X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d4f0b385e0fe3352a023e92cd199969a69d7b4d2..74e53067d0c00064ef01253c0e9f335f1f08ce5a:/src/simix/smx_context_raw.c

diff --git a/src/simix/smx_context_raw.c b/src/simix/smx_context_raw.c
index 5282293bb8..c431cc30c2 100644
--- a/src/simix/smx_context_raw.c
+++ b/src/simix/smx_context_raw.c
@@ -1,4 +1,4 @@
-/* context_raw - context switching with ucontextes from System V           */
+/* context_raw - fast context switching inspired from System V ucontextes   */
 
 /* Copyright (c) 2009, 2010. The SimGrid Team.
  * All rights reserved.                                                     */
@@ -9,32 +9,35 @@
 #include "simix/private.h"
 #include "xbt/parmap.h"
 
-
 #ifdef HAVE_VALGRIND_VALGRIND_H
 #  include <valgrind/valgrind.h>
 #endif                          /* HAVE_VALGRIND_VALGRIND_H */
 
-#ifdef _XBT_WIN32
-#include "win32_ucontext.h"
-#include "win32_ucontext.c"
-#else
-#include "ucontext.h"
-#endif
-
 typedef char * raw_stack_t;
 typedef void (*rawctx_entry_point_t)(void *);
 
 typedef struct s_smx_ctx_raw {
-  s_smx_ctx_base_t super;       /* Fields of super implementation */
-  char *malloced_stack; /* malloced area containing the stack */
-  raw_stack_t stack_top; /* pointer to stack top (within previous area) */
-  raw_stack_t old_stack_top; /* to whom I should return the control */
+  s_smx_ctx_base_t super;         /* Fields of super implementation */
+  char *malloced_stack;           /* malloced area containing the stack */
+  raw_stack_t stack_top;          /* pointer to stack top (within previous area) */
 #ifdef HAVE_VALGRIND_VALGRIND_H
-  unsigned int valgrind_stack_id;       /* the valgrind stack id */
+  unsigned int valgrind_stack_id; /* the valgrind stack id */
+#endif
+#ifdef TIME_BENCH
+  unsigned int thread;            /* Just for measuring purposes */
 #endif
 } s_smx_ctx_raw_t, *smx_ctx_raw_t;
 
-smx_ctx_raw_t maestro_raw_context;
+#ifdef CONTEXT_THREADS
+static xbt_parmap_t raw_parmap;
+static raw_stack_t* raw_workers_stacks;       /* space to save the worker stack in each thread */
+static unsigned long 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 smx_ctx_raw_t raw_maestro_context;
 
 extern raw_stack_t raw_makecontext(char* malloced_stack, int stack_size,
                                    rawctx_entry_point_t entry_point, void* arg);
@@ -42,10 +45,16 @@ extern void raw_swapcontext(raw_stack_t* old, raw_stack_t new);
 
 #ifdef 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  */
    "   movl 12(%esp),%ecx\n"  /* func  */
@@ -62,10 +71,16 @@ __asm__ (
 );
 
 __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
    "   movl 4(%esp),%eax\n" /* old */
    "   movl 8(%esp),%edx\n" /* new */
    "   pushl %ebp\n"
@@ -82,10 +97,16 @@ __asm__ (
 );
 #elif PROCESSOR_x86_64
 __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" /* Calling convention sets the arguments in rdi, rsi, rdx and rcx, respectively */
+   "raw_makecontext:\n"/* Calling convention sets the arguments in rdi, rsi, rdx and rcx, respectively */
+#endif
    "   movq %rdi,%rax\n"      /* stack */
    "   addq %rsi,%rax\n"      /* size  */
    "   movq $0,   -8(%rax)\n" /* @return for func */
@@ -107,10 +128,16 @@ __asm__ (
 );
 
 __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" /* Calling convention sets the arguments in rdi and rsi, respectively */
+#endif
    "   pushq %rdi\n"
    "   pushq %rsi\n"
    "   pushq %rdx\n"
@@ -140,6 +167,10 @@ __asm__ (
    "   retq\n"
 );
 #else
+
+/* If you implement raw contextes for other processors, don't forget to 
+   update the definition of HAVE_RAWCTX in buildtools/Cmake/CompleteInFiles.cmake */
+
 raw_stack_t raw_makecontext(char* malloced_stack, int stack_size,
                             rawctx_entry_point_t entry_point, void* arg) {
    THROW_UNIMPLEMENTED;
@@ -153,22 +184,107 @@ void raw_swapcontext(raw_stack_t* old, raw_stack_t new) {
 
 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
 
-#ifdef CONTEXT_THREADS
-static xbt_parmap_t parmap;
+#ifdef TIME_BENCH
+#include "xbt/xbt_os_time.h"
+#define NUM_THREADS 4
+static xbt_os_timer_t timer;
+static double time_thread_sr[NUM_THREADS];
+static double time_thread_ssr[NUM_THREADS];
+static double time_wasted_sr = 0;
+static double time_wasted_ssr = 0;
+static unsigned int sr_count = 0;
+static unsigned int ssr_count = 0;
+static char new_sr = 0;
 #endif
 
-static smx_context_factory_t raw_factory;
-
 static void smx_ctx_raw_wrapper(smx_ctx_raw_t context);
+static int smx_ctx_raw_factory_finalize(smx_context_factory_t *factory);
+static smx_context_t smx_ctx_raw_create_context(xbt_main_func_t code, int argc,
+    char **argv, void_pfn_smxprocess_t cleanup_func, void *data);
+static void smx_ctx_raw_free(smx_context_t context);
+static void smx_ctx_raw_wrapper(smx_ctx_raw_t context);
+static void smx_ctx_raw_stop(smx_context_t context);
+static void smx_ctx_raw_suspend_serial(smx_context_t context);
+static void smx_ctx_raw_resume_serial(smx_process_t first_process);
+static void smx_ctx_raw_runall_serial(void);
+static void smx_ctx_raw_suspend_parallel(smx_context_t context);
+static void smx_ctx_raw_resume_parallel(smx_process_t first_process);
+static void smx_ctx_raw_runall_parallel(void);
+static void smx_ctx_raw_runall(void);
+
+/**
+ * \brief Initializes the raw context factory.
+ * \param factory where to initialize the factory
+ */
+void SIMIX_ctx_raw_factory_init(smx_context_factory_t *factory)
+{
+  XBT_VERB("Using raw contexts. Because the glibc is just not good enough for us.");
+  smx_ctx_base_factory_init(factory);
 
+  (*factory)->finalize  = smx_ctx_raw_factory_finalize;
+  (*factory)->create_context = smx_ctx_raw_create_context;
+  /* Do not overload that method (*factory)->finalize */
+  (*factory)->free = smx_ctx_raw_free;
+  (*factory)->stop = smx_ctx_raw_stop;
+  (*factory)->name = "smx_raw_context_factory";
+
+  if (SIMIX_context_is_parallel()) {
+#ifdef CONTEXT_THREADS
+    int nthreads = SIMIX_context_get_nthreads();
+    raw_parmap = xbt_parmap_new(nthreads);
+    raw_workers_stacks = xbt_new(raw_stack_t, nthreads);
+    xbt_os_thread_key_create(&raw_worker_id_key);
+#endif
+    if (SIMIX_context_get_parallel_threshold() > 1) {
+      /* choose dynamically */
+      (*factory)->runall = smx_ctx_raw_runall;
+      (*factory)->suspend = NULL;
+    }
+    else {
+      /* always parallel */
+      (*factory)->runall = smx_ctx_raw_runall_parallel;
+      (*factory)->suspend = smx_ctx_raw_suspend_parallel;
+    }
+  }
+  else {
+    /* always serial */
+    (*factory)->runall = smx_ctx_raw_runall_serial;
+    (*factory)->suspend = smx_ctx_raw_suspend_serial;
+  }
+#ifdef TIME_BENCH
+  timer = xbt_os_timer_new();
+#endif
+}
+
+/**
+ * \brief Finalizes the raw context factory.
+ * \param factory the raw context factory
+ */
 static int smx_ctx_raw_factory_finalize(smx_context_factory_t *factory)
-{ 
-  if(parmap)
-      xbt_parmap_destroy(parmap);
+{
+#ifdef TIME_BENCH
+  XBT_CRITICAL("Total wasted time in %u SR: %lf", sr_count, time_wasted_sr);
+  XBT_CRITICAL("Total wasted time in %u SSR: %lf", ssr_count, time_wasted_ssr);
+#endif
+
+#ifdef CONTEXT_THREADS
+  if (raw_parmap)
+    xbt_parmap_destroy(raw_parmap);
+  xbt_free(raw_workers_stacks);
+#endif
   return smx_ctx_base_factory_finalize(factory);
 }
 
-
+/**
+ * \brief Creates a new raw context.
+ * \param code main function of this context or NULL to create the maestro
+ * context
+ * \param argc argument number
+ * \param argv arguments to pass to the main function
+ * \param cleanup_func a function to call to free the user data when the
+ * context finished
+ * \param data user data
+ */
 static smx_context_t
 smx_ctx_raw_create_context(xbt_main_func_t code, int argc, char **argv,
     void_pfn_smxprocess_t cleanup_func,
@@ -184,13 +300,13 @@ smx_ctx_raw_create_context(xbt_main_func_t code, int argc, char **argv,
           cleanup_func,
           data);
 
-  /* If the user provided a function for the process then use it
-     otherwise is the context for maestro */
+  /* if the user provided a function for the process then use it,
+     otherwise it is the context for maestro */
      if (code) {
        context->malloced_stack = xbt_malloc0(smx_context_stack_size);
        context->stack_top =
            raw_makecontext(context->malloced_stack, smx_context_stack_size,
-               (void(*)(void*))smx_ctx_raw_wrapper,context);
+               (void_f_pvoid_t) smx_ctx_raw_wrapper, context);
 
 #ifdef HAVE_VALGRIND_VALGRIND_H
        context->valgrind_stack_id =
@@ -198,13 +314,17 @@ smx_ctx_raw_create_context(xbt_main_func_t code, int argc, char **argv,
                context->malloced_stack + smx_context_stack_size);
 #endif                          /* HAVE_VALGRIND_VALGRIND_H */
 
-     }else{
-       maestro_raw_context = context;
+     } else {
+       raw_maestro_context = context;
      }
 
      return (smx_context_t) context;
 }
 
+/**
+ * \brief Destroys a raw context.
+ * \param context a raw context
+ */
 static void smx_ctx_raw_free(smx_context_t context)
 {
 
@@ -215,109 +335,251 @@ static void smx_ctx_raw_free(smx_context_t context)
         context)->valgrind_stack_id);
 #endif                          /* HAVE_VALGRIND_VALGRIND_H */
 
-    free(((smx_ctx_raw_t)context)->malloced_stack);
+    free(((smx_ctx_raw_t) context)->malloced_stack);
   }
   smx_ctx_base_free(context);
 }
 
-static void smx_ctx_raw_suspend(smx_context_t context)
+/**
+ * \brief Wrapper for the main function of a context.
+ * \param context a raw context
+ */
+static void smx_ctx_raw_wrapper(smx_ctx_raw_t context)
 {
-  smx_current_context = (smx_context_t)maestro_raw_context;
-  raw_swapcontext(
-      &((smx_ctx_raw_t) context)->stack_top,
-      ((smx_ctx_raw_t) context)->old_stack_top);
+  (context->super.code) (context->super.argc, context->super.argv);
+
+  smx_ctx_raw_stop((smx_context_t) context);
 }
 
+/**
+ * \brief Stops a raw context.
+ *
+ * This function is called when the main function of the context if finished.
+ *
+ * \param context the current context
+ */
 static void smx_ctx_raw_stop(smx_context_t context)
 {
   smx_ctx_base_stop(context);
-  smx_ctx_raw_suspend(context);
+  simix_global->context_factory->suspend(context);
 }
 
-static void smx_ctx_raw_wrapper(smx_ctx_raw_t context)
-{ 
-  (context->super.code) (context->super.argc, context->super.argv);
-
-  smx_ctx_raw_stop((smx_context_t) context);
+/**
+ * \brief Suspends a running context and resumes another one or returns to
+ * maestro.
+ * \param context the current context
+ */
+static void smx_ctx_raw_suspend_serial(smx_context_t context)
+{
+  /* determine the next context */
+  smx_context_t next_context;
+  unsigned long int 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 = 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 = (smx_context_t) raw_maestro_context;
+  }
+  SIMIX_context_set_current(next_context);
+  raw_swapcontext(&((smx_ctx_raw_t) context)->stack_top,
+      ((smx_ctx_raw_t) next_context)->stack_top);
 }
 
-static void smx_ctx_raw_resume(smx_process_t process)
+/**
+ * \brief Resumes sequentially all processes ready to run.
+ * \param first_process the first process to resume
+ */
+static void smx_ctx_raw_resume_serial(smx_process_t first_process)
 {
-  smx_ctx_raw_t context = (smx_ctx_raw_t)process->context;
-  smx_current_context = (smx_context_t)context;
-  raw_swapcontext(
-      &((smx_ctx_raw_t) context)->old_stack_top,
+  smx_ctx_raw_t context = (smx_ctx_raw_t) first_process->context;
+  SIMIX_context_set_current((smx_context_t) context);
+  raw_swapcontext(&raw_maestro_context->stack_top,
       ((smx_ctx_raw_t) context)->stack_top);
 }
 
-
+#ifdef TIME_BENCH
 static void smx_ctx_raw_runall_serial(xbt_dynar_t processes)
 {
   smx_process_t process;
   unsigned int cursor;
 
+  double elapsed = 0;
+  double tmax = 0;
+  unsigned long num_proc = xbt_dynar_length(processes);
+  unsigned int t=0;
+  unsigned int data_size = (num_proc / NUM_THREADS) + ((num_proc % NUM_THREADS) ? 1 : 0);
+
+  ssr_count++;
+  time_thread_ssr[0] = 0;
   xbt_dynar_foreach(processes, cursor, process) {
-    DEBUG2("Schedule item %u of %lu",cursor,xbt_dynar_length(processes));
+    XBT_DEBUG("Schedule item %u of %lu",cursor,xbt_dynar_length(processes));
+    if(cursor >= t * data_size + data_size){
+      if(time_thread_ssr[t] > tmax)
+        tmax = time_thread_ssr[t];
+      t++;
+      time_thread_ssr[t] = 0;
+    }
+
+    if(new_sr){
+      ((smx_ctx_raw_t)process->context)->thread = t;
+      time_thread_sr[t] = 0;
+    }
+
+    xbt_os_timer_start(timer);
     smx_ctx_raw_resume(process);
+    xbt_os_timer_stop(timer);
+    elapsed = xbt_os_timer_elapsed(timer);
+    time_thread_ssr[t] += elapsed;
+    time_thread_sr[((smx_ctx_raw_t)process->context)->thread] += elapsed;
+  }
+
+  if(new_sr)
+    new_sr = FALSE;
+
+  if(time_thread_ssr[t] > tmax)
+    tmax = time_thread_ssr[t];
+
+  for(cursor=0; cursor <= t; cursor++){
+    XBT_VERB("Time SSR thread %u = %lf (max %lf)", cursor, time_thread_ssr[cursor], tmax);
+    time_wasted_ssr += tmax - time_thread_ssr[cursor];
   }
-  xbt_dynar_reset(processes);
 }
 
-static void smx_ctx_raw_runall_parallel(xbt_dynar_t processes)
+void smx_ctx_raw_new_sr(void);
+void smx_ctx_raw_new_sr(void)
 {
-  xbt_parmap_apply(parmap, (void_f_pvoid_t)smx_ctx_raw_resume, processes);
-  xbt_dynar_reset(processes);
+  int i;
+  double tmax = 0;
+  new_sr = TRUE;
+  sr_count++;
+  for(i=0; i < NUM_THREADS; i++){
+    if(time_thread_sr[i] > tmax)
+      tmax = time_thread_sr[i];
+  }
+
+  for(i=0; i < NUM_THREADS; i++){
+    XBT_VERB("Time SR thread %u = %lf (max %lf)", i, time_thread_sr[i], tmax);
+    time_wasted_sr += tmax - time_thread_sr[i];
+  }
+
+  XBT_VERB("New scheduling round");
 }
+#else
 
-static smx_context_t smx_ctx_raw_self_parallel(void)
+/**
+ * \brief Resumes sequentially all processes ready to run.
+ */
+static void smx_ctx_raw_runall_serial(void)
 {
-  return smx_current_context;
+  if (!xbt_dynar_is_empty(simix_global->process_to_run)) {
+    smx_process_t first_process =
+        xbt_dynar_get_as(simix_global->process_to_run, 0, smx_process_t);
+    raw_process_index = 1;
+
+    /* execute the first process */
+    smx_ctx_raw_resume_serial(first_process);
+  }
 }
+#endif
 
-static int smx_ctx_raw_get_thread_id(){
-  return (int)(unsigned long)xbt_os_thread_get_extra_data();
+/**
+ * \brief Stops a raw context.
+ *
+ * This function is called when the main function of the context if finished.
+ *
+ * \param context the context of the current worker thread
+ */
+static void smx_ctx_raw_stop_parallel(smx_context_t context)
+{
+  smx_ctx_base_stop(context);
+  smx_ctx_raw_suspend_parallel(context);
 }
 
-static void smx_ctx_raw_runall(xbt_dynar_t processes)
+/**
+ * \brief Suspends a running context and resumes another one or returns to
+ * the main function of the current worker thread.
+ * \param context the context of the current worker thread
+ */
+static void smx_ctx_raw_suspend_parallel(smx_context_t context)
 {
-  if(xbt_dynar_length(processes) > 10){
-    DEBUG1("Runall // %lu", xbt_dynar_length(processes));
-    raw_factory->self = smx_ctx_raw_self_parallel;
-    raw_factory->get_thread_id = smx_ctx_raw_get_thread_id;
-    smx_ctx_raw_runall_parallel(processes);
-  }else{
-    DEBUG1("Runall serial %lu", xbt_dynar_length(processes));
-    raw_factory->self = smx_ctx_base_self;
-    raw_factory->get_thread_id = smx_ctx_base_get_thread_id;
-    smx_ctx_raw_runall_serial(processes);
+#ifdef CONTEXT_THREADS
+  /* determine the next context */
+  smx_process_t next_work = xbt_parmap_next(raw_parmap);
+  smx_context_t next_context;
+  raw_stack_t next_stack;
+
+  if (next_work != NULL) {
+    /* there is a next process to resume */
+    XBT_DEBUG("Run next process");
+    next_context = next_work->context;
+    next_stack = ((smx_ctx_raw_t) next_context)->stack_top;
   }
+  else {
+    /* all processes were run, go to the barrier */
+    XBT_DEBUG("No more processes to run");
+    next_context = (smx_context_t) raw_maestro_context;
+    unsigned long worker_id =
+        (unsigned long) xbt_os_thread_get_specific(raw_worker_id_key);
+    XBT_DEBUG("Restoring worker stack %lu (working threads = %lu)",
+        worker_id, raw_threads_working);
+    next_stack = raw_workers_stacks[worker_id];
+  }
+
+  SIMIX_context_set_current(next_context);
+  raw_swapcontext(&((smx_ctx_raw_t) context)->stack_top, next_stack);
+#endif
 }
 
-void SIMIX_ctx_raw_factory_init(smx_context_factory_t *factory)
+/**
+ * \brief Resumes sequentially in the current worker thread the processes ready
+ * to run.
+ * \param first_process the first process to resume
+ */
+static void smx_ctx_raw_resume_parallel(smx_process_t first_process)
 {
-  VERB0("Using raw contexts. Because the glibc is just not good enough for us.");
-  smx_ctx_base_factory_init(factory);
-
-  (*factory)->finalize  = smx_ctx_raw_factory_finalize;
-  (*factory)->create_context = smx_ctx_raw_create_context;
-  /* Do not overload that method (*factory)->finalize */
-  (*factory)->free = smx_ctx_raw_free;
-  (*factory)->stop = smx_ctx_raw_stop;
-  (*factory)->suspend = smx_ctx_raw_suspend;
-  (*factory)->name = "smx_raw_context_factory";
-  (*factory)->runall = smx_ctx_raw_runall;
+#ifdef CONTEXT_THREADS
+  unsigned long worker_id = __sync_fetch_and_add(&raw_threads_working, 1);
+  xbt_os_thread_set_specific(raw_worker_id_key, (void*) worker_id);
+  XBT_DEBUG("Saving worker stack %lu", worker_id);
+  raw_stack_t* worker_stack = &raw_workers_stacks[worker_id];
+
+  smx_context_t context = first_process->context;
+  SIMIX_context_set_current(context);
+  raw_swapcontext(worker_stack, ((smx_ctx_raw_t) context)->stack_top);
+#endif
+}
 
-  if (SIMIX_context_is_parallel()) {
-#ifdef CONTEXT_THREADS  /* To use parallel ucontexts a thread pool is needed */
-    parmap = xbt_parmap_new(2);
-    (*factory)->self = smx_ctx_raw_self_parallel;
-    (*factory)->get_thread_id = smx_ctx_raw_get_thread_id;
-#else
-    THROW0(arg_error, 0, "No thread support for parallel context execution");
+/**
+ * \brief Resumes in parallel all processes ready to run.
+ */
+static void smx_ctx_raw_runall_parallel(void)
+{
+#ifdef CONTEXT_THREADS
+  raw_threads_working = 0;
+  xbt_parmap_apply(raw_parmap, (void_f_pvoid_t) smx_ctx_raw_resume_parallel,
+      simix_global->process_to_run);
 #endif
+}
+
+/**
+ * \brief Resumes all processes ready to run.
+ */
+static void smx_ctx_raw_runall(void)
+{
+  unsigned long nb_processes = xbt_dynar_length(simix_global->process_to_run);
+  if (nb_processes >= SIMIX_context_get_parallel_threshold()) {
+    XBT_DEBUG("Runall // %lu", nb_processes);
+    simix_global->context_factory->suspend = smx_ctx_raw_suspend_parallel;
+    smx_ctx_raw_runall_parallel();
   } else {
-    (*factory)->runall = smx_ctx_raw_runall;
+    XBT_DEBUG("Runall serial %lu", nb_processes);
+    simix_global->context_factory->suspend = smx_ctx_raw_suspend_serial;
+    smx_ctx_raw_runall_serial();
   }
-
-  raw_factory = *factory;
 }