<div dir="ltr">This causes a severe performance degradation if a test with lots of threads setting their names simultaneously. <div>Previously, we did not intercept  <span style="font-family:arial,sans-serif;font-size:13px">pthread_setname_np and relied on prctl interceptor. </span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px">Now on every </span><span style="font-family:arial,sans-serif;font-size:13px">pthread_setname_np we do a mutex lock and O(n_threads) operations under a lock.</span></div>
<div><span style="font-family:arial,sans-serif;font-size:13px">Please fix. </span></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Oct 29, 2013 at 2:30 PM, Dmitry Vyukov <span dir="ltr"><<a href="mailto:dvyukov@google.com" target="_blank">dvyukov@google.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: dvyukov<br>
Date: Tue Oct 29 05:30:39 2013<br>
New Revision: 193602<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=193602&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=193602&view=rev</a><br>
Log:<br>
tsan/asan: support pthread_setname_np to set thread names<br>
<br>
<br>
Added:<br>
    compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc<br>
Modified:<br>
    compiler-rt/trunk/lib/asan/asan_interceptors.cc<br>
    compiler-rt/trunk/lib/msan/msan_interceptors.cc<br>
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc<br>
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h<br>
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc<br>
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h<br>
    compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc<br>
    compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc<br>
    compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h<br>
<br>
Modified: compiler-rt/trunk/lib/asan/asan_interceptors.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/asan/asan_interceptors.cc (original)<br>
+++ compiler-rt/trunk/lib/asan/asan_interceptors.cc Tue Oct 29 05:30:39 2013<br>
@@ -130,6 +130,8 @@ DECLARE_REAL_AND_INTERCEPTOR(void, free,<br>
   do {                                                      \<br>
   } while (false)<br>
 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) SetThreadName(name)<br>
+#define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \<br>
+    asanThreadRegistry().SetThreadNameByUserId(thread, name)<br>
 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)<br>
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()<br>
 #include "sanitizer_common/sanitizer_common_interceptors.inc"<br>
<br>
Modified: compiler-rt/trunk/lib/msan/msan_interceptors.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/msan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/msan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/msan/msan_interceptors.cc (original)<br>
+++ compiler-rt/trunk/lib/msan/msan_interceptors.cc Tue Oct 29 05:30:39 2013<br>
@@ -1224,6 +1224,9 @@ extern "C" int *__errno_location(void);<br>
 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \<br>
   do {                                                \<br>
   } while (false)  // FIXME<br>
+#define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \<br>
+  do {                                                         \<br>
+  } while (false)  // FIXME<br>
 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)<br>
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()<br>
 #include "sanitizer_common/sanitizer_common_interceptors.inc"<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc Tue Oct 29 05:30:39 2013<br>
@@ -23,6 +23,7 @@<br>
 //   COMMON_INTERCEPTOR_ON_EXIT<br>
 //   COMMON_INTERCEPTOR_MUTEX_LOCK<br>
 //   COMMON_INTERCEPTOR_MUTEX_UNLOCK<br>
+//   COMMON_INTERCEPTOR_SET_PTHREAD_NAME<br>
 //===----------------------------------------------------------------------===//<br>
 #include "interception/interception.h"<br>
 #include "sanitizer_platform_interceptors.h"<br>
@@ -34,19 +35,19 @@<br>
 #endif // _WIN32<br>
<br>
 #ifndef COMMON_INTERCEPTOR_INITIALIZE_RANGE<br>
-#define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ctx, p, size)<br>
+#define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ctx, p, size) {}<br>
 #endif<br>
<br>
 #ifndef COMMON_INTERCEPTOR_FD_ACCESS<br>
-#define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd)<br>
+#define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) {}<br>
 #endif<br>
<br>
 #ifndef COMMON_INTERCEPTOR_MUTEX_LOCK<br>
-#define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m)<br>
+#define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m) {}<br>
 #endif<br>
<br>
 #ifndef COMMON_INTERCEPTOR_MUTEX_UNLOCK<br>
-#define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m)<br>
+#define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) {}<br>
 #endif<br>
<br>
 #if SANITIZER_INTERCEPT_STRCMP<br>
@@ -2655,6 +2656,18 @@ INTERCEPTOR(char *, tempnam, char *dir,<br>
 #define INIT_TEMPNAM<br>
 #endif<br>
<br>
+#if SANITIZER_INTERCEPT_PTHREAD_SETNAME_NP<br>
+INTERCEPTOR(int, pthread_setname_np, uptr thread, const char *name) {<br>
+  void *ctx;<br>
+  COMMON_INTERCEPTOR_ENTER(ctx, pthread_setname_np, thread, name);<br>
+  COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name);<br>
+  return REAL(pthread_setname_np)(thread, name);<br>
+}<br>
+#define INIT_PTHREAD_SETNAME_NP INTERCEPT_FUNCTION(pthread_setname_np);<br>
+#else<br>
+#define INIT_PTHREAD_SETNAME_NP<br>
+#endif<br>
+<br>
<br>
 #define SANITIZER_COMMON_INTERCEPTORS_INIT \<br>
   INIT_STRCMP;                             \<br>
@@ -2757,4 +2770,5 @@ INTERCEPTOR(char *, tempnam, char *dir,<br>
   INIT_TMPNAM;                             \<br>
   INIT_TMPNAM_R;                           \<br>
   INIT_TEMPNAM;                            \<br>
+  INIT_PTHREAD_SETNAME_NP;                 \<br>
 /**/<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h Tue Oct 29 05:30:39 2013<br>
@@ -149,5 +149,6 @@<br>
<br>
 # define SANITIZER_INTERCEPT_PHTREAD_MUTEX SI_NOT_WINDOWS<br>
 # define SANITIZER_INTERCEPT_PTHREAD_COND SI_NOT_WINDOWS<br>
+# define SANITIZER_INTERCEPT_PTHREAD_SETNAME_NP SI_LINUX_NOT_ANDROID<br>
<br>
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.cc Tue Oct 29 05:30:39 2013<br>
@@ -200,6 +200,18 @@ void ThreadRegistry::SetThreadName(u32 t<br>
   tctx->SetName(name);<br>
 }<br>
<br>
+void ThreadRegistry::SetThreadNameByUserId(uptr user_id, const char *name) {<br>
+  BlockingMutexLock l(&mtx_);<br>
+  for (u32 tid = 0; tid < n_contexts_; tid++) {<br>
+    ThreadContextBase *tctx = threads_[tid];<br>
+    if (tctx != 0 && tctx->user_id == user_id &&<br>
+        tctx->status != ThreadStatusInvalid) {<br>
+      tctx->SetName(name);<br>
+      return;<br>
+    }<br>
+  }<br>
+}<br>
+<br>
 void ThreadRegistry::DetachThread(u32 tid) {<br>
   BlockingMutexLock l(&mtx_);<br>
   CHECK_LT(tid, n_contexts_);<br>
<br>
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h (original)<br>
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_thread_registry.h Tue Oct 29 05:30:39 2013<br>
@@ -109,6 +109,7 @@ class ThreadRegistry {<br>
   ThreadContextBase *FindThreadContextByOsIDLocked(uptr os_id);<br>
<br>
   void SetThreadName(u32 tid, const char *name);<br>
+  void SetThreadNameByUserId(uptr user_id, const char *name);<br>
   void DetachThread(u32 tid);<br>
   void JoinThread(u32 tid, void *arg);<br>
   void FinishThread(u32 tid);<br>
<br>
Added: compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc?rev=193602&view=auto" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc?rev=193602&view=auto</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc (added)<br>
+++ compiler-rt/trunk/lib/tsan/lit_tests/thread_name2.cc Tue Oct 29 05:30:39 2013<br>
@@ -0,0 +1,32 @@<br>
+// RUN: %clangxx_tsan -O1 %s -o %t && not %t 2>&1 | FileCheck %s<br>
+#include <pthread.h><br>
+#include <stdio.h><br>
+#include <unistd.h><br>
+<br>
+int Global;<br>
+<br>
+void *Thread1(void *x) {<br>
+  sleep(1);<br>
+  Global++;<br>
+  return 0;<br>
+}<br>
+<br>
+void *Thread2(void *x) {<br>
+  pthread_setname_np(pthread_self(), "foobar2");<br>
+  Global--;<br>
+  return 0;<br>
+}<br>
+<br>
+int main() {<br>
+  pthread_t t[2];<br>
+  pthread_create(&t[0], 0, Thread1, 0);<br>
+  pthread_create(&t[1], 0, Thread2, 0);<br>
+  pthread_setname_np(t[0], "foobar1");<br>
+  pthread_join(t[0], NULL);<br>
+  pthread_join(t[1], NULL);<br>
+}<br>
+<br>
+// CHECK: WARNING: ThreadSanitizer: data race<br>
+// CHECK:   Thread T1 'foobar1'<br>
+// CHECK:   Thread T2 'foobar2'<br>
+<br>
<br>
Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc (original)<br>
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc Tue Oct 29 05:30:39 2013<br>
@@ -1837,38 +1837,54 @@ struct TsanInterceptorContext {<br>
 #define COMMON_INTERCEPTOR_UNPOISON_PARAM(ctx, count) \<br>
   do {                                                \<br>
   } while (false)<br>
+<br>
 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                    \<br>
   MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr,                 \<br>
                     ((TsanInterceptorContext *)ctx)->pc, (uptr)ptr, size, \<br>
                     true)<br>
+<br>
 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                       \<br>
   MemoryAccessRange(((TsanInterceptorContext *) ctx)->thr,                  \<br>
                     ((TsanInterceptorContext *) ctx)->pc, (uptr) ptr, size, \<br>
                     false)<br>
+<br>
 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)      \<br>
   SCOPED_TSAN_INTERCEPTOR(func, __VA_ARGS__);         \<br>
   TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \<br>
   ctx = (void *)&_ctx;                                \<br>
   (void) ctx;<br>
+<br>
 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \<br>
   FdAcquire(((TsanInterceptorContext *) ctx)->thr, pc, fd)<br>
+<br>
 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \<br>
   FdRelease(((TsanInterceptorContext *) ctx)->thr, pc, fd)<br>
+<br>
 #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) \<br>
   FdAccess(((TsanInterceptorContext *) ctx)->thr, pc, fd)<br>
+<br>
 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \<br>
   FdSocketAccept(((TsanInterceptorContext *) ctx)->thr, pc, fd, newfd)<br>
+<br>
 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \<br>
   ThreadSetName(((TsanInterceptorContext *) ctx)->thr, name)<br>
+<br>
+#define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \<br>
+  CTX()->thread_registry->SetThreadNameByUserId(thread, name)<br>
+<br>
 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) BLOCK_REAL(name)<br>
+<br>
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \<br>
   OnExit(((TsanInterceptorContext *) ctx)->thr)<br>
+<br>
 #define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m) \<br>
   MutexLock(((TsanInterceptorContext *)ctx)->thr, \<br>
             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)<br>
+<br>
 #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \<br>
   MutexUnlock(((TsanInterceptorContext *)ctx)->thr, \<br>
             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)<br>
+<br>
 #include "sanitizer_common/sanitizer_common_interceptors.inc"<br>
<br>
 #define TSAN_SYSCALL() \<br>
<br>
Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc (original)<br>
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_stat.cc Tue Oct 29 05:30:39 2013<br>
@@ -182,6 +182,7 @@ void StatOutput(u64 *stat) {<br>
   name[StatInt_pthread_barrier_wait]     = "  pthread_barrier_wait            ";<br>
   name[StatInt_pthread_once]             = "  pthread_once                    ";<br>
   name[StatInt_pthread_getschedparam]    = "  pthread_getschedparam           ";<br>
+  name[StatInt_pthread_setname_np]       = "  pthread_setname_np              ";<br>
   name[StatInt_sem_init]                 = "  sem_init                        ";<br>
   name[StatInt_sem_destroy]              = "  sem_destroy                     ";<br>
   name[StatInt_sem_wait]                 = "  sem_wait                        ";<br>
<br>
Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h?rev=193602&r1=193601&r2=193602&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h?rev=193602&r1=193601&r2=193602&view=diff</a><br>

==============================================================================<br>
--- compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h (original)<br>
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_stat.h Tue Oct 29 05:30:39 2013<br>
@@ -177,6 +177,7 @@ enum StatType {<br>
   StatInt_pthread_barrier_wait,<br>
   StatInt_pthread_once,<br>
   StatInt_pthread_getschedparam,<br>
+  StatInt_pthread_setname_np,<br>
   StatInt_sem_init,<br>
   StatInt_sem_destroy,<br>
   StatInt_sem_wait,<br>
<br>
<br>
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</blockquote></div><br></div>