Module: ppl/ppl Branch: master Commit: e6ed324723fa3ef52c2e80f1ebdc8c7361b7aca3 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=e6ed324723fa3...

Author: Enea Zaffanella zaffanella@cs.unipr.it Date: Sun Jul 12 18:36:43 2009 +0200

The deterministic timeout facilities are in the C language interface.

---

interfaces/C/ppl_c_header.h | 39 ++++++++++++++++++++ interfaces/C/ppl_c_implementation_common.cc | 52 +++++++++++++++++++++++++++ src/globals.types.hh | 2 + 3 files changed, 93 insertions(+), 0 deletions(-)

diff --git a/interfaces/C/ppl_c_header.h b/interfaces/C/ppl_c_header.h index a9fc702..2834a15 100644 --- a/interfaces/C/ppl_c_header.h +++ b/interfaces/C/ppl_c_header.h @@ -382,6 +382,45 @@ ppl_set_timeout PPL_PROTO((unsigned time)); int ppl_reset_timeout PPL_PROTO((void));

+/*! \brief + Sets a threshold for computations whose completion could require + an exponential amount of time. + + \param weight + The maximum computational weight allowed. + It must be strictly greater than zero. + + Computations taking exponential time will be interrupted some time + after reaching the \p weight complexity threshold. If the computation + is interrupted that way, the interrupted function will return error code + <code>PPL_TIMEOUT_EXCEPTION</code>. + Otherwise, if the computation completes without being interrupted, + then the deterministic timeout should be reset by calling + <code>ppl_reset_deterministic_timeout()</code>. + + \note + This "timeout" checking functionality is said to be \e deterministic + because it is not based on actual elapsed time. Its behavior will + only depend on (some of the) computations performed in the PPL library + and it will be otherwise independent from the computation environment + (CPU, operating system, compiler, etc.). + + \warning + The weight mechanism is under alpha testing. In particular, + there is still no clear relation between the weight threshold and + the actual computational complexity. As a consequence, client + applications should be ready to reconsider the tuning of these + weight thresholds when upgrading to newer version of the PPL. +*/ +int +ppl_set_deterministic_timeout PPL_PROTO((unsigned weight)); + +/*! \brief + Resets the deterministic timeout so that the computation is not interrupted. +*/ +int +ppl_reset_deterministic_timeout PPL_PROTO((void)); + /*@}*/ /* Timeout Handling */

/*! \defgroup Datatypes Library Datatypes diff --git a/interfaces/C/ppl_c_implementation_common.cc b/interfaces/C/ppl_c_implementation_common.cc index d061695..0e6c509 100644 --- a/interfaces/C/ppl_c_implementation_common.cc +++ b/interfaces/C/ppl_c_implementation_common.cc @@ -97,6 +97,12 @@ notify_error(enum ppl_enum_error_code code, const char* description) {

Parma_Watchdog_Library::Watchdog* p_timeout_object = 0;

+typedef +Parma_Watchdog_Library::Threshold_Watcher +<Parma_Polyhedra_Library::Weightwatch_Traits> Weightwatch; + +Weightwatch* p_deterministic_timeout_object = 0; + #endif // PPL_WATCHDOG_LIBRARY_ENABLED

void @@ -110,6 +116,17 @@ reset_timeout() { #endif // PPL_WATCHDOG_LIBRARY_ENABLED }

+void +reset_deterministic_timeout() { +#ifdef PPL_WATCHDOG_LIBRARY_ENABLED + if (p_deterministic_timeout_object) { + delete p_deterministic_timeout_object; + p_deterministic_timeout_object = 0; + abandon_expensive_computations = 0; + } +#endif // PPL_WATCHDOG_LIBRARY_ENABLED +} + } // namespace C

} // namespace Interfaces @@ -119,6 +136,11 @@ reset_timeout() { using namespace Parma_Polyhedra_Library; using namespace Parma_Polyhedra_Library::Interfaces::C;

+#ifdef PPL_WATCHDOG_LIBRARY_ENABLED +template <> Weightwatch::Initialize +Weightwatch::init = Weightwatch::Initialize(); +#endif // PPL_WATCHDOG_LIBRARY_ENABLED + unsigned int PPL_POLY_CON_RELATION_IS_DISJOINT; unsigned int PPL_POLY_CON_RELATION_STRICTLY_INTERSECTS; unsigned int PPL_POLY_CON_RELATION_IS_INCLUDED; @@ -232,6 +254,36 @@ ppl_reset_timeout(void) try { CATCH_ALL

int +ppl_set_deterministic_timeout(unsigned weight) try { +#ifndef PPL_WATCHDOG_LIBRARY_ENABLED + const char* what = "PPL C interface error:\n" + "ppl_set_deterministic_timeout: the PPL Watchdog library is not enabled."; + throw std::runtime_error(what); +#else + // In case a deterministic timeout was already set. + reset_deterministic_timeout(); + static timeout_exception e; + p_deterministic_timeout_object + = new Weightwatch(weight, abandon_expensive_computations, e); + return 0; +#endif // PPL_WATCHDOG_LIBRARY_ENABLED +} +CATCH_ALL + +int +ppl_reset_deterministic_timeout(void) try { +#ifndef PPL_WATCHDOG_LIBRARY_ENABLED + const char* what = "PPL C interface error:\n" + "ppl_reset_deterministic_timeout: the PPL Watchdog library is not enabled."; + throw std::runtime_error(what); +#else + reset_deterministic_timeout(); + return 0; +#endif // PPL_WATCHDOG_LIBRARY_ENABLED +} +CATCH_ALL + +int ppl_set_rounding_for_PPL(void) try { set_rounding_for_PPL(); return 0; diff --git a/src/globals.types.hh b/src/globals.types.hh index 569f965..a6d7058 100644 --- a/src/globals.types.hh +++ b/src/globals.types.hh @@ -152,6 +152,8 @@ enum Bounded_Integer_Type_Overflow { OVERFLOW_IMPOSSIBLE };

+struct Weightwatch_Traits; + } // namespace Parma_Polyhedra_Library

#endif // !defined(PPL_globals_types_hh)