Mercurial > hg > release > icedtea8-forest-3.0 > jdk
changeset 1725:060c4c7082ef
6529758: JVMTI Waiters demo crashes. Double free.
Reviewed-by: ohair, tbell
author | alanb |
---|---|
date | Mon, 14 Sep 2009 15:29:13 +0100 |
parents | 020a0fed38c9 |
children | aac01ec2cec4 |
files | src/share/demo/jvmti/waiters/Agent.cpp src/share/demo/jvmti/waiters/Agent.hpp src/share/demo/jvmti/waiters/Monitor.cpp src/share/demo/jvmti/waiters/Monitor.hpp |
diffstat | 4 files changed, 52 insertions(+), 37 deletions(-) [+] |
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--- a/src/share/demo/jvmti/waiters/Agent.cpp Sat Sep 12 15:30:13 2009 -0700 +++ b/src/share/demo/jvmti/waiters/Agent.cpp Mon Sep 14 15:29:13 2009 +0100 @@ -72,36 +72,30 @@ { jvmtiError err; Monitor *m; - - /* We use tags to track these, the tag is the Monitor pointer */ - err = jvmti->RawMonitorEnter(lock); { - check_jvmti_error(jvmti, err, "raw monitor enter"); + jlong tag; - /* The raw monitor enter/exit protects us from creating two - * instances for the same object. - */ - jlong tag; - - m = NULL; - tag = (jlong)0; - err = jvmti->GetTag(object, &tag); - check_jvmti_error(jvmti, err, "get tag"); + m = NULL; + tag = (jlong)0; + err = jvmti->GetTag(object, &tag); + check_jvmti_error(jvmti, err, "get tag"); + /*LINTED*/ + m = (Monitor *)(void *)(ptrdiff_t)tag; + if ( m == NULL ) { + m = new Monitor(jvmti, env, object); + /* Save monitor on list */ + if (monitor_count == monitor_list_size) { + monitor_list_size += monitor_list_grow_size; + monitor_list = (Monitor**)realloc((void*)monitor_list, + (monitor_list_size)*(int)sizeof(Monitor*)); + } + monitor_list[monitor_count] = m; + m->set_slot(monitor_count); + monitor_count++; /*LINTED*/ - m = (Monitor *)(void *)(ptrdiff_t)tag; - if ( m == NULL ) { - m = new Monitor(jvmti, env, object); - /*LINTED*/ - tag = (jlong)(ptrdiff_t)(void *)m; - err = jvmti->SetTag(object, tag); - check_jvmti_error(jvmti, err, "set tag"); - /* Save monitor on list */ - monitor_list = (Monitor**)realloc((void*)monitor_list, - (monitor_count+1)*(int)sizeof(Monitor*)); - monitor_list[monitor_count++] = m; - } - } err = jvmti->RawMonitorExit(lock); - check_jvmti_error(jvmti, err, "raw monitor exit"); - + tag = (jlong)(ptrdiff_t)(void *)m; + err = jvmti->SetTag(object, tag); + check_jvmti_error(jvmti, err, "set tag"); + } return m; } @@ -112,12 +106,11 @@ stdout_message("Agent created..\n"); stdout_message("VMInit...\n"); - /* Create a Monitor lock to use */ - err = jvmti->CreateRawMonitor("waiters Agent lock", &lock); - check_jvmti_error(jvmti, err, "create raw monitor"); /* Start monitor list */ monitor_count = 0; - monitor_list = (Monitor**)malloc((int)sizeof(Monitor*)); + monitor_list_size = initial_monitor_list_size; + monitor_list = (Monitor**) + malloc(monitor_list_size*(int)sizeof(Monitor*)); } Agent::~Agent() @@ -134,9 +127,6 @@ delete monitor_list[i]; } free(monitor_list); - /* Destroy the Monitor lock to use */ - err = jvmti->DestroyRawMonitor(lock); - check_jvmti_error(jvmti, err, "destroy raw monitor"); /* Print death message */ stdout_message("VMDeath...\n"); } @@ -215,8 +205,16 @@ /* We just cast the tag to a C++ pointer and delete it. * we know it can only be a Monitor *. */ - Monitor *m; + Monitor *m; /*LINTED*/ m = (Monitor *)(ptrdiff_t)tag; + if (monitor_count > 1) { + /* Move the last element to this Monitor's slot */ + int slot = m->get_slot(); + Monitor *last = monitor_list[monitor_count-1]; + monitor_list[slot] = last; + last->set_slot(slot); + } + monitor_count--; delete m; }
--- a/src/share/demo/jvmti/waiters/Agent.hpp Sat Sep 12 15:30:13 2009 -0700 +++ b/src/share/demo/jvmti/waiters/Agent.hpp Mon Sep 14 15:29:13 2009 +0100 @@ -34,8 +34,12 @@ class Agent { private: - jrawMonitorID lock; + enum { + initial_monitor_list_size = 64, + monitor_list_grow_size = 16 + }; Monitor **monitor_list; + unsigned monitor_list_size; unsigned monitor_count; Thread *get_thread(jvmtiEnv *jvmti, JNIEnv *env, jthread thread); Monitor *get_monitor(jvmtiEnv *jvmti, JNIEnv *env, jobject object);
--- a/src/share/demo/jvmti/waiters/Monitor.cpp Sat Sep 12 15:30:13 2009 -0700 +++ b/src/share/demo/jvmti/waiters/Monitor.cpp Mon Sep 14 15:29:13 2009 +0100 @@ -73,6 +73,16 @@ name, contends, waits, timeouts); } +int Monitor::get_slot() +{ + return slot; +} + +void Monitor::set_slot(int aslot) +{ + slot = aslot; +} + void Monitor::contended() { contends++;
--- a/src/share/demo/jvmti/waiters/Monitor.hpp Sat Sep 12 15:30:13 2009 -0700 +++ b/src/share/demo/jvmti/waiters/Monitor.hpp Mon Sep 14 15:29:13 2009 +0100 @@ -35,6 +35,7 @@ private: char name[64]; + int slot; unsigned contends; unsigned waits; unsigned timeouts; @@ -42,6 +43,8 @@ public: Monitor(jvmtiEnv *jvmti, JNIEnv *env, jobject object); ~Monitor(); + int get_slot(); + void set_slot(int i); void contended(); void waited(); void timeout();