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author | Russ Cox <rsc@swtch.com> | 2020-05-17 08:24:54 -0400 |
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committer | Russ Cox <rsc@swtch.com> | 2020-05-17 20:15:41 -0400 |
commit | baef953da253314657be9adea8f371bfbf4ba09e (patch) | |
tree | d0fa955ae93fec8ba8f167d1711009e983c11285 /src/libthread/threadimpl.h | |
parent | 06687f70ba7a5836c2e872648a85a724a5a1d486 (diff) | |
download | plan9port-baef953da253314657be9adea8f371bfbf4ba09e.tar.gz plan9port-baef953da253314657be9adea8f371bfbf4ba09e.tar.bz2 plan9port-baef953da253314657be9adea8f371bfbf4ba09e.zip |
libthread: add pthreadperthread mode and use under ASAN
ASAN can't deal with the coroutine stacks.
In theory we can call into ASAN runtime to let it know about them,
but ASAN still has problems with fork or exit happening from a
non-system stack. Bypass all possible problems by just having
a full OS thread for each libthread thread. The threads are still
cooperatively scheduled within a proc (in thos mode, a group of OS threads).
Setting the environment variable LIBTHREAD=pthreadperthread
will enable the pthreadperthread mode, as will building with
CC9FLAGS='-fsanitize=address' in $PLAN9/config.
This solution is much more general than ASAN - for example if
you are trying to find all the thread stacks in a reproducible crash
you can use pthreadperthread mode with any debugger that
knows only about OS threads.
Diffstat (limited to 'src/libthread/threadimpl.h')
-rw-r--r-- | src/libthread/threadimpl.h | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/src/libthread/threadimpl.h b/src/libthread/threadimpl.h index cceb1b8e..c7373843 100644 --- a/src/libthread/threadimpl.h +++ b/src/libthread/threadimpl.h @@ -102,6 +102,17 @@ struct Execjob Channel *c; }; +struct _Procrendez +{ + Lock *l; + int asleep; +#ifdef PLAN9PORT_USING_PTHREADS + pthread_cond_t cond; +#else + int pid; +#endif +}; + struct _Thread { _Thread *next; @@ -112,6 +123,11 @@ struct _Thread void (*startfn)(void*); void *startarg; uint id; +#ifdef PLAN9PORT_USING_PTHREADS + pthread_t osprocid; +#else + int osprocid; +#endif uchar *stk; uint stksize; int exiting; @@ -120,17 +136,7 @@ struct _Thread char state[256]; void *udata; Alt *alt; -}; - -struct _Procrendez -{ - Lock *l; - int asleep; -#ifdef PLAN9PORT_USING_PTHREADS - pthread_cond_t cond; -#else - int pid; -#endif + _Procrendez schedrend; }; extern void _procsleep(_Procrendez*); @@ -149,6 +155,7 @@ struct Proc #endif Lock lock; int nswitch; + _Thread *thread0; _Thread *thread; _Thread *pinthread; _Threadlist runqueue; @@ -157,6 +164,8 @@ struct Proc uint nthread; uint sysproc; _Procrendez runrend; + Lock schedlock; + _Thread *schedthread; Context schedcontext; void *udata; Jmp sigjmp; @@ -188,6 +197,8 @@ extern void _threadpexit(void); extern void _threaddaemonize(void); extern void *_threadstkalloc(int); extern void _threadstkfree(void*, int); +extern void _threadpthreadmain(Proc*, _Thread*); +extern void _threadpthreadstart(Proc*, _Thread*); #define USPALIGN(ucp, align) \ (void*)((((uintptr)(ucp)->uc_stack.ss_sp+(ucp)->uc_stack.ss_size)-(align))&~((align)-1)) |