Add gathering per-thread CPU usage to ddsrt

Signed-off-by: Erik Boasson <eb@ilities.com>

src/ddsrt/include/dds/ddsrt/rusage.h

@@ -22,12 +22,15 @@
 # else
 #   define DDSRT_HAVE_RUSAGE 0
 #endif
-#else
+#elif defined (_WIN32) || defined (__linux) || defined (__APPLE__)
 # define DDSRT_HAVE_RUSAGE 1
+#else
+# define DDSRT_HAVE_RUSAGE 0
 #endif
 
 #include "dds/ddsrt/time.h"
 #include "dds/ddsrt/retcode.h"
+#include "dds/ddsrt/threads.h"
 
 #if defined (__cplusplus)
 extern "C" {
@@ -43,8 +46,10 @@ typedef struct {
   size_t nivcsw; /* Involuntary context switches. Not maintained on Windows. */
 } ddsrt_rusage_t;
 
-#define DDSRT_RUSAGE_SELF (0)
-#define DDSRT_RUSAGE_THREAD (1)
+enum ddsrt_getrusage_who {
+  DDSRT_RUSAGE_SELF,
+  DDSRT_RUSAGE_THREAD
+};
 
 /**
  * @brief Get resource usage for the current thread or process.
@@ -61,7 +66,26 @@ typedef struct {
  * @retval DDS_RETCODE_ERROR
  *             An unidentified error occurred.
  */
-DDS_EXPORT dds_return_t ddsrt_getrusage(int who, ddsrt_rusage_t *usage);
+DDS_EXPORT dds_return_t ddsrt_getrusage(enum ddsrt_getrusage_who who, ddsrt_rusage_t *usage);
+
+#if DDSRT_HAVE_THREAD_LIST
+/**
+ * @brief Get resource usage for some thread.
+ *
+ * @param[in]  tid    id of the thread of to get the resource usage for
+ * @param[in]  usage  Structure where resource usage is returned.
+ *
+ * @returns A dds_return_t indicating success or failure.
+ *
+ * @retval DDS_RETCODE_OK
+ *             Resource usage successfully returned in @usage.
+ * @retval DDS_RETCODE_OUT_OF_RESOURCES
+ *             There were not enough resources to get resource usage.
+ * @retval DDS_RETCODE_ERROR
+ *             An unidentified error occurred.
+ */
+DDS_EXPORT dds_return_t ddsrt_getrusage_anythread (ddsrt_thread_list_id_t tid, ddsrt_rusage_t * __restrict usage);
+#endif
 
 #if defined (__cplusplus)
 }

src/ddsrt/include/dds/ddsrt/threads.h

@@ -214,6 +214,53 @@ ddsrt_thread_setname(
   const char *__restrict name);
 #endif
 
+#if DDSRT_HAVE_THREAD_LIST
+/**
+ * @brief Get a list of threads in the calling process
+ *
+ * @param[out]  tids    Array of size elements to be filled with thread
+ *                      identifiers, may be NULL if size is 0
+ * @param[in]   size    The size of the tids array; 0 is allowed
+ *
+ * @returns A dds_return_t indicating the number of threads in the process
+ * or an error code on failure.
+ *
+ * @retval > 0
+ *             Number of threads in the process, may be larger than size
+ *             tids[0 .. (return - 1)] are valid
+ * @retval DDS_RETCODE_ERROR
+ *             Something went wrong, contents of tids is undefined
+ * @retval DDS_RETCODE_UNSUPPORTED
+ *             Not supported on the platform
+ */
+DDS_EXPORT dds_return_t ddsrt_thread_list (ddsrt_thread_list_id_t * __restrict tids, size_t size);
+
+/**
+ * @brief Get the name of the specified thread (in the calling process)
+ *
+ * @param[in]   tid     Thread identifier for which the name is sought
+ * @param[out]  name    Filled with the thread name (or a synthesized one)
+ *                      on successful return; name is silently truncated
+ *                      if the actual name is longer than name can hold;
+ *                      always 0-terminated if size > 0
+ * @param[in]   size    Number of bytes of name that may be assigned, size
+ *                      is 0 is allowed, though somewhat useless
+ *
+ * @returns A dds_return_t indicating success or failure.
+ *
+ * @retval DDS_RETCODE_OK
+ *             Possibly truncated name is returned as a null-terminated
+ *             string in name (provided size > 0).
+ * @retval DDS_RETCODE_NOT_FOUND
+ *             Thread not found; the contents of name is unchanged
+ * @retval DDS_RETCODE_ERROR
+ *             Unspecified failure, the contents of name is undefined
+ * @retval DDS_RETCODE_UNSUPPORTED
+ *             Not supported on the platform
+ */
+DDS_EXPORT dds_return_t ddsrt_thread_getname_anythread (ddsrt_thread_list_id_t tid, char *__restrict name, size_t size);
+#endif
+
 /**
  * @brief Push cleanup handler onto the cleanup stack
  *

src/ddsrt/include/dds/ddsrt/threads/freertos.h

@@ -16,6 +16,7 @@
 #include <task.h>
 
 #define DDSRT_HAVE_THREAD_SETNAME (0)
+#define DDSRT_HAVE_THREAD_LIST (0)
 
 #if defined(__cplusplus)
 extern "C" {

src/ddsrt/include/dds/ddsrt/threads/posix.h

@@ -19,6 +19,11 @@
 #else
 #define DDSRT_HAVE_THREAD_SETNAME (1)
 #endif
+#if defined (__linux) || defined (__APPLE__)
+#define DDSRT_HAVE_THREAD_LIST (1)
+#else
+#define DDSRT_HAVE_THREAD_LIST (0)
+#endif
 
 #if defined (__cplusplus)
 extern "C" {
@@ -27,6 +32,7 @@ extern "C" {
 #if defined(__linux)
 typedef long int ddsrt_tid_t;
 #define PRIdTID "ld"
+typedef long int ddsrt_thread_list_id_t;
 /* __linux */
 #elif defined(__FreeBSD__) && (__FreeBSD_version >= 900031)
 /* FreeBSD >= 9.0 */
@@ -38,6 +44,8 @@ typedef int ddsrt_tid_t;
 /* macOS X >= 10.6 */
 typedef uint64_t ddsrt_tid_t;
 #define PRIdTID PRIu64
+/* ddsrt_thread_list_id_t is actually a mach_port_t */
+typedef uint32_t ddsrt_thread_list_id_t;
 /* __APPLE__ */
 #elif defined(__VXWORKS__)
 /* TODO: Verify taskIdSelf is the right function to use on VxWorks */

src/ddsrt/include/dds/ddsrt/threads/windows.h

@@ -15,6 +15,7 @@
 #include "dds/ddsrt/types.h"
 
 #define DDSRT_HAVE_THREAD_SETNAME (1)
+#define DDSRT_HAVE_THREAD_LIST (1)
 
 #if defined (__cplusplus)
 extern "C" {
@@ -28,6 +29,8 @@ typedef struct {
 typedef DWORD ddsrt_tid_t;
 #define PRIdTID "u"
 
+typedef HANDLE ddsrt_thread_list_id_t;
+
 #if defined (__cplusplus)
 }
 #endif