Files
genode/repos/os/src/test/resource_request/main.cc
2017-01-13 13:07:11 +01:00

133 lines
3.9 KiB
C++

/*
* \brief Test for dynamic resource requests
* \author Norman Feske
* \date 2013-09-27
*
* This test exercises various situations where a component might need to
* request additional resources from its parent.
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#include <base/component.h>
#include <base/log.h>
#include <ram_session/connection.h>
static void print_quota_stats(Genode::Ram_session &ram)
{
Genode::log("quota: avail=", ram.avail(), " used=", ram.used());
}
#define ASSERT(cond) \
if (!(cond)) { \
error("assertion ", #cond, " failed"); \
throw Error(); }
void Component::construct(Genode::Env &env)
{
using namespace Genode;
class Error : Exception { };
log("--- test-resource_request started ---");
/*
* Consume initial quota to let the test trigger the corner cases of
* exceeded quota.
*/
size_t const avail_quota = env.ram().avail();
enum { KEEP_QUOTA = 64*1024 };
size_t const wasted_quota = (avail_quota >= KEEP_QUOTA)
? avail_quota - KEEP_QUOTA : 0;
if (wasted_quota)
env.ram().alloc(wasted_quota);
log("wasted available quota of ", wasted_quota, " bytes");
print_quota_stats(env.ram());
/*
* Out of memory while upgrading session quotas.
*
* This test provokes the signal session to consume more resources than
* donated via the initial session creation. Once drained, we need to
* successively upgrade the session. At one point, we will run out of our
* initial quota. Now, before we can issue another upgrade, we first need
* to request additional resources.
*
* Note that the construction of the signal receiver will consume a part
* of the quota we preserved as 'KEEP_QUOTA'.
*/
log("\n-- draining signal session --");
{
struct Dummy_signal_handler : Signal_handler<Dummy_signal_handler>
{
Dummy_signal_handler(Entrypoint &ep)
: Signal_handler<Dummy_signal_handler>(ep, *this, nullptr) { }
};
enum { NUM_SIGH = 2000U };
static Constructible<Dummy_signal_handler> dummy_handlers[NUM_SIGH];
for (unsigned i = 0; i < NUM_SIGH; i++)
dummy_handlers[i].construct(env.ep());
print_quota_stats(env.ram());
for (unsigned i = 0; i < NUM_SIGH; i++)
dummy_handlers[i].destruct();
}
print_quota_stats(env.ram());
size_t const used_quota_after_draining_session = env.ram().used();
/*
* When creating a new session, we try to donate RAM quota to the server.
* Because, we don't have any RAM quota left, we need to issue another
* resource request to the parent.
*/
log("\n-- out-of-memory during session request --");
static Ram_connection ram(env);
ram.ref_account(env.ram_session_cap());
print_quota_stats(env.ram());
size_t const used_quota_after_session_request = env.ram().used();
/*
* Quota transfers from the component's RAM session may result in resource
* requests, too.
*/
log("\n-- out-of-memory during transfer-quota --");
int ret = env.ram().transfer_quota(ram.cap(), 512*1024);
if (ret != 0) {
error("transfer quota failed (ret = ", ret, ")");
throw Error();
}
print_quota_stats(env.ram());
size_t const used_quota_after_transfer = env.ram().used();
/*
* Finally, resource requests could be caused by a regular allocation,
* which is the most likely case in normal scenarios.
*/
log("\n-- out-of-memory during RAM allocation --");
env.ram().alloc(512*1024);
print_quota_stats(env.ram());
size_t const used_quota_after_alloc = env.ram().used();
/*
* Validate asserted effect of the individual steps on the used quota.
*/
ASSERT(used_quota_after_session_request == used_quota_after_draining_session);
ASSERT(used_quota_after_transfer == used_quota_after_session_request);
ASSERT(used_quota_after_alloc > used_quota_after_transfer);
log("--- finished test-resource_request ---");
env.parent().exit(0);
}