diff options
Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/client/windows/crash_generation/crash_generation_server.cc')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/client/windows/crash_generation/crash_generation_server.cc | 931 |
1 files changed, 931 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/client/windows/crash_generation/crash_generation_server.cc b/toolkit/crashreporter/google-breakpad/src/client/windows/crash_generation/crash_generation_server.cc new file mode 100644 index 000000000..bb0968fe0 --- /dev/null +++ b/toolkit/crashreporter/google-breakpad/src/client/windows/crash_generation/crash_generation_server.cc @@ -0,0 +1,931 @@ +// Copyright (c) 2008, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "client/windows/crash_generation/crash_generation_server.h" +#include <windows.h> +#include <cassert> +#include <list> +#include "client/windows/common/auto_critical_section.h" +#include "common/scoped_ptr.h" + +#include "client/windows/crash_generation/client_info.h" + +namespace google_breakpad { + +// Output buffer size. +static const size_t kOutBufferSize = 64; + +// Input buffer size. +static const size_t kInBufferSize = 64; + +// Access flags for the client on the dump request event. +static const DWORD kDumpRequestEventAccess = EVENT_MODIFY_STATE; + +// Access flags for the client on the dump generated event. +static const DWORD kDumpGeneratedEventAccess = EVENT_MODIFY_STATE | + SYNCHRONIZE; + +// Access flags for the client on the mutex. +static const DWORD kMutexAccess = SYNCHRONIZE; + +// Attribute flags for the pipe. +static const DWORD kPipeAttr = FILE_FLAG_FIRST_PIPE_INSTANCE | + PIPE_ACCESS_DUPLEX | + FILE_FLAG_OVERLAPPED; + +// Mode for the pipe. +static const DWORD kPipeMode = PIPE_TYPE_MESSAGE | + PIPE_READMODE_MESSAGE | + PIPE_WAIT; + +// For pipe I/O, execute the callback in the wait thread itself, +// since the callback does very little work. The callback executes +// the code for one of the states of the server state machine and +// the code for all of the states perform async I/O and hence +// finish very quickly. +static const ULONG kPipeIOThreadFlags = WT_EXECUTEINWAITTHREAD; + +// Dump request threads will, most likely, generate dumps. That may +// take some time to finish, so specify WT_EXECUTELONGFUNCTION flag. +static const ULONG kDumpRequestThreadFlags = WT_EXECUTEINWAITTHREAD | + WT_EXECUTELONGFUNCTION; + +static bool IsClientRequestValid(const ProtocolMessage& msg) { + return msg.tag == MESSAGE_TAG_UPLOAD_REQUEST || + (msg.tag == MESSAGE_TAG_REGISTRATION_REQUEST && + msg.id != 0 && + msg.thread_id != NULL && + msg.exception_pointers != NULL && + msg.assert_info != NULL); +} + +#ifndef NDEBUG +static bool CheckForIOIncomplete(bool success) { + // We should never get an I/O incomplete since we should not execute this + // unless the operation has finished and the overlapped event is signaled. If + // we do get INCOMPLETE, we have a bug in our code. + return success ? false : (GetLastError() == ERROR_IO_INCOMPLETE); +} +#endif + +CrashGenerationServer::CrashGenerationServer( + const std::wstring& pipe_name, + SECURITY_ATTRIBUTES* pipe_sec_attrs, + OnClientConnectedCallback connect_callback, + void* connect_context, + OnClientDumpRequestCallback dump_callback, + void* dump_context, + OnClientExitedCallback exit_callback, + void* exit_context, + OnClientUploadRequestCallback upload_request_callback, + void* upload_context, + bool generate_dumps, + const std::wstring* dump_path) + : pipe_name_(pipe_name), + pipe_sec_attrs_(pipe_sec_attrs), + pipe_(NULL), + pipe_wait_handle_(NULL), + server_alive_handle_(NULL), + connect_callback_(connect_callback), + connect_context_(connect_context), + dump_callback_(dump_callback), + dump_context_(dump_context), + exit_callback_(exit_callback), + exit_context_(exit_context), + upload_request_callback_(upload_request_callback), + upload_context_(upload_context), + generate_dumps_(generate_dumps), + pre_fetch_custom_info_(true), + dump_path_(dump_path ? *dump_path : L""), + server_state_(IPC_SERVER_STATE_UNINITIALIZED), + shutting_down_(false), + overlapped_(), + client_info_(NULL) { + InitializeCriticalSection(&sync_); +} + +// This should never be called from the OnPipeConnected callback. +// Otherwise the UnregisterWaitEx call below will cause a deadlock. +CrashGenerationServer::~CrashGenerationServer() { + // New scope to release the lock automatically. + { + // Make sure no clients are added or removed beyond this point. + // Before adding or removing any clients, the critical section + // must be entered and the shutting_down_ flag checked. The + // critical section is then exited only after the clients_ list + // modifications are done and the list is in a consistent state. + AutoCriticalSection lock(&sync_); + + // Indicate to existing threads that server is shutting down. + shutting_down_ = true; + } + // No one will modify the clients_ list beyond this point - + // not even from another thread. + + // Even if there are no current worker threads running, it is possible that + // an I/O request is pending on the pipe right now but not yet done. + // In fact, it's very likely this is the case unless we are in an ERROR + // state. If we don't wait for the pending I/O to be done, then when the I/O + // completes, it may write to invalid memory. AppVerifier will flag this + // problem too. So we disconnect from the pipe and then wait for the server + // to get into error state so that the pending I/O will fail and get + // cleared. + DisconnectNamedPipe(pipe_); + int num_tries = 100; + while (num_tries-- && server_state_ != IPC_SERVER_STATE_ERROR) { + Sleep(10); + } + + // Unregister wait on the pipe. + if (pipe_wait_handle_) { + // Wait for already executing callbacks to finish. + UnregisterWaitEx(pipe_wait_handle_, INVALID_HANDLE_VALUE); + } + + // Close the pipe to avoid further client connections. + if (pipe_) { + CloseHandle(pipe_); + } + + // Request all ClientInfo objects to unregister all waits. + // No need to enter the critical section because no one is allowed to modify + // the clients_ list once the shutting_down_ flag is set. + std::list<ClientInfo*>::iterator iter; + for (iter = clients_.begin(); iter != clients_.end(); ++iter) { + ClientInfo* client_info = *iter; + // Unregister waits. Wait for already executing callbacks to finish. + // Unregister the client process exit wait first and only then unregister + // the dump request wait. The reason is that the OnClientExit callback + // also unregisters the dump request wait and such a race (doing the same + // unregistration from two threads) is undesirable. + client_info->UnregisterProcessExitWait(true); + client_info->UnregisterDumpRequestWaitAndBlockUntilNoPending(); + + // Destroying the ClientInfo here is safe because all wait operations for + // this ClientInfo were unregistered and no pending or running callbacks + // for this ClientInfo can possible exist (block_until_no_pending option + // was used). + delete client_info; + } + + if (server_alive_handle_) { + // Release the mutex before closing the handle so that clients requesting + // dumps wait for a long time for the server to generate a dump. + ReleaseMutex(server_alive_handle_); + CloseHandle(server_alive_handle_); + } + + if (overlapped_.hEvent) { + CloseHandle(overlapped_.hEvent); + } + + DeleteCriticalSection(&sync_); +} + +bool CrashGenerationServer::Start() { + if (server_state_ != IPC_SERVER_STATE_UNINITIALIZED) { + return false; + } + + server_state_ = IPC_SERVER_STATE_INITIAL; + + server_alive_handle_ = CreateMutex(NULL, TRUE, NULL); + if (!server_alive_handle_) { + return false; + } + + // Event to signal the client connection and pipe reads and writes. + overlapped_.hEvent = CreateEvent(NULL, // Security descriptor. + TRUE, // Manual reset. + FALSE, // Initially nonsignaled. + NULL); // Name. + if (!overlapped_.hEvent) { + return false; + } + + // Register a callback with the thread pool for the client connection. + if (!RegisterWaitForSingleObject(&pipe_wait_handle_, + overlapped_.hEvent, + OnPipeConnected, + this, + INFINITE, + kPipeIOThreadFlags)) { + return false; + } + + pipe_ = CreateNamedPipe(pipe_name_.c_str(), + kPipeAttr, + kPipeMode, + 1, + kOutBufferSize, + kInBufferSize, + 0, + pipe_sec_attrs_); + if (pipe_ == INVALID_HANDLE_VALUE) { + return false; + } + + // Kick-start the state machine. This will initiate an asynchronous wait + // for client connections. + if (!SetEvent(overlapped_.hEvent)) { + server_state_ = IPC_SERVER_STATE_ERROR; + return false; + } + + // If we are in error state, it's because we failed to start listening. + return true; +} + +// If the server thread serving clients ever gets into the +// ERROR state, reset the event, close the pipe and remain +// in the error state forever. Error state means something +// that we didn't account for has happened, and it's dangerous +// to do anything unknowingly. +void CrashGenerationServer::HandleErrorState() { + assert(server_state_ == IPC_SERVER_STATE_ERROR); + + // If the server is shutting down anyway, don't clean up + // here since shut down process will clean up. + if (shutting_down_) { + return; + } + + if (pipe_wait_handle_) { + UnregisterWait(pipe_wait_handle_); + pipe_wait_handle_ = NULL; + } + + if (pipe_) { + CloseHandle(pipe_); + pipe_ = NULL; + } + + if (overlapped_.hEvent) { + CloseHandle(overlapped_.hEvent); + overlapped_.hEvent = NULL; + } +} + +// When the server thread serving clients is in the INITIAL state, +// try to connect to the pipe asynchronously. If the connection +// finishes synchronously, directly go into the CONNECTED state; +// otherwise go into the CONNECTING state. For any problems, go +// into the ERROR state. +void CrashGenerationServer::HandleInitialState() { + assert(server_state_ == IPC_SERVER_STATE_INITIAL); + + if (!ResetEvent(overlapped_.hEvent)) { + EnterErrorState(); + return; + } + + bool success = ConnectNamedPipe(pipe_, &overlapped_) != FALSE; + DWORD error_code = success ? ERROR_SUCCESS : GetLastError(); + + // From MSDN, it is not clear that when ConnectNamedPipe is used + // in an overlapped mode, will it ever return non-zero value, and + // if so, in what cases. + assert(!success); + + switch (error_code) { + case ERROR_IO_PENDING: + EnterStateWhenSignaled(IPC_SERVER_STATE_CONNECTING); + break; + + case ERROR_PIPE_CONNECTED: + EnterStateImmediately(IPC_SERVER_STATE_CONNECTED); + break; + + default: + EnterErrorState(); + break; + } +} + +// When the server thread serving the clients is in the CONNECTING state, +// try to get the result of the asynchronous connection request using +// the OVERLAPPED object. If the result indicates the connection is done, +// go into the CONNECTED state. If the result indicates I/O is still +// INCOMPLETE, remain in the CONNECTING state. For any problems, +// go into the DISCONNECTING state. +void CrashGenerationServer::HandleConnectingState() { + assert(server_state_ == IPC_SERVER_STATE_CONNECTING); + + DWORD bytes_count = 0; + bool success = GetOverlappedResult(pipe_, + &overlapped_, + &bytes_count, + FALSE) != FALSE; + DWORD error_code = success ? ERROR_SUCCESS : GetLastError(); + + if (success) { + EnterStateImmediately(IPC_SERVER_STATE_CONNECTED); + } else if (error_code != ERROR_IO_INCOMPLETE) { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + } else { + // remain in CONNECTING state + } +} + +// When the server thread serving the clients is in the CONNECTED state, +// try to issue an asynchronous read from the pipe. If read completes +// synchronously or if I/O is pending then go into the READING state. +// For any problems, go into the DISCONNECTING state. +void CrashGenerationServer::HandleConnectedState() { + assert(server_state_ == IPC_SERVER_STATE_CONNECTED); + + DWORD bytes_count = 0; + memset(&msg_, 0, sizeof(msg_)); + bool success = ReadFile(pipe_, + &msg_, + sizeof(msg_), + &bytes_count, + &overlapped_) != FALSE; + DWORD error_code = success ? ERROR_SUCCESS : GetLastError(); + + // Note that the asynchronous read issued above can finish before the + // code below executes. But, it is okay to change state after issuing + // the asynchronous read. This is because even if the asynchronous read + // is done, the callback for it would not be executed until the current + // thread finishes its execution. + if (success || error_code == ERROR_IO_PENDING) { + EnterStateWhenSignaled(IPC_SERVER_STATE_READING); + } else { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + } +} + +// When the server thread serving the clients is in the READING state, +// try to get the result of the async read. If async read is done, +// go into the READ_DONE state. For any problems, go into the +// DISCONNECTING state. +void CrashGenerationServer::HandleReadingState() { + assert(server_state_ == IPC_SERVER_STATE_READING); + + DWORD bytes_count = 0; + bool success = GetOverlappedResult(pipe_, + &overlapped_, + &bytes_count, + FALSE) != FALSE; + if (success && bytes_count == sizeof(ProtocolMessage)) { + EnterStateImmediately(IPC_SERVER_STATE_READ_DONE); + return; + } + + assert(!CheckForIOIncomplete(success)); + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); +} + +// When the server thread serving the client is in the READ_DONE state, +// validate the client's request message, register the client by +// creating appropriate objects and prepare the response. Then try to +// write the response to the pipe asynchronously. If that succeeds, +// go into the WRITING state. For any problems, go into the DISCONNECTING +// state. +void CrashGenerationServer::HandleReadDoneState() { + assert(server_state_ == IPC_SERVER_STATE_READ_DONE); + + if (!IsClientRequestValid(msg_)) { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + return; + } + + if (msg_.tag == MESSAGE_TAG_UPLOAD_REQUEST) { + if (upload_request_callback_) + upload_request_callback_(upload_context_, msg_.id); + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + return; + } + + scoped_ptr<ClientInfo> client_info( + new ClientInfo(this, + msg_.id, + msg_.dump_type, + msg_.thread_id, + msg_.exception_pointers, + msg_.assert_info, + msg_.custom_client_info)); + + if (!client_info->Initialize()) { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + return; + } + + // Issues an asynchronous WriteFile call if successful. + // Iff successful, assigns ownership of the client_info pointer to the server + // instance, in which case we must be sure not to free it in this function. + if (!RespondToClient(client_info.get())) { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + return; + } + + // This is only valid as long as it can be found in the clients_ list + client_info_ = client_info.release(); + + // Note that the asynchronous write issued by RespondToClient function + // can finish before the code below executes. But it is okay to change + // state after issuing the asynchronous write. This is because even if + // the asynchronous write is done, the callback for it would not be + // executed until the current thread finishes its execution. + EnterStateWhenSignaled(IPC_SERVER_STATE_WRITING); +} + +// When the server thread serving the clients is in the WRITING state, +// try to get the result of the async write. If the async write is done, +// go into the WRITE_DONE state. For any problems, go into the +// DISONNECTING state. +void CrashGenerationServer::HandleWritingState() { + assert(server_state_ == IPC_SERVER_STATE_WRITING); + + DWORD bytes_count = 0; + bool success = GetOverlappedResult(pipe_, + &overlapped_, + &bytes_count, + FALSE) != FALSE; + if (success) { + EnterStateImmediately(IPC_SERVER_STATE_WRITE_DONE); + return; + } + + assert(!CheckForIOIncomplete(success)); + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); +} + +// When the server thread serving the clients is in the WRITE_DONE state, +// try to issue an async read on the pipe. If the read completes synchronously +// or if I/O is still pending then go into the READING_ACK state. For any +// issues, go into the DISCONNECTING state. +void CrashGenerationServer::HandleWriteDoneState() { + assert(server_state_ == IPC_SERVER_STATE_WRITE_DONE); + + DWORD bytes_count = 0; + bool success = ReadFile(pipe_, + &msg_, + sizeof(msg_), + &bytes_count, + &overlapped_) != FALSE; + DWORD error_code = success ? ERROR_SUCCESS : GetLastError(); + + if (success) { + EnterStateImmediately(IPC_SERVER_STATE_READING_ACK); + } else if (error_code == ERROR_IO_PENDING) { + EnterStateWhenSignaled(IPC_SERVER_STATE_READING_ACK); + } else { + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); + } +} + +// When the server thread serving the clients is in the READING_ACK state, +// try to get result of async read. Go into the DISCONNECTING state. +void CrashGenerationServer::HandleReadingAckState() { + assert(server_state_ == IPC_SERVER_STATE_READING_ACK); + + DWORD bytes_count = 0; + bool success = GetOverlappedResult(pipe_, + &overlapped_, + &bytes_count, + FALSE) != FALSE; + if (success) { + // The connection handshake with the client is now complete; perform + // the callback. + if (connect_callback_) { + // Note that there is only a single copy of the ClientInfo of the + // currently connected client. However it is being referenced from + // two different places: + // - the client_info_ member + // - the clients_ list + // The lifetime of this ClientInfo depends on the lifetime of the + // client process - basically it can go away at any time. + // However, as long as it is referenced by the clients_ list it + // is guaranteed to be valid. Enter the critical section and check + // to see whether the client_info_ can be found in the list. + // If found, execute the callback and only then leave the critical + // section. + AutoCriticalSection lock(&sync_); + + bool client_is_still_alive = false; + std::list<ClientInfo*>::iterator iter; + for (iter = clients_.begin(); iter != clients_.end(); ++iter) { + if (client_info_ == *iter) { + client_is_still_alive = true; + break; + } + } + + if (client_is_still_alive) { + connect_callback_(connect_context_, client_info_); + } + } + } else { + assert(!CheckForIOIncomplete(success)); + } + + EnterStateImmediately(IPC_SERVER_STATE_DISCONNECTING); +} + +// When the server thread serving the client is in the DISCONNECTING state, +// disconnect from the pipe and reset the event. If anything fails, go into +// the ERROR state. If it goes well, go into the INITIAL state and set the +// event to start all over again. +void CrashGenerationServer::HandleDisconnectingState() { + assert(server_state_ == IPC_SERVER_STATE_DISCONNECTING); + + // Done serving the client. + client_info_ = NULL; + + overlapped_.Internal = NULL; + overlapped_.InternalHigh = NULL; + overlapped_.Offset = 0; + overlapped_.OffsetHigh = 0; + overlapped_.Pointer = NULL; + + if (!ResetEvent(overlapped_.hEvent)) { + EnterErrorState(); + return; + } + + if (!DisconnectNamedPipe(pipe_)) { + EnterErrorState(); + return; + } + + // If the server is shutting down do not connect to the + // next client. + if (shutting_down_) { + return; + } + + EnterStateImmediately(IPC_SERVER_STATE_INITIAL); +} + +void CrashGenerationServer::EnterErrorState() { + SetEvent(overlapped_.hEvent); + server_state_ = IPC_SERVER_STATE_ERROR; +} + +void CrashGenerationServer::EnterStateWhenSignaled(IPCServerState state) { + server_state_ = state; +} + +void CrashGenerationServer::EnterStateImmediately(IPCServerState state) { + server_state_ = state; + + if (!SetEvent(overlapped_.hEvent)) { + server_state_ = IPC_SERVER_STATE_ERROR; + } +} + +bool CrashGenerationServer::PrepareReply(const ClientInfo& client_info, + ProtocolMessage* reply) const { + reply->tag = MESSAGE_TAG_REGISTRATION_RESPONSE; + reply->id = GetCurrentProcessId(); + + if (CreateClientHandles(client_info, reply)) { + return true; + } + + // Closing of remote handles (belonging to a different process) can + // only be done through DuplicateHandle. + if (reply->dump_request_handle) { + DuplicateHandle(client_info.process_handle(), // hSourceProcessHandle + reply->dump_request_handle, // hSourceHandle + NULL, // hTargetProcessHandle + 0, // lpTargetHandle + 0, // dwDesiredAccess + FALSE, // bInheritHandle + DUPLICATE_CLOSE_SOURCE); // dwOptions + reply->dump_request_handle = NULL; + } + + if (reply->dump_generated_handle) { + DuplicateHandle(client_info.process_handle(), // hSourceProcessHandle + reply->dump_generated_handle, // hSourceHandle + NULL, // hTargetProcessHandle + 0, // lpTargetHandle + 0, // dwDesiredAccess + FALSE, // bInheritHandle + DUPLICATE_CLOSE_SOURCE); // dwOptions + reply->dump_generated_handle = NULL; + } + + if (reply->server_alive_handle) { + DuplicateHandle(client_info.process_handle(), // hSourceProcessHandle + reply->server_alive_handle, // hSourceHandle + NULL, // hTargetProcessHandle + 0, // lpTargetHandle + 0, // dwDesiredAccess + FALSE, // bInheritHandle + DUPLICATE_CLOSE_SOURCE); // dwOptions + reply->server_alive_handle = NULL; + } + + return false; +} + +bool CrashGenerationServer::CreateClientHandles(const ClientInfo& client_info, + ProtocolMessage* reply) const { + HANDLE current_process = GetCurrentProcess(); + if (!DuplicateHandle(current_process, + client_info.dump_requested_handle(), + client_info.process_handle(), + &reply->dump_request_handle, + kDumpRequestEventAccess, + FALSE, + 0)) { + return false; + } + + if (!DuplicateHandle(current_process, + client_info.dump_generated_handle(), + client_info.process_handle(), + &reply->dump_generated_handle, + kDumpGeneratedEventAccess, + FALSE, + 0)) { + return false; + } + + if (!DuplicateHandle(current_process, + server_alive_handle_, + client_info.process_handle(), + &reply->server_alive_handle, + kMutexAccess, + FALSE, + 0)) { + return false; + } + + return true; +} + +bool CrashGenerationServer::RespondToClient(ClientInfo* client_info) { + ProtocolMessage reply; + if (!PrepareReply(*client_info, &reply)) { + return false; + } + + DWORD bytes_count = 0; + bool success = WriteFile(pipe_, + &reply, + sizeof(reply), + &bytes_count, + &overlapped_) != FALSE; + DWORD error_code = success ? ERROR_SUCCESS : GetLastError(); + + if (!success && error_code != ERROR_IO_PENDING) { + return false; + } + + // Takes over ownership of client_info. We MUST return true if AddClient + // succeeds. + return AddClient(client_info); +} + +// The server thread servicing the clients runs this method. The method +// implements the state machine described in ReadMe.txt along with the +// helper methods HandleXXXState. +void CrashGenerationServer::HandleConnectionRequest() { + // If the server is shutting down, get into ERROR state, reset the event so + // more workers don't run and return immediately. + if (shutting_down_) { + server_state_ = IPC_SERVER_STATE_ERROR; + ResetEvent(overlapped_.hEvent); + return; + } + + switch (server_state_) { + case IPC_SERVER_STATE_ERROR: + HandleErrorState(); + break; + + case IPC_SERVER_STATE_INITIAL: + HandleInitialState(); + break; + + case IPC_SERVER_STATE_CONNECTING: + HandleConnectingState(); + break; + + case IPC_SERVER_STATE_CONNECTED: + HandleConnectedState(); + break; + + case IPC_SERVER_STATE_READING: + HandleReadingState(); + break; + + case IPC_SERVER_STATE_READ_DONE: + HandleReadDoneState(); + break; + + case IPC_SERVER_STATE_WRITING: + HandleWritingState(); + break; + + case IPC_SERVER_STATE_WRITE_DONE: + HandleWriteDoneState(); + break; + + case IPC_SERVER_STATE_READING_ACK: + HandleReadingAckState(); + break; + + case IPC_SERVER_STATE_DISCONNECTING: + HandleDisconnectingState(); + break; + + default: + assert(false); + // This indicates that we added one more state without + // adding handling code. + server_state_ = IPC_SERVER_STATE_ERROR; + break; + } +} + +bool CrashGenerationServer::AddClient(ClientInfo* client_info) { + HANDLE request_wait_handle = NULL; + if (!RegisterWaitForSingleObject(&request_wait_handle, + client_info->dump_requested_handle(), + OnDumpRequest, + client_info, + INFINITE, + kDumpRequestThreadFlags)) { + return false; + } + + client_info->set_dump_request_wait_handle(request_wait_handle); + + // OnClientEnd will be called when the client process terminates. + HANDLE process_wait_handle = NULL; + if (!RegisterWaitForSingleObject(&process_wait_handle, + client_info->process_handle(), + OnClientEnd, + client_info, + INFINITE, + WT_EXECUTEONLYONCE)) { + return false; + } + + client_info->set_process_exit_wait_handle(process_wait_handle); + + // New scope to hold the lock for the shortest time. + { + AutoCriticalSection lock(&sync_); + if (shutting_down_) { + // If server is shutting down, don't add new clients + return false; + } + clients_.push_back(client_info); + } + + return true; +} + +// static +void CALLBACK CrashGenerationServer::OnPipeConnected(void* context, BOOLEAN) { + assert(context); + + CrashGenerationServer* obj = + reinterpret_cast<CrashGenerationServer*>(context); + obj->HandleConnectionRequest(); +} + +// static +void CALLBACK CrashGenerationServer::OnDumpRequest(void* context, BOOLEAN) { + assert(context); + ClientInfo* client_info = reinterpret_cast<ClientInfo*>(context); + + CrashGenerationServer* crash_server = client_info->crash_server(); + assert(crash_server); + if (crash_server->pre_fetch_custom_info_) { + client_info->PopulateCustomInfo(); + } + crash_server->HandleDumpRequest(*client_info); + + ResetEvent(client_info->dump_requested_handle()); +} + +// static +void CALLBACK CrashGenerationServer::OnClientEnd(void* context, BOOLEAN) { + assert(context); + ClientInfo* client_info = reinterpret_cast<ClientInfo*>(context); + + CrashGenerationServer* crash_server = client_info->crash_server(); + assert(crash_server); + + crash_server->HandleClientProcessExit(client_info); +} + +void CrashGenerationServer::HandleClientProcessExit(ClientInfo* client_info) { + assert(client_info); + + // Must unregister the dump request wait operation and wait for any + // dump requests that might be pending to finish before proceeding + // with the client_info cleanup. + client_info->UnregisterDumpRequestWaitAndBlockUntilNoPending(); + + if (exit_callback_) { + exit_callback_(exit_context_, client_info); + } + + // Start a new scope to release lock automatically. + { + AutoCriticalSection lock(&sync_); + if (shutting_down_) { + // The crash generation server is shutting down and as part of the + // shutdown process it will delete all clients from the clients_ list. + return; + } + clients_.remove(client_info); + } + + // Explicitly unregister the process exit wait using the non-blocking method. + // Otherwise, the destructor will attempt to unregister it using the blocking + // method which will lead to a deadlock because it is being called from the + // callback of the same wait operation + client_info->UnregisterProcessExitWait(false); + + delete client_info; +} + +void CrashGenerationServer::HandleDumpRequest(const ClientInfo& client_info) { + bool execute_callback = true; + // Generate the dump only if it's explicitly requested by the + // server application; otherwise the server might want to generate + // dump in the callback. + std::wstring dump_path; + if (generate_dumps_) { + if (!GenerateDump(client_info, &dump_path)) { + // client proccess terminated or some other error + execute_callback = false; + } + } + + if (dump_callback_ && execute_callback) { + std::wstring* ptr_dump_path = (dump_path == L"") ? NULL : &dump_path; + dump_callback_(dump_context_, &client_info, ptr_dump_path); + } + + SetEvent(client_info.dump_generated_handle()); +} + +bool CrashGenerationServer::GenerateDump(const ClientInfo& client, + std::wstring* dump_path) { + assert(client.pid() != 0); + assert(client.process_handle()); + + // We have to get the address of EXCEPTION_INFORMATION from + // the client process address space. + EXCEPTION_POINTERS* client_ex_info = NULL; + if (!client.GetClientExceptionInfo(&client_ex_info)) { + return false; + } + + DWORD client_thread_id = 0; + if (!client.GetClientThreadId(&client_thread_id)) { + return false; + } + + MinidumpGenerator dump_generator(dump_path_, + client.process_handle(), + client.pid(), + client_thread_id, + GetCurrentThreadId(), + client_ex_info, + client.assert_info(), + client.dump_type(), + true); + if (!dump_generator.GenerateDumpFile(dump_path)) { + return false; + } + return dump_generator.WriteMinidump(); +} + +} // namespace google_breakpad |