JPDA Architecture Research 6-agent using environment pointers to access VMS (thread management chapter)

Introduced:

The previous article explained the classification: memory management, now the interface for threading class operations.

Category 2: Threading class operations

A.getthreadstate. Getting thread Status

Jvmtierrorgetthreadstate (jvmtienv* env, Jthread thread, jint* thread_state_ptr)

We all know that threads have many kinds of states, such as alive,terminated,runnable, waiting to enter synchronize block,waiting,sleeping,parked,suspended,interrupted and so on.

It takes the parameter thread to indicate the threads to query, and returns THREAD_STATE_PTR to indicate the thread state.

B.getallthreads. Get all the live threads, these threads must be connected to the current VM and alive.

Jvmtierrorgetallthreads (jvmtienv* env, jint* threads_count_ptr, jthread** threads_ptr)

It returns threads_count_ptr that represents the number of threads alive, and returns a reference array that threads_ptr represents a live thread.

C.suspendthread. Suspending a thread

Jvmtierrorsuspendthread (jvmtienv* env, Jthread thread)

Once a thread is suspended, the corresponding method cannot return until another thread calls ResumeThread.

It takes the parameter thread to indicate which threads to suspend.

D.suspendthreadlist. Suspending a group of threads

Jvmtierrorsuspendthreadlist (jvmtienv* env, Jint request_count, const jthread* request_list, jvmtierror* results)

Once a thread is suspended in threadlist, only one of the other threads is called resumethreadlist or ResumeThread, and the corresponding method can be returned.

The Enter parameter Request_count represents the number of threads to suspend, Request_list, which represents the array of threads to suspend, and returns results that represents the pending result.

E.resumethread. Recovering a suspended thread

Jvmtierrorresumethread (jvmtienv* env, Jthread thread)

F.resumethreadlist. Recovering a suspended thread group

Jvmtierrorresumethreadlist (jvmtienv* env, Jint request_count, const jthread* request_list, jvmtierror* results)

G.stopthread. Kill a Thread

Jvmtierrorstopthread (jvmtienv* env, Jthread thread, Jobject exception)

H.interruptthread. Interrupting a thread

Vmtierrorinterruptthread (jvmtienv* env, Jthread thread)

I.getthreadinfo. Getting information about a thread

typedef struct {char* name; Jint    Priority    Jboolean Is_daemon;    Jthreadgroup Thread_group; Jobject Context_class_loader;} Jvmtithreadinfo;

Jvmtierrorgetthreadinfo (jvmtienv* env, Jthread thread, jvmtithreadinfo* info_ptr)

As you can see here, you can get the name of the thread, the priority, whether the daemon thread, the owning thread group, the context loader, and so on.

J.getownermonitorinfo. Getting a thread-owned monitor (can have multiple) information

Jvmtierrorgetownedmonitorinfo (jvmtienv* env, Jthread thread, jint* owned_monitor_count_ptr, jobject** owned_monitors_ptr)

My understanding of monitor here is the lock the thread holds, which is the object associated with the synchronized.

The incoming parameter is still a given thread, returning the number of monitors and an array of monitor references.

K.getcurrentcontendedmonitor. Gets the current monitor for the thread.

Jvmtierrorgetcurrentcontendedmonitor (jvmtienv* env, Jthread thread, jobject* monitor_ptr)

And the use of the above supporting. Because multiple competitors share a thread at the same time, there must be a current competitor that occupies the execution of this thread.

L.SETTHREADLOCALSTORAGE.VM sets a thread-local value to associate to an environment-thread pair.

Jvmtierrorsetthreadlocalstorage (jvmtienv* env, jthread thread, const void* data)

M.getthreadlocalstorage.agent to get the thread-local value set for a thread.

Jvmtierrorgetthreadlocalstorage (jvmtienv* env, Jthread thread, void** data_ptr)

This article is from the "cohesion of parallel Lines" blog, please be sure to keep this source http://supercharles888.blog.51cto.com/609344/1587694

JPDA Architecture Research 6-agent using environment pointers to access VMS (thread management chapter)