All very logical steps, and steps which I'm sure I tried at some point ;) Firstly, the posix threads solution works just fine, I've included the program I tested (a slight modification of a standard example program). /* * p_hello.c -- a hello program (in pthread) */ #include "mex.h" #include <stdio.h> #include <sys/types.h> #include <pthread.h> #define MAX_THREAD 1000 typedef struct { int id; } parm; void *hello(void *arg) { parm *p=(parm *)arg; printf("Hello from node %d\n", p->id); return (NULL); } void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) { int n,i; pthread_t *threads; pthread_attr_t pthread_custom_attr; parm *p; n=3; if ((n < 1) || (n > MAX_THREAD)) { printf ("The no of thread should between 1 and %d.\n",MAX_THREAD); exit(1); } threads=(pthread_t *)malloc(n*sizeof(*threads)); pthread_attr_init(&pthread_custom_attr); p=(parm *)malloc(sizeof(parm)*n); /* Start up thread */ for (i=0; i<n; i++) { p[i].id=i; pthread_create(&threads[i], &pthread_custom_attr, hello, (void *)(p+i)); } /* Synchronize the completion of each thread. */ for (i=0; i<n; i++) { pthread_join(threads[i],NULL); } free(p); } I tried using boost version 1.38, I realize it's not quite the latest version but it's the latest version easily available to me at the moment. I used the application documented at the start of this thread. Once again, we have a crash dump from matlab: ------------------------------------------------------------------------ Segmentation violation detected at Thu Jun 25 09:37:20 2009 ------------------------------------------------------------------------ Configuration: MATLAB Version: 7.7.0.471 (R2008b) MATLAB License: 166534 Operating System: Linux 2.6.18-128.1.6.el5.centos.plusPAE #1 SMP Thu Apr 2 13:33:12 EDT 2009 i686 GNU C Library: 2.5 stable Window System: No active display Current Visual: None Processor ID: x86 Family 6 Model 7 Stepping 10, GenuineIntel Virtual Machine: Java 1.6.0_04 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode Default Encoding: ISO-8859-1 Fault Count: 1 Register State: eax = 00000000 ebx = 0067eff4 ecx = a830d4a4 edx = a830dbd8 esi = 098d7dd0 edi = 098d7260 ebp = 05a64168 esp = 05a64130 eip = 0067149e flg = 00010202 Stack Trace: [0] libpthread.so.0:pthread_join~(0, 0, 0x098d7270, 0x08aeeae4 "¤)") + 30 bytes [1] libboost_thread-gcc41-mt-1_34_1.so.1.34.1:boost::thread::join()~(0x098d7dd0, 0x098d7264, 0x098d7260, 0x05a641df) + 42 bytes [2] threadtest.mexglx:mexFunction~(0, 0x05a648fc, 0, 0x05a6495c) + 1266 bytes [3] libmex.so:mexRunMexFile(0, 0x05a648fc, 0, 0x05a6495c) + 111 bytes [4] libmex.so:Mfh_mex::runMexFileWithSignalProtection(int, mxArray_tag**, int, mxArray_tag**)(0x098cc8f0 "HÑL", 0, 0x05a648fc, 0) + 119 bytes [5] libmex.so:Mfh_mex::dispatch_file(int, mxArray_tag**, int, mxArray_tag**)(0x098cc8f0 "HÑL", 0, 0x05a648fc, 0) + 257 bytes [6] libmwm_dispatcher.so:Mfh_file::dispatch_fh(int, mxArray_tag**, int, mxArray_tag**)(0x098cc8f0 "HÑL", 0, 0x05a648fc, 0) + 278 bytes [7] libmwm_interpreter.so:inDispatchFromStack(int, char const*, int, int)(561, 0x098cb6bc "threadtest", 0, 0) + 1074 bytes [8] libmwm_interpreter.so:inDispatchCall(char const*, int, int, int, int*, int*)(0, 0x05a64c18, 0x098d7ca8, 0x007c3170) + 160 bytes [9] libmwm_interpreter.so:.L718(1, 0, 1, 0) + 183 bytes [10] libmwm_interpreter.so:protected_inInterp(inDebugCheck, int, int, opcodes, inPcodeNest_tag*, int*)(1, 0, 1, 0) + 120 bytes [11] libmwm_interpreter.so:inInterPcodeSJ(inDebugCheck, int, int, opcodes, inPcodeNest_tag*, int*)(0, 0x098e2dc0, 0x05a6507c, 0x05a6507c) + 286 bytes [12] libmwm_interpreter.so:inExecuteMFunctionOrScript(Mfh_mp*, bool)(0x098c7ef8, 1, 0x05a65ec8, 0) + 803 bytes [13] libmwm_interpreter.so:inRunMfile(int, mxArray_tag**, int, mxArray_tag**, Mfh_mp*, inWorkSpace_tag*)(0, 0x05a65ec8, 0, 0) + 676 bytes [14] libmwm_interpreter.so:Mfh_mp::dispatch_file(_mdUnknown_workspace*, int, mxArray_tag**, int, mxArray_tag**)(0x098c7ef8, 0, 0, 0x05a65ec8) + 64 bytes [15] libmwm_interpreter.so:Mfh_mp::dispatch_file(int, mxArray_tag**, int, mxArray_tag**)(0x098c7ef8, 0, 0x05a65ec8, 0) + 56 bytes [16] libmwm_dispatcher.so:Mfh_file::dispatch_fh(int, mxArray_tag**, int, mxArray_tag**)(0x098c7ef8, 0, 0x05a65ec8, 0) + 278 bytes [17] libmwm_interpreter.so:inEvalPcodeHeaderToWord(_memory_context*, int, mxArray_tag**, _pcodeheader*, Mfh_mp*, unsigned int)(1954952, 0, 0x05a65ec8, 0x05a65d78) + 199 bytes [18] libmwm_interpreter.so:in_local_call_script_function(_memory_context*, _pcodeheader*, int, mxArray_tag**, unsigned int, bool)(0x05a65ec8, 0, 0, 0x01031396) + 108 bytes [19] libmwm_interpreter.so:inEvalStringWithIsVarFcn(_memory_context*, char const*, EvalType, int, mxArray_tag**, inDebugCheck, _pcodeheader*, int*, bool (*)(void*, char const*), void*, bool, bool)(0, 0x05a65ec8, 0, 0) + 2884 bytes [20] libmwm_interpreter.so:InterpBridge::EvalCmdWithLocalReturn(char const*, int*, bool, bool)(0x08bd6e48, 0x098beda0 "threadtest\n", 0, 0) + 151 bytes [21] libmwm_interpreter.so:inEvalCmdWithLocalReturn(0x098beda0 "threadtest\n", 0, 0, 1) + 74 bytes [22] libmwbridge.so:evalCommandWithLongjmpSafety(char const*)(0x098beda0 "threadtest\n", 1, 2746196, 0xb7fc9688) + 116 bytes [23] libmwbridge.so:mnParser(0x098dac00 "x1|", 0x092a2b70 "(öb", 1, 0x08be19b8) + 283 bytes [24] libmwmcr.so:mcrInstance::mnParser()(0x08be19f0, 0x05a66364, 0x08be19b8, 0x08be1a28) + 112 bytes [25] MATLAB:mcrMain(int, char const**)(1, 0xbfb602c4, 5, 0) + 538 bytes [26] libmwmcr.so:runMcrMain(void*)(0xbfb601e8, 0x05a66470 "ôïg", 0x05a66470 "ôïg", 0x05a66470 "ôïg") + 38 bytes [27] libpthread.so.0:0x0067049b(0x05a66b90, 0, 0, 0) And using GDB I obtained the following stack dumps: Thread 12 #0 0x0067149e in pthread_join () from /lib/libpthread.so.0 #1 0x0029055a in boost::thread::join (this=0x9540928) at libs/thread/src/thread.cpp:226 #2 0x00d69296 in mexFunction () from /home/ben/eclipse/ws-sandbox/SandboxWS/libASAMatlab/src/threadtest.mexglx #3 0x0035b84f in mexRunMexFile () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/../../bin/glnx86/libmex.so #4 0x00358891 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/../../bin/glnx86/libmex.so #5 0x00359cfb in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/../../bin/glnx86/libmex.so #6 0x0031b340 in Mfh_file::dispatch_fh () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_dispatcher.so #7 0x00f37d5a in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #8 0x00ee5d84 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #9 0x00ee7127 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #10 0x00eea0de in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #11 0x00ee8f62 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #12 0x00ee99a9 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #13 0x00f4b7fe in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #14 0x00f24d30 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #15 0x00f23c20 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #16 0x0031b340 in Mfh_file::dispatch_fh () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_dispatcher.so #17 0x00f2cb7d in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #18 0x00edc93c in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #19 0x00ee0ad0 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #20 0x00ee10c5 in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #21 0x00eaed28 in inEvalCmdWithLocalReturn () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwm_interpreter.so #22 0x00d943fc in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwbridge.so #23 0x00d951d5 in mnParser () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwbridge.so #24 0x00d2215e in mcrInstance::mnParser () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwmcr.so #25 0x080491c8 in __gxx_personality_v0 () at ../../../../../../sources/gcc/libstdc++-v3/libsupc++/eh_personality.cc:349 #26 0x00d1d78a in ?? () from /usr/local/matlabR2008b/bin/glnx86/../../bin/glnx86/libmwmcr.so #27 0x0067049b in start_thread () from /lib/libpthread.so.0 #28 0x005c742e in clone () from /lib/libc.so.6 Thread 13 #0 0x006738b0 in pthread_mutex_unlock () from /lib/libpthread.so.0 #1 0x0260f1f1 in boost::call_once<void (*)()> () from /usr/lib/libboost_thread-gcc41-mt-1_38.so.1.38.0 #2 0x0260beda in boost::detail::set_current_thread_data () from /usr/lib/libboost_thread-gcc41-mt-1_38.so.1.38.0 #3 0x0260cff3 in thread_proxy () from /usr/lib/libboost_thread-gcc41-mt-1_38.so.1.38.0 #4 0x0067049b in start_thread () from /lib/libpthread.so.0 #5 0x005c742e in clone () from /lib/libc.so.6 Just for fun I wrote another program to see if the problem was anything to do with boost mutexes or conditions (without using other threads), and matlab has no issues with this. -- View this message in context: http://www.nabble.com/Creating-a-boost-thread-in-a-matlab-mex-file-causes-ma... 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