perf_reader : add timeout argument to perf_reader_poll

src/cc/perf_reader.c

@@ -205,11 +205,11 @@ static void event_read(struct perf_reader *reader) {
   }
 }
 
-int perf_reader_poll(int num_readers, struct perf_reader **readers) {
+int perf_reader_poll(int num_readers, struct perf_reader **readers, int timeout) {
   struct pollfd pfds[] = {
     {readers[0]->fd, POLLIN},
   };
-  if (poll(pfds, num_readers, -1) > 0) {
+  if (poll(pfds, num_readers, timeout) > 0) {
     int i;
     for (i = 0; i < num_readers; ++i) {
       if (pfds[i].revents & POLLIN)

src/cc/perf_reader.h

@@ -19,4 +19,4 @@ struct perf_reader;
 struct perf_reader * perf_reader_new(int fd, int page_cnt, perf_reader_cb cb, void *cb_cookie);
 void perf_reader_free(void *ptr);
 int perf_reader_mmap(struct perf_reader *reader, int fd, unsigned long sample_type);
-int perf_reader_poll(int num_readers, struct perf_reader **readers);
+int perf_reader_poll(int num_readers, struct perf_reader **readers, int timeout);

src/python/bcc/__init__.py

@@ -94,7 +94,7 @@ lib.bpf_attach_kprobe.argtypes = [ct.c_int, ct.c_char_p, ct.c_char_p, ct.c_int,
 lib.bpf_detach_kprobe.restype = ct.c_int
 lib.bpf_detach_kprobe.argtypes = [ct.c_char_p]
 lib.perf_reader_poll.restype = ct.c_int
-lib.perf_reader_poll.argtypes = [ct.c_int, ct.POINTER(ct.c_void_p)]
+lib.perf_reader_poll.argtypes = [ct.c_int, ct.POINTER(ct.c_void_p), ct.c_int]
 lib.perf_reader_free.restype = None
 lib.perf_reader_free.argtypes = [ct.c_void_p]
 
@@ -780,7 +780,7 @@ class BPF(object):
         """
         return len(open_kprobes)
 
-    def kprobe_poll(self):
+    def kprobe_poll(self, timeout = -1):
         """kprobe_poll(self)
 
         Poll from the ring buffers for all of the open kprobes, calling the
@@ -790,7 +790,7 @@ class BPF(object):
         for i, v in enumerate(open_kprobes.values()):
             readers[i] = v
         try:
-            lib.perf_reader_poll(len(open_kprobes), readers)
+            lib.perf_reader_poll(len(open_kprobes), readers, timeout)
         except KeyboardInterrupt:
             pass