[adb] Optimize fdevent machinery
- Use one fewer heap allocation per fdevent object
- Lazy-init the fdevent context
Bug: 151239696
Test: various adb commands on Win/Linux
Change-Id: Ic7de207b30495e618f187e097c0276ad42c34005
diff --git a/adb/fdevent/fdevent.cpp b/adb/fdevent/fdevent.cpp
index 562f587..fd55020 100644
--- a/adb/fdevent/fdevent.cpp
+++ b/adb/fdevent/fdevent.cpp
@@ -63,7 +63,10 @@
int fd_num = fd.get();
- fdevent* fde = new fdevent();
+ auto [it, inserted] = this->installed_fdevents_.emplace(fd_num, fdevent{});
+ CHECK(inserted);
+
+ fdevent* fde = &it->second;
fde->id = fdevent_id_++;
fde->state = 0;
fde->fd = std::move(fd);
@@ -76,10 +79,6 @@
LOG(ERROR) << "failed to set non-blocking mode for fd " << fde->fd.get();
}
- auto [it, inserted] = this->installed_fdevents_.emplace(fd_num, fde);
- CHECK(inserted);
- UNUSED(it);
-
this->Register(fde);
return fde;
}
@@ -92,12 +91,12 @@
this->Unregister(fde);
- auto erased = this->installed_fdevents_.erase(fde->fd.get());
+ unique_fd fd = std::move(fde->fd);
+
+ auto erased = this->installed_fdevents_.erase(fd.get());
CHECK_EQ(1UL, erased);
- unique_fd result = std::move(fde->fd);
- delete fde;
- return result;
+ return fd;
}
void fdevent_context::Add(fdevent* fde, unsigned events) {
@@ -123,9 +122,9 @@
for (const auto& [fd, fde] : this->installed_fdevents_) {
UNUSED(fd);
- auto timeout_opt = fde->timeout;
+ auto timeout_opt = fde.timeout;
if (timeout_opt) {
- auto deadline = fde->last_active + *timeout_opt;
+ auto deadline = fde.last_active + *timeout_opt;
auto time_left = duration_cast<std::chrono::milliseconds>(deadline - now);
if (time_left < 0ms) {
time_left = 0ms;
@@ -194,11 +193,13 @@
#endif
}
-static auto& g_ambient_fdevent_context =
- *new std::unique_ptr<fdevent_context>(fdevent_create_context());
+static auto& g_ambient_fdevent_context() {
+ static auto context = fdevent_create_context().release();
+ return context;
+}
static fdevent_context* fdevent_get_ambient() {
- return g_ambient_fdevent_context.get();
+ return g_ambient_fdevent_context();
}
fdevent* fdevent_create(int fd, fd_func func, void* arg) {
@@ -256,5 +257,6 @@
}
void fdevent_reset() {
- g_ambient_fdevent_context = fdevent_create_context();
+ auto old = std::exchange(g_ambient_fdevent_context(), fdevent_create_context().release());
+ delete old;
}
diff --git a/adb/fdevent/fdevent.h b/adb/fdevent/fdevent.h
index 86814d7..9fc3b2c 100644
--- a/adb/fdevent/fdevent.h
+++ b/adb/fdevent/fdevent.h
@@ -52,6 +52,20 @@
unsigned events;
};
+struct fdevent final {
+ uint64_t id;
+
+ unique_fd fd;
+ int force_eof = 0;
+
+ uint16_t state = 0;
+ std::optional<std::chrono::milliseconds> timeout;
+ std::chrono::steady_clock::time_point last_active;
+
+ std::variant<fd_func, fd_func2> func;
+ void* arg = nullptr;
+};
+
struct fdevent_context {
public:
virtual ~fdevent_context() = default;
@@ -113,7 +127,7 @@
std::atomic<bool> terminate_loop_ = false;
protected:
- std::unordered_map<int, fdevent*> installed_fdevents_;
+ std::unordered_map<int, fdevent> installed_fdevents_;
private:
uint64_t fdevent_id_ = 0;
@@ -121,20 +135,6 @@
std::deque<std::function<void()>> run_queue_ GUARDED_BY(run_queue_mutex_);
};
-struct fdevent {
- uint64_t id;
-
- unique_fd fd;
- int force_eof = 0;
-
- uint16_t state = 0;
- std::optional<std::chrono::milliseconds> timeout;
- std::chrono::steady_clock::time_point last_active;
-
- std::variant<fd_func, fd_func2> func;
- void* arg = nullptr;
-};
-
// Backwards compatibility shims that forward to the global fdevent_context.
fdevent* fdevent_create(int fd, fd_func func, void* arg);
fdevent* fdevent_create(int fd, fd_func2 func, void* arg);
diff --git a/adb/fdevent/fdevent_epoll.cpp b/adb/fdevent/fdevent_epoll.cpp
index e3d1674..4ef41d1 100644
--- a/adb/fdevent/fdevent_epoll.cpp
+++ b/adb/fdevent/fdevent_epoll.cpp
@@ -155,15 +155,15 @@
event_map[fde] = events;
}
- for (const auto& [fd, fde] : installed_fdevents_) {
+ for (auto& [fd, fde] : installed_fdevents_) {
unsigned events = 0;
- if (auto it = event_map.find(fde); it != event_map.end()) {
+ if (auto it = event_map.find(&fde); it != event_map.end()) {
events = it->second;
}
if (events == 0) {
- if (fde->timeout) {
- auto deadline = fde->last_active + *fde->timeout;
+ if (fde.timeout) {
+ auto deadline = fde.last_active + *fde.timeout;
if (deadline < post_poll) {
events |= FDE_TIMEOUT;
}
@@ -171,13 +171,13 @@
}
if (events != 0) {
- LOG(DEBUG) << dump_fde(fde) << " got events " << std::hex << std::showbase
+ LOG(DEBUG) << dump_fde(&fde) << " got events " << std::hex << std::showbase
<< events;
- fde_events.push_back({fde, events});
- fde->last_active = post_poll;
+ fde_events.push_back({&fde, events});
+ fde.last_active = post_poll;
}
}
- this->HandleEvents(std::move(fde_events));
+ this->HandleEvents(fde_events);
fde_events.clear();
}
diff --git a/adb/fdevent/fdevent_epoll.h b/adb/fdevent/fdevent_epoll.h
index 684fa32..6214d2e 100644
--- a/adb/fdevent/fdevent_epoll.h
+++ b/adb/fdevent/fdevent_epoll.h
@@ -47,12 +47,7 @@
protected:
virtual void Interrupt() final;
- public:
- // All operations to fdevent should happen only in the main thread.
- // That's why we don't need a lock for fdevent.
- std::unordered_map<int, fdevent*> epoll_node_map_;
- std::list<fdevent*> pending_list_;
-
+ private:
unique_fd epoll_fd_;
unique_fd interrupt_fd_;
fdevent* interrupt_fde_ = nullptr;
diff --git a/adb/fdevent/fdevent_poll.cpp b/adb/fdevent/fdevent_poll.cpp
index cc4a7a1..ac86c08 100644
--- a/adb/fdevent/fdevent_poll.cpp
+++ b/adb/fdevent/fdevent_poll.cpp
@@ -103,24 +103,27 @@
void fdevent_context_poll::Loop() {
main_thread_id_ = android::base::GetThreadId();
+ std::vector<adb_pollfd> pollfds;
+ std::vector<fdevent_event> poll_events;
+
while (true) {
if (terminate_loop_) {
break;
}
D("--- --- waiting for events");
- std::vector<adb_pollfd> pollfds;
+ pollfds.clear();
for (const auto& [fd, fde] : this->installed_fdevents_) {
adb_pollfd pfd;
pfd.fd = fd;
pfd.events = 0;
- if (fde->state & FDE_READ) {
+ if (fde.state & FDE_READ) {
pfd.events |= POLLIN;
}
- if (fde->state & FDE_WRITE) {
+ if (fde.state & FDE_WRITE) {
pfd.events |= POLLOUT;
}
- if (fde->state & FDE_ERROR) {
+ if (fde.state & FDE_ERROR) {
pfd.events |= POLLERR;
}
#if defined(__linux__)
@@ -147,7 +150,6 @@
}
auto post_poll = std::chrono::steady_clock::now();
- std::vector<fdevent_event> poll_events;
for (const auto& pollfd : pollfds) {
unsigned events = 0;
@@ -170,7 +172,7 @@
auto it = this->installed_fdevents_.find(pollfd.fd);
CHECK(it != this->installed_fdevents_.end());
- fdevent* fde = it->second;
+ fdevent* fde = &it->second;
if (events == 0) {
if (fde->timeout) {
@@ -187,7 +189,8 @@
fde->last_active = post_poll;
}
}
- this->HandleEvents(std::move(poll_events));
+ this->HandleEvents(poll_events);
+ poll_events.clear();
}
main_thread_id_.reset();