X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/38e2adf74c9fccec6487e953bcb6895b72786dc1..60087ab28ce5450ad32f128cffbb09eb492eb550:/src/simix/ContextRaw.cpp

diff --git a/src/simix/ContextRaw.cpp b/src/simix/ContextRaw.cpp
new file mode 100644
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+++ b/src/simix/ContextRaw.cpp
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+/* Copyright (c) 2009-2015. 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. */
+
+/** \file RawContext.cpp 
+  * Fast context switching inspired from SystemV ucontexts.
+  *
+  * In contrast to System V context, it does not touch the signal mask
+  * which avoids making a system call (at least on Linux).
+  */
+
+#include <math.h>
+
+#include <utility>
+#include <functional>
+
+#include "src/internal_config.h" 
+
+#include "xbt/log.h"
+#include "xbt/parmap.h"
+#include "xbt/dynar.h"
+
+#include "smx_private.h"
+#include "smx_private.hpp"
+#include "mc/mc.h"
+
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
+
+// ***** Class definitions
+
+namespace simgrid {
+namespace simix {
+
+class RawContext;
+class RawContextFactory;
+
+class RawContext : public Context {
+protected:
+  void* stack_ = nullptr; 
+  /** pointer to top the stack stack */
+  void* stack_top_ = nullptr;
+public:
+  friend class RawContextFactory;
+  RawContext(std::function<void()> code,
+          void_pfn_smxprocess_t cleanup_func,
+          smx_process_t process);
+  ~RawContext();
+public:
+  static void wrapper(void* arg);
+  void stop() override;
+  void suspend() override;
+  void resume();
+private:
+  void suspend_serial();
+  void suspend_parallel();
+  void resume_serial();
+  void resume_parallel();
+};
+
+class RawContextFactory : public ContextFactory {
+public:
+  RawContextFactory();
+  ~RawContextFactory();
+  RawContext* create_context(std::function<void()> code,
+    void_pfn_smxprocess_t, smx_process_t process) override;
+  void run_all() override;
+private:
+  void run_all_adaptative();
+  void run_all_serial();
+  void run_all_parallel();
+};
+
+ContextFactory* raw_factory()
+{
+  XBT_VERB("Using raw contexts. Because the glibc is just not good enough for us.");
+  return new RawContextFactory();
+}
+
+}
+}
+
+// ***** Loads of static stuff
+
+#if HAVE_THREAD_CONTEXTS
+static xbt_parmap_t raw_parmap;
+static simgrid::simix::RawContext** raw_workers_context;    /* space to save the worker context in each thread */
+static uintptr_t raw_threads_working;     /* number of threads that have started their work */
+static xbt_os_thread_key_t raw_worker_id_key; /* thread-specific storage for the thread id */
+#endif
+static unsigned long raw_process_index = 0;   /* index of the next process to run in the
+                                               * list of runnable processes */
+static simgrid::simix::RawContext* raw_maestro_context;
+
+static bool raw_context_parallel = false;
+
+// ***** Raw context routines
+
+typedef void (*rawctx_entry_point_t)(void *);
+
+typedef void* raw_stack_t;
+extern "C" raw_stack_t raw_makecontext(void* malloced_stack, int stack_size,
+                                   rawctx_entry_point_t entry_point, void* arg);
+extern "C" void raw_swapcontext(raw_stack_t* old, raw_stack_t new_context);
+
+// TODO, we should handle FP, MMX and the x87 control-word (for x86 and x86_64)
+
+#if SIMGRID_PROCESSOR_x86_64
+__asm__ (
+#if defined(__APPLE__)
+   ".text\n"
+   ".globl _raw_makecontext\n"
+   "_raw_makecontext:\n"
+#elif defined(_WIN32)
+   ".text\n"
+   ".globl raw_makecontext\n"
+   "raw_makecontext:\n"
+#else
+   ".text\n"
+   ".globl raw_makecontext\n"
+   ".type raw_makecontext,@function\n"
+   "raw_makecontext:\n"/* Calling convention sets the arguments in rdi, rsi, rdx and rcx, respectively */
+#endif
+   "   mov %rdi,%rax\n"      /* stack */
+   "   add %rsi,%rax\n"      /* size  */
+   "   andq $-16, %rax\n"    /* align stack */
+   "   movq $0,   -8(%rax)\n" /* @return for func */
+   "   mov %rdx,-16(%rax)\n" /* func */
+   "   mov %rcx,-24(%rax)\n" /* arg/rdi */
+   "   movq $0,  -32(%rax)\n" /* rsi */
+   "   movq $0,  -40(%rax)\n" /* rdx */
+   "   movq $0,  -48(%rax)\n" /* rcx */
+   "   movq $0,  -56(%rax)\n" /* r8  */
+   "   movq $0,  -64(%rax)\n" /* r9  */
+   "   movq $0,  -72(%rax)\n" /* rbp */
+   "   movq $0,  -80(%rax)\n" /* rbx */
+   "   movq $0,  -88(%rax)\n" /* r12 */
+   "   movq $0,  -96(%rax)\n" /* r13 */
+   "   movq $0, -104(%rax)\n" /* r14 */
+   "   movq $0, -112(%rax)\n" /* r15 */
+   "   sub $112,%rax\n"
+   "   ret\n"
+);
+
+__asm__ (
+#if defined(__APPLE__)
+   ".text\n"
+   ".globl _raw_swapcontext\n"
+   "_raw_swapcontext:\n"
+#elif defined(_WIN32)
+   ".text\n"
+   ".globl raw_swapcontext\n"
+   "raw_swapcontext:\n"
+#else
+   ".text\n"
+   ".globl raw_swapcontext\n"
+   ".type raw_swapcontext,@function\n"
+   "raw_swapcontext:\n" /* Calling convention sets the arguments in rdi and rsi, respectively */
+#endif
+   "   push %rdi\n"
+   "   push %rsi\n"
+   "   push %rdx\n"
+   "   push %rcx\n"
+   "   push %r8\n"
+   "   push %r9\n"
+   "   push %rbp\n"
+   "   push %rbx\n"
+   "   push %r12\n"
+   "   push %r13\n"
+   "   push %r14\n"
+   "   push %r15\n"
+   "   mov %rsp,(%rdi)\n" /* old */
+   "   mov %rsi,%rsp\n" /* new */
+   "   pop %r15\n"
+   "   pop %r14\n"
+   "   pop %r13\n"
+   "   pop %r12\n"
+   "   pop %rbx\n"
+   "   pop %rbp\n"
+   "   pop %r9\n"
+   "   pop %r8\n"
+   "   pop %rcx\n"
+   "   pop %rdx\n"
+   "   pop %rsi\n"
+   "   pop %rdi\n"
+   "   ret\n"
+);
+#elif SIMGRID_PROCESSOR_i686
+__asm__ (
+#if defined(__APPLE__) || defined(_WIN32)
+   ".text\n"
+   ".globl _raw_makecontext\n"
+   "_raw_makecontext:\n"
+#else
+   ".text\n"
+   ".globl raw_makecontext\n"
+   ".type raw_makecontext,@function\n"
+   "raw_makecontext:\n"
+#endif
+   "   movl 4(%esp),%eax\n"   /* stack */
+   "   addl 8(%esp),%eax\n"   /* size  */
+   "   andl $-16, %eax\n"     /* align stack */
+   "   movl 12(%esp),%ecx\n"  /* func  */
+   "   movl 16(%esp),%edx\n"  /* arg   */
+   "   movl %edx, -4(%eax)\n"
+   "   movl $0,   -8(%eax)\n" /* @return for func */
+   "   movl %ecx,-12(%eax)\n"
+   "   movl $0,  -16(%eax)\n" /* ebp */
+   "   movl $0,  -20(%eax)\n" /* ebx */
+   "   movl $0,  -24(%eax)\n" /* esi */
+   "   movl $0,  -28(%eax)\n" /* edi */
+   "   subl $28,%eax\n"
+   "   retl\n"
+);
+
+__asm__ (
+#if defined(__APPLE__) || defined(_WIN32)
+   ".text\n"
+   ".globl _raw_swapcontext\n"
+   "_raw_swapcontext:\n"
+#else
+   ".text\n"
+   ".globl raw_swapcontext\n"
+   ".type raw_swapcontext,@function\n"
+   "raw_swapcontext:\n"
+#endif
+   // Fetch the parameters:
+   "   movl 4(%esp),%eax\n" /* old (raw_stack_t*) */
+   "   movl 8(%esp),%edx\n" /* new (raw_stack_t)  */
+   // Save registers of the current context on the stack:
+   "   pushl %ebp\n"
+   "   pushl %ebx\n"
+   "   pushl %esi\n"
+   "   pushl %edi\n"
+   // Save the current context (stack pointer) in *old:
+   "   movl %esp,(%eax)\n"
+   // Switch to the stack of the new context:
+   "   movl %edx,%esp\n"
+   // Pop the values of the new context:
+   "   popl %edi\n"
+   "   popl %esi\n"
+   "   popl %ebx\n"
+   "   popl %ebp\n"
+   // Return using the return address of the new context:
+   "   retl\n"
+);
+#else
+
+
+/* If you implement raw contexts for other processors, don't forget to
+   update the definition of HAVE_RAW_CONTEXTS in tools/cmake/CompleteInFiles.cmake */
+
+raw_stack_t raw_makecontext(void* malloced_stack, int stack_size,
+                            rawctx_entry_point_t entry_point, void* arg) {
+   THROW_UNIMPLEMENTED;
+}
+
+void raw_swapcontext(raw_stack_t* old, raw_stack_t new_context) {
+   THROW_UNIMPLEMENTED;
+}
+
+#endif
+
+// ***** Method definitions
+
+namespace simgrid {
+namespace simix {
+
+RawContextFactory::RawContextFactory()
+  : ContextFactory("RawContextFactory")
+{
+  raw_context_parallel = SIMIX_context_is_parallel();
+  if (raw_context_parallel) {
+#if HAVE_THREAD_CONTEXTS
+    int nthreads = SIMIX_context_get_nthreads();
+    xbt_os_thread_key_create(&raw_worker_id_key);
+    // TODO, lazily init
+    raw_parmap = nullptr;
+    raw_workers_context = xbt_new(RawContext*, nthreads);
+    raw_maestro_context = nullptr;
+#endif
+    // TODO, if(SIMIX_context_get_parallel_threshold() > 1) => choose dynamically
+  }
+}
+
+RawContextFactory::~RawContextFactory()
+{
+#if HAVE_THREAD_CONTEXTS
+  if (raw_parmap)
+    xbt_parmap_destroy(raw_parmap);
+  xbt_free(raw_workers_context);
+#endif
+}
+
+RawContext* RawContextFactory::create_context(std::function<void()> code,
+    void_pfn_smxprocess_t cleanup, smx_process_t process)
+{
+  return this->new_context<RawContext>(std::move(code),
+    cleanup, process);
+}
+
+void RawContext::wrapper(void* arg)
+{
+  RawContext* context = (RawContext*) arg;
+  (*context)();
+  context->stop();
+}
+
+RawContext::RawContext(std::function<void()> code,
+    void_pfn_smxprocess_t cleanup, smx_process_t process)
+  : Context(std::move(code), cleanup, process)
+{
+   if (has_code()) {
+     this->stack_ = SIMIX_context_stack_new();
+     this->stack_top_ = raw_makecontext(this->stack_,
+                         smx_context_usable_stack_size,
+                         RawContext::wrapper,
+                         this);
+   } else {
+     if(process != nullptr && raw_maestro_context == nullptr)
+       raw_maestro_context = this;
+     if (MC_is_active())
+       MC_ignore_heap(
+         &raw_maestro_context->stack_top_,
+         sizeof(raw_maestro_context->stack_top_));
+   }
+}
+
+RawContext::~RawContext()
+{
+  SIMIX_context_stack_delete(this->stack_);
+}
+
+void RawContext::stop()
+{
+  Context::stop();
+  this->suspend();
+}
+
+void RawContextFactory::run_all()
+{
+  if (raw_context_parallel)
+    run_all_parallel();
+  else
+    run_all_serial();
+}
+
+void RawContextFactory::run_all_serial()
+{
+  smx_process_t first_process =
+      xbt_dynar_get_as(simix_global->process_to_run, 0, smx_process_t);
+  raw_process_index = 1;
+  static_cast<RawContext*>(first_process->context)->resume_serial();
+}
+
+void RawContextFactory::run_all_parallel()
+{
+#if HAVE_THREAD_CONTEXTS
+  raw_threads_working = 0;
+  if (raw_parmap == nullptr)
+    raw_parmap = xbt_parmap_new(
+      SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
+  xbt_parmap_apply(raw_parmap,
+      [](void* arg) {
+        smx_process_t process = static_cast<smx_process_t>(arg);
+        RawContext* context = static_cast<RawContext*>(process->context);
+        context->resume_parallel();
+      },
+      simix_global->process_to_run);
+#else
+  xbt_die("You asked for a parallel execution, but you don't have any threads.");
+#endif
+}
+
+void RawContext::suspend()
+{
+  if (raw_context_parallel)
+    RawContext::suspend_parallel();
+  else
+    RawContext::suspend_serial();
+}
+
+void RawContext::suspend_serial()
+{
+  /* determine the next context */
+  RawContext* next_context = nullptr;
+  unsigned long int i;
+  i = raw_process_index++;
+  if (i < xbt_dynar_length(simix_global->process_to_run)) {
+    /* execute the next process */
+    XBT_DEBUG("Run next process");
+    next_context = (RawContext*) xbt_dynar_get_as(
+        simix_global->process_to_run, i, smx_process_t)->context;
+  }
+  else {
+    /* all processes were run, return to maestro */
+    XBT_DEBUG("No more process to run");
+    next_context = (RawContext*) raw_maestro_context;
+  }
+  SIMIX_context_set_current(next_context);
+  raw_swapcontext(&this->stack_top_, next_context->stack_top_);
+}
+
+void RawContext::suspend_parallel()
+{
+#if HAVE_THREAD_CONTEXTS
+  /* determine the next context */
+  smx_process_t next_work = (smx_process_t) xbt_parmap_next(raw_parmap);
+  RawContext* next_context = nullptr;
+
+  if (next_work != NULL) {
+    /* there is a next process to resume */
+    XBT_DEBUG("Run next process");
+    next_context = (RawContext*) next_work->context;
+  }
+  else {
+    /* all processes were run, go to the barrier */
+    XBT_DEBUG("No more processes to run");
+    uintptr_t worker_id = (uintptr_t)
+      xbt_os_thread_get_specific(raw_worker_id_key);
+    next_context = (RawContext*) raw_workers_context[worker_id];
+    XBT_DEBUG("Restoring worker stack %zu (working threads = %zu)",
+        worker_id, raw_threads_working);
+  }
+
+  SIMIX_context_set_current(next_context);
+  raw_swapcontext(&this->stack_top_, next_context->stack_top_);
+#endif
+}
+
+void RawContext::resume()
+{
+  if (raw_context_parallel)
+    resume_parallel();
+  else
+    resume_serial();
+}
+
+void RawContext::resume_serial()
+{
+  SIMIX_context_set_current(this);
+  raw_swapcontext(&raw_maestro_context->stack_top_, this->stack_top_);
+}
+
+void RawContext::resume_parallel()
+{
+#if HAVE_THREAD_CONTEXTS
+  uintptr_t worker_id = __sync_fetch_and_add(&raw_threads_working, 1);
+  xbt_os_thread_set_specific(raw_worker_id_key, (void*) worker_id);
+  RawContext* worker_context = (RawContext*) SIMIX_context_self();
+  raw_workers_context[worker_id] = worker_context;
+  XBT_DEBUG("Saving worker stack %zu", worker_id);
+  SIMIX_context_set_current(this);
+  raw_swapcontext(&worker_context->stack_top_, this->stack_top_);
+#else
+  xbt_die("Parallel execution disabled");
+#endif
+}
+
+/** @brief Resumes all processes ready to run. */
+void RawContextFactory::run_all_adaptative()
+{
+  unsigned long nb_processes = xbt_dynar_length(simix_global->process_to_run);
+  if (SIMIX_context_is_parallel()
+    && (unsigned long) SIMIX_context_get_parallel_threshold() < nb_processes) {
+        raw_context_parallel = true;
+        XBT_DEBUG("Runall // %lu", nb_processes);
+        this->run_all_parallel();
+    } else {
+        XBT_DEBUG("Runall serial %lu", nb_processes);
+        raw_context_parallel = false;
+        this->run_all_serial();
+    }
+}
+
+}
+}