1 /* context_thread - implementation of context switching with native threads */
3 /* Copyright (c) 2009, 2010. The SimGrid Team.
4 * All rights reserved. */
6 /* This program is free software; you can redistribute it and/or modify it
7 * under the terms of the license (GNU LGPL) which comes with this package. */
9 #include "xbt/function_types.h"
12 #include "portable.h" /* loads context system definitions */
14 #include "xbt/xbt_os_thread.h"
15 #include "xbt_modinter.h" /* prototype of os thread module's init/exit in XBT */
16 #include "simix/smx_context_private.h"
18 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
20 typedef struct s_smx_ctx_thread {
21 s_smx_ctx_base_t super; /* Fields of super implementation */
22 xbt_os_thread_t thread; /* a plain dumb thread (portable to posix or windows) */
23 xbt_os_sem_t begin; /* this semaphore is used to schedule/yield the process */
24 xbt_os_sem_t end; /* this semaphore is used to schedule/unschedule the process */
25 } s_smx_ctx_thread_t, *smx_ctx_thread_t;
28 smx_ctx_thread_factory_create_context(xbt_main_func_t code, int argc,
30 void_f_pvoid_t cleanup_func,
33 static void smx_ctx_thread_free(smx_context_t context);
34 static void smx_ctx_thread_stop(smx_context_t context);
35 static void smx_ctx_thread_suspend(smx_context_t context);
36 static void smx_ctx_thread_resume(smx_context_t new_context);
38 static void *smx_ctx_thread_wrapper(void *param);
40 void SIMIX_ctx_thread_factory_init(smx_context_factory_t * factory)
43 smx_ctx_base_factory_init(factory);
45 (*factory)->create_context = smx_ctx_thread_factory_create_context;
46 /* Do not overload that method (*factory)->finalize */
47 (*factory)->free = smx_ctx_thread_free;
48 (*factory)->stop = smx_ctx_thread_stop;
49 (*factory)->suspend = smx_ctx_thread_suspend;
50 (*factory)->resume = smx_ctx_thread_resume;
51 (*factory)->name = "ctx_thread_factory";
55 smx_ctx_thread_factory_create_context(xbt_main_func_t code, int argc,
57 void_f_pvoid_t cleanup_func,
60 smx_ctx_thread_t context = (smx_ctx_thread_t)
61 smx_ctx_base_factory_create_context_sized(sizeof(s_smx_ctx_thread_t),
63 cleanup_func, cleanup_arg);
65 /* If the user provided a function for the process then use it
66 otherwise is the context for maestro */
68 context->begin = xbt_os_sem_init(0);
69 context->end = xbt_os_sem_init(0);
72 /* create and start the process */
73 /* NOTE: The first argument to xbt_os_thread_create used to be the process *
74 * name, but now the name is stored at SIMIX level, so we pass a null */
76 xbt_os_thread_create(NULL, smx_ctx_thread_wrapper, context);
78 /* wait the starting of the newly created process */
79 xbt_os_sem_acquire(context->end);
82 return (smx_context_t) context;
85 static void smx_ctx_thread_free(smx_context_t pcontext)
87 smx_ctx_thread_t context = (smx_ctx_thread_t) pcontext;
89 /* check if this is the context of maestro (it doesn't has a real thread) */
90 if (context->thread) {
91 /* wait about the thread terminason */
92 xbt_os_thread_join(context->thread, NULL);
94 /* destroy the synchronisation objects */
95 xbt_os_sem_destroy(context->begin);
96 xbt_os_sem_destroy(context->end);
99 smx_ctx_base_free(pcontext);
102 static void smx_ctx_thread_stop(smx_context_t pcontext)
105 smx_ctx_thread_t context = (smx_ctx_thread_t) pcontext;
107 /* please no debug here: our procdata was already free'd */
108 smx_ctx_base_stop(pcontext);
110 /* signal to the maestro that it has finished */
111 xbt_os_sem_release(((smx_ctx_thread_t) context)->end);
114 /* We should provide return value in case other wants it */
115 xbt_os_thread_exit(NULL);
118 static void *smx_ctx_thread_wrapper(void *param)
120 smx_ctx_thread_t context = (smx_ctx_thread_t) param;
122 /* Tell the maestro we are starting, and wait for its green light */
123 xbt_os_sem_release(context->end);
124 xbt_os_sem_acquire(context->begin);
126 (context->super.code) (context->super.argc, context->super.argv);
128 smx_ctx_thread_stop((smx_context_t) context);
132 static void smx_ctx_thread_suspend(smx_context_t context)
134 xbt_os_sem_release(((smx_ctx_thread_t) context)->end);
135 xbt_os_sem_acquire(((smx_ctx_thread_t) context)->begin);
138 static void smx_ctx_thread_resume(smx_context_t new_context)
140 xbt_os_sem_release(((smx_ctx_thread_t) new_context)->begin);
141 xbt_os_sem_acquire(((smx_ctx_thread_t) new_context)->end);