15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* Copyright (c) 2009, Google Inc. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * All rights reserved. 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Redistribution and use in source and binary forms, with or without 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * modification, are permitted provided that the following conditions are 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * met: 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * * Redistributions of source code must retain the above copyright 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * notice, this list of conditions and the following disclaimer. 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * * Redistributions in binary form must reproduce the above 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * copyright notice, this list of conditions and the following disclaimer 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * in the documentation and/or other materials provided with the 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * distribution. 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * * Neither the name of Google Inc. nor the names of its 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * contributors may be used to endorse or promote products derived from 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * this software without specific prior written permission. 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * --- 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Author: Nabeel Mian 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This module manages the cpu profile timers and the associated interrupt 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * handler. When enabled, all registered threads in the program are profiled. 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * (Note: if using linux 2.4 or earlier, you must use the Thread class, in 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * google3/thread, to ensure all threads are profiled.) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Any component interested in receiving a profile timer interrupt can do so by 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * registering a callback. All registered callbacks must be async-signal-safe. 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Note: This module requires the sole ownership of ITIMER_PROF timer and the 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * SIGPROF signal. 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef BASE_PROFILE_HANDLER_H_ 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define BASE_PROFILE_HANDLER_H_ 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "config.h" 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <signal.h> 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef COMPILER_MSVC 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "conflict-signal.h" 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* All this code should be usable from within C apps. */ 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef __cplusplus 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)extern "C" { 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* Forward declaration. */ 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)struct ProfileHandlerToken; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Callback function to be used with ProfilefHandlerRegisterCallback. This 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * function will be called in the context of SIGPROF signal handler and must 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * be async-signal-safe. The first three arguments are the values provided by 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * the SIGPROF signal handler. We use void* to avoid using ucontext_t on 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * non-POSIX systems. 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Requirements: 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Callback must be async-signal-safe. 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - None of the functions in ProfileHandler are async-signal-safe. Therefore, 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * callback function *must* not call any of the ProfileHandler functions. 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Callback is not required to be re-entrant. At most one instance of 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * callback can run at a time. 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Notes: 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - The SIGPROF signal handler saves and restores errno, so the callback 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * doesn't need to. 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Callback code *must* not acquire lock(s) to serialize access to data shared 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * with the code outside the signal handler (callback must be 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * async-signal-safe). If such a serialization is needed, follow the model 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * used by profiler.cc: 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * When code other than the signal handler modifies the shared data it must: 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Acquire lock. 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Unregister the callback with the ProfileHandler. 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Modify shared data. 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Re-register the callback. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - Release lock. 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * and the callback code gets a lockless, read-write access to the data. 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)typedef void (*ProfileHandlerCallback)(int sig, siginfo_t* sig_info, 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void* ucontext, void* callback_arg); 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Registers a new thread with profile handler and should be called only once 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * per thread. The main thread is registered at program startup. This routine 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * is called by the Thread module in google3/thread whenever a new thread is 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * created. This function is not async-signal-safe. 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void ProfileHandlerRegisterThread(); 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Registers a callback routine. This callback function will be called in the 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * context of SIGPROF handler, so must be async-signal-safe. The returned token 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * is to be used when unregistering this callback via 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ProfileHandlerUnregisterCallback. Registering the first callback enables 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * the SIGPROF signal handler. Caller must not free the returned token. This 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * function is not async-signal-safe. 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ProfileHandlerToken* ProfileHandlerRegisterCallback( 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ProfileHandlerCallback callback, void* callback_arg); 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Unregisters a previously registered callback. Expects the token returned 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * by the corresponding ProfileHandlerRegisterCallback and asserts that the 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * passed token is valid. Unregistering the last callback disables the SIGPROF 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * signal handler. It waits for the currently running callback to 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * complete before returning. This function is not async-signal-safe. 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void ProfileHandlerUnregisterCallback(ProfileHandlerToken* token); 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * FOR TESTING ONLY 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Unregisters all the callbacks, stops the timers (if shared) and disables the 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * SIGPROF handler. All the threads, including the main thread, need to be 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * re-registered after this call. This function is not async-signal-safe. 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void ProfileHandlerReset(); 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Stores profile handler's current state. This function is not 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * async-signal-safe. 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)struct ProfileHandlerState { 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int32 frequency; /* Profiling frequency */ 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int32 callback_count; /* Number of callbacks registered */ 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int64 interrupts; /* Number of interrupts received */ 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool allowed; /* Profiling is allowed */ 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void ProfileHandlerGetState(struct ProfileHandlerState* state); 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifdef __cplusplus 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} /* extern "C" */ 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif /* BASE_PROFILE_HANDLER_H_ */ 149