adb/fdevent.cpp - platform/system/core - Gitiles

 /* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c
 **
 ** Copyright 2006, Brian Swetland <swetland@frotz.net>
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 */

 #define TRACE_TAG FDEVENT

 #include "sysdeps.h"
 #include "fdevent.h"

 #include <fcntl.h>
 #include <poll.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
 #include <unistd.h>

 #include <list>
 #include <unordered_map>
 #include <vector>

 #include <base/logging.h>
 #include <base/stringprintf.h>

 #include "adb_io.h"
 #include "adb_trace.h"
 #include "adb_utils.h"

 #if !ADB_HOST
 // This socket is used when a subproc shell service exists.
 // It wakes up the fdevent_loop() and cause the correct handling
 // of the shell's pseudo-tty master. I.e. force close it.
 int SHELL_EXIT_NOTIFY_FD = -1;
 #endif // !ADB_HOST

 #define FDE_EVENTMASK  0x00ff
 #define FDE_STATEMASK  0xff00

 #define FDE_ACTIVE     0x0100
 #define FDE_PENDING    0x0200
 #define FDE_CREATED    0x0400

 struct PollNode {
   fdevent* fde;
   ::pollfd pollfd;

   PollNode(fdevent* fde) : fde(fde) {
       memset(&pollfd, 0, sizeof(pollfd));
       pollfd.fd = fde->fd;

 #if defined(__linux__)
       // Always enable POLLRDHUP, so the host server can take action when some clients disconnect.
       // Then we can avoid leaving many sockets in CLOSE_WAIT state. See http://b/23314034.
       pollfd.events = POLLRDHUP;
 #endif
   }
 };

 // All operations to fdevent should happen only in the main thread.
 // That's why we don't need a lock for fdevent.
 static auto& g_poll_node_map = *new std::unordered_map<int, PollNode>();
 static auto& g_pending_list = *new std::list<fdevent*>();
 static bool main_thread_valid;
 static pthread_t main_thread;

 static void check_main_thread() {
     if (main_thread_valid) {
         CHECK_NE(0, pthread_equal(main_thread, pthread_self()));
     }
 }

 static void set_main_thread() {
     main_thread_valid = true;
     main_thread = pthread_self();
 }

 static std::string dump_fde(const fdevent* fde) {
     std::string state;
     if (fde->state & FDE_ACTIVE) {
         state += "A";
     }
     if (fde->state & FDE_PENDING) {
         state += "P";
     }
     if (fde->state & FDE_CREATED) {
         state += "C";
     }
     if (fde->state & FDE_READ) {
         state += "R";
     }
     if (fde->state & FDE_WRITE) {
         state += "W";
     }
     if (fde->state & FDE_ERROR) {
         state += "E";
     }
     if (fde->state & FDE_DONT_CLOSE) {
         state += "D";
     }
     return android::base::StringPrintf("(fdevent %d %s)", fde->fd, state.c_str());
 }

 fdevent *fdevent_create(int fd, fd_func func, void *arg)
 {
     check_main_thread();
     fdevent *fde = (fdevent*) malloc(sizeof(fdevent));
     if(fde == 0) return 0;
     fdevent_install(fde, fd, func, arg);
     fde->state |= FDE_CREATED;
     return fde;
 }

 void fdevent_destroy(fdevent *fde)
 {
     check_main_thread();
     if(fde == 0) return;
     if(!(fde->state & FDE_CREATED)) {
         LOG(FATAL) << "destroying fde not created by fdevent_create(): " << dump_fde(fde);
     }
     fdevent_remove(fde);
     free(fde);
 }

 void fdevent_install(fdevent* fde, int fd, fd_func func, void* arg) {
     check_main_thread();
     CHECK_GE(fd, 0);
     memset(fde, 0, sizeof(fdevent));
     fde->state = FDE_ACTIVE;
     fde->fd = fd;
     fde->func = func;
     fde->arg = arg;
     if (!set_file_block_mode(fd, false)) {
         // Here is not proper to handle the error. If it fails here, some error is
         // likely to be detected by poll(), then we can let the callback function
         // to handle it.
         LOG(ERROR) << "failed to set non-blocking mode for fd " << fd;
     }
     auto pair = g_poll_node_map.emplace(fde->fd, PollNode(fde));
     CHECK(pair.second) << "install existing fd " << fd;
     D("fdevent_install %s", dump_fde(fde).c_str());
 }

 void fdevent_remove(fdevent* fde) {
     check_main_thread();
     D("fdevent_remove %s", dump_fde(fde).c_str());
     if (fde->state & FDE_ACTIVE) {
         g_poll_node_map.erase(fde->fd);
         if (fde->state & FDE_PENDING) {
             g_pending_list.remove(fde);
         }
         if (!(fde->state & FDE_DONT_CLOSE)) {
             adb_close(fde->fd);
             fde->fd = -1;
         }
         fde->state = 0;
         fde->events = 0;
     }
 }

 static void fdevent_update(fdevent* fde, unsigned events) {
     auto it = g_poll_node_map.find(fde->fd);
     CHECK(it != g_poll_node_map.end());
     PollNode& node = it->second;
     if (events & FDE_READ) {
         node.pollfd.events |= POLLIN;
     } else {
         node.pollfd.events &= ~POLLIN;
     }

     if (events & FDE_WRITE) {
         node.pollfd.events |= POLLOUT;
     } else {
         node.pollfd.events &= ~POLLOUT;
     }
     fde->state = (fde->state & FDE_STATEMASK) | events;
 }

 void fdevent_set(fdevent* fde, unsigned events) {
     check_main_thread();
     events &= FDE_EVENTMASK;
     if ((fde->state & FDE_EVENTMASK) == events) {
         return;
     }
     CHECK(fde->state & FDE_ACTIVE);
     fdevent_update(fde, events);
     D("fdevent_set: %s, events = %u", dump_fde(fde).c_str(), events);

     if (fde->state & FDE_PENDING) {
         // If we are pending, make sure we don't signal an event that is no longer wanted.
         fde->events &= events;
         if (fde->events == 0) {
             g_pending_list.remove(fde);
             fde->state &= ~FDE_PENDING;
         }
     }
 }

 void fdevent_add(fdevent* fde, unsigned events) {
     check_main_thread();
     fdevent_set(fde, (fde->state & FDE_EVENTMASK) | events);
 }

 void fdevent_del(fdevent* fde, unsigned events) {
     check_main_thread();
     fdevent_set(fde, (fde->state & FDE_EVENTMASK) & ~events);
 }

 static std::string dump_pollfds(const std::vector<pollfd>& pollfds) {
     std::string result;
     for (const auto& pollfd : pollfds) {
         std::string op;
         if (pollfd.events & POLLIN) {
             op += "R";
         }
         if (pollfd.events & POLLOUT) {
             op += "W";
         }
         android::base::StringAppendF(&result, " %d(%s)", pollfd.fd, op.c_str());
     }
     return result;
 }

 static void fdevent_process() {
     std::vector<pollfd> pollfds;
     for (const auto& pair : g_poll_node_map) {
         pollfds.push_back(pair.second.pollfd);
     }
     CHECK_GT(pollfds.size(), 0u);
     D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str());
     int ret = TEMP_FAILURE_RETRY(poll(&pollfds[0], pollfds.size(), -1));
     if (ret == -1) {
         PLOG(ERROR) << "poll(), ret = " << ret;
         return;
     }
     for (const auto& pollfd : pollfds) {
         if (pollfd.revents != 0) {
             D("for fd %d, revents = %x", pollfd.fd, pollfd.revents);
         }
         unsigned events = 0;
         if (pollfd.revents & POLLIN) {
             events |= FDE_READ;
         }
         if (pollfd.revents & POLLOUT) {
             events |= FDE_WRITE;
         }
         if (pollfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
             // We fake a read, as the rest of the code assumes that errors will
             // be detected at that point.
             events |= FDE_READ | FDE_ERROR;
         }
 #if defined(__linux__)
         if (pollfd.revents & POLLRDHUP) {
             events |= FDE_READ | FDE_ERROR;
         }
 #endif
         if (events != 0) {
             auto it = g_poll_node_map.find(pollfd.fd);
             CHECK(it != g_poll_node_map.end());
             fdevent* fde = it->second.fde;
             CHECK_EQ(fde->fd, pollfd.fd);
             fde->events |= events;
             D("%s got events %x", dump_fde(fde).c_str(), events);
             fde->state |= FDE_PENDING;
             g_pending_list.push_back(fde);
         }
     }
 }

 static void fdevent_call_fdfunc(fdevent* fde)
 {
     unsigned events = fde->events;
     fde->events = 0;
     CHECK(fde->state & FDE_PENDING);
     fde->state &= (~FDE_PENDING);
     D("fdevent_call_fdfunc %s", dump_fde(fde).c_str());
     fde->func(fde->fd, events, fde->arg);
 }

 #if !ADB_HOST
 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);

     if (ev & FDE_READ) {
         int subproc_fd;

         if(!ReadFdExactly(fd, &subproc_fd, sizeof(subproc_fd))) {
             LOG(FATAL) << "Failed to read the subproc's fd from " << fd;
         }
         auto it = g_poll_node_map.find(subproc_fd);
         if (it == g_poll_node_map.end()) {
             D("subproc_fd %d cleared from fd_table", subproc_fd);
             return;
         }
         fdevent* subproc_fde = it->second.fde;
         if(subproc_fde->fd != subproc_fd) {
             // Already reallocated?
             D("subproc_fd(%d) != subproc_fde->fd(%d)", subproc_fd, subproc_fde->fd);
             return;
         }

         subproc_fde->force_eof = 1;

         int rcount = 0;
         ioctl(subproc_fd, FIONREAD, &rcount);
         D("subproc with fd %d has rcount=%d, err=%d", subproc_fd, rcount, errno);
         if (rcount != 0) {
             // If there is data left, it will show up in the select().
             // This works because there is no other thread reading that
             // data when in this fd_func().
             return;
         }

         D("subproc_fde %s", dump_fde(subproc_fde).c_str());
         subproc_fde->events |= FDE_READ;
         if(subproc_fde->state & FDE_PENDING) {
             return;
         }
         subproc_fde->state |= FDE_PENDING;
         fdevent_call_fdfunc(subproc_fde);
     }
 }

 void fdevent_subproc_setup()
 {
     int s[2];

     if(adb_socketpair(s)) {
         PLOG(FATAL) << "cannot create shell-exit socket-pair";
     }
     D("fdevent_subproc: socket pair (%d, %d)", s[0], s[1]);

     SHELL_EXIT_NOTIFY_FD = s[0];
     fdevent *fde = fdevent_create(s[1], fdevent_subproc_event_func, NULL);
     CHECK(fde != nullptr) << "cannot create fdevent for shell-exit handler";
     fdevent_add(fde, FDE_READ);
 }
 #endif // !ADB_HOST

 void fdevent_loop()
 {
     set_main_thread();
 #if !ADB_HOST
     fdevent_subproc_setup();
 #endif // !ADB_HOST

     while (true) {
         D("--- --- waiting for events");

         fdevent_process();

         while (!g_pending_list.empty()) {
             fdevent* fde = g_pending_list.front();
             g_pending_list.pop_front();
             fdevent_call_fdfunc(fde);
         }
     }
 }

 size_t fdevent_installed_count() {
     return g_poll_node_map.size();
 }

 void fdevent_reset() {
     g_poll_node_map.clear();
     g_pending_list.clear();
     main_thread_valid = false;
 }
	/* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c
	**
	** Copyright 2006, Brian Swetland <swetland@frotz.net>
	**
	** Licensed under the Apache License, Version 2.0 (the "License");
	** you may not use this file except in compliance with the License.
	** You may obtain a copy of the License at
	**
	** http://www.apache.org/licenses/LICENSE-2.0
	**
	** Unless required by applicable law or agreed to in writing, software
	** distributed under the License is distributed on an "AS IS" BASIS,
	** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	** See the License for the specific language governing permissions and
	** limitations under the License.
	*/

	#define TRACE_TAG FDEVENT

	#include "sysdeps.h"
	#include "fdevent.h"

	#include <fcntl.h>
	#include <poll.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/ioctl.h>
	#include <unistd.h>

	#include <list>
	#include <unordered_map>
	#include <vector>

	#include <base/logging.h>
	#include <base/stringprintf.h>

	#include "adb_io.h"
	#include "adb_trace.h"
	#include "adb_utils.h"

	#if !ADB_HOST
	// This socket is used when a subproc shell service exists.
	// It wakes up the fdevent_loop() and cause the correct handling
	// of the shell's pseudo-tty master. I.e. force close it.
	int SHELL_EXIT_NOTIFY_FD = -1;
	#endif // !ADB_HOST

	#define FDE_EVENTMASK 0x00ff
	#define FDE_STATEMASK 0xff00

	#define FDE_ACTIVE 0x0100
	#define FDE_PENDING 0x0200
	#define FDE_CREATED 0x0400

	struct PollNode {
	fdevent* fde;
	::pollfd pollfd;

	PollNode(fdevent* fde) : fde(fde) {
	memset(&pollfd, 0, sizeof(pollfd));
	pollfd.fd = fde->fd;

	#if defined(__linux__)
	// Always enable POLLRDHUP, so the host server can take action when some clients disconnect.
	// Then we can avoid leaving many sockets in CLOSE_WAIT state. See http://b/23314034.
	pollfd.events = POLLRDHUP;
	#endif
	}
	};

	// All operations to fdevent should happen only in the main thread.
	// That's why we don't need a lock for fdevent.
	static auto& g_poll_node_map = *new std::unordered_map<int, PollNode>();
	static auto& g_pending_list = new std::list<fdevent>();
	static bool main_thread_valid;
	static pthread_t main_thread;

	static void check_main_thread() {
	if (main_thread_valid) {
	CHECK_NE(0, pthread_equal(main_thread, pthread_self()));
	}
	}

	static void set_main_thread() {
	main_thread_valid = true;
	main_thread = pthread_self();
	}

	static std::string dump_fde(const fdevent* fde) {
	std::string state;
	if (fde->state & FDE_ACTIVE) {
	state += "A";
	}
	if (fde->state & FDE_PENDING) {
	state += "P";
	}
	if (fde->state & FDE_CREATED) {
	state += "C";
	}
	if (fde->state & FDE_READ) {
	state += "R";
	}
	if (fde->state & FDE_WRITE) {
	state += "W";
	}
	if (fde->state & FDE_ERROR) {
	state += "E";
	}
	if (fde->state & FDE_DONT_CLOSE) {
	state += "D";
	}
	return android::base::StringPrintf("(fdevent %d %s)", fde->fd, state.c_str());
	}

	fdevent fdevent_create(int fd, fd_func func, void arg)
	{
	check_main_thread();
	fdevent fde = (fdevent) malloc(sizeof(fdevent));
	if(fde == 0) return 0;
	fdevent_install(fde, fd, func, arg);
	fde->state \|= FDE_CREATED;
	return fde;
	}

	void fdevent_destroy(fdevent *fde)
	{
	check_main_thread();
	if(fde == 0) return;
	if(!(fde->state & FDE_CREATED)) {
	LOG(FATAL) << "destroying fde not created by fdevent_create(): " << dump_fde(fde);
	}
	fdevent_remove(fde);
	free(fde);
	}

	void fdevent_install(fdevent* fde, int fd, fd_func func, void* arg) {
	check_main_thread();
	CHECK_GE(fd, 0);
	memset(fde, 0, sizeof(fdevent));
	fde->state = FDE_ACTIVE;
	fde->fd = fd;
	fde->func = func;
	fde->arg = arg;
	if (!set_file_block_mode(fd, false)) {
	// Here is not proper to handle the error. If it fails here, some error is
	// likely to be detected by poll(), then we can let the callback function
	// to handle it.
	LOG(ERROR) << "failed to set non-blocking mode for fd " << fd;
	}
	auto pair = g_poll_node_map.emplace(fde->fd, PollNode(fde));
	CHECK(pair.second) << "install existing fd " << fd;
	D("fdevent_install %s", dump_fde(fde).c_str());
	}

	void fdevent_remove(fdevent* fde) {
	check_main_thread();
	D("fdevent_remove %s", dump_fde(fde).c_str());
	if (fde->state & FDE_ACTIVE) {
	g_poll_node_map.erase(fde->fd);
	if (fde->state & FDE_PENDING) {
	g_pending_list.remove(fde);
	}
	if (!(fde->state & FDE_DONT_CLOSE)) {
	adb_close(fde->fd);
	fde->fd = -1;
	}
	fde->state = 0;
	fde->events = 0;
	}
	}

	static void fdevent_update(fdevent* fde, unsigned events) {
	auto it = g_poll_node_map.find(fde->fd);
	CHECK(it != g_poll_node_map.end());
	PollNode& node = it->second;
	if (events & FDE_READ) {
	node.pollfd.events \|= POLLIN;
	} else {
	node.pollfd.events &= ~POLLIN;
	}

	if (events & FDE_WRITE) {
	node.pollfd.events \|= POLLOUT;
	} else {
	node.pollfd.events &= ~POLLOUT;
	}
	fde->state = (fde->state & FDE_STATEMASK) \| events;
	}

	void fdevent_set(fdevent* fde, unsigned events) {
	check_main_thread();
	events &= FDE_EVENTMASK;
	if ((fde->state & FDE_EVENTMASK) == events) {
	return;
	}
	CHECK(fde->state & FDE_ACTIVE);
	fdevent_update(fde, events);
	D("fdevent_set: %s, events = %u", dump_fde(fde).c_str(), events);

	if (fde->state & FDE_PENDING) {
	// If we are pending, make sure we don't signal an event that is no longer wanted.
	fde->events &= events;
	if (fde->events == 0) {
	g_pending_list.remove(fde);
	fde->state &= ~FDE_PENDING;
	}
	}
	}

	void fdevent_add(fdevent* fde, unsigned events) {
	check_main_thread();
	fdevent_set(fde, (fde->state & FDE_EVENTMASK) \| events);
	}

	void fdevent_del(fdevent* fde, unsigned events) {
	check_main_thread();
	fdevent_set(fde, (fde->state & FDE_EVENTMASK) & ~events);
	}

	static std::string dump_pollfds(const std::vector<pollfd>& pollfds) {
	std::string result;
	for (const auto& pollfd : pollfds) {
	std::string op;
	if (pollfd.events & POLLIN) {
	op += "R";
	}
	if (pollfd.events & POLLOUT) {
	op += "W";
	}
	android::base::StringAppendF(&result, " %d(%s)", pollfd.fd, op.c_str());
	}
	return result;
	}

	static void fdevent_process() {
	std::vector<pollfd> pollfds;
	for (const auto& pair : g_poll_node_map) {
	pollfds.push_back(pair.second.pollfd);
	}
	CHECK_GT(pollfds.size(), 0u);
	D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str());
	int ret = TEMP_FAILURE_RETRY(poll(&pollfds[0], pollfds.size(), -1));
	if (ret == -1) {
	PLOG(ERROR) << "poll(), ret = " << ret;
	return;
	}
	for (const auto& pollfd : pollfds) {
	if (pollfd.revents != 0) {
	D("for fd %d, revents = %x", pollfd.fd, pollfd.revents);
	}
	unsigned events = 0;
	if (pollfd.revents & POLLIN) {
	events \|= FDE_READ;
	}
	if (pollfd.revents & POLLOUT) {
	events \|= FDE_WRITE;
	}
	if (pollfd.revents & (POLLERR \| POLLHUP \| POLLNVAL)) {
	// We fake a read, as the rest of the code assumes that errors will
	// be detected at that point.
	events \|= FDE_READ \| FDE_ERROR;
	}
	#if defined(__linux__)
	if (pollfd.revents & POLLRDHUP) {
	events \|= FDE_READ \| FDE_ERROR;
	}
	#endif
	if (events != 0) {
	auto it = g_poll_node_map.find(pollfd.fd);
	CHECK(it != g_poll_node_map.end());
	fdevent* fde = it->second.fde;
	CHECK_EQ(fde->fd, pollfd.fd);
	fde->events \|= events;
	D("%s got events %x", dump_fde(fde).c_str(), events);
	fde->state \|= FDE_PENDING;
	g_pending_list.push_back(fde);
	}
	}
	}

	static void fdevent_call_fdfunc(fdevent* fde)
	{
	unsigned events = fde->events;
	fde->events = 0;
	CHECK(fde->state & FDE_PENDING);
	fde->state &= (~FDE_PENDING);
	D("fdevent_call_fdfunc %s", dump_fde(fde).c_str());
	fde->func(fde->fd, events, fde->arg);
	}

	#if !ADB_HOST
	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);

	if (ev & FDE_READ) {
	int subproc_fd;

	if(!ReadFdExactly(fd, &subproc_fd, sizeof(subproc_fd))) {
	LOG(FATAL) << "Failed to read the subproc's fd from " << fd;
	}
	auto it = g_poll_node_map.find(subproc_fd);
	if (it == g_poll_node_map.end()) {
	D("subproc_fd %d cleared from fd_table", subproc_fd);
	return;
	}
	fdevent* subproc_fde = it->second.fde;
	if(subproc_fde->fd != subproc_fd) {
	// Already reallocated?
	D("subproc_fd(%d) != subproc_fde->fd(%d)", subproc_fd, subproc_fde->fd);
	return;
	}

	subproc_fde->force_eof = 1;

	int rcount = 0;
	ioctl(subproc_fd, FIONREAD, &rcount);
	D("subproc with fd %d has rcount=%d, err=%d", subproc_fd, rcount, errno);
	if (rcount != 0) {
	// If there is data left, it will show up in the select().
	// This works because there is no other thread reading that
	// data when in this fd_func().
	return;
	}

	D("subproc_fde %s", dump_fde(subproc_fde).c_str());
	subproc_fde->events \|= FDE_READ;
	if(subproc_fde->state & FDE_PENDING) {
	return;
	}
	subproc_fde->state \|= FDE_PENDING;
	fdevent_call_fdfunc(subproc_fde);
	}
	}

	void fdevent_subproc_setup()
	{
	int s[2];

	if(adb_socketpair(s)) {
	PLOG(FATAL) << "cannot create shell-exit socket-pair";
	}
	D("fdevent_subproc: socket pair (%d, %d)", s[0], s[1]);

	SHELL_EXIT_NOTIFY_FD = s[0];
	fdevent *fde = fdevent_create(s[1], fdevent_subproc_event_func, NULL);
	CHECK(fde != nullptr) << "cannot create fdevent for shell-exit handler";
	fdevent_add(fde, FDE_READ);
	}
	#endif // !ADB_HOST

	void fdevent_loop()
	{
	set_main_thread();
	#if !ADB_HOST
	fdevent_subproc_setup();
	#endif // !ADB_HOST

	while (true) {
	D("--- --- waiting for events");

	fdevent_process();

	while (!g_pending_list.empty()) {
	fdevent* fde = g_pending_list.front();
	g_pending_list.pop_front();
	fdevent_call_fdfunc(fde);
	}
	}
	}

	size_t fdevent_installed_count() {
	return g_poll_node_map.size();
	}

	void fdevent_reset() {
	g_poll_node_map.clear();
	g_pending_list.clear();
	main_thread_valid = false;
	}