1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
FindThreads
-----------
This module determines the thread library of the system.
Imported Targets
^^^^^^^^^^^^^^^^
.. versionadded:: 3.1
This module defines the following :prop_tgt:`IMPORTED` target:
``Threads::Threads``
The thread library, if found.
Result Variables
^^^^^^^^^^^^^^^^
The following variables are set:
``Threads_FOUND``
If a supported thread library was found.
``CMAKE_THREAD_LIBS_INIT``
The thread library to use. This may be empty if the thread functions
are provided by the system libraries and no special flags are needed
to use them.
``CMAKE_USE_WIN32_THREADS_INIT``
If the found thread library is the win32 one.
``CMAKE_USE_PTHREADS_INIT``
If the found thread library is pthread compatible.
``CMAKE_HP_PTHREADS_INIT``
If the found thread library is the HP thread library.
Variables Affecting Behavior
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. variable:: THREADS_PREFER_PTHREAD_FLAG
.. versionadded:: 3.1
If the use of the -pthread compiler and linker flag is preferred then
the caller can set this variable to TRUE. The compiler flag can only be
used with the imported target. Use of both the imported target as well
as this switch is highly recommended for new code.
This variable has no effect if the system libraries provide the
thread functions, i.e. when ``CMAKE_THREAD_LIBS_INIT`` will be empty.
#]=======================================================================]
include (CheckLibraryExists)
set(Threads_FOUND FALSE)
set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET})
set(CMAKE_REQUIRED_QUIET ${Threads_FIND_QUIETLY})
if(CMAKE_C_COMPILER_LOADED)
include (CheckIncludeFile)
include (CheckCSourceCompiles)
elseif(CMAKE_CXX_COMPILER_LOADED)
include (CheckIncludeFileCXX)
include (CheckCXXSourceCompiles)
else()
message(FATAL_ERROR "FindThreads only works if either C or CXX language is enabled")
endif()
# simple pthread test code
set(PTHREAD_C_CXX_TEST_SOURCE [====[
#include <pthread.h>
static void* test_func(void* data)
{
return data;
}
int main(void)
{
pthread_t thread;
pthread_create(&thread, NULL, test_func, NULL);
pthread_detach(thread);
pthread_cancel(thread);
pthread_join(thread, NULL);
pthread_atfork(NULL, NULL, NULL);
pthread_exit(NULL);
return 0;
}
]====])
# Internal helper macro.
# Do NOT even think about using it outside of this file!
macro(_threads_check_libc)
if(NOT Threads_FOUND)
if(CMAKE_C_COMPILER_LOADED)
CHECK_C_SOURCE_COMPILES("${PTHREAD_C_CXX_TEST_SOURCE}" CMAKE_HAVE_LIBC_PTHREAD)
elseif(CMAKE_CXX_COMPILER_LOADED)
CHECK_CXX_SOURCE_COMPILES("${PTHREAD_C_CXX_TEST_SOURCE}" CMAKE_HAVE_LIBC_PTHREAD)
endif()
if(CMAKE_HAVE_LIBC_PTHREAD)
set(CMAKE_THREAD_LIBS_INIT "")
set(Threads_FOUND TRUE)
endif()
endif ()
endmacro()
# Internal helper macro.
# Do NOT even think about using it outside of this file!
macro(_threads_check_lib LIBNAME FUNCNAME VARNAME)
if(NOT Threads_FOUND)
CHECK_LIBRARY_EXISTS(${LIBNAME} ${FUNCNAME} "" ${VARNAME})
if(${VARNAME})
set(CMAKE_THREAD_LIBS_INIT "-l${LIBNAME}")
set(Threads_FOUND TRUE)
endif()
endif ()
endmacro()
# Internal helper macro.
# Do NOT even think about using it outside of this file!
macro(_threads_check_flag_pthread)
if(NOT Threads_FOUND)
# If we did not find -lpthreads, -lpthread, or -lthread, look for -pthread
# except on compilers known to not have it.
if(MSVC)
# Compilers targeting the MSVC ABI do not have a -pthread flag.
set(THREADS_HAVE_PTHREAD_ARG FALSE)
elseif(NOT DEFINED THREADS_HAVE_PTHREAD_ARG)
message(CHECK_START "Check if compiler accepts -pthread")
if(CMAKE_C_COMPILER_LOADED)
set(_threads_src ${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c)
elseif(CMAKE_CXX_COMPILER_LOADED)
set(_threads_src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindThreads/CheckForPthreads.cxx)
configure_file(${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c "${_threads_src}" COPYONLY)
endif()
try_compile(THREADS_HAVE_PTHREAD_ARG
SOURCES ${_threads_src}
CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread
OUTPUT_VARIABLE _cmake_check_pthreads_output)
string(APPEND _cmake_find_threads_output "${_cmake_check_pthreads_output}")
unset(_cmake_check_pthreads_output)
unset(_threads_src)
if(THREADS_HAVE_PTHREAD_ARG)
set(Threads_FOUND TRUE)
message(CHECK_PASS "yes")
else()
message(CHECK_FAIL "no")
endif()
endif()
if(THREADS_HAVE_PTHREAD_ARG)
set(Threads_FOUND TRUE)
set(CMAKE_THREAD_LIBS_INIT "-pthread")
endif()
endif()
endmacro()
# Check if pthread functions are in normal C library.
# We list some pthread functions in PTHREAD_C_CXX_TEST_SOURCE test code.
# If the pthread functions already exist in C library, we could just use
# them instead of linking to the additional pthread library.
_threads_check_libc()
# Check for -pthread first if enabled. This is the recommended
# way, but not backwards compatible as one must also pass -pthread
# as compiler flag then.
if (THREADS_PREFER_PTHREAD_FLAG)
_threads_check_flag_pthread()
endif ()
if(CMAKE_SYSTEM MATCHES "GHS-MULTI")
_threads_check_lib(posix pthread_create CMAKE_HAVE_PTHREADS_CREATE)
endif()
_threads_check_lib(pthreads pthread_create CMAKE_HAVE_PTHREADS_CREATE)
_threads_check_lib(pthread pthread_create CMAKE_HAVE_PTHREAD_CREATE)
if (NOT THREADS_PREFER_PTHREAD_FLAG)
_threads_check_flag_pthread()
endif()
if(CMAKE_THREAD_LIBS_INIT OR CMAKE_HAVE_LIBC_PTHREAD)
set(CMAKE_USE_PTHREADS_INIT 1)
set(Threads_FOUND TRUE)
endif()
if(CMAKE_SYSTEM_NAME MATCHES "Windows")
set(CMAKE_USE_WIN32_THREADS_INIT 1)
set(Threads_FOUND TRUE)
endif()
if(CMAKE_USE_PTHREADS_INIT)
if(CMAKE_SYSTEM_NAME MATCHES "HP-UX")
# Use libcma if it exists and can be used. It provides more
# symbols than the plain pthread library. CMA threads
# have actually been deprecated:
# http://docs.hp.com/en/B3920-90091/ch12s03.html#d0e11395
# http://docs.hp.com/en/947/d8.html
# but we need to maintain compatibility here.
# The CMAKE_HP_PTHREADS setting actually indicates whether CMA threads
# are available.
CHECK_LIBRARY_EXISTS(cma pthread_attr_create "" CMAKE_HAVE_HP_CMA)
if(CMAKE_HAVE_HP_CMA)
set(CMAKE_THREAD_LIBS_INIT "-lcma")
set(CMAKE_HP_PTHREADS_INIT 1)
set(Threads_FOUND TRUE)
endif()
set(CMAKE_USE_PTHREADS_INIT 1)
endif()
if(CMAKE_SYSTEM MATCHES "OSF1-V")
set(CMAKE_USE_PTHREADS_INIT 0)
set(CMAKE_THREAD_LIBS_INIT )
endif()
if(CMAKE_SYSTEM MATCHES "CYGWIN_NT" OR CMAKE_SYSTEM MATCHES "MSYS_NT")
set(CMAKE_USE_PTHREADS_INIT 1)
set(Threads_FOUND TRUE)
set(CMAKE_THREAD_LIBS_INIT )
set(CMAKE_USE_WIN32_THREADS_INIT 0)
endif()
endif()
set(CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET_SAVE})
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(Threads DEFAULT_MSG Threads_FOUND)
if(THREADS_FOUND AND NOT TARGET Threads::Threads)
add_library(Threads::Threads INTERFACE IMPORTED)
if(THREADS_HAVE_PTHREAD_ARG)
set_property(TARGET Threads::Threads
PROPERTY INTERFACE_COMPILE_OPTIONS "$<$<COMPILE_LANG_AND_ID:CUDA,NVIDIA>:SHELL:-Xcompiler -pthread>"
"$<$<NOT:$<COMPILE_LANG_AND_ID:CUDA,NVIDIA>>:-pthread>")
endif()
if(CMAKE_THREAD_LIBS_INIT)
set_property(TARGET Threads::Threads PROPERTY INTERFACE_LINK_LIBRARIES "${CMAKE_THREAD_LIBS_INIT}")
endif()
elseif(NOT THREADS_FOUND AND _cmake_find_threads_output)
file(APPEND
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if compiler accepts -pthread failed with the following output:\n${_cmake_find_threads_output}\n\n")
endif()
unset(_cmake_find_threads_output)
|
