| /* |
| * Copyright (c) 2003, 2011, Oracle and/or its affiliates. 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 Oracle 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. |
| */ |
| |
| /* |
| * This source code is provided to illustrate the usage of a given feature |
| * or technique and has been deliberately simplified. Additional steps |
| * required for a production-quality application, such as security checks, |
| * input validation and proper error handling, might not be present in |
| * this sample code. |
| */ |
| |
| |
| #include "hprof.h" |
| |
| /* This file contains the cpu loop for the option cpu=samples */ |
| |
| /* The cpu_loop thread basically waits for gdata->sample_interval millisecs |
| * then wakes up, and for each running thread it gets their stack trace, |
| * and updates the traces with 'hits'. |
| * |
| * No threads are suspended or resumed, and the thread sampling is in the |
| * file hprof_tls.c, which manages all active threads. The sampling |
| * technique (what is sampled) is also in hprof_tls.c. |
| * |
| * No adjustments are made to the pause time or sample interval except |
| * by the user via the interval=n option (default is 10ms). |
| * |
| * This thread can cause havoc when started prematurely or not terminated |
| * properly, see cpu_sample_init() and cpu_term(), and their calls in hprof_init.c. |
| * |
| * The listener loop (hprof_listener.c) can dynamically turn on or off the |
| * sampling of all or selected threads. |
| * |
| */ |
| |
| /* Private functions */ |
| |
| static void JNICALL |
| cpu_loop_function(jvmtiEnv *jvmti, JNIEnv *env, void *p) |
| { |
| int loop_trip_counter; |
| jboolean cpu_loop_running; |
| |
| loop_trip_counter = 0; |
| |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| gdata->cpu_loop_running = JNI_TRUE; |
| cpu_loop_running = gdata->cpu_loop_running; |
| /* Notify cpu_sample_init() that we have started */ |
| rawMonitorNotifyAll(gdata->cpu_loop_lock); |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| |
| rawMonitorEnter(gdata->cpu_sample_lock); /* Only waits inside loop let go */ |
| |
| while ( cpu_loop_running ) { |
| |
| ++loop_trip_counter; |
| |
| LOG3("cpu_loop()", "iteration", loop_trip_counter); |
| |
| /* If a dump is in progress, we pause sampling. */ |
| rawMonitorEnter(gdata->dump_lock); { |
| if (gdata->dump_in_process) { |
| gdata->pause_cpu_sampling = JNI_TRUE; |
| } |
| } rawMonitorExit(gdata->dump_lock); |
| |
| /* Check to see if we need to pause sampling (listener_loop command) */ |
| if (gdata->pause_cpu_sampling) { |
| |
| /* |
| * Pause sampling for now. Reset sample controls if |
| * sampling is resumed again. |
| */ |
| |
| rawMonitorWait(gdata->cpu_sample_lock, 0); |
| |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| cpu_loop_running = gdata->cpu_loop_running; |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| |
| /* Continue the while loop, which will terminate if done. */ |
| continue; |
| } |
| |
| /* This is the normal short timed wait before getting a sample */ |
| rawMonitorWait(gdata->cpu_sample_lock, (jlong)gdata->sample_interval); |
| |
| /* Make sure we really want to continue */ |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| cpu_loop_running = gdata->cpu_loop_running; |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| |
| /* Break out if we are done */ |
| if ( !cpu_loop_running ) { |
| break; |
| } |
| |
| /* |
| * If a dump request came in after we checked at the top of |
| * the while loop, then we catch that fact here. We |
| * don't want to perturb the data that is being dumped so |
| * we just ignore the data from this sampling loop. |
| */ |
| rawMonitorEnter(gdata->dump_lock); { |
| if (gdata->dump_in_process) { |
| gdata->pause_cpu_sampling = JNI_TRUE; |
| } |
| } rawMonitorExit(gdata->dump_lock); |
| |
| /* Sample all the threads and update trace costs */ |
| if ( !gdata->pause_cpu_sampling) { |
| tls_sample_all_threads(env); |
| } |
| |
| /* Check to see if we need to finish */ |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| cpu_loop_running = gdata->cpu_loop_running; |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| |
| } |
| rawMonitorExit(gdata->cpu_sample_lock); |
| |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| /* Notify cpu_sample_term() that we are done. */ |
| rawMonitorNotifyAll(gdata->cpu_loop_lock); |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| |
| LOG2("cpu_loop()", "clean termination"); |
| } |
| |
| /* External functions */ |
| |
| void |
| cpu_sample_init(JNIEnv *env) |
| { |
| gdata->cpu_sampling = JNI_TRUE; |
| |
| /* Create the raw monitors needed */ |
| gdata->cpu_loop_lock = createRawMonitor("HPROF cpu loop lock"); |
| gdata->cpu_sample_lock = createRawMonitor("HPROF cpu sample lock"); |
| |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| createAgentThread(env, "HPROF cpu sampling thread", |
| &cpu_loop_function); |
| /* Wait for cpu_loop_function() to notify us it has started. */ |
| rawMonitorWait(gdata->cpu_loop_lock, 0); |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| } |
| |
| void |
| cpu_sample_off(JNIEnv *env, ObjectIndex object_index) |
| { |
| jint count; |
| |
| count = 1; |
| if (object_index != 0) { |
| tls_set_sample_status(object_index, 0); |
| count = tls_sum_sample_status(); |
| } |
| if ( count == 0 ) { |
| gdata->pause_cpu_sampling = JNI_TRUE; |
| } else { |
| gdata->pause_cpu_sampling = JNI_FALSE; |
| } |
| } |
| |
| void |
| cpu_sample_on(JNIEnv *env, ObjectIndex object_index) |
| { |
| if ( gdata->cpu_loop_lock == NULL ) { |
| cpu_sample_init(env); |
| } |
| |
| if (object_index == 0) { |
| gdata->cpu_sampling = JNI_TRUE; |
| gdata->pause_cpu_sampling = JNI_FALSE; |
| } else { |
| jint count; |
| |
| tls_set_sample_status(object_index, 1); |
| count = tls_sum_sample_status(); |
| if ( count > 0 ) { |
| gdata->pause_cpu_sampling = JNI_FALSE; |
| } |
| } |
| |
| /* Notify the CPU sampling thread that sampling is on */ |
| rawMonitorEnter(gdata->cpu_sample_lock); { |
| rawMonitorNotifyAll(gdata->cpu_sample_lock); |
| } rawMonitorExit(gdata->cpu_sample_lock); |
| |
| } |
| |
| void |
| cpu_sample_term(JNIEnv *env) |
| { |
| gdata->pause_cpu_sampling = JNI_FALSE; |
| rawMonitorEnter(gdata->cpu_sample_lock); { |
| /* Notify the CPU sampling thread to get out of any sampling Wait */ |
| rawMonitorNotifyAll(gdata->cpu_sample_lock); |
| } rawMonitorExit(gdata->cpu_sample_lock); |
| rawMonitorEnter(gdata->cpu_loop_lock); { |
| if ( gdata->cpu_loop_running ) { |
| gdata->cpu_loop_running = JNI_FALSE; |
| /* Wait for cpu_loop_function() thread to tell us it completed. */ |
| rawMonitorWait(gdata->cpu_loop_lock, 0); |
| } |
| } rawMonitorExit(gdata->cpu_loop_lock); |
| } |
