[core] Detect pthread_getname* availability

CMakeLists.txt

@@ -275,6 +275,9 @@ if (DEFINED HAVE_INET_PTON)
 	add_definitions(-DHAVE_INET_PTON=1)
 endif()
 
+include(FindPThreadGetSetName)
+FindPThreadGetSetName() # Defines HAVE_PTHREAD_GETNAME_* and HAVE_PTHREAD_SETNAME_*
+
 if (ENABLE_MONOTONIC_CLOCK)
 	if (NOT ENABLE_MONOTONIC_CLOCK_DEFAULT)
 		message(FATAL_ERROR "Your platform does not support CLOCK_MONOTONIC. Build with -DENABLE_MONOTONIC_CLOCK=OFF.")

scripts/FindPThreadGetSetName.cmake

@@ -0,0 +1,82 @@
+#
+# SRT - Secure, Reliable, Transport
+# Copyright (c) 2021 Haivision Systems Inc.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+
+# Check for pthread_getname_np(3) and pthread_setname_np(3)
+#    used in srtcore/threadname.h.
+#
+# Some BSD distros need to include <pthread_np.h> for pthread_getname_np().
+#
+# TODO: Some BSD distros have pthread_get_name_np() and pthread_set_name_np()
+#     instead of pthread_getname_np() and pthread_setname_np().
+#
+# Sets:
+#     HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H
+#     HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H
+#     HAVE_PTHREAD_GETNAME_NP
+#     HAVE_PTHREAD_SETNAME_NP
+# Sets as appropriate:
+#     add_definitions(-DHAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H=1)
+#     add_definitions(-DHAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H=1)
+#     add_definitions(-DHAVE_PTHREAD_GETNAME_NP=1)
+#     add_definitions(-DHAVE_PTHREAD_SETNAME_NP=1)
+
+include(CheckSymbolExists)
+
+function(FindPThreadGetSetName)
+
+	unset(HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H)
+	unset(HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H PARENT_SCOPE)
+	unset(HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H CACHE)
+	unset(HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H)
+	unset(HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H PARENT_SCOPE)
+	unset(HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H CACHE)
+
+	unset(HAVE_PTHREAD_GETNAME_NP)
+	unset(HAVE_PTHREAD_GETNAME_NP PARENT_SCOPE)
+	unset(HAVE_PTHREAD_GETNAME_NP CACHE)
+	unset(HAVE_PTHREAD_SETNAME_NP)
+	unset(HAVE_PTHREAD_SETNAME_NP PARENT_SCOPE)
+	unset(HAVE_PTHREAD_SETNAME_NP CACHE)
+
+	set(CMAKE_REQUIRED_DEFINITIONS
+		-D_GNU_SOURCE -D_DARWIN_C_SOURCE -D_POSIX_SOURCE=1)
+	set(CMAKE_REQUIRED_FLAGS "-pthread")
+
+	message(STATUS "Checking for pthread_(g/s)etname_np in 'pthread_np.h':")
+	check_symbol_exists(
+		pthread_getname_np "pthread_np.h" HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H)
+	if (HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H)
+		add_definitions(-DHAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H=1)
+	endif()
+	check_symbol_exists(
+		pthread_setname_np "pthread_np.h" HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H)
+	if (HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H)
+		add_definitions(-DHAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H=1)
+	endif()
+
+	message(STATUS "Checking for pthread_(g/s)etname_np in 'pthread.h':")
+	check_symbol_exists(pthread_getname_np "pthread.h" HAVE_PTHREAD_GETNAME_NP)
+	if (HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H)
+		set(HAVE_PTHREAD_GETNAME_NP TRUE PARENT_SCOPE)
+	endif()
+	check_symbol_exists(pthread_setname_np "pthread.h" HAVE_PTHREAD_SETNAME_NP)
+	if (HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H)
+		set(HAVE_PTHREAD_SETNAME_NP TRUE PARENT_SCOPE)
+	endif()
+	if (HAVE_PTHREAD_GETNAME_NP)
+		add_definitions(-DHAVE_PTHREAD_GETNAME_NP=1)
+	endif()
+	if (HAVE_PTHREAD_SETNAME_NP)
+		add_definitions(-DHAVE_PTHREAD_SETNAME_NP=1)
+	endif()
+
+	unset(CMAKE_REQUIRED_DEFINITIONS)
+	unset(CMAKE_REQUIRED_FLAGS)
+
+endfunction(FindPThreadGetSetName)

srtcore/srt_attr_defs.h

@@ -116,7 +116,7 @@ used by SRT library internally.
 #define SRT_ATTR_NO_THREAD_SAFETY_ANALYSIS
 #else
 
-#if defined(__clang__)
+#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ > 5)
 #define THREAD_ANNOTATION_ATTRIBUTE__(x)   __attribute__((x))
 #else
 #define THREAD_ANNOTATION_ATTRIBUTE__(x)   // no-op

srtcore/threadname.h

@@ -16,24 +16,60 @@ written by
 #ifndef INC_SRT_THREADNAME_H
 #define INC_SRT_THREADNAME_H
 
-#if defined(__APPLE__) || defined(__linux__)
-#if defined(__linux__)
-#include <sys/prctl.h>
+// NOTE:
+//    HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H
+//    HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H
+//    HAVE_PTHREAD_GETNAME_NP
+//    HAVE_PTHREAD_GETNAME_NP
+//    Are detected and set in ../CMakeLists.txt.
+//    OS Availability of pthread_getname_np(..) and pthread_setname_np(..)::
+//       MacOS(10.6)
+//       iOS(3.2)
+//       AIX(7.1)
+//       FreeBSD(version?), OpenBSD(Version?)
+//       Linux-GLIBC(GLIBC-2.12).
+//       Linux-MUSL(MUSL-1.1.20 Partial Implementation. See below).
+//       MINGW-W64(4.0.6)
+
+#if defined(HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H) \
+   || defined(HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H)
+   #include <pthread_np.h>
+   #if defined(HAVE_PTHREAD_GETNAME_NP_IN_PTHREAD_NP_H) \
+      && !defined(HAVE_PTHREAD_GETNAME_NP)
+      #define HAVE_PTHREAD_GETNAME_NP 1
+   #endif
+   #if defined(HAVE_PTHREAD_SETNAME_NP_IN_PTHREAD_NP_H) \
+      && !defined(HAVE_PTHREAD_SETNAME_NP)
+      #define HAVE_PTHREAD_SETNAME_NP 1
+   #endif
 #endif
 
-#include <pthread.h>
+#if (defined(HAVE_PTHREAD_GETNAME_NP) && defined(HAVE_PTHREAD_GETNAME_NP)) \
+   || defined(__linux__)
+   // NOTE:
+   //    Linux pthread_getname_np() and pthread_setname_np() became available
+   //       in GLIBC-2.12 and later.
+   //    Some Linux runtimes do not have pthread_getname_np(), but have
+   //       pthread_setname_np(), for instance MUSL at least as of v1.1.20.
+   //    So using the prctl() for Linux is more portable.
+   #if defined(__linux__)
+      #include <sys/prctl.h>
+   #endif
+   #include <pthread.h>
 #endif
 
 #include <cstdio>
 #include <cstring>
 #include <string>
 
+#include "common.h"
 #include "sync.h"
 
 class ThreadName
 {
 
-#if defined(__APPLE__) || defined(__linux__)
+#if (defined(HAVE_PTHREAD_GETNAME_NP) && defined(HAVE_PTHREAD_GETNAME_NP)) \
+   || defined(__linux__)
 
     class ThreadNameImpl
     {
@@ -47,8 +83,7 @@ class ThreadName
             // since Linux 2.6.11. The buffer should allow space for up to 16
             // bytes; the returned string will be null-terminated.
             return prctl(PR_GET_NAME, (unsigned long)namebuf, 0, 0) != -1;
-#elif defined(__APPLE__)
-            // since macos(10.6), ios(3.2)
+#elif defined(HAVE_PTHREAD_GETNAME_NP)
             return pthread_getname_np(pthread_self(), namebuf, BUFSIZE) == 0;
 #else
 #error "unsupported platform"
@@ -57,14 +92,18 @@ class ThreadName
 
         static bool set(const char* name)
         {
+            SRT_ASSERT(name != NULL);
 #if defined(__linux__)
             // The name can be up to 16 bytes long, including the terminating
             // null byte. (If the length of the string, including the terminating
             // null byte, exceeds 16 bytes, the string is silently truncated.)
             return prctl(PR_SET_NAME, (unsigned long)name, 0, 0) != -1;
-#elif defined(__APPLE__)
-            // since macos(10.6), ios(3.2)
+#elif defined(HAVE_PTHREAD_SETNAME_NP)
+    #if defined(__APPLE__)
             return pthread_setname_np(name) == 0;
+    #else
+            return pthread_setname_np(pthread_self(), name) == 0;
+    #endif
 #else
 #error "unsupported platform"
 #endif