On 27 Dec 2020, at 14:54, Sergey Kaplun <skaplun@tarantool.org> wrote:

Hi, Sergos!

Thanks for the review!

On 27.12.20, Sergey Ostanevich wrote:

Hi!

Thanks for the patch! Just one question below, looks good otherwise.

Sergos

diff --git a/src/lj_memprof.c b/src/lj_memprof.c
new file mode 100644
index 0000000..e0df057
--- /dev/null
+++ b/src/lj_memprof.c

<snipped>

+static int memprof_stop(const struct lua_State *L)
+{
+  struct memprof *mp = &memprof;
+  struct alloc *oalloc = &mp->orig_alloc;
+  struct lj_wbuf *out = &mp->out;
+  int return_status = PROFILE_SUCCESS;
+  int saved_errno = 0;
+  struct lua_State *main_L;
+  int cb_status;
+
+  memprof_lock();
+
+  if (mp->state == MPS_HALT) {
+    errno = mp->saved_errno;
+    mp->state = MPS_IDLE
+    memprof_unlock();
+    return PROFILE_ERRIO;
+  }
+
+  if (mp->state != MPS_PROFILE) {
+    memprof_unlock();
+    return PROFILE_ERRRUN;
+  }
+

+  if (L != NULL && mp->g != G(L)) {
+    memprof_unlock();
+    return PROFILE_ERR;
+  }
+
+  mp->state = MPS_IDLE;
+
+  lua_assert(mp->g != NULL);
+  main_L = mainthread(mp->g);
+
+  lua_assert(memprof_allocf == lua_getallocf(main_L, NULL));
+  lua_assert(oalloc->allocf != NULL);
+  lua_assert(oalloc->state != NULL);
+  lua_setallocf(main_L, oalloc->allocf, oalloc->state);
+
+  if (LJ_UNLIKELY(lj_wbuf_test_flag(out, STREAM_STOP))) {
+    lua_assert(lj_wbuf_test_flag(out, STREAM_ERR_IO));
+    mp->state = MPS_HALT;
+    /* on_stop call may change errno value. */
+    mp->saved_errno = lj_wbuf_errno(out);
+    /* Ignore possible errors. mp->opt.buf == NULL here. */
+    mp->opt.on_stop(mp->opt.ctx, mp->opt.buf);
+    lj_wbuf_terminate(out);
+    memprof_unlock();
+    return PROFILE_ERRIO;
+  }
+  lj_wbuf_addbyte(out, LJM_EPILOGUE_HEADER);
+
+  lj_wbuf_flush(out);
+
+  cb_status = mp->opt.on_stop(mp->opt.ctx, mp->opt.buf);
+  if (LJ_UNLIKELY(lj_wbuf_test_flag(out, STREAM_ERR_IO) || cb_status != 0)) {
+    saved_errno = lj_wbuf_errno(out);

Previous return of PROFILE_ERRIO causes MPS_HALT. Should it be the same?

Yes, you're right! Previous MPS_HALT is redundant -- profiler anyway
should stop (IDLE) immediately, there is no reason to set HALT there.
Thanks! Fixed!

See the iterative diff below. Branch is force-pushed.

+    return_status = PROFILE_ERRIO;
+  }
+
+  lj_wbuf_terminate(out);
+
+  memprof_unlock();
+  errno = saved_errno;
+  return return_status;
+}

===================================================================
diff --git a/src/lj_memprof.c b/src/lj_memprof.c
index e0df057..998cbea 100644
--- a/src/lj_memprof.c
+++ b/src/lj_memprof.c
@@ -354,13 +354,13 @@ static int memprof_stop(const struct lua_State *L)

  if (LJ_UNLIKELY(lj_wbuf_test_flag(out, STREAM_STOP))) {
    lua_assert(lj_wbuf_test_flag(out, STREAM_ERR_IO));
-    mp->state = MPS_HALT;
    /* on_stop call may change errno value. */
-    mp->saved_errno = lj_wbuf_errno(out);
+    saved_errno = lj_wbuf_errno(out);
    /* Ignore possible errors. mp->opt.buf == NULL here. */
    mp->opt.on_stop(mp->opt.ctx, mp->opt.buf);
    lj_wbuf_terminate(out);
    memprof_unlock();
+    errno = saved_errno;
    return PROFILE_ERRIO;
  }
  lj_wbuf_addbyte(out, LJM_EPILOGUE_HEADER);
===================================================================

-- 
Best regards,
Sergey Kaplun