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#include "tensorflow/core/common_runtime/gpu/gpu_allocator_retry.h"
#include "tensorflow/core/lib/core/notification.h"
#include "tensorflow/core/platform/port.h"
#include "tensorflow/core/platform/logging.h"
#include "tensorflow/core/platform/thread_annotations.h"
#include "tensorflow/core/public/env.h"
#include <gtest/gtest.h>
namespace tensorflow {
namespace {
class FakeAllocator {
public:
FakeAllocator(size_t cap, int millis_to_wait)
: memory_capacity_(cap), millis_to_wait_(millis_to_wait) {}
// Allocate just keeps track of the number of outstanding allocations,
// not their sizes. Assume a constant size for each.
void* AllocateRaw(size_t alignment, size_t num_bytes) {
return retry_.AllocateRaw(
[this](size_t a, size_t nb, bool v) {
mutex_lock l(mu_);
if (memory_capacity_ > 0) {
--memory_capacity_;
return good_ptr_;
} else {
return static_cast<void*>(nullptr);
}
},
millis_to_wait_, alignment, num_bytes);
}
void DeallocateRaw(void* ptr) {
retry_.DeallocateRaw(
[this](void* p) {
mutex_lock l(mu_);
++memory_capacity_;
},
ptr);
}
private:
GPUAllocatorRetry retry_;
void* good_ptr_ = reinterpret_cast<void*>(0xdeadbeef);
mutex mu_;
size_t memory_capacity_ GUARDED_BY(mu_);
int millis_to_wait_;
};
class GPUAllocatorRetryTest : public ::testing::Test {
protected:
GPUAllocatorRetryTest() {}
void LaunchConsumerThreads(int num_consumers, int cap_needed) {
consumer_count_.resize(num_consumers, 0);
for (int i = 0; i < num_consumers; ++i) {
consumers_.push_back(Env::Default()->StartThread(
ThreadOptions(), "anon_thread", [this, i, cap_needed]() {
do {
void* ptr = nullptr;
for (int j = 0; j < cap_needed; ++j) {
ptr = alloc_->AllocateRaw(16, 1);
if (ptr == nullptr) {
mutex_lock l(mu_);
has_failed_ = true;
return;
}
}
++consumer_count_[i];
for (int j = 0; j < cap_needed; ++j) {
alloc_->DeallocateRaw(ptr);
}
} while (!notifier_.HasBeenNotified());
}));
}
}
// Wait up to wait_micros microseconds for has_failed_ to equal expected,
// then terminate all threads.
void JoinConsumerThreads(bool expected, int wait_micros) {
while (wait_micros > 0) {
{
mutex_lock l(mu_);
if (has_failed_ == expected) break;
}
int interval_micros = std::min(1000, wait_micros);
Env::Default()->SleepForMicroseconds(interval_micros);
wait_micros -= interval_micros;
}
notifier_.Notify();
for (auto c : consumers_) {
// Blocks until thread terminates.
delete c;
}
}
std::unique_ptr<FakeAllocator> alloc_;
std::vector<Thread*> consumers_;
std::vector<int> consumer_count_;
Notification notifier_;
mutex mu_;
bool has_failed_ GUARDED_BY(mu_) = false;
int count_ GUARDED_BY(mu_) = 0;
};
// Verifies correct retrying when memory is slightly overcommitted but
// we allow retry.
TEST_F(GPUAllocatorRetryTest, RetrySuccess) {
// Support up to 2 allocations simultaneously, waits up to 10 msec for
// a chance to alloc.
alloc_.reset(new FakeAllocator(2, 10000));
// Launch 3 consumers, each of whom needs 1 unit at a time.
LaunchConsumerThreads(3, 1);
// This should be enough time for each consumer to be satisfied many times.
Env::Default()->SleepForMicroseconds(50000);
JoinConsumerThreads(false, 0);
for (int i = 0; i < 3; ++i) {
LOG(INFO) << "Consumer " << i << " is " << consumer_count_[i];
}
{
mutex_lock l(mu_);
EXPECT_FALSE(has_failed_);
}
EXPECT_GT(consumer_count_[0], 0);
EXPECT_GT(consumer_count_[1], 0);
EXPECT_GT(consumer_count_[2], 0);
}
// Verifies OutOfMemory failure when memory is slightly overcommitted
// and retry is not allowed.
TEST_F(GPUAllocatorRetryTest, NoRetryFail) {
// Support up to 2 allocations simultaneously, waits up to 0 msec for
// a chance to alloc.
alloc_.reset(new FakeAllocator(2, 0));
// Launch 3 consumers, each of whom needs 1 unit at a time.
LaunchConsumerThreads(3, 1);
Env::Default()->SleepForMicroseconds(50000);
// Will wait up to 10 seconds for proper race condition to occur, resulting
// in failure.
JoinConsumerThreads(true, 10000000);
for (int i = 0; i < 3; ++i) {
LOG(INFO) << "Consumer " << i << " is " << consumer_count_[i];
}
{
mutex_lock l(mu_);
EXPECT_TRUE(has_failed_);
}
}
// Verifies OutOfMemory failure when retry is allowed but memory capacity
// is too low even for retry.
TEST_F(GPUAllocatorRetryTest, RetryInsufficientFail) {
// Support up to 2 allocations simultaneously, waits up to 10 msec for
// a chance to alloc.
alloc_.reset(new FakeAllocator(2, 10000));
// Launch 3 consumers, each of whom needs 2 units at a time. We expect
// deadlock where 2 consumers each hold 1 unit, and timeout trying to
// get the second.
LaunchConsumerThreads(3, 2);
Env::Default()->SleepForMicroseconds(50000);
// Will wait up to 10 seconds for proper race condition to occur, resulting
// in failure.
JoinConsumerThreads(true, 10000000);
for (int i = 0; i < 3; ++i) {
LOG(INFO) << "Consumer " << i << " is " << consumer_count_[i];
}
{
mutex_lock l(mu_);
EXPECT_TRUE(has_failed_);
}
}
} // namespace
} // namespace tensorflow
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