From 1469d5e26e27bf5fe4d065a6f3c87edd804f2888 Mon Sep 17 00:00:00 2001 From: Paul Elder Date: Wed, 26 Aug 2020 17:26:47 +0900 Subject: libcamera: ProcessManager: make ProcessManager lifetime explicitly managed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If any Process instances are destroyed after the ProcessManager is destroyed, then a segfault will occur. Fix this by making the lifetime of the ProcessManager explicit, and make the CameraManager construct and deconstruct (automatically, via a member variable) the ProcessManager. Update the tests accordingly. Signed-off-by: Paul Elder Reviewed-by: Laurent Pinchart Reviewed-by: Niklas Söderlund Reviewed-by: Jacopo Mondi --- include/libcamera/internal/process.h | 29 +++++++++++++++++++++++ src/libcamera/camera_manager.cpp | 2 ++ src/libcamera/process.cpp | 46 +++++++++++++++--------------------- test/log/log_process.cpp | 2 ++ test/process/process_test.cpp | 2 ++ 5 files changed, 54 insertions(+), 27 deletions(-) diff --git a/include/libcamera/internal/process.h b/include/libcamera/internal/process.h index 2688557c..254cda85 100644 --- a/include/libcamera/internal/process.h +++ b/include/libcamera/internal/process.h @@ -7,6 +7,7 @@ #ifndef __LIBCAMERA_INTERNAL_PROCESS_H__ #define __LIBCAMERA_INTERNAL_PROCESS_H__ +#include #include #include @@ -14,6 +15,8 @@ namespace libcamera { +class EventNotifier; + class Process final { public: @@ -50,6 +53,32 @@ private: friend class ProcessManager; }; +class ProcessManager +{ +public: + ProcessManager(); + ~ProcessManager(); + + void registerProcess(Process *proc); + + static ProcessManager *instance(); + + int writePipe() const; + + const struct sigaction &oldsa() const; + +private: + static ProcessManager *self_; + + void sighandler(EventNotifier *notifier); + + std::list processes_; + + struct sigaction oldsa_; + EventNotifier *sigEvent_; + int pipe_[2]; +}; + } /* namespace libcamera */ #endif /* __LIBCAMERA_INTERNAL_PROCESS_H__ */ diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp index 47d56256..b8d3ccc8 100644 --- a/src/libcamera/camera_manager.cpp +++ b/src/libcamera/camera_manager.cpp @@ -18,6 +18,7 @@ #include "libcamera/internal/ipa_manager.h" #include "libcamera/internal/log.h" #include "libcamera/internal/pipeline_handler.h" +#include "libcamera/internal/process.h" #include "libcamera/internal/thread.h" #include "libcamera/internal/utils.h" @@ -67,6 +68,7 @@ private: std::unique_ptr enumerator_; IPAManager ipaManager_; + ProcessManager processManager_; }; CameraManager::Private::Private(CameraManager *cm) diff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp index 994190dc..72b5afe2 100644 --- a/src/libcamera/process.cpp +++ b/src/libcamera/process.cpp @@ -41,28 +41,6 @@ LOG_DEFINE_CATEGORY(Process) * The ProcessManager singleton keeps track of all created Process instances, * and manages the signal handling involved in terminating processes. */ -class ProcessManager -{ -public: - void registerProcess(Process *proc); - - static ProcessManager *instance(); - - int writePipe() const; - - const struct sigaction &oldsa() const; - -private: - void sighandler(EventNotifier *notifier); - ProcessManager(); - ~ProcessManager(); - - std::list processes_; - - struct sigaction oldsa_; - EventNotifier *sigEvent_; - int pipe_[2]; -}; namespace { @@ -127,8 +105,20 @@ void ProcessManager::registerProcess(Process *proc) processes_.push_back(proc); } +ProcessManager *ProcessManager::self_ = nullptr; + +/** + * \brief Construct a ProcessManager instance + * + * The ProcessManager class is meant to only be instantiated once, by the + * CameraManager. + */ ProcessManager::ProcessManager() { + if (self_) + LOG(Process, Fatal) + << "Multiple ProcessManager objects are not allowed"; + sigaction(SIGCHLD, NULL, &oldsa_); struct sigaction sa; @@ -145,6 +135,8 @@ ProcessManager::ProcessManager() << "Failed to initialize pipe for signal handling"; sigEvent_ = new EventNotifier(pipe_[0], EventNotifier::Read); sigEvent_->activated.connect(this, &ProcessManager::sighandler); + + self_ = this; } ProcessManager::~ProcessManager() @@ -153,21 +145,21 @@ ProcessManager::~ProcessManager() delete sigEvent_; close(pipe_[0]); close(pipe_[1]); + + self_ = nullptr; } /** * \brief Retrieve the Process manager instance * - * The ProcessManager is a singleton and can't be constructed manually. This - * method shall instead be used to retrieve the single global instance of the - * manager. + * The ProcessManager is constructed by the CameraManager. This function shall + * be used to retrieve the single instance of the manager. * * \return The Process manager instance */ ProcessManager *ProcessManager::instance() { - static ProcessManager processManager; - return &processManager; + return self_; } /** diff --git a/test/log/log_process.cpp b/test/log/log_process.cpp index b024f002..2a826222 100644 --- a/test/log/log_process.cpp +++ b/test/log/log_process.cpp @@ -132,6 +132,8 @@ private: exitCode_ = exitCode; } + ProcessManager processManager_; + Process proc_; Process::ExitStatus exitStatus_; string logPath_; diff --git a/test/process/process_test.cpp b/test/process/process_test.cpp index 42a26749..a3eaef80 100644 --- a/test/process/process_test.cpp +++ b/test/process/process_test.cpp @@ -87,6 +87,8 @@ private: exitCode_ = exitCode; } + ProcessManager processManager_; + Process proc_; enum Process::ExitStatus exitStatus_; int exitCode_; -- cgit v1.2.1