[compiler-rt santizer] Use clock_gettime instead of timespec_get

[jeroen.dobbelaere]

Summary

On RH66, timespec_get is not available. Use clock_gettime instead.

This problem was introduced with D87120

[vitalybuka]

compiler-rt/lib/memprof/memprof_allocator.cpp

57

maybe we can keep only clock_gettime(CLOCK_REALTIME, &ts); ?

[jeroen.dobbelaere]

compiler-rt/lib/memprof/memprof_allocator.cpp

57

As far as I see, clock_gettime is POSIX, where timespec_get is C11. You might as wel get in a situation where timespec_get is available, but clock_gettime is not ?

Besides that, I don't really have a preference. If you think that it makes sense to settle on clock_gettime, I can create a patch doing just that. Maybe @tejohnson can elaborate on the choice of timespec_get ?

[tejohnson]

compiler-rt/lib/memprof/memprof_allocator.cpp

57

I selected timespec_get since I saw it used in some other code I was looking at, but since it looks like clock_gettime is more portable, let's just switch to that. In fact, looks like glibc implements the former in terms of the latter.

[jeroen.dobbelaere]

Always use clock_gettime.

[tejohnson]

lgtm

[jeroen.dobbelaere]

Could you commit this for me ? I don't have write access. Thanks !

[tejohnson]

In D91687#2436458, @jeroen.dobbelaere wrote:

Could you commit this for me ? I don't have write access. Thanks !

I'm having some new issues committing at the moment that I can't figure out (just emailed llvm-dev). @vitalybuka can you commit this?

[jeroen.dobbelaere]

I'm having some new issues committing at the moment that I can't figure out (just emailed llvm-dev). @vitalybuka can you commit this?

Maybe they are caused by the change in the branch names ('master' -> 'main') ?

[tejohnson]

In D91687#2439944, @jeroen.dobbelaere wrote:

I'm having some new issues committing at the moment that I can't figure out (just emailed llvm-dev). @vitalybuka can you commit this?

Maybe they are caused by the change in the branch names ('master' -> 'main') ?

Yep, just figured that out after I sent the llvm-dev email. I can push now. I'll push your change in a little bit.

compiler-rt/lib/memprof/memprof_allocator.cpp

static int GetTimestamp(void) {
   // timespec_get will segfault if called from dl_init
   if (!memprof_timestamp_inited) {
     // By returning 0, this will be effectively treated as being
     // timestamped at memprof init time (when memprof_init_timestamp_s
     // is initialized).
     return 0;
   }
   timespec ts;
-  timespec_get(&ts, TIME_UTC);
+  clock_gettime(CLOCK_REALTIME, &ts);
   return (ts.tv_sec - memprof_init_timestamp_s) * 1000 + ts.tv_nsec / 1000000;
 }
 
 static MemprofAllocator &get_allocator();
 
 // The memory chunk allocated from the underlying allocator looks like this:
 // H H U U U U U U
 //   H -- ChunkHeader (32 bytes)
 //   U -- user memory.
 

compiler-rt/lib/memprof/memprof_rtl.cpp

static void MemprofInitInternal() {
 
   memprof_init_done = 1;
 }
 
 void MemprofInitTime() {
   if (LIKELY(memprof_timestamp_inited))
     return;
   timespec ts;
-  timespec_get(&ts, TIME_UTC);
+  clock_gettime(CLOCK_REALTIME, &ts);
   memprof_init_timestamp_s = ts.tv_sec;
   memprof_timestamp_inited = 1;
 }
 
 // Initialize as requested from some part of MemProf runtime library
 // (interceptors, allocator, etc).
 void MemprofInitFromRtl() { MemprofInitInternal(); }