/*
* Since memory has been exhausted, avoid the normal error-handling path which
* allocates an error object, report and callstack. If code is running, simply
* throw the static atom "out of memory". If code is not running, call the
* error reporter directly.
*
* Furthermore, callers of ReportOutOfMemory (viz., malloc) assume a GC does
* not occur, so GC must be avoided or suppressed.
*/
void
js::ReportOutOfMemory(ExclusiveContext* cxArg)
{
#ifdef JS_MORE_DETERMINISTIC
/*
* OOMs are non-deterministic, especially across different execution modes
* (e.g. interpreter vs JIT). In more-deterministic builds, print to stderr
* so that the fuzzers can detect this.
*/
fprintf(stderr, "ReportOutOfMemory called\n");
#endif
if (!cxArg->isJSContext())
return cxArg->addPendingOutOfMemory();
JSContext* cx = cxArg->asJSContext();
cx->runtime()->hadOutOfMemory = true;
AutoSuppressGC suppressGC(cx);
/* Report the oom. */
if (JS::OutOfMemoryCallback oomCallback = cx->runtime()->oomCallback)
oomCallback(cx, cx->runtime()->oomCallbackData);
if (cx->options().autoJSAPIOwnsErrorReporting() || JS_IsRunning(cx)) {
cx->setPendingException(StringValue(cx->names().outOfMemory));
return;
}
/* Get the message for this error, but we don't expand any arguments. */
const JSErrorFormatString* efs = GetErrorMessage(nullptr, JSMSG_OUT_OF_MEMORY);
const char* msg = efs ? efs->format : "Out of memory";
/* Fill out the report, but don't do anything that requires allocation. */
JSErrorReport report;
report.flags = JSREPORT_ERROR;
report.errorNumber = JSMSG_OUT_OF_MEMORY;
PopulateReportBlame(cx, &report);
/* Report the error. */
if (JSErrorReporter onError = cx->runtime()->errorReporter)
onError(cx, msg, &report);
/*
* We would like to enforce the invariant that any exception reported
* during an OOM situation does not require wrapping. Besides avoiding
* allocation when memory is low, this reduces the number of places where
* we might need to GC.
*
* When JS code is running, we set the pending exception to an atom, which
* does not need wrapping. If no JS code is running, no exception should be
* set at all.
*/
MOZ_ASSERT(!cx->isExceptionPending());
}
