userData)
+{
+#if defined(LINUX)
+#define INITIAL_BUFFER_SIZE 4096
+	char path[PATH_MAX];
+	uintptr_t callback_result = 0;
+	uintptr_t pid;
+	intptr_t file = 0;
+	uintptr_t buffer_size = INITIAL_BUFFER_SIZE;
+	intptr_t bytes_read = 0;
+	intptr_t total_bytes_read = 0;
+	uintptr_t new_size = 0;
+	intptr_t i = 0;
+	char *command = NULL;
+	char *end = NULL;
+	char *new_command = NULL;
+	DIR *dir = opendir("/proc");
+	if (NULL == dir) {
+		int32_t rc = findError(errno);
+		portLibrary->error_set_last_error(portLibrary, errno, rc);
+		Trc_PRT_sysinfo_get_processes_failedOpeningProcFS(rc);
+		return (uintptr_t)(intptr_t)rc;
+	}
+	/* Allocate initial buffer. */
+	command = (char *)portLibrary->mem_allocate_memory(portLibrary, buffer_size, OMR_GET_CALLSITE(), OMRMEM_CATEGORY_PORT_LIBRARY);
+	if (NULL == command) {
+		closedir(dir);
+		return OMRPORT_ERROR_SYSINFO_MEMORY_ALLOC_FAILED;
+	}
+	for (;;) {
+		struct dirent *entry = readdir(dir);
+		if (NULL == entry) {
+			break;
+		}
+		if ('\0' == entry->d_name[0]) {
+			continue;
+		}
+		/* Convert name to pid, skipping non-numeric entries. */
+		pid = (uintptr_t)strtoull(entry->d_name, &end, 10);
+		if ('\0' != *end) {
+			continue;
+		}
+		/* Try reading /proc/[pid]/cmdline. */
+		portLibrary->str_printf(portLibrary, path, sizeof(path), "/proc/%s/cmdline", entry->d_name);
+		file = portLibrary->file_open(portLibrary, path, EsOpenRead, 0);
+		total_bytes_read = 0;
+		if (file >= 0) {
+			for (;;) {
+				bytes_read = portLibrary->file_read(portLibrary, file, command + total_bytes_read, buffer_size - 1 - total_bytes_read);
+				if (bytes_read < 0) {
+					break;
+				}
+				total_bytes_read += bytes_read;
+				if (total_bytes_read == buffer_size - 1) {
+					/* Buffer may be too small, increase and retry. */
+					new_size = buffer_size * 2;
+					new_command = (char *)portLibrary->mem_reallocate_memory(
+						portLibrary,
+						command,
+						new_size, OMR_GET_CALLSITE(), OMRMEM_CATEGORY_PORT_LIBRARY);
+					if (NULL == new_command) {
+						break;
+					}
+					command = new_command;
+					buffer_size = new_size;
+					continue;
+				}
+				break;
+			}
+			bytes_read = total_bytes_read;
+			portLibrary->file_close(portLibrary, file);
+		}
+		/* If cmdline is empty, try reading from comm. */
+		if (bytes_read <= 0) {
+			portLibrary->str_printf(portLibrary, path, sizeof(path), "/proc/%s/comm", entry->d_name);
+			file = portLibrary->file_open(portLibrary, path, EsOpenRead, 0);
+			if (file >= 0) {
+				bytes_read = portLibrary->file_read(portLibrary, file, command, buffer_size - 1);
+				portLibrary->file_close(portLibrary, file);
+			}
+		}
+		/* Skip process if no data. */
+		if (bytes_read <= 0) {
+			continue;
+		}
+		/* Replace null terminators with spaces. */
+		for (i = 0; i < bytes_read; i++) {
+			if ('\0' == command[i]) {
+				command[i] = ' ';
+			}
+		}
+		command[bytes_read] = '\0';
+		/* Call the callback function with PID and command. */
+		callback_result = callback(pid, command, userData);
+		if (0 != callback_result) {
+			break;
+		}
+	}
+	portLibrary->mem_free_memory(portLibrary, command);
+	closedir(dir);
+	return callback_result;
+#else /* defined(LINUX) */
+	/* sysinfo_get_processes is not supported on this platform. */
+	return OMRPORT_ERROR_SYSINFO_NOT_SUPPORTED;
+#endif /* defined(LINUX) */
+}