X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/15311a88748c43e1cce725bbfca20ea95e9debea..67d66b0cf79b9fc02c0450f254584693dbf21d3b:/src/bindings/java/JavaContext.cpp diff --git a/src/bindings/java/JavaContext.cpp b/src/bindings/java/JavaContext.cpp index 7796bda171..48e1da96e2 100644 --- a/src/bindings/java/JavaContext.cpp +++ b/src/bindings/java/JavaContext.cpp @@ -1,6 +1,6 @@ /* Context switching within the JVM. */ -/* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2009-2021. 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. */ @@ -8,7 +8,6 @@ #include "JavaContext.hpp" #include "jxbt_utilities.hpp" #include "simgrid/Exception.hpp" -#include "src/simix/smx_private.hpp" #include #include @@ -27,138 +26,55 @@ ContextFactory* java_factory() return new JavaContextFactory(); } -JavaContextFactory::JavaContextFactory(): ContextFactory("JavaContextFactory") +JavaContextFactory::JavaContextFactory() : ContextFactory() { + xbt_assert(xbt::binary_name == "java"); } JavaContextFactory::~JavaContextFactory()=default; -JavaContext* JavaContextFactory::self() +Context* JavaContextFactory::create_context(std::function&& code, actor::ActorImpl* actor) { - return static_cast(xbt_os_thread_get_extra_data()); -} - -JavaContext* JavaContextFactory::create_context(std::function code, void_pfn_smxprocess_t cleanup_fun, - smx_actor_t actor) -{ - return this->new_context(std::move(code), cleanup_fun, actor); + return this->new_context(std::move(code), actor); } void JavaContextFactory::run_all() { - for (smx_actor_t const& process : simgrid::simix::process_get_runnable()) { - static_cast(process->context_)->resume(); - } + SerialThreadContext::run_all(); } -JavaContext::JavaContext(std::function code, - void_pfn_smxprocess_t cleanup_func, - smx_actor_t process) - : Context(std::move(code), cleanup_func, process) +JavaContext::JavaContext(std::function&& code, smx_actor_t actor) + : SerialThreadContext(std::move(code), actor, false /* not maestro */) { - /* If the user provided a function for the process then use it. Otherwise is the context for maestro */ - if (has_code()) { - this->begin_ = xbt_os_sem_init(0); - this->end_ = xbt_os_sem_init(0); - - this->thread_ = xbt_os_thread_create(nullptr, JavaContext::wrapper, this, nullptr); - } else { - xbt_os_thread_set_extra_data(this); - } + /* ThreadContext already does all we need */ } -JavaContext::~JavaContext() +void JavaContext::start_hook() { - if (this->thread_) { - // We are not in maestro context - xbt_os_thread_join(this->thread_, nullptr); - xbt_os_sem_destroy(this->begin_); - xbt_os_sem_destroy(this->end_); - } -} + Context::set_current(this); // We need to attach it also for maestro, in contrary to our ancestor -void* JavaContext::wrapper(void *data) -{ - JavaContext* context = static_cast(data); - xbt_os_thread_set_extra_data(context); //Attach the thread to the JVM - JNIEnv *env; - XBT_ATTRIB_UNUSED jint error = __java_vm->AttachCurrentThread((void**)&env, nullptr); - xbt_assert((error == JNI_OK), "The thread could not be attached to the JVM"); - context->jenv_ = env; - //Wait for the first scheduling round to happen. - xbt_os_sem_acquire(context->begin_); - //Create the "Process" object if needed. - (*context)(); - context->stop(); - return nullptr; + xbt_assert(__java_vm->AttachCurrentThread((void**)&env, nullptr) == JNI_OK, + "The thread could not be attached to the JVM"); + this->jenv_ = env; } -void JavaContext::stop() +void JavaContext::stop_hook() { - /* I was asked to die (either with kill() or because of a failed element) */ - if (this->iwannadie) { - this->iwannadie = 0; - JNIEnv *env = get_current_thread_env(); - XBT_DEBUG("Gonna launch Killed Error"); - // When the process wants to stop before its regular end, we should cut its call stack quickly. - // The easiest way to do so is to raise an exception that will be catched in its top calling level. - // - // For that, we raise a ProcessKilledError that is catched in Process::run() (in msg/Process.java) - // - // Throwing a Java exception to stop the actor may be an issue for pure C actors - // (as the ones created for the VM migration). The Java exception will not be catched anywhere. - // Bad things happen currently if these actors get killed, unfortunately. - jxbt_throw_by_name(env, "org/simgrid/msg/ProcessKilledError", - std::string("Process ") + this->process()->get_cname() + " killed from file JavaContext.cpp"); - - // (remember that throwing a java exception from C does not break the C execution path. - // Instead, it marks the exception to be raised when returning to the Java world and - // continues to execute the C function until it ends or returns). - - // Once the Java stack is marked to be unrolled, a C cancel_error is raised to kill the simcall - // on which the killed actor is blocked (if any). - // Not doing so would prevent the actor to notice that it's dead, leading to segfaults when it wakes up. - // This is dangerous: if the killed actor is not actually blocked, the cancel_error will not get catched. - // But it should be OK in most cases: - // - If I kill myself, I must do so with Process.kill(). - // The binding of this function in jmsg_process.cpp adds a try/catch around the MSG_process_kill() leading to us - // - If I kill someone else that is blocked, the cancel_error will unblock it. - // - // A problem remains probably if I kill a process that is ready_to_run in the same scheduling round. - // I guess that this will kill the whole simulation because the victim does not catch the exception. - // The only solution I see to that problem would be to completely rewrite the process killing sequence - // (also in C) so that it's based on regular C++ exceptions that would be catched anyway. - // In other words, we need to do in C++ what we do in Java for sake of uniformity. - // - // Plus, C++ RAII would work in that case, too. - - XBT_DEBUG("Trigger a cancel error at the C level"); - THROWF(cancel_error, 0, "process cancelled"); - } else { - Context::stop(); - /* detach the thread and kills it */ JNIEnv* env = this->jenv_; env->DeleteGlobalRef(this->jprocess_); - XBT_ATTRIB_UNUSED jint error = __java_vm->DetachCurrentThread(); - xbt_assert((error == JNI_OK), "The thread couldn't be detached."); - xbt_os_sem_release(this->end_); - xbt_os_thread_exit(nullptr); - } -} - -void JavaContext::suspend() -{ - xbt_os_sem_release(this->end_); - xbt_os_sem_acquire(this->begin_); -} - -// FIXME: inline those functions -void JavaContext::resume() -{ - xbt_os_sem_release(this->begin_); - xbt_os_sem_acquire(this->end_); + jint error = __java_vm->DetachCurrentThread(); + if (error != JNI_OK) { + /* This is probably a Java thread, ie an actor not created from the XML (and thus from the C++), + * but from Java with something like new Process().start(). + * + * We should not even try to detach such threads. Instead, we throw a Java exception that will raise up + * until run_jprocess(), IIUC. + */ + jxbt_throw_by_name(env, "org/simgrid/msg/ProcessKilledError", "Process killed"); + XBT_DEBUG("Cannot detach the current thread"); + } } }}} // namespace simgrid::kernel::context