adb: add fdevent_run_on_main_thread.
Add a function to run a function on the main thread, to allow fdevents
that depend on a blocking function to be registered.
Bug: http://b/37869663
Test: adb_test on linux
Change-Id: I84a0b372360420b7647057297b8f437e8afa874e
diff --git a/adb/fdevent.cpp b/adb/fdevent.cpp
index 72c9eef..b28de4b 100644
--- a/adb/fdevent.cpp
+++ b/adb/fdevent.cpp
@@ -26,15 +26,19 @@
#include <unistd.h>
#include <atomic>
+#include <functional>
#include <list>
+#include <mutex>
#include <unordered_map>
#include <vector>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
+#include <android-base/thread_annotations.h>
#include "adb_io.h"
#include "adb_trace.h"
+#include "adb_unique_fd.h"
#include "adb_utils.h"
#if !ADB_HOST
@@ -75,6 +79,10 @@
static bool main_thread_valid;
static unsigned long main_thread_id;
+static auto& run_queue_notify_fd = *new unique_fd();
+static auto& run_queue_mutex = *new std::mutex();
+static auto& run_queue GUARDED_BY(run_queue_mutex) = *new std::vector<std::function<void()>>();
+
void check_main_thread() {
if (main_thread_valid) {
CHECK_EQ(main_thread_id, adb_thread_id());
@@ -112,8 +120,7 @@
return android::base::StringPrintf("(fdevent %d %s)", fde->fd, state.c_str());
}
-fdevent *fdevent_create(int fd, fd_func func, void *arg)
-{
+fdevent* fdevent_create(int fd, fd_func func, void* arg) {
check_main_thread();
fdevent *fde = (fdevent*) malloc(sizeof(fdevent));
if(fde == 0) return 0;
@@ -122,8 +129,7 @@
return fde;
}
-void fdevent_destroy(fdevent *fde)
-{
+void fdevent_destroy(fdevent* fde) {
check_main_thread();
if(fde == 0) return;
if(!(fde->state & FDE_CREATED)) {
@@ -278,8 +284,7 @@
}
}
-static void fdevent_call_fdfunc(fdevent* fde)
-{
+static void fdevent_call_fdfunc(fdevent* fde) {
unsigned events = fde->events;
fde->events = 0;
CHECK(fde->state & FDE_PENDING);
@@ -292,10 +297,7 @@
#include <sys/ioctl.h>
-static void fdevent_subproc_event_func(int fd, unsigned ev,
- void* /* userdata */)
-{
-
+static void fdevent_subproc_event_func(int fd, unsigned ev, void* /* userdata */) {
D("subproc handling on fd = %d, ev = %x", fd, ev);
CHECK_GE(fd, 0);
@@ -342,8 +344,7 @@
}
}
-void fdevent_subproc_setup()
-{
+static void fdevent_subproc_setup() {
int s[2];
if(adb_socketpair(s)) {
@@ -358,12 +359,63 @@
}
#endif // !ADB_HOST
-void fdevent_loop()
-{
+static void fdevent_run_flush() REQUIRES(run_queue_mutex) {
+ for (auto& f : run_queue) {
+ f();
+ }
+ run_queue.clear();
+}
+
+static void fdevent_run_func(int fd, unsigned ev, void* /* userdata */) {
+ CHECK_GE(fd, 0);
+ CHECK(ev & FDE_READ);
+
+ char buf[1024];
+
+ // Empty the fd.
+ if (adb_read(fd, buf, sizeof(buf)) == -1) {
+ PLOG(FATAL) << "failed to empty run queue notify fd";
+ }
+
+ std::lock_guard<std::mutex> lock(run_queue_mutex);
+ fdevent_run_flush();
+}
+
+static void fdevent_run_setup() {
+ std::lock_guard<std::mutex> lock(run_queue_mutex);
+ CHECK(run_queue_notify_fd.get() == -1);
+ int s[2];
+ if (adb_socketpair(s) != 0) {
+ PLOG(FATAL) << "failed to create run queue notify socketpair";
+ }
+
+ run_queue_notify_fd.reset(s[0]);
+ fdevent* fde = fdevent_create(s[1], fdevent_run_func, nullptr);
+ CHECK(fde != nullptr);
+ fdevent_add(fde, FDE_READ);
+
+ fdevent_run_flush();
+}
+
+void fdevent_run_on_main_thread(std::function<void()> fn) {
+ std::lock_guard<std::mutex> lock(run_queue_mutex);
+ run_queue.push_back(std::move(fn));
+
+ // run_queue_notify_fd could still be -1 if we're called before fdevent has finished setting up.
+ // In that case, rely on the setup code to flush the queue without a notification being needed.
+ if (run_queue_notify_fd != -1) {
+ if (adb_write(run_queue_notify_fd.get(), "", 1) != 1) {
+ PLOG(FATAL) << "failed to write to run queue notify fd";
+ }
+ }
+}
+
+void fdevent_loop() {
set_main_thread();
#if !ADB_HOST
fdevent_subproc_setup();
#endif // !ADB_HOST
+ fdevent_run_setup();
while (true) {
if (terminate_loop) {
@@ -393,6 +445,11 @@
void fdevent_reset() {
g_poll_node_map.clear();
g_pending_list.clear();
+
+ std::lock_guard<std::mutex> lock(run_queue_mutex);
+ run_queue_notify_fd.reset();
+ run_queue.clear();
+
main_thread_valid = false;
terminate_loop = false;
}
diff --git a/adb/fdevent.h b/adb/fdevent.h
index e32845a..896400a 100644
--- a/adb/fdevent.h
+++ b/adb/fdevent.h
@@ -20,6 +20,8 @@
#include <stddef.h>
#include <stdint.h> /* for int64_t */
+#include <functional>
+
/* events that may be observed */
#define FDE_READ 0x0001
#define FDE_WRITE 0x0002
@@ -78,6 +80,9 @@
void check_main_thread();
+// Queue an operation to run on the main thread.
+void fdevent_run_on_main_thread(std::function<void()> fn);
+
// The following functions are used only for tests.
void fdevent_terminate_loop();
size_t fdevent_installed_count();
diff --git a/adb/fdevent_test.cpp b/adb/fdevent_test.cpp
index bdb973a..86e0209 100644
--- a/adb/fdevent_test.cpp
+++ b/adb/fdevent_test.cpp
@@ -173,3 +173,24 @@
std::thread thread(InvalidFdThreadFunc);
thread.join();
}
+
+TEST_F(FdeventTest, run_on_main_thread) {
+ std::vector<int> vec;
+
+ PrepareThread();
+ std::thread thread(fdevent_loop);
+
+ for (int i = 0; i < 100; ++i) {
+ fdevent_run_on_main_thread([i, &vec]() {
+ check_main_thread();
+ vec.push_back(i);
+ });
+ }
+
+ TerminateThread(thread);
+
+ ASSERT_EQ(100u, vec.size());
+ for (int i = 0; i < 100; ++i) {
+ ASSERT_EQ(i, vec[i]);
+ }
+}
diff --git a/adb/fdevent_test.h b/adb/fdevent_test.h
index f4215ae..5ca49ac 100644
--- a/adb/fdevent_test.h
+++ b/adb/fdevent_test.h
@@ -53,11 +53,11 @@
size_t GetAdditionalLocalSocketCount() {
#if ADB_HOST
- // dummy socket installed in PrepareThread()
- return 1;
-#else
- // dummy socket and one more socket installed in fdevent_subproc_setup()
+ // dummy socket installed in PrepareThread() + fdevent_run_on_main_thread socket
return 2;
+#else
+ // dummy socket + fdevent_run_on_main_thread + fdevent_subproc_setup() sockets
+ return 3;
#endif
}