X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/795359a4a2c81571bb061f8dfbcc6c15323c9bf3..9fd6cbc6c3b06f4b09e3c3339ffb3cc8a68f9bfa:/src/simix/smx_context.cpp

diff --git a/src/simix/smx_context.cpp b/src/simix/smx_context.cpp
index 75ddf214f0..d07d747b97 100644
--- a/src/simix/smx_context.cpp
+++ b/src/simix/smx_context.cpp
@@ -1,21 +1,16 @@
 /* a fast and simple context switching library                              */
 
-/* Copyright (c) 2009-2015. The SimGrid Team.
- * All rights reserved.                                                     */
+/* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-#include "src/portable.h"
-#include "xbt/log.h"
-#include "xbt/swag.h"
-#include "xbt/xbt_os_thread.h"
-#include "smx_private.h"
-#include "smx_private.hpp"
-#include "simgrid/sg_config.h"
-#include "src/internal_config.h"
 #include "simgrid/modelchecker.h"
+#include "src/internal_config.h"
+#include "src/simix/smx_private.hpp"
+#include "xbt/config.hpp"
 
+#include <thread>
 
 #ifdef _WIN32
 #include <windows.h>
@@ -24,121 +19,147 @@
 #include <sys/mman.h>
 #endif
 
-#ifdef __MINGW32__ 
-#define _aligned_malloc __mingw_aligned_malloc 
-#define _aligned_free  __mingw_aligned_free 
-#endif //MINGW
+#ifdef __MINGW32__
+#define _aligned_malloc __mingw_aligned_malloc
+#define _aligned_free  __mingw_aligned_free
+#endif /*MINGW*/
 
-#ifdef HAVE_VALGRIND_VALGRIND_H
+#if HAVE_VALGRIND_H
 # include <valgrind/valgrind.h>
 #endif
 
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
-                                "Context switching mechanism");
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, "Context switching mechanism");
+
+static std::pair<const char*, simgrid::kernel::context::ContextFactoryInitializer> context_factories[] = {
+#if HAVE_RAW_CONTEXTS
+  { "raw", &simgrid::kernel::context::raw_factory },
+#endif
+#if HAVE_UCONTEXT_CONTEXTS
+  { "ucontext", &simgrid::kernel::context::sysv_factory },
+#endif
+#if HAVE_BOOST_CONTEXTS
+  { "boost", &simgrid::kernel::context::boost_factory },
+#endif
+#if HAVE_THREAD_CONTEXTS
+  { "thread", &simgrid::kernel::context::thread_factory },
+#endif
+};
+
+static_assert(sizeof(context_factories) != 0, "No context factories are enabled for this build");
+
+// Create the list of possible contexts:
+static inline
+std::string contexts_list()
+{
+  std::string res;
+  const std::size_t n = sizeof(context_factories) / sizeof(context_factories[0]);
+  for (std::size_t i = 1; i != n; ++i) {
+    res += ", ";
+    res += context_factories[i].first;
+  }
+  return res;
+}
+
+static simgrid::config::Flag<std::string> context_factory_name(
+  "contexts/factory",
+  (std::string("Possible values: ")+contexts_list()).c_str(),
+  context_factories[0].first);
 
-char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contexts/factory:value */
-int smx_context_stack_size;
+unsigned smx_context_stack_size;
 int smx_context_stack_size_was_set = 0;
-int smx_context_guard_size;
+unsigned smx_context_guard_size;
 int smx_context_guard_size_was_set = 0;
-#ifdef HAVE_THREAD_LOCAL_STORAGE
-static XBT_THREAD_LOCAL smx_context_t smx_current_context_parallel;
-#else
-static xbt_os_thread_key_t smx_current_context_key = 0;
-#endif
+static thread_local smx_context_t smx_current_context_parallel;
 static smx_context_t smx_current_context_serial;
 static int smx_parallel_contexts = 1;
 static int smx_parallel_threshold = 2;
 static e_xbt_parmap_mode_t smx_parallel_synchronization_mode = XBT_PARMAP_DEFAULT;
 
-/** 
+/**
  * This function is called by SIMIX_global_init() to initialize the context module.
  */
-void SIMIX_context_mod_init(void)
+void SIMIX_context_mod_init()
 {
-#if defined(HAVE_THREAD_CONTEXTS) && !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
-  if (!simix_global->context_factory) {
-    /* select the context factory to use to create the contexts */
-    if (simgrid::simix::factory_initializer)
-      simix_global->context_factory = simgrid::simix::factory_initializer();
-    else { /* use the factory specified by --cfg=contexts/factory:value */
-#if defined(HAVE_THREAD_CONTEXTS)
-      if (!strcmp(smx_context_factory_name, "thread"))
-        simix_global->context_factory = simgrid::simix::thread_factory();
-#else
-      if (0);
-#endif
-#ifdef HAVE_UCONTEXT_CONTEXTS
-      else if (!strcmp(smx_context_factory_name, "ucontext"))
-        simix_global->context_factory = simgrid::simix::sysv_factory();
-#endif
-#ifdef HAVE_RAW_CONTEXTS
-      else if (!strcmp(smx_context_factory_name, "raw"))
-        simix_global->context_factory = simgrid::simix::raw_factory();
+  xbt_assert(simix_global->context_factory == nullptr);
+
+  smx_context_stack_size_was_set = not simgrid::config::is_default("contexts/stack-size");
+  smx_context_guard_size_was_set = not simgrid::config::is_default("contexts/guard-size");
+
+#if HAVE_SMPI && (defined(__APPLE__) || defined(__NetBSD__))
+  std::string priv = simgrid::config::get_value<std::string>("smpi/privatization");
+  if (context_factory_name == "thread" && (priv == "dlopen" || priv == "yes" || priv == "default" || priv == "1")) {
+    XBT_WARN("dlopen+thread broken on Apple and BSD. Switching to raw contexts.");
+    context_factory_name = "raw";
+  }
 #endif
-#ifdef HAVE_BOOST_CONTEXTS
-      else if (!strcmp(smx_context_factory_name, "boost"))
-        simix_global->context_factory = simgrid::simix::boost_factory();
+
+#if HAVE_SMPI && defined(__FreeBSD__)
+  if (context_factory_name == "thread" && simgrid::config::get_value<std::string>("smpi/privatization") != "no") {
+    XBT_WARN("mmap broken on FreeBSD, but dlopen+thread broken too. Switching to dlopen+raw contexts.");
+    context_factory_name = "raw";
+  }
 #endif
-      else {
-        XBT_ERROR("Invalid context factory specified. Valid factories on this machine:");
-#ifdef HAVE_RAW_CONTEXTS
-        XBT_ERROR("  raw: high performance context factory implemented specifically for SimGrid");
+
+  /* select the context factory to use to create the contexts */
+  if (simgrid::kernel::context::factory_initializer) { // Give Java a chance to hijack the factory mechanism
+    simix_global->context_factory = simgrid::kernel::context::factory_initializer();
+    return;
+  }
+  /* use the factory specified by --cfg=contexts/factory:value */
+  for (auto const& factory : context_factories)
+    if (context_factory_name == factory.first) {
+      simix_global->context_factory = factory.second();
+      break;
+    }
+
+  if (simix_global->context_factory == nullptr) {
+    XBT_ERROR("Invalid context factory specified. Valid factories on this machine:");
+#if HAVE_RAW_CONTEXTS
+    XBT_ERROR("  raw: high performance context factory implemented specifically for SimGrid");
 #else
-        XBT_ERROR("  (raw contexts were disabled at compilation time on this machine -- check configure logs for details)");
+    XBT_ERROR("  (raw contexts were disabled at compilation time on this machine -- check configure logs for details)");
 #endif
-#ifdef HAVE_UCONTEXT_CONTEXTS
-        XBT_ERROR("  ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)");
+#if HAVE_UCONTEXT_CONTEXTS
+    XBT_ERROR("  ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)");
 #else
-        XBT_ERROR("  (ucontext was disabled at compilation time on this machine -- check configure logs for details)");
+    XBT_ERROR("  (ucontext was disabled at compilation time on this machine -- check configure logs for details)");
 #endif
-#ifdef HAVE_BOOST_CONTEXTS
-        XBT_ERROR("  boost: this uses the boost libraries context implementation");
+#if HAVE_BOOST_CONTEXTS
+    XBT_ERROR("  boost: this uses the boost libraries context implementation");
 #else
-        XBT_ERROR("  (boost was disabled at compilation time on this machine -- check configure logs for details. Did you install the libboost-context-dev package?)");
+    XBT_ERROR("  (boost was disabled at compilation time on this machine -- check configure logs for details. Did you install the libboost-context-dev package?)");
 #endif
-        XBT_ERROR("  thread: slow portability layer using system threads (pthreads on UNIX, CreateThread() on windows)");
-        xbt_die("Please use a valid factory.");
-      }
-    }
+    XBT_ERROR("  thread: slow portability layer using pthreads as provided by gcc");
+    xbt_die("Please use a valid factory.");
   }
 }
 
 /**
  * This function is called by SIMIX_clean() to finalize the context module.
  */
-void SIMIX_context_mod_exit(void)
+void SIMIX_context_mod_exit()
 {
   delete simix_global->context_factory;
   simix_global->context_factory = nullptr;
 }
 
-void *SIMIX_context_stack_new(void)
+void *SIMIX_context_stack_new()
 {
   void *stack;
 
-  /* FIXME: current code for stack overflow protection assumes that stacks are
-   * growing downward (PTH_STACKGROWTH == -1).  Protected pages need to be put
-   * after the stack when PTH_STACKGROWTH == 1. */
+  if (smx_context_guard_size > 0 && not MC_is_active()) {
 
-  if (smx_context_guard_size > 0 && !MC_is_active()) {
-
-#if defined(_WIN32) || (PTH_STACKGROWTH != -1)
-    static int warned_once = 0;
-    if (!warned_once) {
-      XBT_WARN("Stack overflow protection is known to be broken on your system.  Either you're on Windows or PTH_STACKGROWTH != -1 (current value is %d).",
-               PTH_STACKGROWTH);
-      warned_once = 1;
-    }
+#if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1)
+    xbt_die("Stack overflow protection is known to be broken on your system: you stacks grow upwards (or detection is "
+            "broken). "
+            "Please disable stack guards with --cfg=contexts:guard-size:0");
+    /* Current code for stack overflow protection assumes that stacks are growing downward (PTH_STACKGROWTH == -1).
+     * Protected pages need to be put after the stack when PTH_STACKGROWTH == 1. */
 #endif
 
     size_t size = smx_context_stack_size + smx_context_guard_size;
-#ifdef HAVE_MC
-    /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the
+#if SIMGRID_HAVE_MC
+    /* Cannot use posix_memalign when SIMGRID_HAVE_MC. Align stack by hand, and save the
      * pointer returned by xbt_malloc0. */
     char *alloc = (char*)xbt_malloc0(size + xbt_pagesize);
     stack = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize;
@@ -152,9 +173,13 @@ void *SIMIX_context_stack_new(void)
 
 #ifndef _WIN32
     if (mprotect(stack, smx_context_guard_size, PROT_NONE) == -1) {
-      xbt_die("Failed to protect stack: %s", strerror(errno));
-      /* This is fatal. We are going to fail at some point when
-         we tryi reusing this. */
+      xbt_die(
+          "Failed to protect stack: %s.\n"
+          "If you are running a lot of actors, you may be exceeding the amount of mappings allowed per process.\n"
+          "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n"
+          "Please see http://simgrid.gforge.inria.fr/simgrid/latest/doc/html/options.html#options_virt for more info.",
+          strerror(errno));
+      /* This is fatal. We are going to fail at some point when we try reusing this. */
     }
 #endif
     stack = (char *)stack + smx_context_guard_size;
@@ -162,11 +187,9 @@ void *SIMIX_context_stack_new(void)
     stack = xbt_malloc0(smx_context_stack_size);
   }
 
-#ifdef HAVE_VALGRIND_VALGRIND_H
-  unsigned int valgrind_stack_id =
-    VALGRIND_STACK_REGISTER(stack, (char *)stack + smx_context_stack_size);
-  memcpy((char *)stack + smx_context_usable_stack_size, &valgrind_stack_id,
-         sizeof valgrind_stack_id);
+#if HAVE_VALGRIND_H
+  unsigned int valgrind_stack_id = VALGRIND_STACK_REGISTER(stack, (char *)stack + smx_context_stack_size);
+  memcpy((char *)stack + smx_context_usable_stack_size, &valgrind_stack_id, sizeof valgrind_stack_id);
 #endif
 
   return stack;
@@ -174,96 +197,86 @@ void *SIMIX_context_stack_new(void)
 
 void SIMIX_context_stack_delete(void *stack)
 {
-  if (!stack)
+  if (not stack)
     return;
 
-#ifdef HAVE_VALGRIND_VALGRIND_H
+#if HAVE_VALGRIND_H
   unsigned int valgrind_stack_id;
-  memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size,
-         sizeof valgrind_stack_id);
+  memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size, sizeof valgrind_stack_id);
   VALGRIND_STACK_DEREGISTER(valgrind_stack_id);
 #endif
 
 #ifndef _WIN32
-  if (smx_context_guard_size > 0 && !MC_is_active()) {
+  if (smx_context_guard_size > 0 && not MC_is_active()) {
     stack = (char *)stack - smx_context_guard_size;
-    if (mprotect(stack, smx_context_guard_size,
-                 PROT_READ | PROT_WRITE) == -1) {
+    if (mprotect(stack, smx_context_guard_size, PROT_READ | PROT_WRITE) == -1) {
       XBT_WARN("Failed to remove page protection: %s", strerror(errno));
       /* try to pursue anyway */
     }
-#ifdef HAVE_MC
+#if SIMGRID_HAVE_MC
     /* Retrieve the saved pointer.  See SIMIX_context_stack_new above. */
     stack = *((void **)stack - 1);
 #endif
   }
-#endif
+#endif /* not windows */
 
   xbt_free(stack);
 }
 
-/**
- * \brief Returns whether some parallel threads are used
- * for the user contexts.
- * \return 1 if parallelism is used
- */
-int SIMIX_context_is_parallel(void) {
+/** @brief Returns whether some parallel threads are used for the user contexts. */
+int SIMIX_context_is_parallel() {
   return smx_parallel_contexts > 1;
 }
 
 /**
- * \brief Returns the number of parallel threads used
- * for the user contexts.
- * \return the number of threads (1 means no parallelism)
+ * @brief Returns the number of parallel threads used for the user contexts.
+ * @return the number of threads (1 means no parallelism)
  */
-int SIMIX_context_get_nthreads(void) {
+int SIMIX_context_get_nthreads() {
   return smx_parallel_contexts;
 }
 
 /**
- * \brief Sets the number of parallel threads to use
+ * @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 (1 thread only).
  * If the value is greater than 1, the thread support must be enabled.
  *
- * \param nb_threads the number of threads to use
+ * @param nb_threads the number of threads to use
  */
 void SIMIX_context_set_nthreads(int nb_threads) {
-  if (nb_threads<=0) {  
-     nb_threads = xbt_os_get_numcores();
-     XBT_INFO("Auto-setting contexts/nthreads to %d",nb_threads);
-  }   
-  
-  if (nb_threads > 1) {
-#ifndef HAVE_THREAD_CONTEXTS
-    THROWF(arg_error, 0, "The thread factory cannot be run in parallel");
-#endif
+  if (nb_threads<=0) {
+    nb_threads = std::thread::hardware_concurrency();
+    XBT_INFO("Auto-setting contexts/nthreads to %d", nb_threads);
   }
+#if !HAVE_THREAD_CONTEXTS
+  xbt_assert(nb_threads == 1, "Parallel runs are impossible when the pthreads are missing.");
+#endif
   smx_parallel_contexts = nb_threads;
 }
 
 /**
- * \brief Returns the threshold above which user processes are run in parallel.
+ * @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
+ * @return when the number of user processes ready to run is above
  * this threshold, they are run in parallel
  */
-int SIMIX_context_get_parallel_threshold(void) {
+int SIMIX_context_get_parallel_threshold() {
   return smx_parallel_threshold;
 }
 
 /**
- * \brief Sets the threshold above which user processes are run in parallel.
+ * @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
+ * @param threshold when the number of user processes ready to run is above
  * this threshold, they are run in parallel
  */
 void SIMIX_context_set_parallel_threshold(int threshold) {
@@ -271,35 +284,31 @@ void SIMIX_context_set_parallel_threshold(int threshold) {
 }
 
 /**
- * \brief Returns the synchronization mode used when processes are run in
+ * @brief Returns the synchronization mode used when processes are run in
  * parallel.
- * \return how threads are synchronized if processes are run in parallel
+ * @return how threads are synchronized if processes are run in parallel
  */
-e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode(void) {
+e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode() {
   return smx_parallel_synchronization_mode;
 }
 
 /**
- * \brief Sets the synchronization mode to use when processes are run in
+ * @brief Sets the synchronization mode to use when processes are run in
  * parallel.
- * \param mode how to synchronize threads if processes are run in parallel
+ * @param mode how to synchronize threads if processes are run in parallel
  */
 void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) {
   smx_parallel_synchronization_mode = mode;
 }
 
 /**
- * \brief Returns the current context of this thread.
- * \return the current context of this thread
+ * @brief Returns the current context of this thread.
+ * @return the current context of this thread
  */
-smx_context_t SIMIX_context_get_current(void)
+smx_context_t SIMIX_context_get_current()
 {
   if (SIMIX_context_is_parallel()) {
-#ifdef HAVE_THREAD_LOCAL_STORAGE
     return smx_current_context_parallel;
-#else
-    return xbt_os_thread_get_specific(smx_current_context_key);
-#endif
   }
   else {
     return smx_current_context_serial;
@@ -307,17 +316,13 @@ smx_context_t SIMIX_context_get_current(void)
 }
 
 /**
- * \brief Sets the current context of this thread.
- * \param context the context to set
+ * @brief Sets the current context of this thread.
+ * @param context the context to set
  */
 void SIMIX_context_set_current(smx_context_t context)
 {
   if (SIMIX_context_is_parallel()) {
-#ifdef HAVE_THREAD_LOCAL_STORAGE
     smx_current_context_parallel = context;
-#else
-    xbt_os_thread_set_specific(smx_current_context_key, context);
-#endif
   }
   else {
     smx_current_context_serial = context;