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 "xbt/ex_interface.h"
12 #include "context_sysv_config.h" /* loads context system definitions */
14 #include <ucontext.h> /* context relative declarations */
16 /* lower this if you want to reduce the memory consumption */
17 #define STACK_SIZE 128*1024
19 #ifdef HAVE_VALGRIND_VALGRIND_H
20 # include <valgrind/valgrind.h>
21 #endif /* HAVE_VALGRIND_VALGRIND_H */
23 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
25 typedef struct s_smx_ctx_sysv {
27 ucontext_t uc; /* the thread that execute the code */
28 char stack[STACK_SIZE]; /* the thread stack size */
29 struct s_smx_ctx_sysv *prev; /* the previous process */
30 #ifdef HAVE_VALGRIND_VALGRIND_H
31 unsigned int valgrind_stack_id; /* the valgrind stack id */
33 } s_smx_ctx_sysv_t, *smx_ctx_sysv_t;
36 /* callback: context fetching */
37 static ex_ctx_t *xbt_jcontext_ex_ctx(void);
39 /* callback: termination */
40 static void xbt_jcontext_ex_terminate(xbt_ex_t *e);
43 smx_ctx_sysv_factory_create_context(xbt_main_func_t code, int argc, char** argv,
44 void_f_pvoid_t cleanup_func, void* cleanup_arg);
46 static int smx_ctx_sysv_factory_finalize(smx_context_factory_t *factory);
48 static void smx_ctx_sysv_free(smx_context_t context);
50 static void smx_ctx_sysv_start(smx_context_t context);
52 static void smx_ctx_sysv_stop(smx_context_t context);
54 static void smx_ctx_sysv_suspend(smx_context_t context);
57 smx_ctx_sysv_resume(smx_context_t old_context, smx_context_t new_context);
59 static void smx_ctx_sysv_wrapper(void);
61 /* callback: context fetching */
62 static ex_ctx_t *xbt_ctx_sysv_ex_ctx(void)
64 /*FIXME: the factory should access simix level datastructures! */
65 return simix_global->current_process->context->exception;
68 /* callback: termination */
69 static void xbt_ctx_sysv_ex_terminate(xbt_ex_t * e)
75 void SIMIX_ctx_sysv_factory_init(smx_context_factory_t *factory)
77 *factory = xbt_new0(s_smx_context_factory_t, 1);
79 (*factory)->create_context = smx_ctx_sysv_factory_create_context;
80 (*factory)->finalize = smx_ctx_sysv_factory_finalize;
81 (*factory)->free = smx_ctx_sysv_free;
82 (*factory)->start = smx_ctx_sysv_start;
83 (*factory)->stop = smx_ctx_sysv_stop;
84 (*factory)->suspend = smx_ctx_sysv_suspend;
85 (*factory)->resume = smx_ctx_sysv_resume;
86 (*factory)->name = "smx_sysv_context_factory";
88 /* context exception handlers */
89 __xbt_ex_ctx = xbt_ctx_sysv_ex_ctx;
90 __xbt_ex_terminate = xbt_ctx_sysv_ex_terminate;
93 static int smx_ctx_sysv_factory_finalize(smx_context_factory_t * factory)
95 /*FIXME free(maestro_context->exception);*/
102 smx_ctx_sysv_factory_create_context(xbt_main_func_t code, int argc, char** argv,
103 void_f_pvoid_t cleanup_func, void* cleanup_arg)
105 smx_ctx_sysv_t context = xbt_new0(s_smx_ctx_sysv_t, 1);
107 context->exception = xbt_new(ex_ctx_t, 1);
108 XBT_CTX_INITIALIZE(context->exception);
110 /* If the user provided a function for the process then use it
111 otherwise is the context for maestro */
113 context->code = code;
115 xbt_assert2(getcontext(&(context->uc)) == 0,
116 "Error in context saving: %d (%s)", errno, strerror(errno));
118 context->uc.uc_link = NULL;
120 context->uc.uc_stack.ss_sp =
121 pth_skaddr_makecontext(context->stack, STACK_SIZE);
123 context->uc.uc_stack.ss_size =
124 pth_sksize_makecontext(context->stack, STACK_SIZE);
126 #ifdef HAVE_VALGRIND_VALGRIND_H
127 context->valgrind_stack_id =
128 VALGRIND_STACK_REGISTER(context->uc.uc_stack.ss_sp,
129 ((char *) context->uc.uc_stack.ss_sp) +
130 context->uc.uc_stack.ss_size);
131 #endif /* HAVE_VALGRIND_VALGRIND_H */
133 context->argc = argc;
134 context->argv = argv;
135 context->cleanup_func = cleanup_func;
136 context->cleanup_arg = cleanup_arg;
139 return (smx_context_t)context;
142 static void smx_ctx_sysv_free(smx_context_t pcontext)
145 smx_ctx_sysv_t context = (smx_ctx_sysv_t)pcontext;
148 if (context->exception)
149 free(context->exception);
151 #ifdef HAVE_VALGRIND_VALGRIND_H
152 VALGRIND_STACK_DEREGISTER(((smx_ctx_sysv_t) context)->valgrind_stack_id);
153 #endif /* HAVE_VALGRIND_VALGRIND_H */
157 for (i = 0; i < context->argc; i++)
158 if (context->argv[i])
159 free(context->argv[i]);
164 /* destroy the context */
169 static void smx_ctx_sysv_start(smx_context_t context)
171 makecontext(&((smx_ctx_sysv_t)context)->uc, smx_ctx_sysv_wrapper, 0);
174 static void smx_ctx_sysv_stop(smx_context_t pcontext)
176 smx_ctx_sysv_t context = (smx_ctx_sysv_t)pcontext;
178 if (context->cleanup_func)
179 (*context->cleanup_func) (context->cleanup_arg);
181 smx_ctx_sysv_suspend((smx_context_t)context);
184 static void smx_ctx_sysv_wrapper()
186 /*FIXME: I would like to avoid accesing simix_global to get the current
187 context by passing it as an argument of the wrapper function. The problem
188 is that this function is called from smx_ctx_sysv_start, and uses
189 makecontext for calling it, and the stupid posix specification states that
190 all the arguments of the function should be int(32 bits), making it useless
191 in 64-bit architectures where pointers are 64 bit long.
193 smx_ctx_sysv_t context =
194 (smx_ctx_sysv_t)simix_global->current_process->context;
196 (context->code) (context->argc, context->argv);
198 smx_ctx_sysv_stop((smx_context_t)context);
201 static void smx_ctx_sysv_suspend(smx_context_t context)
205 smx_ctx_sysv_t prev_context = ((smx_ctx_sysv_t) context)->prev;
207 ((smx_ctx_sysv_t) context)->prev = NULL;
209 rv = swapcontext(&((smx_ctx_sysv_t) context)->uc, &prev_context->uc);
211 xbt_assert0((rv == 0), "Context swapping failure");
215 smx_ctx_sysv_resume(smx_context_t old_context, smx_context_t new_context)
219 ((smx_ctx_sysv_t) new_context)->prev = (smx_ctx_sysv_t)old_context;
221 rv = swapcontext(&((smx_ctx_sysv_t)old_context)->uc,
222 &((smx_ctx_sysv_t)new_context)->uc);
224 xbt_assert0((rv == 0), "Context swapping failure");