diff options
| author | Gurusamy Sarathy <gsar@cpan.org> | 1998-11-29 12:40:28 +0000 |
|---|---|---|
| committer | Gurusamy Sarathy <gsar@cpan.org> | 1998-11-29 12:40:28 +0000 |
| commit | b099ddc068b2498767e6f04ac167d9633b895ec4 (patch) | |
| tree | c5565911f062bddb5d68139f8aed5d8489d2a488 /thread.h | |
| parent | bfc605f9e1d41dd7493c0c0fcfd1304c238dbe4d (diff) | |
| download | perl-b099ddc068b2498767e6f04ac167d9633b895ec4.tar.gz | |
various fixes for race conditions under threads: mutex locks based
on PL_threadnum were seriously flawed, since it means more than one
thread could enter the critical region; PL_na was global instead of
thread-local; child thread could finish and free thr structures
before Thread->new() got around to creating the Thread object;
cv_clone() needed locking, as it mucks with PL_comppad and other
global data; new_struct_thread() needed to lock template-thread's
mutex while copying its data
p4raw-id: //depot/perl@2385
Diffstat (limited to 'thread.h')
| -rw-r--r-- | thread.h | 15 |
1 files changed, 7 insertions, 8 deletions
@@ -216,6 +216,8 @@ struct perl_thread *getTHR _((void)); * from thrsv which is cached in the per-interpreter structure. * Systems with very fast pthread_get_specific (which should be all systems * but unfortunately isn't) may wish to simplify to "...*thr = THR". + * + * The use of PL_threadnum should be safe here. */ #ifndef dTHR # define dTHR \ @@ -238,30 +240,27 @@ struct perl_thread *getTHR _((void)); * try only locking them if there may be more than one thread in existence. * Systems with very fast mutexes (and/or slow conditionals) may wish to * remove the "if (threadnum) ..." test. + * XXX do NOT use C<if (PL_threadnum) ...> -- it sets up race conditions! */ #define LOCK_SV_MUTEX \ STMT_START { \ - if (PL_threadnum) \ - MUTEX_LOCK(&PL_sv_mutex); \ + MUTEX_LOCK(&PL_sv_mutex); \ } STMT_END #define UNLOCK_SV_MUTEX \ STMT_START { \ - if (PL_threadnum) \ - MUTEX_UNLOCK(&PL_sv_mutex); \ + MUTEX_UNLOCK(&PL_sv_mutex); \ } STMT_END /* Likewise for strtab_mutex */ #define LOCK_STRTAB_MUTEX \ STMT_START { \ - if (PL_threadnum) \ - MUTEX_LOCK(&PL_strtab_mutex); \ + MUTEX_LOCK(&PL_strtab_mutex); \ } STMT_END #define UNLOCK_STRTAB_MUTEX \ STMT_START { \ - if (PL_threadnum) \ - MUTEX_UNLOCK(&PL_strtab_mutex); \ + MUTEX_UNLOCK(&PL_strtab_mutex); \ } STMT_END #ifndef THREAD_RET_TYPE |