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{ "id": 1662, "url": "https://patchwork.libcamera.org/api/patches/1662/?format=api", "web_url": "https://patchwork.libcamera.org/patch/1662/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20190711185047.11671-4-paul.elder@ideasonboard.com>", "date": "2019-07-11T18:50:42", "name": "[libcamera-devel,v4,3/8] libcamera: Add Process and ProcessManager classes", "commit_ref": null, "pull_url": null, "state": "accepted", "archived": false, "hash": "d5d85d30b1f91dde7d74749c4511a4858a801bea", "submitter": { "id": 17, "url": "https://patchwork.libcamera.org/api/people/17/?format=api", "name": "Paul Elder", "email": "paul.elder@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/1662/mbox/", "series": [ { "id": 420, "url": "https://patchwork.libcamera.org/api/series/420/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=420", "date": "2019-07-11T18:50:39", "name": "Add IPA process isolation", "version": 4, "mbox": "https://patchwork.libcamera.org/series/420/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/1662/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/1662/checks/", "tags": {}, "headers": { "Return-Path": "<paul.elder@ideasonboard.com>", "Received": [ "from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0A9D260BC8\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 11 Jul 2019 20:51:10 +0200 (CEST)", "from neptunite.amanokami.net (softbank126163157105.bbtec.net\n\t[126.163.157.105])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 4435631C;\n\tThu, 11 Jul 2019 20:51:08 +0200 (CEST)" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1562871069;\n\tbh=gTxU/yV34VSN9mpAeOUb4stPKpO1eKoW6NHHw/ASNM0=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=cshHpWfupvo5jWQwFCXarmzCrvtAUokc5pY9Li50Ksi9BqpCzr1vcXbyF1W63xuGG\n\tx6HCZwa/+2OSgx5G610DpHNZ5eeQc5pQNVmFqyMCIf5chU+L/7FATdLGFfe9fr9Uh0\n\tesECQwp+Q9dudKZqr0Rn1RmhZgQG3F7nKL8TCxqU=", "From": "Paul Elder <paul.elder@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Fri, 12 Jul 2019 03:50:42 +0900", "Message-Id": "<20190711185047.11671-4-paul.elder@ideasonboard.com>", "X-Mailer": "git-send-email 2.20.1", "In-Reply-To": "<20190711185047.11671-1-paul.elder@ideasonboard.com>", "References": "<20190711185047.11671-1-paul.elder@ideasonboard.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Subject": "[libcamera-devel] [PATCH v4 3/8] libcamera: Add Process and\n\tProcessManager classes", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.23", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "X-List-Received-Date": "Thu, 11 Jul 2019 18:51:10 -0000" }, "content": "Add a Process class to abstract a process, and a ProcessManager singleton\nto monitor and manage the processes.\n\nSigned-off-by: Paul Elder <paul.elder@ideasonboard.com>\n---\nChanges in v4:\n- rename enum ExitStatus members\n- use a running_ flag (instead of state_)\n- fix sigaction registration (on Process construction)\n- restore old signal handler (on Process destruction)\n- replace closefrom_except() with closeAllFdsExcept()\n- unsetenv LIBCAMERA_LOG_FILE on fork (before exec)\n\nChanges in v3:\n- add Process test\n- move ProcessManager header to process.cpp\n- make Process final\n- add a bunch of things for monitoring and signals on process\n termination\n\nNew in v2\n\n src/libcamera/include/process.h | 55 +++++\n src/libcamera/meson.build | 3 +\n src/libcamera/process.cpp | 357 ++++++++++++++++++++++++++++++\n src/libcamera/process_manager.cpp | 0\n test/meson.build | 1 +\n test/process/meson.build | 12 +\n test/process/process_test.cpp | 100 +++++++++\n 7 files changed, 528 insertions(+)\n create mode 100644 src/libcamera/include/process.h\n create mode 100644 src/libcamera/process.cpp\n create mode 100644 src/libcamera/process_manager.cpp\n create mode 100644 test/process/meson.build\n create mode 100644 test/process/process_test.cpp", "diff": "diff --git a/src/libcamera/include/process.h b/src/libcamera/include/process.h\nnew file mode 100644\nindex 0000000..d322fce\n--- /dev/null\n+++ b/src/libcamera/include/process.h\n@@ -0,0 +1,55 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * process.h - Process object\n+ */\n+#ifndef __LIBCAMERA_PROCESS_H__\n+#define __LIBCAMERA_PROCESS_H__\n+\n+#include <string>\n+#include <vector>\n+\n+#include <libcamera/event_notifier.h>\n+\n+namespace libcamera {\n+\n+class Process final\n+{\n+public:\n+\tenum ExitStatus {\n+\t\tNotExited,\n+\t\tNormalExit,\n+\t\tSignalExit,\n+\t};\n+\n+\tProcess();\n+\t~Process();\n+\n+\tint start(const std::string &path,\n+\t\t const std::vector<std::string> &args = std::vector<std::string>(),\n+\t\t const std::vector<int> &fds = std::vector<int>());\n+\n+\tExitStatus exitStatus() const { return exitStatus_; }\n+\tint exitCode() const { return exitCode_; }\n+\n+\tvoid kill();\n+\n+\tSignal<Process *, enum ExitStatus, int> finished;\n+\n+private:\n+\tvoid closeAllFdsExcept(const std::vector<int> &fds);\n+\tint isolate();\n+\tvoid died(int wstatus);\n+\n+\tpid_t pid_;\n+\tbool running_;\n+\tenum ExitStatus exitStatus_;\n+\tint exitCode_;\n+\n+\tfriend class ProcessManager;\n+};\n+\n+} /* namespace libcamera */\n+\n+#endif /* __LIBCAMERA_PROCESS_H__ */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex eda506b..01565c1 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -21,6 +21,8 @@ libcamera_sources = files([\n 'message.cpp',\n 'object.cpp',\n 'pipeline_handler.cpp',\n+ 'process.cpp',\n+ 'process_manager.cpp',\n 'request.cpp',\n 'signal.cpp',\n 'stream.cpp',\n@@ -48,6 +50,7 @@ libcamera_headers = files([\n 'include/media_object.h',\n 'include/message.h',\n 'include/pipeline_handler.h',\n+ 'include/process.h',\n 'include/thread.h',\n 'include/utils.h',\n 'include/v4l2_device.h',\ndiff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp\nnew file mode 100644\nindex 0000000..736d59f\n--- /dev/null\n+++ b/src/libcamera/process.cpp\n@@ -0,0 +1,357 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * process.cpp - Process object\n+ */\n+\n+#include \"process.h\"\n+\n+#include <algorithm>\n+#include <dirent.h>\n+#include <fcntl.h>\n+#include <iostream>\n+#include <list>\n+#include <signal.h>\n+#include <string.h>\n+#include <sys/socket.h>\n+#include <sys/types.h>\n+#include <sys/wait.h>\n+#include <unistd.h>\n+#include <vector>\n+\n+#include <libcamera/event_notifier.h>\n+\n+#include \"log.h\"\n+#include \"utils.h\"\n+\n+/**\n+ * \\file process.h\n+ * \\brief Process object\n+ */\n+\n+namespace libcamera {\n+\n+LOG_DEFINE_CATEGORY(Process)\n+\n+/**\n+ * \\class ProcessManager\n+ * \\brief Manager of processes\n+ *\n+ * The ProcessManager singleton keeps track of all created Process instances,\n+ * and manages the signal handling involved in terminating processes.\n+ */\n+class ProcessManager\n+{\n+public:\n+\tvoid registerProcess(Process *proc);\n+\n+\tstatic ProcessManager *instance();\n+\n+\tint writePipe() const;\n+\n+\tconst struct sigaction &oldsa() const;\n+\n+private:\n+\tvoid sighandler(EventNotifier *notifier);\n+\tProcessManager();\n+\t~ProcessManager();\n+\n+\tstd::list<Process *> processes_;\n+\n+\tstruct sigaction oldsa_;\n+\tEventNotifier *sigEvent_;\n+\tint pipe_[2];\n+};\n+\n+namespace {\n+\n+void sigact(int signal, siginfo_t *info, void *ucontext)\n+{\n+\tchar data = 0;\n+\twrite(ProcessManager::instance()->writePipe(), &data, sizeof(data));\n+\n+\tconst struct sigaction &oldsa = ProcessManager::instance()->oldsa();\n+\tif (oldsa.sa_flags & SA_SIGINFO) {\n+\t\toldsa.sa_sigaction(signal, info, ucontext);\n+\t} else {\n+\t\tif (oldsa.sa_handler != SIG_IGN && oldsa.sa_handler != SIG_DFL)\n+\t\t\toldsa.sa_handler(signal);\n+\t}\n+}\n+\n+} /* namespace */\n+\n+void ProcessManager::sighandler(EventNotifier *notifier)\n+{\n+\tchar data;\n+\tread(pipe_[0], &data, sizeof(data));\n+\n+\tfor (auto it = processes_.begin(); it != processes_.end(); ) {\n+\t\tProcess *process = *it;\n+\n+\t\tint wstatus;\n+\t\tpid_t pid = waitpid(process->pid_, &wstatus, WNOHANG);\n+\t\tif (process->pid_ != pid) {\n+\t\t\t++it;\n+\t\t\tcontinue;\n+\t\t}\n+\n+\t\tit = processes_.erase(it);\n+\t\tprocess->died(wstatus);\n+\t}\n+}\n+\n+/**\n+ * \\brief Register process with process manager\n+ * \\param[in] proc Process to register\n+ *\n+ * This method registers the \\a proc with the process manager. It\n+ * shall be called by the parent process after successfully forking, in\n+ * order to let the parent signal process termination.\n+ */\n+void ProcessManager::registerProcess(Process *proc)\n+{\n+\tprocesses_.push_back(proc);\n+}\n+\n+ProcessManager::ProcessManager()\n+{\n+\tsigaction(SIGCHLD, NULL, &oldsa_);\n+\n+\tstruct sigaction sa;\n+\tmemset(&sa, 0, sizeof(sa));\n+\tsa.sa_sigaction = &sigact;\n+\tmemcpy(&sa.sa_mask, &oldsa_.sa_mask, sizeof(sa.sa_mask));\n+\tsigaddset(&sa.sa_mask, SIGCHLD);\n+\tsa.sa_flags = oldsa_.sa_flags | SA_SIGINFO;\n+\n+\tsigaction(SIGCHLD, &sa, NULL);\n+\n+\tpipe2(pipe_, O_CLOEXEC | O_DIRECT | O_NONBLOCK);\n+\tsigEvent_ = new EventNotifier(pipe_[0], EventNotifier::Read);\n+\tsigEvent_->activated.connect(this, &ProcessManager::sighandler);\n+}\n+\n+ProcessManager::~ProcessManager()\n+{\n+\tdelete sigEvent_;\n+\tclose(pipe_[0]);\n+\tclose(pipe_[1]);\n+\tsigaction(SIGCHLD, &oldsa_, NULL);\n+}\n+\n+/**\n+ * \\brief Retrieve the Process manager instance\n+ *\n+ * The ProcessManager is a singleton and can't be constructed manually. This\n+ * method shall instead be used to retrieve the single global instance of the\n+ * manager.\n+ *\n+ * \\return The Process manager instance\n+ */\n+ProcessManager *ProcessManager::instance()\n+{\n+\tstatic ProcessManager processManager;\n+\treturn &processManager;\n+}\n+\n+/**\n+ * \\brief Retrieve the Process manager's write pipe\n+ *\n+ * This method is meant only to be used by the static signal handler.\n+ *\n+ * \\return Pipe for writing\n+ */\n+int ProcessManager::writePipe() const\n+{\n+\treturn pipe_[1];\n+}\n+\n+/**\n+ * \\brief Retrive the old signal action data\n+ *\n+ * This method is meant only to be used by the static signal handler.\n+ *\n+ * \\return The old signal action data\n+ */\n+const struct sigaction &ProcessManager::oldsa() const\n+{\n+\treturn oldsa_;\n+}\n+\n+\n+/**\n+ * \\class Process\n+ * \\brief Process object\n+ *\n+ * The Process class models a process, and simplifies spawning new processes\n+ * and monitoring the exiting of a process.\n+ */\n+\n+/**\n+ * \\enum Process::ExitStatus\n+ * \\brief Exit status of process\n+ * \\var Process::NotExited\n+ * The process hasn't exited yet\n+ * \\var Process::NormalExit\n+ * The process exited normally, either via exit() or returning from main\n+ * \\var Process::SignalExit\n+ * The process was terminated by a signal (this includes crashing)\n+ */\n+\n+Process::Process()\n+\t: pid_(-1), running_(false), exitStatus_(NotExited), exitCode_(0)\n+{\n+}\n+\n+Process::~Process()\n+{\n+\tkill();\n+\t/* \\todo wait for child process to exit */\n+}\n+\n+/**\n+ * \\brief Fork and exec a process, and close fds\n+ * \\param[in] path Path to executable\n+ * \\param[in] args Arguments to pass to executable (optional)\n+ * \\param[in] fds Vector of file descriptors to keep open (optional)\n+ *\n+ * Fork a process, and exec the executable specified by path. Prior to\n+ * exec'ing, but after forking, all file descriptors except for those\n+ * specified in fds will be closed.\n+ *\n+ * All indexes of args will be incremented by 1 before being fed to exec(),\n+ * so args[0] should not need to be equal to path.\n+ *\n+ * \\return zero on successful fork, exec, and closing the file descriptors,\n+ * or a negative error code otherwise\n+ */\n+int Process::start(const std::string &path,\n+\t\t const std::vector<std::string> &args,\n+\t\t const std::vector<int> &fds)\n+{\n+\tint ret;\n+\n+\tif (running_ == true)\n+\t\treturn 0;\n+\n+\tint childPid = fork();\n+\tif (childPid == -1) {\n+\t\tret = -errno;\n+\t\tLOG(Process, Error) << \"Failed to fork: \" << strerror(-ret);\n+\t\treturn ret;\n+\t} else if (childPid) {\n+\t\tpid_ = childPid;\n+\t\tProcessManager::instance()->registerProcess(this);\n+\n+\t\trunning_ = true;\n+\n+\t\treturn 0;\n+\t} else {\n+\t\tif (isolate())\n+\t\t\t_exit(EXIT_FAILURE);\n+\n+\t\tcloseAllFdsExcept(fds);\n+\n+\t\tunsetenv(\"LIBCAMERA_LOG_FILE\");\n+\n+\t\tconst char **argv = new const char *[args.size() + 2];\n+\t\tunsigned int len = args.size();\n+\t\targv[0] = path.c_str();\n+\t\tfor (unsigned int i = 0; i < len; i++)\n+\t\t\targv[i+1] = args[i].c_str();\n+\t\targv[len+1] = nullptr;\n+\n+\t\texecv(path.c_str(), (char **)argv);\n+\n+\t\texit(EXIT_FAILURE);\n+\t}\n+}\n+\n+void Process::closeAllFdsExcept(const std::vector<int> &fds)\n+{\n+\tstd::vector<int> v(fds);\n+\tsort(v.begin(), v.end());\n+\n+\tDIR *dir = opendir(\"/proc/self/fd\");\n+\tif (!dir)\n+\t\treturn;\n+\n+\tint dfd = dirfd(dir);\n+\n+\tstruct dirent *ent;\n+\twhile ((ent = readdir(dir)) != nullptr) {\n+\t\tchar *endp;\n+\t\tint fd = strtoul(ent->d_name, &endp, 10);\n+\t\tif (*endp)\n+\t\t\tcontinue;\n+\n+\t\tif (fd >= 0 && fd != dfd &&\n+\t\t !std::binary_search(v.begin(), v.end(), fd))\n+\t\t\tclose(fd);\n+\t}\n+\n+\tclosedir(dir);\n+}\n+\n+int Process::isolate()\n+{\n+\treturn unshare(CLONE_NEWUSER | CLONE_NEWNET);\n+}\n+\n+/**\n+ * \\brief SIGCHLD handler\n+ * \\param[in] wstatus The status as output by waitpid()\n+ *\n+ * This method is called when the process associated with Process terminates.\n+ * It emits the Process::finished signal.\n+ */\n+void Process::died(int wstatus)\n+{\n+\trunning_ = false;\n+\texitStatus_ = WIFEXITED(wstatus) ? NormalExit : SignalExit;\n+\texitCode_ = exitStatus_ == NormalExit ? WEXITSTATUS(wstatus) : -1;\n+\n+\tfinished.emit(this, exitStatus_, exitCode_);\n+}\n+\n+/**\n+ * \\fn Process::exitStatus()\n+ * \\brief Retrieve the exit status of the process\n+ *\n+ * Return the exit status of the process, that is, whether the process\n+ * has exited via exit() or returning from main, or if the process was\n+ * terminated by a signal.\n+ *\n+ * \\sa ExitStatus\n+ *\n+ * \\return The process exit status\n+ */\n+\n+/**\n+ * \\fn Process::exitCode()\n+ * \\brief Retrieve the exit code of the process\n+ *\n+ * This method is only valid if exitStatus() returned NormalExit.\n+ *\n+ * \\return Exit code\n+ */\n+\n+/**\n+ * \\var Process::finished\n+ *\n+ * Signal that is emitted when the process is confirmed to have terminated.\n+ */\n+\n+/**\n+ * \\brief Kill the process\n+ *\n+ * Sends SIGKILL to the process.\n+ */\n+void Process::kill()\n+{\n+\t::kill(pid_, SIGKILL);\n+}\n+\n+} /* namespace libcamera */\ndiff --git a/src/libcamera/process_manager.cpp b/src/libcamera/process_manager.cpp\nnew file mode 100644\nindex 0000000..e69de29\ndiff --git a/test/meson.build b/test/meson.build\nindex d308ac9..ad1a2f2 100644\n--- a/test/meson.build\n+++ b/test/meson.build\n@@ -6,6 +6,7 @@ subdir('ipa')\n subdir('ipc')\n subdir('media_device')\n subdir('pipeline')\n+subdir('process')\n subdir('stream')\n subdir('v4l2_subdevice')\n subdir('v4l2_videodevice')\ndiff --git a/test/process/meson.build b/test/process/meson.build\nnew file mode 100644\nindex 0000000..c4d83d6\n--- /dev/null\n+++ b/test/process/meson.build\n@@ -0,0 +1,12 @@\n+process_tests = [\n+ [ 'process_test', 'process_test.cpp' ],\n+]\n+\n+foreach t : process_tests\n+ exe = executable(t[0], t[1],\n+ dependencies : libcamera_dep,\n+ link_with : test_libraries,\n+ include_directories : test_includes_internal)\n+\n+ test(t[0], exe, suite : 'process', is_parallel : false)\n+endforeach\ndiff --git a/test/process/process_test.cpp b/test/process/process_test.cpp\nnew file mode 100644\nindex 0000000..8a7d09f\n--- /dev/null\n+++ b/test/process/process_test.cpp\n@@ -0,0 +1,100 @@\n+/* SPDX-License-Identifier: GPL-2.0-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * process_test.cpp - Process test\n+ */\n+\n+#include <iostream>\n+#include <unistd.h>\n+#include <vector>\n+\n+#include <libcamera/camera_manager.h>\n+#include <libcamera/event_dispatcher.h>\n+#include <libcamera/timer.h>\n+\n+#include \"process.h\"\n+#include \"test.h\"\n+#include \"utils.h\"\n+\n+using namespace std;\n+using namespace libcamera;\n+\n+class ProcessTestChild\n+{\n+public:\n+\tint run(int status)\n+\t{\n+\t\tusleep(50000);\n+\n+\t\treturn status;\n+\t}\n+};\n+\n+class ProcessTest : public Test\n+{\n+public:\n+\tProcessTest()\n+\t{\n+\t}\n+\n+protected:\n+\tint run()\n+\t{\n+\t\tEventDispatcher *dispatcher = CameraManager::instance()->eventDispatcher();\n+\t\tTimer timeout;\n+\n+\t\tint exitCode = 42;\n+\t\tvector<std::string> args;\n+\t\targs.push_back(to_string(exitCode));\n+\t\tint ret = proc_.start(\"/proc/self/exe\", args);\n+\t\tif (ret) {\n+\t\t\tcerr << \"failed to fork\" << endl;\n+\t\t\treturn TestFail;\n+\t\t}\n+\t\tproc_.finished.connect(this, &ProcessTest::procFinished);\n+\n+\t\ttimeout.start(80);\n+\t\twhile (timeout.isRunning())\n+\t\t\tdispatcher->processEvents();\n+\n+\t\tif (exitStatus_ != Process::NormalExit) {\n+\t\t\tcerr << \"process did not exit normally\" << endl;\n+\t\t\treturn TestFail;\n+\t\t}\n+\n+\t\tif (exitCode != exitCode_) {\n+\t\t\tcerr << \"exit code should be \" << exitCode\n+\t\t\t << \", actual is \" << exitCode_ << endl;\n+\t\t\treturn TestFail;\n+\t\t}\n+\n+\t\treturn TestPass;\n+\t}\n+\n+private:\n+\tvoid procFinished(Process *proc, enum Process::ExitStatus exitStatus, int exitCode)\n+\t{\n+\t\texitStatus_ = exitStatus;\n+\t\texitCode_ = exitCode;\n+\t}\n+\n+\tProcess proc_;\n+\tenum Process::ExitStatus exitStatus_;\n+\tint exitCode_;\n+};\n+\n+/*\n+ * Can't use TEST_REGISTER() as single binary needs to act as both\n+ * parent and child processes.\n+ */\n+int main(int argc, char **argv)\n+{\n+\tif (argc == 2) {\n+\t\tint status = std::stoi(argv[1]);\n+\t\tProcessTestChild child;\n+\t\treturn child.run(status);\n+\t}\n+\n+\treturn ProcessTest().execute();\n+}\n", "prefixes": [ "libcamera-devel", "v4", "3/8" ] }