I think the volatiles are there to ensure the compiler doesn't optimise away reads or function calls which has been a problem with this interface in the past.
On 8 Nov 2011, at 22:18, George Bosilca wrote: > MPIR_Breakpoint, as the name indicates, it is just a breakpoint used by the > startup process or the MPI application to signal changes to the debugger. No > return value, nothing more than a breakpoint. > > I wonder how the volatile got there, there is no such requirement on > variables that cannot be changed during execution. > > george. > > On Nov 8, 2011, at 08:36 , Jeff Squyres wrote: > >> I think the only possible controversial change in this commit is changing >> MPIR_Breakpoint() to return (void) instead of (void*). Oddly, I see that >> MPICH2 has 2 different prototypes for MPIR_Breakpoint -- one returns >> (void*), another returns (int). Assuming that MPICH2 works fine with the >> debuggers, this suggests that the return is ignored by the tools -- as it >> should be. >> >> I didn't check the volatile removals; I'm assuming that George got them >> right. :-) >> >> I'll bet that this change does not cause any problems, but it might be worth >> checking with the big 3+1: >> >> - DDT >> - Totalview >> - padb >> - stat >> >> >> On Nov 7, 2011, at 8:24 PM, bosi...@osl.iu.edu wrote: >> >>> Author: bosilca >>> Date: 2011-11-07 20:24:16 EST (Mon, 07 Nov 2011) >>> New Revision: 25456 >>> URL: https://svn.open-mpi.org/trac/ompi/changeset/25456 >>> >>> Log: >>> Put the interface of our MPIR support in sync with the document accepted by >>> the MPI >>> Forum (http://www.mpi-forum.org/docs/mpir-specification-10-11-2010.pdf). >>> >>> Text files modified: >>> trunk/ompi/debuggers/debuggers.h | 28 >>> ++++++++++++++-------------- >>> trunk/orte/mca/debugger/base/base.h | 10 +++++----- >>> >>> trunk/orte/mca/debugger/base/debugger_base_fns.c | 6 +++--- >>> >>> trunk/orte/mca/debugger/base/debugger_base_open.c | 6 +++--- >>> >>> 4 files changed, 25 insertions(+), 25 deletions(-) >>> >>> Modified: trunk/ompi/debuggers/debuggers.h >>> ============================================================================== >>> --- trunk/ompi/debuggers/debuggers.h (original) >>> +++ trunk/ompi/debuggers/debuggers.h 2011-11-07 20:24:16 EST (Mon, >>> 07 Nov 2011) >>> @@ -31,20 +31,20 @@ >>> >>> BEGIN_C_DECLS >>> >>> - /** >>> - * Wait for a debugger if asked. >>> - */ >>> - extern void ompi_wait_for_debugger(void); >>> - >>> - /** >>> - * Notify a debugger that we're about to abort >>> - */ >>> - extern void ompi_debugger_notify_abort(char *string); >>> - >>> - /** >>> - * Breakpoint function for parallel debuggers. >>> - */ >>> - ORTE_DECLSPEC extern void *MPIR_Breakpoint(void); >>> +/** >>> + * Wait for a debugger if asked. >>> + */ >>> +extern void ompi_wait_for_debugger(void); >>> + >>> +/** >>> + * Notify a debugger that we're about to abort >>> + */ >>> +extern void ompi_debugger_notify_abort(char *string); >>> + >>> +/** >>> + * Breakpoint function for parallel debuggers. >>> + */ >>> +ORTE_DECLSPEC extern void MPIR_Breakpoint(void); >>> >>> END_C_DECLS >>> >>> >>> Modified: trunk/orte/mca/debugger/base/base.h >>> ============================================================================== >>> --- trunk/orte/mca/debugger/base/base.h (original) >>> +++ trunk/orte/mca/debugger/base/base.h 2011-11-07 20:24:16 EST (Mon, >>> 07 Nov 2011) >>> @@ -61,18 +61,18 @@ >>> ORTE_DECLSPEC extern int MPIR_proctable_size; >>> ORTE_DECLSPEC extern volatile int MPIR_being_debugged; >>> ORTE_DECLSPEC extern volatile int MPIR_debug_state; >>> -ORTE_DECLSPEC extern volatile int MPIR_i_am_starter; >>> +ORTE_DECLSPEC extern int MPIR_i_am_starter; >>> ORTE_DECLSPEC extern int MPIR_partial_attach_ok; >>> -ORTE_DECLSPEC extern volatile char >>> MPIR_executable_path[MPIR_MAX_PATH_LENGTH]; >>> -ORTE_DECLSPEC extern volatile char >>> MPIR_server_arguments[MPIR_MAX_ARG_LENGTH]; >>> +ORTE_DECLSPEC extern char MPIR_executable_path[MPIR_MAX_PATH_LENGTH]; >>> +ORTE_DECLSPEC extern char MPIR_server_arguments[MPIR_MAX_ARG_LENGTH]; >>> ORTE_DECLSPEC extern volatile int MPIR_forward_output; >>> ORTE_DECLSPEC extern volatile int MPIR_forward_comm; >>> ORTE_DECLSPEC extern char MPIR_attach_fifo[MPIR_MAX_PATH_LENGTH]; >>> ORTE_DECLSPEC extern int MPIR_force_to_main; >>> >>> -typedef void* (*orte_debugger_breakpoint_fn_t)(void); >>> +typedef void (*orte_debugger_breakpoint_fn_t)(void); >>> >>> -ORTE_DECLSPEC void* MPIR_Breakpoint(void); >>> +ORTE_DECLSPEC void MPIR_Breakpoint(void); >>> >>> /* --- end MPICH/TotalView std debugger interface definitions */ >>> >>> >>> Modified: trunk/orte/mca/debugger/base/debugger_base_fns.c >>> ============================================================================== >>> --- trunk/orte/mca/debugger/base/debugger_base_fns.c (original) >>> +++ trunk/orte/mca/debugger/base/debugger_base_fns.c 2011-11-07 >>> 20:24:16 EST (Mon, 07 Nov 2011) >>> @@ -168,7 +168,7 @@ >>> */ >>> ORTE_PROGRESSED_WAIT(false, jdata->num_reported, jdata->num_procs); >>> >>> - (void) MPIR_Breakpoint(); >>> + MPIR_Breakpoint(); >>> >>> /* send a message to rank=0 to release it */ >>> OBJ_CONSTRUCT(&buf, opal_buffer_t); /* don't need anything in this */ >>> @@ -186,7 +186,7 @@ >>> /* >>> * Breakpoint function for parallel debuggers >>> */ >>> -void *MPIR_Breakpoint(void) >>> +void MPIR_Breakpoint(void) >>> { >>> - return NULL; >>> + return; >>> } >>> >>> Modified: trunk/orte/mca/debugger/base/debugger_base_open.c >>> ============================================================================== >>> --- trunk/orte/mca/debugger/base/debugger_base_open.c (original) >>> +++ trunk/orte/mca/debugger/base/debugger_base_open.c 2011-11-07 >>> 20:24:16 EST (Mon, 07 Nov 2011) >>> @@ -43,10 +43,10 @@ >>> int MPIR_proctable_size = 0; >>> volatile int MPIR_being_debugged = 0; >>> volatile int MPIR_debug_state = 0; >>> -volatile int MPIR_i_am_starter = 0; >>> +int MPIR_i_am_starter = 0; >>> int MPIR_partial_attach_ok = 1; >>> -volatile char MPIR_executable_path[MPIR_MAX_PATH_LENGTH]; >>> -volatile char MPIR_server_arguments[MPIR_MAX_ARG_LENGTH]; >>> +char MPIR_executable_path[MPIR_MAX_PATH_LENGTH]; >>> +char MPIR_server_arguments[MPIR_MAX_ARG_LENGTH]; >>> volatile int MPIR_forward_output = 0; >>> volatile int MPIR_forward_comm = 0; >>> char MPIR_attach_fifo[MPIR_MAX_PATH_LENGTH]; >>> _______________________________________________ >>> svn-full mailing list >>> svn-f...@open-mpi.org >>> http://www.open-mpi.org/mailman/listinfo.cgi/svn-full >> >> >> -- >> Jeff Squyres >> jsquy...@cisco.com >> For corporate legal information go to: >> http://www.cisco.com/web/about/doing_business/legal/cri/ >> >> >> _______________________________________________ >> devel mailing list >> de...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
