#include "portable.h"
#include "xbt/log.h"
#include "xbt/swag.h"
-#include "private.h"
-#include "simix/smx_context_private.h"
+#include "xbt/xbt_os_thread.h"
+#include "src/simix/private.h"
+#include "simix/context.h"
+#include "gras_config.h"
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
"Context switching mecanism");
-SIMIX_ctx_factory_initializer_t factory_initializer_to_use = NULL;
+char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contexts/factory:value */
+smx_ctx_factory_initializer_t smx_factory_initializer_to_use = NULL;
+int smx_context_stack_size = 128 * 1024;
+
+#ifdef HAVE_THREAD_LOCAL_STORAGE
+__thread smx_context_t smx_current_context;
+#else
+smx_context_t smx_current_context; /* define it anyway, will be used in non-parallel mode */
+static xbt_os_thread_key_t smx_current_context_key = 0;
+#endif
+
+static int smx_parallel_contexts = 1;
+static int smx_parallel_threshold = 2;
/**
* This function is called by SIMIX_global_init() to initialize the context module.
void SIMIX_context_mod_init(void)
{
if (!simix_global->context_factory) {
- /* select context factory to use to create the context(depends of the macro definitions) */
- if (factory_initializer_to_use) {
- (*factory_initializer_to_use)(&(simix_global->context_factory));
+ /* select the context factory to use to create the contexts */
+ if (smx_factory_initializer_to_use) {
+ (*smx_factory_initializer_to_use)(&(simix_global->context_factory));
}
- else {
-#ifdef CONTEXT_THREADS /* Use os threads (either pthreads or windows ones) */
- SIMIX_ctx_thread_factory_init(&simix_global->context_factory);
-#elif defined(CONTEXT_UCONTEXT) /* use ucontext */
- SIMIX_ctx_sysv_factory_init(&simix_global->context_factory);
+ else { /* use the factory specified by --cfg=contexts/factory:value */
+
+ if (smx_context_factory_name == NULL) {
+ /* use the default factory */
+#ifdef CONTEXT_UCONTEXT
+ SIMIX_ctx_sysv_factory_init(&simix_global->context_factory);
+#else
+ SIMIX_ctx_thread_factory_init(&simix_global->context_factory);
+#endif
+ }
+ else if (!strcmp(smx_context_factory_name, "ucontext")) {
+ /* use ucontext */
+#ifdef CONTEXT_UCONTEXT
+ SIMIX_ctx_sysv_factory_init(&simix_global->context_factory);
#else
-#error ERROR [__FILE__, line __LINE__]: no context implementation specified.
+ xbt_die("The context factory 'ucontext' unavailable on your system");
#endif
+ }
+ else if (!strcmp(smx_context_factory_name, "thread")) {
+ /* use os threads (either pthreads or windows ones) */
+ SIMIX_ctx_thread_factory_init(&simix_global->context_factory);
+ }
+ else if (!strcmp(smx_context_factory_name, "raw")) {
+ /* use raw contexts */
+ SIMIX_ctx_raw_factory_init(&simix_global->context_factory);
+ }
+ else {
+ xbt_die("Invalid context factory specified");
+ }
}
}
+
+#if defined(CONTEXT_THREADS) && !defined(HAVE_THREAD_LOCAL_STORAGE)
+ /* the __thread storage class is not available on this platform:
+ * use getspecific/setspecific instead to store the current context in each thread */
+ xbt_os_thread_key_create(&smx_current_context_key);
+#endif
}
/**
finalize_factory = simix_global->context_factory->finalize;
(*finalize_factory) (&simix_global->context_factory);
}
+ xbt_dict_remove((xbt_dict_t) _surf_cfg_set,"contexts/factory");
}
+
+/**
+ * \brief Sets the number of parallel threads to use
+ * for the user contexts.
+ *
+ * This function should be called before initializing SIMIX.
+ * A value of 1 means no parallelism.
+ * If the value is greater than 1, the thread support must be enabled.
+ *
+ * \param nb_threads the number of threads to use
+ */
+XBT_INLINE void SIMIX_context_set_nthreads(int nb_threads) {
+
+ xbt_assert(nb_threads > 0, "Invalid number of parallel threads: %d", nb_threads);
+
+ if (nb_threads > 1) {
+#ifndef CONTEXT_THREADS
+ THROWF(arg_error, 0, "No thread support for parallel context execution");
+#endif
+ }
+
+ smx_parallel_contexts = nb_threads;
+}
+
+/**
+ * \brief Returns the number of parallel threads used
+ * for the user contexts.
+ * \return the number of threads (1 means no parallelism)
+ */
+XBT_INLINE int SIMIX_context_get_nthreads(void) {
+ return smx_parallel_contexts;
+}
+
+/**
+ * \brief Returns whether some parallel threads are used
+ * for the user contexts.
+ * \return 1 if parallelism is used
+ */
+XBT_INLINE int SIMIX_context_is_parallel(void) {
+ return smx_parallel_contexts > 1;
+}
+
+/**
+ * \brief Sets the threshold above which user processes are run in parallel.
+ *
+ * If the number of threads is set to 1, there is no parallelism and this
+ * threshold has no effect.
+ *
+ * \param threshold when the number of user processes ready to run is above
+ * this threshold, they are run in parallel
+ */
+XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) {
+ smx_parallel_threshold = threshold;
+}
+
+/**
+ * \brief Returns the threshold above which user processes are run in parallel.
+ *
+ * If the number of threads is set to 1, there is no parallelism and this
+ * threshold has no effect.
+ *
+ * \return when the number of user processes ready to run is above
+ * this threshold, they are run in parallel
+ */
+XBT_INLINE int SIMIX_context_get_parallel_threshold(void) {
+ return smx_parallel_threshold;
+}
+
+/**
+ * \brief Returns the current context of this thread.
+ * \return the current context of this thread
+ */
+XBT_INLINE smx_context_t SIMIX_context_get_current(void)
+{
+#ifdef HAVE_THREAD_LOCAL_STORAGE
+ return smx_current_context;
+#else
+ return xbt_os_thread_get_specific(smx_current_context_key);
+#endif
+}
+
+/**
+ * \brief Sets the current context of this thread.
+ * \param context the context to set
+ */
+XBT_INLINE void SIMIX_context_set_current(smx_context_t context)
+{
+#ifdef HAVE_THREAD_LOCAL_STORAGE
+ smx_current_context = context;
+#else
+ xbt_os_thread_set_specific(smx_current_context_key, context);
+#endif
+}
+
