/* \file UContext.cpp Context switching with ucontexts from System V */
-#include <ucontext.h> /* context relative declarations */
+#include "ContextUnix.hpp"
#include "mc/mc.h"
#include "src/mc/mc_ignore.h"
#include "src/simix/ActorImpl.hpp"
-#include "src/simix/smx_private.hpp"
-#include "xbt/parmap.hpp"
+
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
/** Many integers are needed to store a pointer
*
- * This is a bit paranoid about sizeof(smx_ctx_sysv_t) not being a multiple
- * of sizeof(int), but it doesn't harm. */
-#define CTX_ADDR_LEN \
- (sizeof(void*) / sizeof(int) + \
- !!(sizeof(void*) % sizeof(int)))
+ * Support up to two ints. */
+constexpr int CTX_ADDR_LEN = 2;
+
+static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int),
+ "Ucontexts are not supported on this arch yet");
/** A better makecontext
*
* Makecontext expects integer arguments, we the context
* variable is decomposed into a serie of integers and
* each integer is passed as argument to makecontext. */
-static void simgrid_makecontext(ucontext_t* ucp, void (*func)(int first, ...), void* arg)
+static void simgrid_makecontext(ucontext_t* ucp, void (*func)(int, int), simgrid::kernel::context::UContext* arg)
{
- int ctx_addr[CTX_ADDR_LEN];
- memcpy(ctx_addr, &arg, sizeof(void*));
- switch (CTX_ADDR_LEN) {
- case 1:
- makecontext(ucp, (void (*)())func, 1, ctx_addr[0]);
- break;
- case 2:
- makecontext(ucp, (void (*)()) func, 2, ctx_addr[0], ctx_addr[1]);
- break;
- default:
- xbt_die("Ucontexts are not supported on this arch yet (addr len = %zu/%zu = %zu)", sizeof(void*), sizeof(int), CTX_ADDR_LEN);
- }
+ int ctx_addr[CTX_ADDR_LEN]{};
+ memcpy(ctx_addr, &arg, sizeof arg);
+ makecontext(ucp, (void (*)())func, 2, ctx_addr[0], ctx_addr[1]);
}
-XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
-
-namespace simgrid {
-namespace kernel {
-namespace context {
- class UContext;
- class SerialUContext;
- class ParallelUContext;
- class UContextFactory;
-}}}
-
#if HAVE_THREAD_CONTEXTS
static simgrid::xbt::Parmap<smx_actor_t>* sysv_parmap;
-static simgrid::kernel::context::ParallelUContext** sysv_workers_context; /* space to save the worker's context in each thread */
+static simgrid::kernel::context::UContext** sysv_workers_context; /* space to save the worker's context
+ * in each thread */
static uintptr_t sysv_threads_working; /* number of threads that have started their work */
static xbt_os_thread_key_t sysv_worker_id_key; /* thread-specific storage for the thread id */
#endif
// The name of this function is currently hardcoded in the code (as string).
// Do not change it without fixing those references as well.
-static void smx_ctx_sysv_wrapper(int first, ...);
+static void smx_ctx_sysv_wrapper(int, int);
namespace simgrid {
namespace kernel {
namespace context {
-class UContext : public Context {
-protected:
- ucontext_t uc_; /* the ucontext that executes the code */
- char *stack_ = nullptr; /* the thread stack */
-public:
- friend UContextFactory;
- UContext(std::function<void()> code,
- void_pfn_smxprocess_t cleanup_func, smx_actor_t process);
- ~UContext() override;
- void stop() override;
-};
-
-class SerialUContext : public UContext {
-public:
- SerialUContext(std::function<void()> code,
- void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
- : UContext(std::move(code), cleanup_func, process)
- {}
- void suspend() override;
- void resume();
-};
-
-class ParallelUContext : public UContext {
-public:
- ParallelUContext(std::function<void()> code,
- void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
- : UContext(std::move(code), cleanup_func, process)
- {}
- void suspend() override;
- void resume();
-};
-
-class UContextFactory : public ContextFactory {
-public:
- friend UContext;
- friend SerialUContext;
- friend ParallelUContext;
-
- UContextFactory();
- ~UContextFactory() override;
- Context* create_context(std::function<void()> code,
- void_pfn_smxprocess_t cleanup, smx_actor_t process) override;
- void run_all() override;
-};
-
XBT_PRIVATE ContextFactory* sysv_factory()
{
XBT_VERB("Activating SYSV context factory");
#if HAVE_THREAD_CONTEXTS /* To use parallel ucontexts a thread pool is needed */
int nthreads = SIMIX_context_get_nthreads();
sysv_parmap = nullptr;
- sysv_workers_context = new ParallelUContext*[nthreads];
+ sysv_workers_context = new UContext*[nthreads];
sysv_maestro_context = nullptr;
xbt_os_thread_key_create(&sysv_worker_id_key);
#else
}
}}} // namespace simgrid::kernel::context
-static void smx_ctx_sysv_wrapper(int first, ...)
+static void smx_ctx_sysv_wrapper(int i1, int i2)
{
// Rebuild the Context* pointer from the integers:
- int ctx_addr[CTX_ADDR_LEN];
+ int ctx_addr[CTX_ADDR_LEN] = {i1, i2};
simgrid::kernel::context::UContext* context;
- ctx_addr[0] = first;
- if (CTX_ADDR_LEN > 1) {
- va_list ap;
- va_start(ap, first);
- for (unsigned i = 1; i < CTX_ADDR_LEN; i++)
- ctx_addr[i] = va_arg(ap, int);
- va_end(ap);
- }
- memcpy(&context, ctx_addr, sizeof(simgrid::kernel::context::UContext*));
+ memcpy(&context, ctx_addr, sizeof context);
try {
(*context)();
void SerialUContext::suspend()
{
/* determine the next context */
- SerialUContext* next_context = nullptr;
- unsigned long int i = sysv_process_index++;
+ UContext* next_context = nullptr;
+ unsigned long int i = sysv_process_index;
+ sysv_process_index++;
if (i < simix_global->process_to_run.size()) {
/* execute the next process */
XBT_DEBUG("Run next process");
- next_context = static_cast<SerialUContext*>(simix_global->process_to_run[i]->context);
+ next_context = static_cast<UContext*>(simix_global->process_to_run[i]->context);
} else {
/* all processes were run, return to maestro */
XBT_DEBUG("No more process to run");
- next_context = static_cast<SerialUContext*>(sysv_maestro_context);
+ next_context = sysv_maestro_context;
}
SIMIX_context_set_current(next_context);
- swapcontext(&this->uc_, &next_context->uc_);
+ UContext::swap(this, next_context);
}
// UContextSerial
void SerialUContext::resume()
{
SIMIX_context_set_current(this);
- swapcontext(&static_cast<SerialUContext*>(sysv_maestro_context)->uc_, &this->uc_);
+ UContext::swap(sysv_maestro_context, this);
}
/** Run one particular simulated process on the current thread. */
// Store the number of my containing body in os-thread-specific area :
xbt_os_thread_set_specific(sysv_worker_id_key, (void*) worker_id);
// Get my current soul:
- ParallelUContext* worker_context = static_cast<ParallelUContext*>(SIMIX_context_self());
+ UContext* worker_context = static_cast<UContext*>(SIMIX_context_self());
// Write down that this soul is hosted in that body (for now)
sysv_workers_context[worker_id] = worker_context;
- // Retrieve the system-level info that fuels this soul:
- ucontext_t* worker_stack = &worker_context->uc_;
// Write in simix that I switched my soul
SIMIX_context_set_current(this);
// Actually do that using the relevant library call:
- swapcontext(worker_stack, &this->uc_);
+ UContext::swap(worker_context, this);
// No body runs that soul anymore at this point.
// Instead the current body took the soul of simulated process
// The simulated process wakes back after the call to
/* determine the next context */
// Get the next soul to embody now:
boost::optional<smx_actor_t> next_work = sysv_parmap->next();
- ParallelUContext* next_context;
+ UContext* next_context;
if (next_work) {
// There is a next soul to embody (ie, a next process to resume)
XBT_DEBUG("Run next process");
- next_context = static_cast<ParallelUContext*>(next_work.get()->context);
+ next_context = static_cast<UContext*>(next_work.get()->context);
} else {
// All processes were run, go to the barrier
XBT_DEBUG("No more processes to run");
// When given that soul, the body will wait for the next scheduling round
}
- // Will contain the next soul to run, either simulated or initial minion's one
- ucontext_t* next_stack = &next_context->uc_;
-
SIMIX_context_set_current(next_context);
- // Get that next soul:
- swapcontext(&this->uc_, next_stack);
+ // Get the next soul to run, either simulated or initial minion's one:
+ UContext::swap(this, next_context);
#endif
}
