3 /* context_sysv - implementation of context switching with ucontextes from Sys V */
5 /* Copyright (c) 2004-2008 the SimGrid team. All right reserved */
7 /* This program is free software; you can redistribute it and/or modify it
8 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #include "smx_context_private.h"
11 #include "context_sysv_config.h" /* loads context system definitions */
13 #include <ucontext.h> /* context relative declarations */
15 /* lower this if you want to reduce the memory consumption */
16 #define STACK_SIZE 128*1024
18 #ifdef HAVE_VALGRIND_VALGRIND_H
19 # include <valgrind/valgrind.h>
20 #endif /* HAVE_VALGRIND_VALGRIND_H */
22 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
24 typedef struct s_smx_ctx_sysv {
25 s_smx_ctx_base_t super; /* Fields of super implementation */
26 ucontext_t uc; /* the thread that execute the code */
27 char stack[STACK_SIZE]; /* the thread stack size */
28 #ifdef HAVE_VALGRIND_VALGRIND_H
29 unsigned int valgrind_stack_id; /* the valgrind stack id */
31 } s_smx_ctx_sysv_t, *smx_ctx_sysv_t;
34 smx_ctx_sysv_create_context(xbt_main_func_t code, int argc, char** argv,
35 void_f_pvoid_t cleanup_func, void* cleanup_arg);
38 static void smx_ctx_sysv_wrapper(void);
40 void SIMIX_ctx_sysv_factory_init(smx_context_factory_t *factory) {
42 smx_ctx_base_factory_init(factory);
44 (*factory)->create_context = smx_ctx_sysv_create_context;
45 /* Do not overload that method (*factory)->finalize */
46 (*factory)->free = smx_ctx_sysv_free;
47 (*factory)->stop = smx_ctx_sysv_stop;
48 (*factory)->suspend = smx_ctx_sysv_suspend;
49 (*factory)->resume = smx_ctx_sysv_resume;
50 (*factory)->name = "smx_sysv_context_factory";
54 smx_ctx_sysv_create_context_sized(size_t size, xbt_main_func_t code, int argc, char** argv,
55 void_f_pvoid_t cleanup_func, void* cleanup_arg) {
57 smx_ctx_sysv_t context = (smx_ctx_sysv_t)smx_ctx_base_factory_create_context_sized
58 (size, code,argc,argv,cleanup_func,cleanup_arg);
60 /* If the user provided a function for the process then use it
61 otherwise is the context for maestro */
64 xbt_assert2(getcontext(&(context->uc)) == 0,
65 "Error in context saving: %d (%s)", errno, strerror(errno));
67 context->uc.uc_link = NULL;
69 context->uc.uc_stack.ss_sp =
70 pth_skaddr_makecontext(context->stack, STACK_SIZE);
72 context->uc.uc_stack.ss_size =
73 pth_sksize_makecontext(context->stack, STACK_SIZE);
75 #ifdef HAVE_VALGRIND_VALGRIND_H
76 context->valgrind_stack_id =
77 VALGRIND_STACK_REGISTER(context->uc.uc_stack.ss_sp,
78 ((char *) context->uc.uc_stack.ss_sp) +
79 context->uc.uc_stack.ss_size);
80 #endif /* HAVE_VALGRIND_VALGRIND_H */
82 makecontext(&((smx_ctx_sysv_t)context)->uc, smx_ctx_sysv_wrapper, 0);
85 return (smx_context_t)context;
90 smx_ctx_sysv_create_context(xbt_main_func_t code, int argc, char** argv,
91 void_f_pvoid_t cleanup_func, void* cleanup_arg) {
93 return smx_ctx_sysv_create_context_sized(sizeof(s_smx_ctx_sysv_t),
94 code,argc,argv,cleanup_func,cleanup_arg);
98 void smx_ctx_sysv_free(smx_context_t context) {
102 #ifdef HAVE_VALGRIND_VALGRIND_H
103 VALGRIND_STACK_DEREGISTER(((smx_ctx_sysv_t) context)->valgrind_stack_id);
104 #endif /* HAVE_VALGRIND_VALGRIND_H */
107 smx_ctx_base_free(context);
110 void smx_ctx_sysv_stop(smx_context_t context) {
111 smx_ctx_base_stop(context);
113 smx_ctx_sysv_suspend(context);
116 void smx_ctx_sysv_wrapper() {
117 /*FIXME: I would like to avoid accessing simix_global to get the current
118 context by passing it as an argument of the wrapper function. The problem
119 is that this function is called from smx_ctx_sysv_start, and uses
120 makecontext for calling it, and the stupid posix specification states that
121 all the arguments of the function should be int(32 bits), making it useless
122 in 64-bit architectures where pointers are 64 bit long.
124 smx_ctx_sysv_t context =
125 (smx_ctx_sysv_t)simix_global->current_process->context;
127 (context->super.code) (context->super.argc, context->super.argv);
129 smx_ctx_sysv_stop((smx_context_t)context);
132 void smx_ctx_sysv_suspend(smx_context_t context) {
133 ucontext_t maestro_ctx = ((smx_ctx_sysv_t)simix_global->maestro_process->context)->uc;
135 int rv = swapcontext(&((smx_ctx_sysv_t) context)->uc, &maestro_ctx);
137 xbt_assert0((rv == 0), "Context swapping failure");
140 void smx_ctx_sysv_resume(smx_context_t new_context) {
141 smx_ctx_sysv_t maestro = (smx_ctx_sysv_t)simix_global->maestro_process->context;
143 int rv = swapcontext(&(maestro->uc), &((smx_ctx_sysv_t)new_context)->uc);
145 xbt_assert0((rv == 0), "Context swapping failure");